OpenCloudOS-Kernel/arch/x86/power/cpu.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Suspend support specific for i386/x86-64.
*
* Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
* Copyright (c) 2002 Pavel Machek <pavel@ucw.cz>
* Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
*/
#include <linux/suspend.h>
#include <linux/export.h>
#include <linux/smp.h>
#include <linux/perf_event.h>
x86 / hibernate: Use hlt_play_dead() when resuming from hibernation On Intel hardware, native_play_dead() uses mwait_play_dead() by default and only falls back to the other methods if that fails. That also happens during resume from hibernation, when the restore (boot) kernel runs disable_nonboot_cpus() to take all of the CPUs except for the boot one offline. However, that is problematic, because the address passed to __monitor() in mwait_play_dead() is likely to be written to in the last phase of hibernate image restoration and that causes the "dead" CPU to start executing instructions again. Unfortunately, the page containing the address in that CPU's instruction pointer may not be valid any more at that point. First, that page may have been overwritten with image kernel memory contents already, so the instructions the CPU attempts to execute may simply be invalid. Second, the page tables previously used by that CPU may have been overwritten by image kernel memory contents, so the address in its instruction pointer is impossible to resolve then. A report from Varun Koyyalagunta and investigation carried out by Chen Yu show that the latter sometimes happens in practice. To prevent it from happening, temporarily change the smp_ops.play_dead pointer during resume from hibernation so that it points to a special "play dead" routine which uses hlt_play_dead() and avoids the inadvertent "revivals" of "dead" CPUs this way. A slightly unpleasant consequence of this change is that if the system is hibernated with one or more CPUs offline, it will generally draw more power after resume than it did before hibernation, because the physical state entered by CPUs via hlt_play_dead() is higher-power than the mwait_play_dead() one in the majority of cases. It is possible to work around this, but it is unclear how much of a problem that's going to be in practice, so the workaround will be implemented later if it turns out to be necessary. Link: https://bugzilla.kernel.org/show_bug.cgi?id=106371 Reported-by: Varun Koyyalagunta <cpudebug@centtech.com> Original-by: Chen Yu <yu.c.chen@intel.com> Tested-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 09:55:23 +08:00
#include <linux/tboot.h>
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
#include <linux/dmi.h>
[PATCH] x86_64: Set up safe page tables during resume The following patch makes swsusp avoid the possible temporary corruption of page translation tables during resume on x86-64. This is achieved by creating a copy of the relevant page tables that will not be modified by swsusp and can be safely used by it on resume. The problem is that during resume on x86-64 swsusp may temporarily corrupt the page tables used for the direct mapping of RAM. If that happens, a page fault occurs and cannot be handled properly, which leads to the solid hang of the affected system. This leads to the loss of the system's state from before suspend and may result in the loss of data or the corruption of filesystems, so it is a serious issue. Also, it appears to happen quite often (for me, as often as 50% of the time). The problem is related to the fact that (at least) one of the PMD entries used in the direct memory mapping (starting at PAGE_OFFSET) points to a page table the physical address of which is much greater than the physical address of the PMD entry itself. Moreover, unfortunately, the physical address of the page table before suspend (i.e. the one stored in the suspend image) happens to be different to the physical address of the corresponding page table used during resume (i.e. the one that is valid right before swsusp_arch_resume() in arch/x86_64/kernel/suspend_asm.S is executed). Thus while the image is restored, the "offending" PMD entry gets overwritten, so it does not point to the right physical address any more (i.e. there's no page table at the address pointed to by it, because it points to the address the page table has been at during suspend). Consequently, if the PMD entry is used later on, and it _is_ used in the process of copying the image pages, a page fault occurs, but it cannot be handled in the normal way and the system hangs. In principle we can call create_resume_mapping() from swsusp_arch_resume() (ie. from suspend_asm.S), but then the memory allocations in create_resume_mapping(), resume_pud_mapping(), and resume_pmd_mapping() must be made carefully so that we use _only_ NosaveFree pages in them (the other pages are overwritten by the loop in swsusp_arch_resume()). Additionally, we are in atomic context at that time, so we cannot use GFP_KERNEL. Moreover, if one of the allocations fails, we should free all of the allocated pages, so we need to trace them somehow. All of this is done in the appended patch, except that the functions populating the page tables are located in arch/x86_64/kernel/suspend.c rather than in init.c. It may be done in a more elegan way in the future, with the help of some swsusp patches that are in the works now. [AK: move some externs into headers, renamed a function] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-10 03:19:40 +08:00
#include <asm/pgtable.h>
#include <asm/proto.h>
#include <asm/mtrr.h>
#include <asm/page.h>
#include <asm/mce.h>
#include <asm/suspend.h>
#include <asm/fpu/internal.h>
#include <asm/debugreg.h>
#include <asm/cpu.h>
#include <asm/mmu_context.h>
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
#include <asm/cpu_device_id.h>
#ifdef CONFIG_X86_32
__visible unsigned long saved_context_ebx;
__visible unsigned long saved_context_esp, saved_context_ebp;
__visible unsigned long saved_context_esi, saved_context_edi;
__visible unsigned long saved_context_eflags;
#endif
x86, gdt, hibernate: Store/load GDT for hibernate path. The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37 ("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.") assumes that for the hibernate path the booting kernel and the resuming kernel MUST be the same. That is certainly the case for a 32-bit kernel (see check_image_kernel and CONFIG_ARCH_HIBERNATION_HEADER config option). However for 64-bit kernels it is OK to have a different kernel version (and size of the image) of the booting and resuming kernels. Hence the above mentioned git commit introduces an regression. This patch fixes it by introducing a 'struct desc_ptr gdt_desc' back in the 'struct saved_context'. However instead of having in the 'save_processor_state' and 'restore_processor_state' the store/load_gdt calls, we are only saving the GDT in the save_processor_state. For the restore path the lgdt operation is done in hibernate_asm_[32|64].S in the 'restore_registers' path. The apt reader of this description will recognize that only 64-bit kernels need this treatment, not 32-bit. This patch adds the logic in the 32-bit path to be more similar to 64-bit so that in the future the unification process can take advantage of this. [ hpa: this also reverts an inadvertent on-disk format change ] Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/1367459610-9656-2-git-send-email-konrad.wilk@oracle.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-05-02 09:53:30 +08:00
struct saved_context saved_context;
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
static void msr_save_context(struct saved_context *ctxt)
{
struct saved_msr *msr = ctxt->saved_msrs.array;
struct saved_msr *end = msr + ctxt->saved_msrs.num;
while (msr < end) {
msr->valid = !rdmsrl_safe(msr->info.msr_no, &msr->info.reg.q);
msr++;
}
}
static void msr_restore_context(struct saved_context *ctxt)
{
struct saved_msr *msr = ctxt->saved_msrs.array;
struct saved_msr *end = msr + ctxt->saved_msrs.num;
while (msr < end) {
if (msr->valid)
wrmsrl(msr->info.msr_no, msr->info.reg.q);
msr++;
}
}
/**
* __save_processor_state - save CPU registers before creating a
* hibernation image and before restoring the memory state from it
* @ctxt - structure to store the registers contents in
*
* NOTE: If there is a CPU register the modification of which by the
* boot kernel (ie. the kernel used for loading the hibernation image)
* might affect the operations of the restored target kernel (ie. the one
* saved in the hibernation image), then its contents must be saved by this
* function. In other words, if kernel A is hibernated and different
* kernel B is used for loading the hibernation image into memory, the
* kernel A's __save_processor_state() function must save all registers
* needed by kernel A, so that it can operate correctly after the resume
* regardless of what kernel B does in the meantime.
*/
static void __save_processor_state(struct saved_context *ctxt)
{
#ifdef CONFIG_X86_32
mtrr_save_fixed_ranges(NULL);
#endif
kernel_fpu_begin();
/*
* descriptor tables
*/
store_idt(&ctxt->idt);
x86, gdt, hibernate: Store/load GDT for hibernate path. The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37 ("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.") assumes that for the hibernate path the booting kernel and the resuming kernel MUST be the same. That is certainly the case for a 32-bit kernel (see check_image_kernel and CONFIG_ARCH_HIBERNATION_HEADER config option). However for 64-bit kernels it is OK to have a different kernel version (and size of the image) of the booting and resuming kernels. Hence the above mentioned git commit introduces an regression. This patch fixes it by introducing a 'struct desc_ptr gdt_desc' back in the 'struct saved_context'. However instead of having in the 'save_processor_state' and 'restore_processor_state' the store/load_gdt calls, we are only saving the GDT in the save_processor_state. For the restore path the lgdt operation is done in hibernate_asm_[32|64].S in the 'restore_registers' path. The apt reader of this description will recognize that only 64-bit kernels need this treatment, not 32-bit. This patch adds the logic in the 32-bit path to be more similar to 64-bit so that in the future the unification process can take advantage of this. [ hpa: this also reverts an inadvertent on-disk format change ] Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/1367459610-9656-2-git-send-email-konrad.wilk@oracle.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-05-02 09:53:30 +08:00
/*
* We save it here, but restore it only in the hibernate case.
* For ACPI S3 resume, this is loaded via 'early_gdt_desc' in 64-bit
* mode in "secondary_startup_64". In 32-bit mode it is done via
* 'pmode_gdt' in wakeup_start.
*/
ctxt->gdt_desc.size = GDT_SIZE - 1;
x86: Remap GDT tables in the fixmap section Each processor holds a GDT in its per-cpu structure. The sgdt instruction gives the base address of the current GDT. This address can be used to bypass KASLR memory randomization. With another bug, an attacker could target other per-cpu structures or deduce the base of the main memory section (PAGE_OFFSET). This patch relocates the GDT table for each processor inside the fixmap section. The space is reserved based on number of supported processors. For consistency, the remapping is done by default on 32 and 64-bit. Each processor switches to its remapped GDT at the end of initialization. For hibernation, the main processor returns with the original GDT and switches back to the remapping at completion. This patch was tested on both architectures. Hibernation and KVM were both tested specially for their usage of the GDT. Thanks to Boris Ostrovsky <boris.ostrovsky@oracle.com> for testing and recommending changes for Xen support. Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@suse.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Luis R . Rodriguez <mcgrof@kernel.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rafael J . Wysocki <rjw@rjwysocki.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: kasan-dev@googlegroups.com Cc: kernel-hardening@lists.openwall.com Cc: kvm@vger.kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pm@vger.kernel.org Cc: xen-devel@lists.xenproject.org Cc: zijun_hu <zijun_hu@htc.com> Link: http://lkml.kernel.org/r/20170314170508.100882-2-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-15 01:05:07 +08:00
ctxt->gdt_desc.address = (unsigned long)get_cpu_gdt_rw(smp_processor_id());
x86, gdt, hibernate: Store/load GDT for hibernate path. The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37 ("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.") assumes that for the hibernate path the booting kernel and the resuming kernel MUST be the same. That is certainly the case for a 32-bit kernel (see check_image_kernel and CONFIG_ARCH_HIBERNATION_HEADER config option). However for 64-bit kernels it is OK to have a different kernel version (and size of the image) of the booting and resuming kernels. Hence the above mentioned git commit introduces an regression. This patch fixes it by introducing a 'struct desc_ptr gdt_desc' back in the 'struct saved_context'. However instead of having in the 'save_processor_state' and 'restore_processor_state' the store/load_gdt calls, we are only saving the GDT in the save_processor_state. For the restore path the lgdt operation is done in hibernate_asm_[32|64].S in the 'restore_registers' path. The apt reader of this description will recognize that only 64-bit kernels need this treatment, not 32-bit. This patch adds the logic in the 32-bit path to be more similar to 64-bit so that in the future the unification process can take advantage of this. [ hpa: this also reverts an inadvertent on-disk format change ] Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/1367459610-9656-2-git-send-email-konrad.wilk@oracle.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-05-02 09:53:30 +08:00
store_tr(ctxt->tr);
/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
/*
* segment registers
*/
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
#ifdef CONFIG_X86_32_LAZY_GS
savesegment(gs, ctxt->gs);
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
#endif
#ifdef CONFIG_X86_64
savesegment(gs, ctxt->gs);
savesegment(fs, ctxt->fs);
savesegment(ds, ctxt->ds);
savesegment(es, ctxt->es);
rdmsrl(MSR_FS_BASE, ctxt->fs_base);
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
rdmsrl(MSR_GS_BASE, ctxt->kernelmode_gs_base);
rdmsrl(MSR_KERNEL_GS_BASE, ctxt->usermode_gs_base);
mtrr_save_fixed_ranges(NULL);
rdmsrl(MSR_EFER, ctxt->efer);
#endif
/*
* control registers
*/
ctxt->cr0 = read_cr0();
ctxt->cr2 = read_cr2();
ctxt->cr3 = __read_cr3();
ctxt->cr4 = __read_cr4();
ctxt->misc_enable_saved = !rdmsrl_safe(MSR_IA32_MISC_ENABLE,
&ctxt->misc_enable);
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
msr_save_context(ctxt);
}
/* Needed by apm.c */
void save_processor_state(void)
{
__save_processor_state(&saved_context);
x86_platform.save_sched_clock_state();
}
#ifdef CONFIG_X86_32
EXPORT_SYMBOL(save_processor_state);
#endif
static void do_fpu_end(void)
{
/*
* Restore FPU regs if necessary.
*/
kernel_fpu_end();
}
static void fix_processor_context(void)
{
int cpu = smp_processor_id();
#ifdef CONFIG_X86_64
x86: Remap GDT tables in the fixmap section Each processor holds a GDT in its per-cpu structure. The sgdt instruction gives the base address of the current GDT. This address can be used to bypass KASLR memory randomization. With another bug, an attacker could target other per-cpu structures or deduce the base of the main memory section (PAGE_OFFSET). This patch relocates the GDT table for each processor inside the fixmap section. The space is reserved based on number of supported processors. For consistency, the remapping is done by default on 32 and 64-bit. Each processor switches to its remapped GDT at the end of initialization. For hibernation, the main processor returns with the original GDT and switches back to the remapping at completion. This patch was tested on both architectures. Hibernation and KVM were both tested specially for their usage of the GDT. Thanks to Boris Ostrovsky <boris.ostrovsky@oracle.com> for testing and recommending changes for Xen support. Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@suse.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Luis R . Rodriguez <mcgrof@kernel.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rafael J . Wysocki <rjw@rjwysocki.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: kasan-dev@googlegroups.com Cc: kernel-hardening@lists.openwall.com Cc: kvm@vger.kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pm@vger.kernel.org Cc: xen-devel@lists.xenproject.org Cc: zijun_hu <zijun_hu@htc.com> Link: http://lkml.kernel.org/r/20170314170508.100882-2-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-15 01:05:07 +08:00
struct desc_struct *desc = get_cpu_gdt_rw(cpu);
tss_desc tss;
#endif
/*
* We need to reload TR, which requires that we change the
* GDT entry to indicate "available" first.
*
* XXX: This could probably all be replaced by a call to
* force_reload_TR().
*/
set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
#ifdef CONFIG_X86_64
memcpy(&tss, &desc[GDT_ENTRY_TSS], sizeof(tss_desc));
tss.type = 0x9; /* The available 64-bit TSS (see AMD vol 2, pg 91 */
write_gdt_entry(desc, GDT_ENTRY_TSS, &tss, DESC_TSS);
syscall_init(); /* This sets MSR_*STAR and related */
#else
if (boot_cpu_has(X86_FEATURE_SEP))
enable_sep_cpu();
#endif
load_TR_desc(); /* This does ltr */
load_mm_ldt(current->active_mm); /* This does lldt */
initialize_tlbstate_and_flush();
fpu__resume_cpu();
x86: Remap GDT tables in the fixmap section Each processor holds a GDT in its per-cpu structure. The sgdt instruction gives the base address of the current GDT. This address can be used to bypass KASLR memory randomization. With another bug, an attacker could target other per-cpu structures or deduce the base of the main memory section (PAGE_OFFSET). This patch relocates the GDT table for each processor inside the fixmap section. The space is reserved based on number of supported processors. For consistency, the remapping is done by default on 32 and 64-bit. Each processor switches to its remapped GDT at the end of initialization. For hibernation, the main processor returns with the original GDT and switches back to the remapping at completion. This patch was tested on both architectures. Hibernation and KVM were both tested specially for their usage of the GDT. Thanks to Boris Ostrovsky <boris.ostrovsky@oracle.com> for testing and recommending changes for Xen support. Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@suse.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Luis R . Rodriguez <mcgrof@kernel.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rafael J . Wysocki <rjw@rjwysocki.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: kasan-dev@googlegroups.com Cc: kernel-hardening@lists.openwall.com Cc: kvm@vger.kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pm@vger.kernel.org Cc: xen-devel@lists.xenproject.org Cc: zijun_hu <zijun_hu@htc.com> Link: http://lkml.kernel.org/r/20170314170508.100882-2-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-15 01:05:07 +08:00
/* The processor is back on the direct GDT, load back the fixmap */
load_fixmap_gdt(cpu);
}
/**
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
* __restore_processor_state - restore the contents of CPU registers saved
* by __save_processor_state()
* @ctxt - structure to load the registers contents from
*
* The asm code that gets us here will have restored a usable GDT, although
* it will be pointing to the wrong alias.
*/
x86, power, suspend: Annotate restore_processor_state() with notrace ftrace_stop() is used to stop function tracing during suspend and resume which removes a lot of possible debugging opportunities with tracing. The reason was that some function in the resume path was causing a triple fault if it were to be traced. The issue I found was that doing something as simple as calling smp_processor_id() would reboot the box! When function tracing was first created I didn't have a good way to figure out what function was having issues, or it looked to be multiple ones. To fix it, we just created a big hammer approach to the problem which was to add a flag in the mcount trampoline that could be checked and not call the traced functions. Lately I developed better ways to find problem functions and I can bisect down to see what function is causing the issue. I removed the flag that stopped tracing and proceeded to find the problem function and it ended up being restore_processor_state(). This function makes sense as when the CPU comes back online from a suspend it calls this function to set up registers, amongst them the GS register, which stores things such as what CPU the processor is (if you call smp_processor_id() without this set up properly, it would fault). By making restore_processor_state() notrace, the system can suspend and resume without the need of the big hammer tracing to stop. Link: http://lkml.kernel.org/r/3577662.BSnUZfboWb@vostro.rjw.lan Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-25 08:58:26 +08:00
static void notrace __restore_processor_state(struct saved_context *ctxt)
{
if (ctxt->misc_enable_saved)
wrmsrl(MSR_IA32_MISC_ENABLE, ctxt->misc_enable);
/*
* control registers
*/
/* cr4 was introduced in the Pentium CPU */
#ifdef CONFIG_X86_32
if (ctxt->cr4)
__write_cr4(ctxt->cr4);
#else
/* CONFIG X86_64 */
wrmsrl(MSR_EFER, ctxt->efer);
__write_cr4(ctxt->cr4);
#endif
write_cr3(ctxt->cr3);
write_cr2(ctxt->cr2);
write_cr0(ctxt->cr0);
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
/* Restore the IDT. */
load_idt(&ctxt->idt);
/*
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
* Just in case the asm code got us here with the SS, DS, or ES
* out of sync with the GDT, update them.
*/
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
loadsegment(ss, __KERNEL_DS);
loadsegment(ds, __USER_DS);
loadsegment(es, __USER_DS);
/*
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
* Restore percpu access. Percpu access can happen in exception
* handlers or in complicated helpers like load_gs_index().
x86/power: Fix some ordering bugs in __restore_processor_context() __restore_processor_context() had a couple of ordering bugs. It restored GSBASE after calling load_gs_index(), and the latter can call into tracing code. It also tried to restore segment registers before restoring the LDT, which is straight-up wrong. Reorder the code so that we restore GSBASE, then the descriptor tables, then the segments. This fixes two bugs. First, it fixes a regression that broke resume under certain configurations due to irqflag tracing in native_load_gs_index(). Second, it fixes resume when the userspace process that initiated suspect had funny segments. The latter can be reproduced by compiling this: // SPDX-License-Identifier: GPL-2.0 /* * ldt_echo.c - Echo argv[1] while using an LDT segment */ int main(int argc, char **argv) { int ret; size_t len; char *buf; const struct user_desc desc = { .entry_number = 0, .base_addr = 0, .limit = 0xfffff, .seg_32bit = 1, .contents = 0, /* Data, grow-up */ .read_exec_only = 0, .limit_in_pages = 1, .seg_not_present = 0, .useable = 0 }; if (argc != 2) errx(1, "Usage: %s STRING", argv[0]); len = asprintf(&buf, "%s\n", argv[1]); if (len < 0) errx(1, "Out of memory"); ret = syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)); if (ret < -1) errno = -ret; if (ret) err(1, "modify_ldt"); asm volatile ("movw %0, %%es" :: "rm" ((unsigned short)7)); write(1, buf, len); return 0; } and running ldt_echo >/sys/power/mem Without the fix, the latter causes a triple fault on resume. Fixes: ca37e57bbe0c ("x86/entry/64: Add missing irqflags tracing to native_load_gs_index()") Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/6b31721ea92f51ea839e79bd97ade4a75b1eeea2.1512057304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-30 23:57:57 +08:00
*/
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
#ifdef CONFIG_X86_64
wrmsrl(MSR_GS_BASE, ctxt->kernelmode_gs_base);
#else
loadsegment(fs, __KERNEL_PERCPU);
loadsegment(gs, __KERNEL_STACK_CANARY);
x86/power: Fix some ordering bugs in __restore_processor_context() __restore_processor_context() had a couple of ordering bugs. It restored GSBASE after calling load_gs_index(), and the latter can call into tracing code. It also tried to restore segment registers before restoring the LDT, which is straight-up wrong. Reorder the code so that we restore GSBASE, then the descriptor tables, then the segments. This fixes two bugs. First, it fixes a regression that broke resume under certain configurations due to irqflag tracing in native_load_gs_index(). Second, it fixes resume when the userspace process that initiated suspect had funny segments. The latter can be reproduced by compiling this: // SPDX-License-Identifier: GPL-2.0 /* * ldt_echo.c - Echo argv[1] while using an LDT segment */ int main(int argc, char **argv) { int ret; size_t len; char *buf; const struct user_desc desc = { .entry_number = 0, .base_addr = 0, .limit = 0xfffff, .seg_32bit = 1, .contents = 0, /* Data, grow-up */ .read_exec_only = 0, .limit_in_pages = 1, .seg_not_present = 0, .useable = 0 }; if (argc != 2) errx(1, "Usage: %s STRING", argv[0]); len = asprintf(&buf, "%s\n", argv[1]); if (len < 0) errx(1, "Out of memory"); ret = syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)); if (ret < -1) errno = -ret; if (ret) err(1, "modify_ldt"); asm volatile ("movw %0, %%es" :: "rm" ((unsigned short)7)); write(1, buf, len); return 0; } and running ldt_echo >/sys/power/mem Without the fix, the latter causes a triple fault on resume. Fixes: ca37e57bbe0c ("x86/entry/64: Add missing irqflags tracing to native_load_gs_index()") Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/6b31721ea92f51ea839e79bd97ade4a75b1eeea2.1512057304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-30 23:57:57 +08:00
#endif
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
/* Restore the TSS, RO GDT, LDT, and usermode-relevant MSRs. */
x86/power: Fix some ordering bugs in __restore_processor_context() __restore_processor_context() had a couple of ordering bugs. It restored GSBASE after calling load_gs_index(), and the latter can call into tracing code. It also tried to restore segment registers before restoring the LDT, which is straight-up wrong. Reorder the code so that we restore GSBASE, then the descriptor tables, then the segments. This fixes two bugs. First, it fixes a regression that broke resume under certain configurations due to irqflag tracing in native_load_gs_index(). Second, it fixes resume when the userspace process that initiated suspect had funny segments. The latter can be reproduced by compiling this: // SPDX-License-Identifier: GPL-2.0 /* * ldt_echo.c - Echo argv[1] while using an LDT segment */ int main(int argc, char **argv) { int ret; size_t len; char *buf; const struct user_desc desc = { .entry_number = 0, .base_addr = 0, .limit = 0xfffff, .seg_32bit = 1, .contents = 0, /* Data, grow-up */ .read_exec_only = 0, .limit_in_pages = 1, .seg_not_present = 0, .useable = 0 }; if (argc != 2) errx(1, "Usage: %s STRING", argv[0]); len = asprintf(&buf, "%s\n", argv[1]); if (len < 0) errx(1, "Out of memory"); ret = syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)); if (ret < -1) errno = -ret; if (ret) err(1, "modify_ldt"); asm volatile ("movw %0, %%es" :: "rm" ((unsigned short)7)); write(1, buf, len); return 0; } and running ldt_echo >/sys/power/mem Without the fix, the latter causes a triple fault on resume. Fixes: ca37e57bbe0c ("x86/entry/64: Add missing irqflags tracing to native_load_gs_index()") Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/6b31721ea92f51ea839e79bd97ade4a75b1eeea2.1512057304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-30 23:57:57 +08:00
fix_processor_context();
/*
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
* Now that we have descriptor tables fully restored and working
* exception handling, restore the usermode segments.
*/
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
#ifdef CONFIG_X86_64
loadsegment(ds, ctxt->es);
loadsegment(es, ctxt->es);
loadsegment(fs, ctxt->fs);
load_gs_index(ctxt->gs);
x86/power: Fix some ordering bugs in __restore_processor_context() __restore_processor_context() had a couple of ordering bugs. It restored GSBASE after calling load_gs_index(), and the latter can call into tracing code. It also tried to restore segment registers before restoring the LDT, which is straight-up wrong. Reorder the code so that we restore GSBASE, then the descriptor tables, then the segments. This fixes two bugs. First, it fixes a regression that broke resume under certain configurations due to irqflag tracing in native_load_gs_index(). Second, it fixes resume when the userspace process that initiated suspect had funny segments. The latter can be reproduced by compiling this: // SPDX-License-Identifier: GPL-2.0 /* * ldt_echo.c - Echo argv[1] while using an LDT segment */ int main(int argc, char **argv) { int ret; size_t len; char *buf; const struct user_desc desc = { .entry_number = 0, .base_addr = 0, .limit = 0xfffff, .seg_32bit = 1, .contents = 0, /* Data, grow-up */ .read_exec_only = 0, .limit_in_pages = 1, .seg_not_present = 0, .useable = 0 }; if (argc != 2) errx(1, "Usage: %s STRING", argv[0]); len = asprintf(&buf, "%s\n", argv[1]); if (len < 0) errx(1, "Out of memory"); ret = syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)); if (ret < -1) errno = -ret; if (ret) err(1, "modify_ldt"); asm volatile ("movw %0, %%es" :: "rm" ((unsigned short)7)); write(1, buf, len); return 0; } and running ldt_echo >/sys/power/mem Without the fix, the latter causes a triple fault on resume. Fixes: ca37e57bbe0c ("x86/entry/64: Add missing irqflags tracing to native_load_gs_index()") Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/6b31721ea92f51ea839e79bd97ade4a75b1eeea2.1512057304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-30 23:57:57 +08:00
/*
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
* Restore FSBASE and GSBASE after restoring the selectors, since
* restoring the selectors clobbers the bases. Keep in mind
* that MSR_KERNEL_GS_BASE is horribly misnamed.
x86/power: Fix some ordering bugs in __restore_processor_context() __restore_processor_context() had a couple of ordering bugs. It restored GSBASE after calling load_gs_index(), and the latter can call into tracing code. It also tried to restore segment registers before restoring the LDT, which is straight-up wrong. Reorder the code so that we restore GSBASE, then the descriptor tables, then the segments. This fixes two bugs. First, it fixes a regression that broke resume under certain configurations due to irqflag tracing in native_load_gs_index(). Second, it fixes resume when the userspace process that initiated suspect had funny segments. The latter can be reproduced by compiling this: // SPDX-License-Identifier: GPL-2.0 /* * ldt_echo.c - Echo argv[1] while using an LDT segment */ int main(int argc, char **argv) { int ret; size_t len; char *buf; const struct user_desc desc = { .entry_number = 0, .base_addr = 0, .limit = 0xfffff, .seg_32bit = 1, .contents = 0, /* Data, grow-up */ .read_exec_only = 0, .limit_in_pages = 1, .seg_not_present = 0, .useable = 0 }; if (argc != 2) errx(1, "Usage: %s STRING", argv[0]); len = asprintf(&buf, "%s\n", argv[1]); if (len < 0) errx(1, "Out of memory"); ret = syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)); if (ret < -1) errno = -ret; if (ret) err(1, "modify_ldt"); asm volatile ("movw %0, %%es" :: "rm" ((unsigned short)7)); write(1, buf, len); return 0; } and running ldt_echo >/sys/power/mem Without the fix, the latter causes a triple fault on resume. Fixes: ca37e57bbe0c ("x86/entry/64: Add missing irqflags tracing to native_load_gs_index()") Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/6b31721ea92f51ea839e79bd97ade4a75b1eeea2.1512057304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-30 23:57:57 +08:00
*/
wrmsrl(MSR_FS_BASE, ctxt->fs_base);
x86/power: Make restore_processor_context() sane My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 05:19:07 +08:00
wrmsrl(MSR_KERNEL_GS_BASE, ctxt->usermode_gs_base);
#elif defined(CONFIG_X86_32_LAZY_GS)
loadsegment(gs, ctxt->gs);
#endif
do_fpu_end();
tsc_verify_tsc_adjust(true);
x86_platform.restore_sched_clock_state();
mtrr_bp_restore();
perf_restore_debug_store();
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
msr_restore_context(ctxt);
}
/* Needed by apm.c */
x86, power, suspend: Annotate restore_processor_state() with notrace ftrace_stop() is used to stop function tracing during suspend and resume which removes a lot of possible debugging opportunities with tracing. The reason was that some function in the resume path was causing a triple fault if it were to be traced. The issue I found was that doing something as simple as calling smp_processor_id() would reboot the box! When function tracing was first created I didn't have a good way to figure out what function was having issues, or it looked to be multiple ones. To fix it, we just created a big hammer approach to the problem which was to add a flag in the mcount trampoline that could be checked and not call the traced functions. Lately I developed better ways to find problem functions and I can bisect down to see what function is causing the issue. I removed the flag that stopped tracing and proceeded to find the problem function and it ended up being restore_processor_state(). This function makes sense as when the CPU comes back online from a suspend it calls this function to set up registers, amongst them the GS register, which stores things such as what CPU the processor is (if you call smp_processor_id() without this set up properly, it would fault). By making restore_processor_state() notrace, the system can suspend and resume without the need of the big hammer tracing to stop. Link: http://lkml.kernel.org/r/3577662.BSnUZfboWb@vostro.rjw.lan Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-25 08:58:26 +08:00
void notrace restore_processor_state(void)
{
__restore_processor_state(&saved_context);
}
#ifdef CONFIG_X86_32
EXPORT_SYMBOL(restore_processor_state);
#endif
x86 / hibernate: Use hlt_play_dead() when resuming from hibernation On Intel hardware, native_play_dead() uses mwait_play_dead() by default and only falls back to the other methods if that fails. That also happens during resume from hibernation, when the restore (boot) kernel runs disable_nonboot_cpus() to take all of the CPUs except for the boot one offline. However, that is problematic, because the address passed to __monitor() in mwait_play_dead() is likely to be written to in the last phase of hibernate image restoration and that causes the "dead" CPU to start executing instructions again. Unfortunately, the page containing the address in that CPU's instruction pointer may not be valid any more at that point. First, that page may have been overwritten with image kernel memory contents already, so the instructions the CPU attempts to execute may simply be invalid. Second, the page tables previously used by that CPU may have been overwritten by image kernel memory contents, so the address in its instruction pointer is impossible to resolve then. A report from Varun Koyyalagunta and investigation carried out by Chen Yu show that the latter sometimes happens in practice. To prevent it from happening, temporarily change the smp_ops.play_dead pointer during resume from hibernation so that it points to a special "play dead" routine which uses hlt_play_dead() and avoids the inadvertent "revivals" of "dead" CPUs this way. A slightly unpleasant consequence of this change is that if the system is hibernated with one or more CPUs offline, it will generally draw more power after resume than it did before hibernation, because the physical state entered by CPUs via hlt_play_dead() is higher-power than the mwait_play_dead() one in the majority of cases. It is possible to work around this, but it is unclear how much of a problem that's going to be in practice, so the workaround will be implemented later if it turns out to be necessary. Link: https://bugzilla.kernel.org/show_bug.cgi?id=106371 Reported-by: Varun Koyyalagunta <cpudebug@centtech.com> Original-by: Chen Yu <yu.c.chen@intel.com> Tested-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 09:55:23 +08:00
#if defined(CONFIG_HIBERNATION) && defined(CONFIG_HOTPLUG_CPU)
static void resume_play_dead(void)
{
play_dead_common();
tboot_shutdown(TB_SHUTDOWN_WFS);
hlt_play_dead();
}
int hibernate_resume_nonboot_cpu_disable(void)
{
void (*play_dead)(void) = smp_ops.play_dead;
int ret;
/*
* Ensure that MONITOR/MWAIT will not be used in the "play dead" loop
* during hibernate image restoration, because it is likely that the
* monitored address will be actually written to at that time and then
* the "dead" CPU will attempt to execute instructions again, but the
* address in its instruction pointer may not be possible to resolve
* any more at that point (the page tables used by it previously may
* have been overwritten by hibernate image data).
x86/power: Fix 'nosmt' vs hibernation triple fault during resume As explained in 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") we always, no matter what, have to bring up x86 HT siblings during boot at least once in order to avoid first MCE bringing the system to its knees. That means that whenever 'nosmt' is supplied on the kernel command-line, all the HT siblings are as a result sitting in mwait or cpudile after going through the online-offline cycle at least once. This causes a serious issue though when a kernel, which saw 'nosmt' on its commandline, is going to perform resume from hibernation: if the resume from the hibernated image is successful, cr3 is flipped in order to point to the address space of the kernel that is being resumed, which in turn means that all the HT siblings are all of a sudden mwaiting on address which is no longer valid. That results in triple fault shortly after cr3 is switched, and machine reboots. Fix this by always waking up all the SMT siblings before initiating the 'restore from hibernation' process; this guarantees that all the HT siblings will be properly carried over to the resumed kernel waiting in resume_play_dead(), and acted upon accordingly afterwards, based on the target kernel configuration. Symmetricaly, the resumed kernel has to push the SMT siblings to mwait again in case it has SMT disabled; this means it has to online all the siblings when resuming (so that they come out of hlt) and offline them again to let them reach mwait. Cc: 4.19+ <stable@vger.kernel.org> # v4.19+ Debugged-by: Thomas Gleixner <tglx@linutronix.de> Fixes: 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-05-30 06:09:39 +08:00
*
* First, make sure that we wake up all the potentially disabled SMT
* threads which have been initially brought up and then put into
* mwait/cpuidle sleep.
* Those will be put to proper (not interfering with hibernation
* resume) sleep afterwards, and the resumed kernel will decide itself
* what to do with them.
x86 / hibernate: Use hlt_play_dead() when resuming from hibernation On Intel hardware, native_play_dead() uses mwait_play_dead() by default and only falls back to the other methods if that fails. That also happens during resume from hibernation, when the restore (boot) kernel runs disable_nonboot_cpus() to take all of the CPUs except for the boot one offline. However, that is problematic, because the address passed to __monitor() in mwait_play_dead() is likely to be written to in the last phase of hibernate image restoration and that causes the "dead" CPU to start executing instructions again. Unfortunately, the page containing the address in that CPU's instruction pointer may not be valid any more at that point. First, that page may have been overwritten with image kernel memory contents already, so the instructions the CPU attempts to execute may simply be invalid. Second, the page tables previously used by that CPU may have been overwritten by image kernel memory contents, so the address in its instruction pointer is impossible to resolve then. A report from Varun Koyyalagunta and investigation carried out by Chen Yu show that the latter sometimes happens in practice. To prevent it from happening, temporarily change the smp_ops.play_dead pointer during resume from hibernation so that it points to a special "play dead" routine which uses hlt_play_dead() and avoids the inadvertent "revivals" of "dead" CPUs this way. A slightly unpleasant consequence of this change is that if the system is hibernated with one or more CPUs offline, it will generally draw more power after resume than it did before hibernation, because the physical state entered by CPUs via hlt_play_dead() is higher-power than the mwait_play_dead() one in the majority of cases. It is possible to work around this, but it is unclear how much of a problem that's going to be in practice, so the workaround will be implemented later if it turns out to be necessary. Link: https://bugzilla.kernel.org/show_bug.cgi?id=106371 Reported-by: Varun Koyyalagunta <cpudebug@centtech.com> Original-by: Chen Yu <yu.c.chen@intel.com> Tested-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 09:55:23 +08:00
*/
x86/power: Fix 'nosmt' vs hibernation triple fault during resume As explained in 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") we always, no matter what, have to bring up x86 HT siblings during boot at least once in order to avoid first MCE bringing the system to its knees. That means that whenever 'nosmt' is supplied on the kernel command-line, all the HT siblings are as a result sitting in mwait or cpudile after going through the online-offline cycle at least once. This causes a serious issue though when a kernel, which saw 'nosmt' on its commandline, is going to perform resume from hibernation: if the resume from the hibernated image is successful, cr3 is flipped in order to point to the address space of the kernel that is being resumed, which in turn means that all the HT siblings are all of a sudden mwaiting on address which is no longer valid. That results in triple fault shortly after cr3 is switched, and machine reboots. Fix this by always waking up all the SMT siblings before initiating the 'restore from hibernation' process; this guarantees that all the HT siblings will be properly carried over to the resumed kernel waiting in resume_play_dead(), and acted upon accordingly afterwards, based on the target kernel configuration. Symmetricaly, the resumed kernel has to push the SMT siblings to mwait again in case it has SMT disabled; this means it has to online all the siblings when resuming (so that they come out of hlt) and offline them again to let them reach mwait. Cc: 4.19+ <stable@vger.kernel.org> # v4.19+ Debugged-by: Thomas Gleixner <tglx@linutronix.de> Fixes: 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-05-30 06:09:39 +08:00
ret = cpuhp_smt_enable();
if (ret)
return ret;
x86 / hibernate: Use hlt_play_dead() when resuming from hibernation On Intel hardware, native_play_dead() uses mwait_play_dead() by default and only falls back to the other methods if that fails. That also happens during resume from hibernation, when the restore (boot) kernel runs disable_nonboot_cpus() to take all of the CPUs except for the boot one offline. However, that is problematic, because the address passed to __monitor() in mwait_play_dead() is likely to be written to in the last phase of hibernate image restoration and that causes the "dead" CPU to start executing instructions again. Unfortunately, the page containing the address in that CPU's instruction pointer may not be valid any more at that point. First, that page may have been overwritten with image kernel memory contents already, so the instructions the CPU attempts to execute may simply be invalid. Second, the page tables previously used by that CPU may have been overwritten by image kernel memory contents, so the address in its instruction pointer is impossible to resolve then. A report from Varun Koyyalagunta and investigation carried out by Chen Yu show that the latter sometimes happens in practice. To prevent it from happening, temporarily change the smp_ops.play_dead pointer during resume from hibernation so that it points to a special "play dead" routine which uses hlt_play_dead() and avoids the inadvertent "revivals" of "dead" CPUs this way. A slightly unpleasant consequence of this change is that if the system is hibernated with one or more CPUs offline, it will generally draw more power after resume than it did before hibernation, because the physical state entered by CPUs via hlt_play_dead() is higher-power than the mwait_play_dead() one in the majority of cases. It is possible to work around this, but it is unclear how much of a problem that's going to be in practice, so the workaround will be implemented later if it turns out to be necessary. Link: https://bugzilla.kernel.org/show_bug.cgi?id=106371 Reported-by: Varun Koyyalagunta <cpudebug@centtech.com> Original-by: Chen Yu <yu.c.chen@intel.com> Tested-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 09:55:23 +08:00
smp_ops.play_dead = resume_play_dead;
ret = disable_nonboot_cpus();
smp_ops.play_dead = play_dead;
return ret;
}
#endif
/*
* When bsp_check() is called in hibernate and suspend, cpu hotplug
* is disabled already. So it's unnessary to handle race condition between
* cpumask query and cpu hotplug.
*/
static int bsp_check(void)
{
if (cpumask_first(cpu_online_mask) != 0) {
pr_warn("CPU0 is offline.\n");
return -ENODEV;
}
return 0;
}
static int bsp_pm_callback(struct notifier_block *nb, unsigned long action,
void *ptr)
{
int ret = 0;
switch (action) {
case PM_SUSPEND_PREPARE:
case PM_HIBERNATION_PREPARE:
ret = bsp_check();
break;
#ifdef CONFIG_DEBUG_HOTPLUG_CPU0
case PM_RESTORE_PREPARE:
/*
* When system resumes from hibernation, online CPU0 because
* 1. it's required for resume and
* 2. the CPU was online before hibernation
*/
if (!cpu_online(0))
_debug_hotplug_cpu(0, 1);
break;
case PM_POST_RESTORE:
/*
* When a resume really happens, this code won't be called.
*
* This code is called only when user space hibernation software
* prepares for snapshot device during boot time. So we just
* call _debug_hotplug_cpu() to restore to CPU0's state prior to
* preparing the snapshot device.
*
* This works for normal boot case in our CPU0 hotplug debug
* mode, i.e. CPU0 is offline and user mode hibernation
* software initializes during boot time.
*
* If CPU0 is online and user application accesses snapshot
* device after boot time, this will offline CPU0 and user may
* see different CPU0 state before and after accessing
* the snapshot device. But hopefully this is not a case when
* user debugging CPU0 hotplug. Even if users hit this case,
* they can easily online CPU0 back.
*
* To simplify this debug code, we only consider normal boot
* case. Otherwise we need to remember CPU0's state and restore
* to that state and resolve racy conditions etc.
*/
_debug_hotplug_cpu(0, 0);
break;
#endif
default:
break;
}
return notifier_from_errno(ret);
}
static int __init bsp_pm_check_init(void)
{
/*
* Set this bsp_pm_callback as lower priority than
* cpu_hotplug_pm_callback. So cpu_hotplug_pm_callback will be called
* earlier to disable cpu hotplug before bsp online check.
*/
pm_notifier(bsp_pm_callback, -INT_MAX);
return 0;
}
core_initcall(bsp_pm_check_init);
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
static int msr_build_context(const u32 *msr_id, const int num)
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
{
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
struct saved_msrs *saved_msrs = &saved_context.saved_msrs;
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
struct saved_msr *msr_array;
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
int total_num;
int i, j;
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
total_num = saved_msrs->num + num;
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
msr_array = kmalloc_array(total_num, sizeof(struct saved_msr), GFP_KERNEL);
if (!msr_array) {
pr_err("x86/pm: Can not allocate memory to save/restore MSRs during suspend.\n");
return -ENOMEM;
}
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
if (saved_msrs->array) {
/*
* Multiple callbacks can invoke this function, so copy any
* MSR save requests from previous invocations.
*/
memcpy(msr_array, saved_msrs->array,
sizeof(struct saved_msr) * saved_msrs->num);
kfree(saved_msrs->array);
}
for (i = saved_msrs->num, j = 0; i < total_num; i++, j++) {
msr_array[i].info.msr_no = msr_id[j];
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
msr_array[i].valid = false;
msr_array[i].info.reg.q = 0;
}
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
saved_msrs->num = total_num;
saved_msrs->array = msr_array;
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
return 0;
}
/*
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
* The following sections are a quirk framework for problematic BIOSen:
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
* Sometimes MSRs are modified by the BIOSen after suspended to
* RAM, this might cause unexpected behavior after wakeup.
* Thus we save/restore these specified MSRs across suspend/resume
* in order to work around it.
*
* For any further problematic BIOSen/platforms,
* please add your own function similar to msr_initialize_bdw.
*/
static int msr_initialize_bdw(const struct dmi_system_id *d)
{
/* Add any extra MSR ids into this array. */
u32 bdw_msr_id[] = { MSR_IA32_THERM_CONTROL };
pr_info("x86/pm: %s detected, MSR saving is needed during suspending.\n", d->ident);
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
return msr_build_context(bdw_msr_id, ARRAY_SIZE(bdw_msr_id));
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
}
static const struct dmi_system_id msr_save_dmi_table[] = {
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
{
.callback = msr_initialize_bdw,
.ident = "BROADWELL BDX_EP",
.matches = {
DMI_MATCH(DMI_PRODUCT_NAME, "GRANTLEY"),
DMI_MATCH(DMI_PRODUCT_VERSION, "E63448-400"),
},
},
{}
};
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
static int msr_save_cpuid_features(const struct x86_cpu_id *c)
{
u32 cpuid_msr_id[] = {
MSR_AMD64_CPUID_FN_1,
};
pr_info("x86/pm: family %#hx cpu detected, MSR saving is needed during suspending.\n",
c->family);
return msr_build_context(cpuid_msr_id, ARRAY_SIZE(cpuid_msr_id));
}
static const struct x86_cpu_id msr_save_cpu_table[] = {
{
.vendor = X86_VENDOR_AMD,
.family = 0x15,
.model = X86_MODEL_ANY,
.feature = X86_FEATURE_ANY,
.driver_data = (kernel_ulong_t)msr_save_cpuid_features,
},
{
.vendor = X86_VENDOR_AMD,
.family = 0x16,
.model = X86_MODEL_ANY,
.feature = X86_FEATURE_ANY,
.driver_data = (kernel_ulong_t)msr_save_cpuid_features,
},
{}
};
typedef int (*pm_cpu_match_t)(const struct x86_cpu_id *);
static int pm_cpu_check(const struct x86_cpu_id *c)
{
const struct x86_cpu_id *m;
int ret = 0;
m = x86_match_cpu(msr_save_cpu_table);
if (m) {
pm_cpu_match_t fn;
fn = (pm_cpu_match_t)m->driver_data;
ret = fn(m);
}
return ret;
}
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
static int pm_check_save_msr(void)
{
dmi_check_system(msr_save_dmi_table);
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
2019-08-19 23:52:35 +08:00
pm_cpu_check(msr_save_cpu_table);
x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25 01:03:41 +08:00
return 0;
}
device_initcall(pm_check_save_msr);