commit 8d9ffb2fe65a6c4ef114e8d4f947958a12751bbe upstream.
The kdump kernel is broken on SME systems with CONFIG_IMA_KEXEC=y enabled.
Debugging traced the issue back to
b69a2afd5a ("x86/kexec: Carry forward IMA measurement log on kexec").
Testing was previously not conducted on SME systems with CONFIG_IMA_KEXEC
enabled, which led to the oversight, with the following incarnation:
...
ima: No TPM chip found, activating TPM-bypass!
Loading compiled-in module X.509 certificates
Loaded X.509 cert 'Build time autogenerated kernel key: 18ae0bc7e79b64700122bb1d6a904b070fef2656'
ima: Allocated hash algorithm: sha256
Oops: general protection fault, probably for non-canonical address 0xcfacfdfe6660003e: 0000 [#1] PREEMPT SMP NOPTI
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-rc2+ #14
Hardware name: Dell Inc. PowerEdge R7425/02MJ3T, BIOS 1.20.0 05/03/2023
RIP: 0010:ima_restore_measurement_list
Call Trace:
<TASK>
? show_trace_log_lvl
? show_trace_log_lvl
? ima_load_kexec_buffer
? __die_body.cold
? die_addr
? exc_general_protection
? asm_exc_general_protection
? ima_restore_measurement_list
? vprintk_emit
? ima_load_kexec_buffer
ima_load_kexec_buffer
ima_init
? __pfx_init_ima
init_ima
? __pfx_init_ima
do_one_initcall
do_initcalls
? __pfx_kernel_init
kernel_init_freeable
kernel_init
ret_from_fork
? __pfx_kernel_init
ret_from_fork_asm
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
...
Kernel panic - not syncing: Fatal exception
Kernel Offset: disabled
Rebooting in 10 seconds..
Adding debug printks showed that the stored addr and size of ima_kexec buffer
are not decrypted correctly like:
ima: ima_load_kexec_buffer, buffer:0xcfacfdfe6660003e, size:0xe48066052d5df359
Three types of setup_data info
— SETUP_EFI,
- SETUP_IMA, and
- SETUP_RNG_SEED
are passed to the kexec/kdump kernel. Only the ima_kexec buffer
experienced incorrect decryption. Debugging identified a bug in
early_memremap_is_setup_data(), where an incorrect range calculation
occurred due to the len variable in struct setup_data ended up only
representing the length of the data field, excluding the struct's size,
and thus leading to miscalculation.
Address a similar issue in memremap_is_setup_data() while at it.
[ bp: Heavily massage. ]
Fixes: b3c72fc9a7 ("x86/boot: Introduce setup_indirect")
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/20240911081615.262202-3-bhe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3b299b99556c1753923f8d9bbd9304bcd139282f ]
LAM can only be enabled when a process is single-threaded. But _kernel_
threads can temporarily use a single-threaded process's mm.
If LAM is enabled by a userspace process while a kthread is using its
mm, the kthread will not observe LAM enablement (i.e. LAM will be
disabled in CR3). This could be fine for the kthread itself, as LAM only
affects userspace addresses. However, if the kthread context switches to
a thread in the same userspace process, CR3 may or may not be updated
because the mm_struct doesn't change (based on pending TLB flushes). If
CR3 is not updated, the userspace thread will run incorrectly with LAM
disabled, which may cause page faults when using tagged addresses.
Example scenario:
CPU 1 CPU 2
/* kthread */
kthread_use_mm()
/* user thread */
prctl_enable_tagged_addr()
/* LAM enabled on CPU 2 */
/* LAM disabled on CPU 1 */
context_switch() /* to CPU 1 */
/* Switching to user thread */
switch_mm_irqs_off()
/* CR3 not updated */
/* LAM is still disabled on CPU 1 */
Synchronize LAM enablement by sending an IPI to all CPUs running with
the mm_struct to enable LAM. This makes sure LAM is enabled on CPU 1
in the above scenario before prctl_enable_tagged_addr() returns and
userspace starts using tagged addresses, and before it's possible to
run the userspace process on CPU 1.
In switch_mm_irqs_off(), move reading the LAM mask until after
mm_cpumask() is updated. This ensures that if an outdated LAM mask is
written to CR3, an IPI is received to update it right after IRQs are
re-enabled.
[ dhansen: Add a LAM enabling helper and comment it ]
Fixes: 82721d8b25 ("x86/mm: Handle LAM on context switch")
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/all/20240702132139.3332013-2-yosryahmed%40google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 2eda374e883ad297bd9fe575a16c1dc850346075 upstream.
New CPU #defines encode vendor and family as well as model.
[ dhansen: vertically align 0's in invlpg_miss_ids[] ]
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/all/20240424181518.41946-1-tony.luck%40intel.com
[ Ricardo: I used the old match macro X86_MATCH_INTEL_FAM6_MODEL()
instead of X86_MATCH_VFM() as in the upstream commit. ]
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c48b5a4cf3125adb679e28ef093f66ff81368d05 upstream.
So it turns out that we have to do two passes of
pti_clone_entry_text(), once before initcalls, such that device and
late initcalls can use user-mode-helper / modprobe and once after
free_initmem() / mark_readonly().
Now obviously mark_readonly() can cause PMD splits, and
pti_clone_pgtable() doesn't like that much.
Allow the late clone to split PMDs so that pagetables stay in sync.
[peterz: Changelog and comments]
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lkml.kernel.org/r/20240806184843.GX37996@noisy.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ea72ce5da22806d5713f3ffb39a6d5ae73841f93 upstream.
iounmap() on x86 occasionally fails to unmap because the provided valid
ioremap address is not below high_memory. It turned out that this
happens due to KASLR.
KASLR uses the full address space between PAGE_OFFSET and vaddr_end to
randomize the starting points of the direct map, vmalloc and vmemmap
regions. It thereby limits the size of the direct map by using the
installed memory size plus an extra configurable margin for hot-plug
memory. This limitation is done to gain more randomization space
because otherwise only the holes between the direct map, vmalloc,
vmemmap and vaddr_end would be usable for randomizing.
The limited direct map size is not exposed to the rest of the kernel, so
the memory hot-plug and resource management related code paths still
operate under the assumption that the available address space can be
determined with MAX_PHYSMEM_BITS.
request_free_mem_region() allocates from (1 << MAX_PHYSMEM_BITS) - 1
downwards. That means the first allocation happens past the end of the
direct map and if unlucky this address is in the vmalloc space, which
causes high_memory to become greater than VMALLOC_START and consequently
causes iounmap() to fail for valid ioremap addresses.
MAX_PHYSMEM_BITS cannot be changed for that because the randomization
does not align with address bit boundaries and there are other places
which actually require to know the maximum number of address bits. All
remaining usage sites of MAX_PHYSMEM_BITS have been analyzed and found
to be correct.
Cure this by exposing the end of the direct map via PHYSMEM_END and use
that for the memory hot-plug and resource management related places
instead of relying on MAX_PHYSMEM_BITS. In the KASLR case PHYSMEM_END
maps to a variable which is initialized by the KASLR initialization and
otherwise it is based on MAX_PHYSMEM_BITS as before.
To prevent future hickups add a check into add_pages() to catch callers
trying to add memory above PHYSMEM_END.
Fixes: 0483e1fa6e ("x86/mm: Implement ASLR for kernel memory regions")
Reported-by: Max Ramanouski <max8rr8@gmail.com>
Reported-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-By: Max Ramanouski <max8rr8@gmail.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/87ed6soy3z.ffs@tglx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3db03fb4995ef85fc41e86262ead7b4852f4bcf0 ]
While x86_64 has PMD aligned text sections, i386 does not have this
luxery. Notably ALIGN_ENTRY_TEXT_END is empty and _etext has PAGE
alignment.
This means that text on i386 can be page granular at the tail end,
which in turn means that the PTI text clones should consistently
account for this.
Make pti_clone_entry_text() consistent with pti_clone_kernel_text().
Fixes: 16a3fe634f ("x86/mm/pti: Clone kernel-image on PTE level for 32 bit")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 41e71dbb0e0a0fe214545fe64af031303a08524c ]
Guenter reported dodgy crashes on an i386-nosmp build using GCC-11
that had the form of endless traps until entry stack exhaust and then
#DF from the stack guard.
It turned out that pti_clone_pgtable() had alignment assumptions on
the start address, notably it hard assumes start is PMD aligned. This
is true on x86_64, but very much not true on i386.
These assumptions can cause the end condition to malfunction, leading
to a 'short' clone. Guess what happens when the user mapping has a
short copy of the entry text?
Use the correct increment form for addr to avoid alignment
assumptions.
Fixes: 16a3fe634f ("x86/mm/pti: Clone kernel-image on PTE level for 32 bit")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20240731163105.GG33588@noisy.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0bd7feb2df7ef092c6b8914acca706fb21826f80 upstream.
Parse the pti= and nopti cmdline options using early_param to fix 'Unknown
kernel command line parameters "nopti", will be passed to user space'
warnings in the kernel log when nopti or pti= are passed to the kernel
cmdline on x86 platforms.
Additionally allow the kernel to warn for malformed pti= options.
Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20230819080921.5324-2-jo.vanbulck@cs.kuleuven.be
Signed-off-by: Like Xu <likexu@tencent.com>
commit 3a5a8d343e1cf96eb9971b17cbd4b832ab19b8e7 upstream.
__split_huge_pmd_locked() can be called for a present THP, devmap or
(non-present) migration entry. It calls pmdp_invalidate() unconditionally
on the pmdp and only determines if it is present or not based on the
returned old pmd. This is a problem for the migration entry case because
pmd_mkinvalid(), called by pmdp_invalidate() must only be called for a
present pmd.
On arm64 at least, pmd_mkinvalid() will mark the pmd such that any future
call to pmd_present() will return true. And therefore any lockless
pgtable walker could see the migration entry pmd in this state and start
interpretting the fields as if it were present, leading to BadThings (TM).
GUP-fast appears to be one such lockless pgtable walker.
x86 does not suffer the above problem, but instead pmd_mkinvalid() will
corrupt the offset field of the swap entry within the swap pte. See link
below for discussion of that problem.
Fix all of this by only calling pmdp_invalidate() for a present pmd. And
for good measure let's add a warning to all implementations of
pmdp_invalidate[_ad](). I've manually reviewed all other
pmdp_invalidate[_ad]() call sites and believe all others to be conformant.
This is a theoretical bug found during code review. I don't have any test
case to trigger it in practice.
Link: https://lkml.kernel.org/r/20240501143310.1381675-1-ryan.roberts@arm.com
Link: https://lore.kernel.org/all/0dd7827a-6334-439a-8fd0-43c98e6af22b@arm.com/
Fixes: 84c3fc4e9c ("mm: thp: check pmd migration entry in common path")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f9f67e5adc8dc2e1cc51ab2d3d6382fa97f074d4 ]
For configurations that have the kconfig option NUMA_KEEP_MEMINFO
disabled, numa_fill_memblks() only returns with NUMA_NO_MEMBLK (-1).
SRAT lookup fails then because an existing SRAT memory range cannot be
found for a CFMWS address range. This causes the addition of a
duplicate numa_memblk with a different node id and a subsequent page
fault and kernel crash during boot.
Fix this by making numa_fill_memblks() always available regardless of
NUMA_KEEP_MEMINFO.
As Dan suggested, the fix is implemented to remove numa_fill_memblks()
from sparsemem.h and alos using __weak for the function.
Note that the issue was initially introduced with [1]. But since
phys_to_target_node() was originally used that returned the valid node
0, an additional numa_memblk was not added. Though, the node id was
wrong too, a message is seen then in the logs:
kernel/numa.c: pr_info_once("Unknown target node for memory at 0x%llx, assuming node 0\n",
[1] commit fd49f99c18 ("ACPI: NUMA: Add a node and memblk for each
CFMWS not in SRAT")
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/all/66271b0072317_69102944c@dwillia2-xfh.jf.intel.com.notmuch/
Fixes: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5bc8b0f5dac04cd4ebe47f8090a5942f2f2647ef ]
When running as Xen PV guest in some cases W^X violation WARN()s have
been observed. Those WARN()s are produced by verify_rwx(), which looks
into the PTE to verify that writable kernel pages have the NX bit set
in order to avoid code modifications of the kernel by rogue code.
As the NX bits of all levels of translation entries are or-ed and the
RW bits of all levels are and-ed, looking just into the PTE isn't enough
for the decision that a writable page is executable, too.
When running as a Xen PV guest, the direct map PMDs and kernel high
map PMDs share the same set of PTEs. Xen kernel initialization will set
the NX bit in the direct map PMD entries, and not the shared PTEs.
Fixes: 652c5bf380 ("x86/mm: Refuse W^X violations")
Reported-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240412151258.9171-5-jgross@suse.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 02eac06b820c3eae73e5736ae62f986d37fed991 ]
Modify _lookup_address_cpa() to no longer use lookup_address(), but
only lookup_address_in_pgd().
This is done in preparation of using lookup_address_in_pgd_attr().
No functional change intended.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240412151258.9171-4-jgross@suse.com
Stable-dep-of: 5bc8b0f5dac0 ("x86/pat: Fix W^X violation false-positives when running as Xen PV guest")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ceb647b4b529fdeca9021cd34486f5a170746bda ]
Add lookup_address_in_pgd_attr() doing the same as the already
existing lookup_address_in_pgd(), but returning the effective settings
of the NX and RW bits of all walked page table levels, too.
This will be needed in order to match hardware behavior when looking
for effective access rights, especially for detecting writable code
pages.
In order to avoid code duplication, let lookup_address_in_pgd() call
lookup_address_in_pgd_attr() with dummy parameters.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240412151258.9171-2-jgross@suse.com
Stable-dep-of: 5bc8b0f5dac0 ("x86/pat: Fix W^X violation false-positives when running as Xen PV guest")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 02b670c1f88e78f42a6c5aee155c7b26960ca054 ]
The syzbot-reported stack trace from hell in this discussion thread
actually has three nested page faults:
https://lore.kernel.org/r/000000000000d5f4fc0616e816d4@google.com
... and I think that's actually the important thing here:
- the first page fault is from user space, and triggers the vsyscall
emulation.
- the second page fault is from __do_sys_gettimeofday(), and that should
just have caused the exception that then sets the return value to
-EFAULT
- the third nested page fault is due to _raw_spin_unlock_irqrestore() ->
preempt_schedule() -> trace_sched_switch(), which then causes a BPF
trace program to run, which does that bpf_probe_read_compat(), which
causes that page fault under pagefault_disable().
It's quite the nasty backtrace, and there's a lot going on.
The problem is literally the vsyscall emulation, which sets
current->thread.sig_on_uaccess_err = 1;
and that causes the fixup_exception() code to send the signal *despite* the
exception being caught.
And I think that is in fact completely bogus. It's completely bogus
exactly because it sends that signal even when it *shouldn't* be sent -
like for the BPF user mode trace gathering.
In other words, I think the whole "sig_on_uaccess_err" thing is entirely
broken, because it makes any nested page-faults do all the wrong things.
Now, arguably, I don't think anybody should enable vsyscall emulation any
more, but this test case clearly does.
I think we should just make the "send SIGSEGV" be something that the
vsyscall emulation does on its own, not this broken per-thread state for
something that isn't actually per thread.
The x86 page fault code actually tried to deal with the "incorrect nesting"
by having that:
if (in_interrupt())
return;
which ignores the sig_on_uaccess_err case when it happens in interrupts,
but as shown by this example, these nested page faults do not need to be
about interrupts at all.
IOW, I think the only right thing is to remove that horrendously broken
code.
The attached patch looks like the ObviouslyCorrect(tm) thing to do.
NOTE! This broken code goes back to this commit in 2011:
4fc3490114 ("x86-64: Set siginfo and context on vsyscall emulation faults")
... and back then the reason was to get all the siginfo details right.
Honestly, I do not for a moment believe that it's worth getting the siginfo
details right here, but part of the commit says:
This fixes issues with UML when vsyscall=emulate.
... and so my patch to remove this garbage will probably break UML in this
situation.
I do not believe that anybody should be running with vsyscall=emulate in
2024 in the first place, much less if you are doing things like UML. But
let's see if somebody screams.
Reported-and-tested-by: syzbot+83e7f982ca045ab4405c@syzkaller.appspotmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/CAHk-=wh9D6f7HUkDgZHKmDCHUQmp+Co89GP+b8+z+G56BKeyNg@mail.gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Upstream: no
It's not performance friendly in the loop invoking
notify_page_enc_status_changed() just handling one page, if those pages
are physically contiguous, merge them into a large range to get
better performance.
Signed-off-by: yangwencheng <yangwencheng@hygon.cn>
Signed-off-by: hanliyang <hanliyang@hygon.cn>
Upstream: no
Print Hygon secure virtualization feature. Add CSV3 info in feature
list if CSV3 is active.
Signed-off-by: Xin Jiang <jiangxin@hygon.cn>
Signed-off-by: hanliyang <hanliyang@hygon.cn>
Upstream: no
Add support for changing the memory to private or shared memory for
multiple pages if CSV3 is active.
When CSV3 guest wants to share data with host like SWIOTLB or change
the unused shared memory to private memory, it must perform an secure
call command to the secure processor to update mapping in nested page
table.
Signed-off-by: Xin Jiang <jiangxin@hygon.cn>
Signed-off-by: hanliyang <hanliyang@hygon.cn>
Upstream: no
Add functions to change the memory shared/private attribute in
early boot code.
When CSV3 is active, the decrypted memory must be mapped to normal
(non-isolated) memory in nested page table so that hypervisor and
guest can access shared data.
But in-place encrypt/decrypt action on the memory is not applicable
in CSV3 as CSV3 guest's private page will not be changed to shared
page until the secure processor update NPT.
Also new secure call pages should be initialized for per cpu to
support multiple cpu secure call commands simultaneously.
Signed-off-by: Xin Jiang <jiangxin@hygon.cn>
Signed-off-by: hanliyang <hanliyang@hygon.cn>
Upstream: no
The functions are needed to set memory as private/shared memory or
reset all memory as private memory at the stage where the identity
mapping page table is available.
Generally, at early runtime of the decompressed kernel, it needs to
obtain CSV3 secure call pages then reset all memory as private before
switching to new kernel page table. Otherwise, prior shared memory
regions will be wrongly used and private data in guest may be
accessed maliciously.
Signed-off-by: Xin Jiang <jiangxin@hygon.cn>
Signed-off-by: hanliyang <hanliyang@hygon.cn>
Upstream: no
The private memory of a CSV3 guest is isolated from VMM and has to be
physically contiguous. CMA (Contiguous Memory Allocator) is a memory
allocator within the kernel for contiguous physical memory.
Use the CMA for the CSV3 private memory management. In order to
support CSV3, select MMU and CMA when CONIFG_HYGON_CSV is
configured.
Signed-off-by: Xin Jiang <jiangxin@hygon.cn>
Signed-off-by: hanliyang <hanliyang@hygon.cn>
Upstream: no
Add CSV and CSV2 to the list of memory encryption features. Also
print CPU vendor while printing CSV infos.
Signed-off-by: hanliyang <hanliyang@hygon.cn>
Upstream: no
Provide CONFIG_HYGON_CSV to the arch/x86/Kconfig, and build HYGON's
specific memory encryption support into the kernel when
CONFIG_HYGON_CSV=y.
Besides, add arch/x86/include/asm/processor-hygon.h to contains
helpers to determine the Hygon CPUs so that we can call functions
specific to CSV in the native code and reduce code intruision.
Signed-off-by: hanliyang <hanliyang@hygon.cn>
commit cd0d9d92c8bb46e77de62efd7df13069ddd61e7d upstream.
The early SME/SEV code parses the command line very early, in order to
decide whether or not memory encryption should be enabled, which needs
to occur even before the initial page tables are created.
This is problematic for a number of reasons:
- this early code runs from the 1:1 mapping provided by the decompressor
or firmware, which uses a different translation than the one assumed by
the linker, and so the code needs to be built in a special way;
- parsing external input while the entire kernel image is still mapped
writable is a bad idea in general, and really does not belong in
security minded code;
- the current code ignores the built-in command line entirely (although
this appears to be the case for the entire decompressor)
Given that the decompressor/EFI stub is an intrinsic part of the x86
bootable kernel image, move the command line parsing there and out of
the core kernel. This removes the need to build lib/cmdline.o in a
special way, or to use RIP-relative LEA instructions in inline asm
blocks.
This involves a new xloadflag in the setup header to indicate
that mem_encrypt=on appeared on the kernel command line.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240227151907.387873-17-ardb+git@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 48204aba801f1b512b3abed10b8e1a63e03f3dd1 upstream.
The .head.text section is the initial primary entrypoint of the core
kernel, and is entered with the CPU executing from a 1:1 mapping of
memory. Such code must never access global variables using absolute
references, as these are based on the kernel virtual mapping which is
not active yet at this point.
Given that the SME startup code is also called from this early execution
context, move it into .head.text as well. This will allow more thorough
build time checks in the future to ensure that early startup code only
uses RIP-relative references to global variables.
Also replace some occurrences of __pa_symbol() [which relies on the
compiler generating an absolute reference, which is not guaranteed] and
an open coded RIP-relative access with RIP_REL_REF().
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240227151907.387873-18-ardb+git@google.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 04c35ab3bdae7fefbd7c7a7355f29fa03a035221 upstream.
PAT handling won't do the right thing in COW mappings: the first PTE (or,
in fact, all PTEs) can be replaced during write faults to point at anon
folios. Reliably recovering the correct PFN and cachemode using
follow_phys() from PTEs will not work in COW mappings.
Using follow_phys(), we might just get the address+protection of the anon
folio (which is very wrong), or fail on swap/nonswap entries, failing
follow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and
track_pfn_copy(), not properly calling free_pfn_range().
In free_pfn_range(), we either wouldn't call memtype_free() or would call
it with the wrong range, possibly leaking memory.
To fix that, let's update follow_phys() to refuse returning anon folios,
and fallback to using the stored PFN inside vma->vm_pgoff for COW mappings
if we run into that.
We will now properly handle untrack_pfn() with COW mappings, where we
don't need the cachemode. We'll have to fail fork()->track_pfn_copy() if
the first page was replaced by an anon folio, though: we'd have to store
the cachemode in the VMA to make this work, likely growing the VMA size.
For now, lets keep it simple and let track_pfn_copy() just fail in that
case: it would have failed in the past with swap/nonswap entries already,
and it would have done the wrong thing with anon folios.
Simple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn():
<--- C reproducer --->
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <liburing.h>
int main(void)
{
struct io_uring_params p = {};
int ring_fd;
size_t size;
char *map;
ring_fd = io_uring_setup(1, &p);
if (ring_fd < 0) {
perror("io_uring_setup");
return 1;
}
size = p.sq_off.array + p.sq_entries * sizeof(unsigned);
/* Map the submission queue ring MAP_PRIVATE */
map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
ring_fd, IORING_OFF_SQ_RING);
if (map == MAP_FAILED) {
perror("mmap");
return 1;
}
/* We have at least one page. Let's COW it. */
*map = 0;
pause();
return 0;
}
<--- C reproducer --->
On a system with 16 GiB RAM and swap configured:
# ./iouring &
# memhog 16G
# killall iouring
[ 301.552930] ------------[ cut here ]------------
[ 301.553285] WARNING: CPU: 7 PID: 1402 at arch/x86/mm/pat/memtype.c:1060 untrack_pfn+0xf4/0x100
[ 301.553989] Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_g
[ 301.558232] CPU: 7 PID: 1402 Comm: iouring Not tainted 6.7.5-100.fc38.x86_64 #1
[ 301.558772] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebu4
[ 301.559569] RIP: 0010:untrack_pfn+0xf4/0x100
[ 301.559893] Code: 75 c4 eb cf 48 8b 43 10 8b a8 e8 00 00 00 3b 6b 28 74 b8 48 8b 7b 30 e8 ea 1a f7 000
[ 301.561189] RSP: 0018:ffffba2c0377fab8 EFLAGS: 00010282
[ 301.561590] RAX: 00000000ffffffea RBX: ffff9208c8ce9cc0 RCX: 000000010455e047
[ 301.562105] RDX: 07fffffff0eb1e0a RSI: 0000000000000000 RDI: ffff9208c391d200
[ 301.562628] RBP: 0000000000000000 R08: ffffba2c0377fab8 R09: 0000000000000000
[ 301.563145] R10: ffff9208d2292d50 R11: 0000000000000002 R12: 00007fea890e0000
[ 301.563669] R13: 0000000000000000 R14: ffffba2c0377fc08 R15: 0000000000000000
[ 301.564186] FS: 0000000000000000(0000) GS:ffff920c2fbc0000(0000) knlGS:0000000000000000
[ 301.564773] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 301.565197] CR2: 00007fea88ee8a20 CR3: 00000001033a8000 CR4: 0000000000750ef0
[ 301.565725] PKRU: 55555554
[ 301.565944] Call Trace:
[ 301.566148] <TASK>
[ 301.566325] ? untrack_pfn+0xf4/0x100
[ 301.566618] ? __warn+0x81/0x130
[ 301.566876] ? untrack_pfn+0xf4/0x100
[ 301.567163] ? report_bug+0x171/0x1a0
[ 301.567466] ? handle_bug+0x3c/0x80
[ 301.567743] ? exc_invalid_op+0x17/0x70
[ 301.568038] ? asm_exc_invalid_op+0x1a/0x20
[ 301.568363] ? untrack_pfn+0xf4/0x100
[ 301.568660] ? untrack_pfn+0x65/0x100
[ 301.568947] unmap_single_vma+0xa6/0xe0
[ 301.569247] unmap_vmas+0xb5/0x190
[ 301.569532] exit_mmap+0xec/0x340
[ 301.569801] __mmput+0x3e/0x130
[ 301.570051] do_exit+0x305/0xaf0
...
Link: https://lkml.kernel.org/r/20240403212131.929421-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Wupeng Ma <mawupeng1@huawei.com>
Closes: https://lkml.kernel.org/r/20240227122814.3781907-1-mawupeng1@huawei.com
Fixes: b1a86e15dc ("x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines")
Fixes: 5899329b19 ("x86: PAT: implement track/untrack of pfnmap regions for x86 - v3")
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c567f2948f57bdc03ed03403ae0234085f376b7d ]
This reverts commit d794734c9bbfe22f86686dc2909c25f5ffe1a572.
While the original change tries to fix a bug, it also unintentionally broke
existing systems, see the regressions reported at:
https://lore.kernel.org/all/3a1b9909-45ac-4f97-ad68-d16ef1ce99db@pavinjoseph.com/
Since d794734c9bbf was also marked for -stable, let's back it out before
causing more damage.
Note that due to another upstream change the revert was not 100% automatic:
0a845e0f6348 mm/treewide: replace pud_large() with pud_leaf()
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Cc: Russ Anderson <rja@hpe.com>
Cc: Steve Wahl <steve.wahl@hpe.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/3a1b9909-45ac-4f97-ad68-d16ef1ce99db@pavinjoseph.com/
Fixes: d794734c9bbf ("x86/mm/ident_map: Use gbpages only where full GB page should be mapped.")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0a845e0f6348ccfa2dcc8c450ffd1c9ffe8c4add ]
pud_large() is always defined as pud_leaf(). Merge their usages. Chose
pud_leaf() because pud_leaf() is a global API, while pud_large() is not.
Link: https://lkml.kernel.org/r/20240305043750.93762-9-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: c567f2948f57 ("Revert "x86/mm/ident_map: Use gbpages only where full GB page should be mapped."")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0f4a1e80989aca185d955fcd791d7750082044a2 upstream.
SEV-SNP requires encrypted memory to be validated before access.
Because the ROM memory range is not part of the e820 table, it is not
pre-validated by the BIOS. Therefore, if a SEV-SNP guest kernel wishes
to access this range, the guest must first validate the range.
The current SEV-SNP code does indeed scan the ROM range during early
boot and thus attempts to validate the ROM range in probe_roms().
However, this behavior is neither sufficient nor necessary for the
following reasons:
* With regards to sufficiency, if EFI_CONFIG_TABLES are not enabled and
CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK is set, the kernel will
attempt to access the memory at SMBIOS_ENTRY_POINT_SCAN_START (which
falls in the ROM range) prior to validation.
For example, Project Oak Stage 0 provides a minimal guest firmware
that currently meets these configuration conditions, meaning guests
booting atop Oak Stage 0 firmware encounter a problematic call chain
during dmi_setup() -> dmi_scan_machine() that results in a crash
during boot if SEV-SNP is enabled.
* With regards to necessity, SEV-SNP guests generally read garbage
(which changes across boots) from the ROM range, meaning these scans
are unnecessary. The guest reads garbage because the legacy ROM range
is unencrypted data but is accessed via an encrypted PMD during early
boot (where the PMD is marked as encrypted due to potentially mapping
actually-encrypted data in other PMD-contained ranges).
In one exceptional case, EISA probing treats the ROM range as
unencrypted data, which is inconsistent with other probing.
Continuing to allow SEV-SNP guests to use garbage and to inconsistently
classify ROM range encryption status can trigger undesirable behavior.
For instance, if garbage bytes appear to be a valid signature, memory
may be unnecessarily reserved for the ROM range. Future code or other
use cases may result in more problematic (arbitrary) behavior that
should be avoided.
While one solution would be to overhaul the early PMD mapping to always
treat the ROM region of the PMD as unencrypted, SEV-SNP guests do not
currently rely on data from the ROM region during early boot (and even
if they did, they would be mostly relying on garbage data anyways).
As a simpler solution, skip the ROM range scans (and the otherwise-
necessary range validation) during SEV-SNP guest early boot. The
potential SEV-SNP guest crash due to lack of ROM range validation is
thus avoided by simply not accessing the ROM range.
In most cases, skip the scans by overriding problematic x86_init
functions during sme_early_init() to SNP-safe variants, which can be
likened to x86_init overrides done for other platforms (ex: Xen); such
overrides also avoid the spread of cc_platform_has() checks throughout
the tree.
In the exceptional EISA case, still use cc_platform_has() for the
simplest change, given (1) checks for guest type (ex: Xen domain status)
are already performed here, and (2) these checks occur in a subsys
initcall instead of an x86_init function.
[ bp: Massage commit message, remove "we"s. ]
Fixes: 9704c07bf9 ("x86/kernel: Validate ROM memory before accessing when SEV-SNP is active")
Signed-off-by: Kevin Loughlin <kevinloughlin@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/20240313121546.2964854-1-kevinloughlin@google.com
Signed-off-by: Kevin Loughlin <kevinloughlin@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1c811d403afd73f04bde82b83b24c754011bd0e8 upstream.
The early startup code executes from a 1:1 mapping of memory, which
differs from the mapping that the code was linked and/or relocated to
run at. The latter mapping is not active yet at this point, and so
symbol references that rely on it will fault.
Given that the core kernel is built without -fPIC, symbol references are
typically emitted as absolute, and so any such references occuring in
the early startup code will therefore crash the kernel.
While an attempt was made to work around this for the early SEV/SME
startup code, by forcing RIP-relative addressing for certain global
SEV/SME variables via inline assembly (see snp_cpuid_get_table() for
example), RIP-relative addressing must be pervasively enforced for
SEV/SME global variables when accessed prior to page table fixups.
__startup_64() already handles this issue for select non-SEV/SME global
variables using fixup_pointer(), which adjusts the pointer relative to a
`physaddr` argument. To avoid having to pass around this `physaddr`
argument across all functions needing to apply pointer fixups, introduce
a macro RIP_RELATIVE_REF() which generates a RIP-relative reference to
a given global variable. It is used where necessary to force
RIP-relative accesses to global variables.
For backporting purposes, this patch makes no attempt at cleaning up
other occurrences of this pattern, involving either inline asm or
fixup_pointer(). Those will be addressed later.
[ bp: Call it "rip_rel_ref" everywhere like other code shortens
"rIP-relative reference" and make the asm wrapper __always_inline. ]
Co-developed-by: Kevin Loughlin <kevinloughlin@google.com>
Signed-off-by: Kevin Loughlin <kevinloughlin@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/all/20240130220845.1978329-1-kevinloughlin@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 29956748339aa8757a7e2f927a8679dd08f24bb6 upstream.
It was meant well at the time but nothing's using it so get rid of it.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240202163510.GDZb0Zvj8qOndvFOiZ@fat_crate.local
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e814b59e6c2b11f5a3d007b2e61f7d550c354c3a ]
Commit
cbebd68f59 ("x86/mm: Fix use of uninitialized buffer in sme_enable()")
'fixed' an issue in sme_enable() detected by static analysis, and broke
the common case in the process.
cmdline_find_option() will return < 0 on an error, or when the command
line argument does not appear at all. In this particular case, the
latter is not an error condition, and so the early exit is wrong.
Instead, without mem_encrypt= on the command line, the compile time
default should be honoured, which could be to enable memory encryption,
and this is currently broken.
Fix it by setting sme_me_mask to a preliminary value based on the
compile time default, and only omitting the command line argument test
when cmdline_find_option() returns an error.
[ bp: Drop active_by_default while at it. ]
Fixes: cbebd68f59 ("x86/mm: Fix use of uninitialized buffer in sme_enable()")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240126163918.2908990-2-ardb+git@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 32019c659ecfe1d92e3bf9fcdfbb11a7c70acd58 ]
When trying to use copy_from_kernel_nofault() to read vsyscall page
through a bpf program, the following oops was reported:
BUG: unable to handle page fault for address: ffffffffff600000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 3231067 P4D 3231067 PUD 3233067 PMD 3235067 PTE 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 1 PID: 20390 Comm: test_progs ...... 6.7.0+ #58
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ......
RIP: 0010:copy_from_kernel_nofault+0x6f/0x110
......
Call Trace:
<TASK>
? copy_from_kernel_nofault+0x6f/0x110
bpf_probe_read_kernel+0x1d/0x50
bpf_prog_2061065e56845f08_do_probe_read+0x51/0x8d
trace_call_bpf+0xc5/0x1c0
perf_call_bpf_enter.isra.0+0x69/0xb0
perf_syscall_enter+0x13e/0x200
syscall_trace_enter+0x188/0x1c0
do_syscall_64+0xb5/0xe0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
</TASK>
......
---[ end trace 0000000000000000 ]---
The oops is triggered when:
1) A bpf program uses bpf_probe_read_kernel() to read from the vsyscall
page and invokes copy_from_kernel_nofault() which in turn calls
__get_user_asm().
2) Because the vsyscall page address is not readable from kernel space,
a page fault exception is triggered accordingly.
3) handle_page_fault() considers the vsyscall page address as a user
space address instead of a kernel space address. This results in the
fix-up setup by bpf not being applied and a page_fault_oops() is invoked
due to SMAP.
Considering handle_page_fault() has already considered the vsyscall page
address as a userspace address, fix the problem by disallowing vsyscall
page read for copy_from_kernel_nofault().
Originally-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: syzbot+72aa0161922eba61b50e@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/CAG48ez06TZft=ATH1qh2c5mpS5BT8UakwNkzi6nvK5_djC-4Nw@mail.gmail.com
Reported-by: xingwei lee <xrivendell7@gmail.com>
Closes: https://lore.kernel.org/bpf/CABOYnLynjBoFZOf3Z4BhaZkc5hx_kHfsjiW+UWLoB=w33LvScw@mail.gmail.com
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240202103935.3154011-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ee0e39a63b78849f8abbef268b13e4838569f646 ]
Move is_vsyscall_vaddr() into asm/vsyscall.h to make it available for
copy_from_kernel_nofault_allowed() in arch/x86/mm/maccess.c.
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20240202103935.3154011-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b626070ffc14acca5b87a2aa5f581db98617584c ]
The compare function used to sort memblks into starting address
order fails when the result of its u64 address subtraction gets
truncated to an int upon return.
The impact of the bad sort is that memblks will be filled out
incorrectly. Depending on the set of memblks, a user may see no
errors at all but still have a bad fill, or see messages reporting
a node overlap that leads to numa init failure:
[] node 0 [mem: ] overlaps with node 1 [mem: ]
[] No NUMA configuration found
Replace with a comparison that can only result in: 1, 0, -1.
Fixes: 8f012db27c95 ("x86/numa: Introduce numa_fill_memblks()")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/99dcb3ae87e04995e9f293f6158dc8fa0749a487.1705085543.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9b99c17f7510bed2adbe17751fb8abddba5620bc ]
numa_fill_memblks() fills in the gaps in numa_meminfo memblks over a
physical address range. To do so, it first creates a list of existing
memblks that overlap that address range. The issue is that it is off
by one when comparing to the end of the address range, so memblks
that do not overlap are selected.
The impact of selecting a memblk that does not actually overlap is
that an existing memblk may be filled when the expected action is to
do nothing and return NUMA_NO_MEMBLK to the caller. The caller can
then add a new NUMA node and memblk.
Replace the broken open-coded search for address overlap with the
memblock helper memblock_addrs_overlap(). Update the kernel doc
and in code comments.
Suggested by: "Huang, Ying" <ying.huang@intel.com>
Fixes: 8f012db27c95 ("x86/numa: Introduce numa_fill_memblks()")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/10a3e6109c34c21a8dd4c513cf63df63481a2b07.1705085543.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d794734c9bbfe22f86686dc2909c25f5ffe1a572 upstream.
When ident_pud_init() uses only gbpages to create identity maps, large
ranges of addresses not actually requested can be included in the
resulting table; a 4K request will map a full GB. On UV systems, this
ends up including regions that will cause hardware to halt the system
if accessed (these are marked "reserved" by BIOS). Even processor
speculation into these regions is enough to trigger the system halt.
Only use gbpages when map creation requests include the full GB page
of space. Fall back to using smaller 2M pages when only portions of a
GB page are included in the request.
No attempt is made to coalesce mapping requests. If a request requires
a map entry at the 2M (pmd) level, subsequent mapping requests within
the same 1G region will also be at the pmd level, even if adjacent or
overlapping such requests could have been combined to map a full
gbpage. Existing usage starts with larger regions and then adds
smaller regions, so this should not have any great consequence.
[ dhansen: fix up comment formatting, simplifty changelog ]
Signed-off-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240126164841.170866-1-steve.wahl%40hpe.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ upstream commit b82a8dbd3d2f4563156f7150c6f2ecab6e960b30 ]
The INT 0x80 instruction is used for 32-bit x86 Linux syscalls. The
kernel expects to receive a software interrupt as a result of the INT
0x80 instruction. However, an external interrupt on the same vector
triggers the same handler.
The kernel interprets an external interrupt on vector 0x80 as a 32-bit
system call that came from userspace.
A VMM can inject external interrupts on any arbitrary vector at any
time. This remains true even for TDX and SEV guests where the VMM is
untrusted.
Put together, this allows an untrusted VMM to trigger int80 syscall
handling at any given point. The content of the guest register file at
that moment defines what syscall is triggered and its arguments. It
opens the guest OS to manipulation from the VMM side.
Disable 32-bit emulation by default for TDX and SEV. User can override
it with the ia32_emulation=y command line option.
[ dhansen: reword the changelog ]
Reported-by: Supraja Sridhara <supraja.sridhara@inf.ethz.ch>
Reported-by: Benedict Schlüter <benedict.schlueter@inf.ethz.ch>
Reported-by: Mark Kuhne <mark.kuhne@inf.ethz.ch>
Reported-by: Andrin Bertschi <andrin.bertschi@inf.ethz.ch>
Reported-by: Shweta Shinde <shweta.shinde@inf.ethz.ch>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@vger.kernel.org> # 6.0+: 1da5c9b x86: Introduce ia32_enabled()
Cc: <stable@vger.kernel.org> # 6.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a1e2b8b36820d8c91275f207e77e91645b7c6836 ]
Qi Zheng reported crashes in a production environment and provided a
simplified example as a reproducer:
| For example, if we use Qemu to start a two NUMA node kernel,
| one of the nodes has 2M memory (less than NODE_MIN_SIZE),
| and the other node has 2G, then we will encounter the
| following panic:
|
| BUG: kernel NULL pointer dereference, address: 0000000000000000
| <...>
| RIP: 0010:_raw_spin_lock_irqsave+0x22/0x40
| <...>
| Call Trace:
| <TASK>
| deactivate_slab()
| bootstrap()
| kmem_cache_init()
| start_kernel()
| secondary_startup_64_no_verify()
The crashes happen because of inconsistency between the nodemask that
has nodes with less than 4MB as memoryless, and the actual memory fed
into the core mm.
The commit:
9391a3f9c7 ("[PATCH] x86_64: Clear more state when ignoring empty node in SRAT parsing")
... that introduced minimal size of a NUMA node does not explain why
a node size cannot be less than 4MB and what boot failures this
restriction might fix.
Fixes have been submitted to the core MM code to tighten up the
memory topologies it accepts and to not crash on weird input:
mm: page_alloc: skip memoryless nodes entirely
mm: memory_hotplug: drop memoryless node from fallback lists
Andrew has accepted them into the -mm tree, but there are no
stable SHA1's yet.
This patch drops the limitation for minimal node size on x86:
- which works around the crash without the fixes to the core MM.
- makes x86 topologies less weird,
- removes an arbitrary and undocumented limitation on NUMA topologies.
[ mingo: Improved changelog clarity. ]
Reported-by: Qi Zheng <zhengqi.arch@bytedance.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lore.kernel.org/r/ZS+2qqjEO5/867br@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f79936545fb122856bd78b189d3c7ee59928c751 ]
Previously, if copy_from_kernel_nofault() was called before
boot_cpu_data.x86_virt_bits was set up, then it would trigger undefined
behavior due to a shift by 64.
This ended up causing boot failures in the latest version of ubuntu2204
in the gcp project when using SEV-SNP.
Specifically, this function is called during an early #VC handler which
is triggered by a CPUID to check if NX is implemented.
Fixes: 1aa9aa8ee5 ("x86/sev-es: Setup GHCB-based boot #VC handler")
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Adam Dunlap <acdunlap@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jacob Xu <jacobhxu@google.com>
Link: https://lore.kernel.org/r/20230912002703.3924521-2-acdunlap@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8f012db27c9516be1a7aca93ea4a6ca9c75056c9 ]
numa_fill_memblks() fills in the gaps in numa_meminfo memblks
over an physical address range.
The ACPI driver will use numa_fill_memblks() to implement a new Linux
policy that prescribes extending proximity domains in a portion of a
CFMWS window to the entire window.
Dan Williams offered this explanation of the policy:
A CFWMS is an ACPI data structure that indicates *potential* locations
where CXL memory can be placed. It is the playground where the CXL
driver has free reign to establish regions. That space can be populated
by BIOS created regions, or driver created regions, after hotplug or
other reconfiguration.
When BIOS creates a region in a CXL Window it additionally describes
that subset of the Window range in the other typical ACPI tables SRAT,
SLIT, and HMAT. The rationale for BIOS not pre-describing the entire
CXL Window in SRAT, SLIT, and HMAT is that it can not predict the
future. I.e. there is nothing stopping higher or lower performance
devices being placed in the same Window. Compare that to ACPI memory
hotplug that just onlines additional capacity in the proximity domain
with little freedom for dynamic performance differentiation.
That leaves the OS with a choice, should unpopulated window capacity
match the proximity domain of an existing region, or should it allocate
a new one? This patch takes the simple position of minimizing proximity
domain proliferation by reusing any proximity domain intersection for
the entire Window. If the Window has no intersections then allocate a
new proximity domain. Note that SRAT, SLIT and HMAT information can be
enumerated dynamically in a standard way from device provided data.
Think of CXL as the end of ACPI needing to describe memory attributes,
CXL offers a standard discovery model for performance attributes, but
Linux still needs to interoperate with the old regime.
Reported-by: Derick Marks <derick.w.marks@intel.com>
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Derick Marks <derick.w.marks@intel.com>
Link: https://lore.kernel.org/all/ef078a6f056ca974e5af85997013c0fda9e3326d.1689018477.git.alison.schofield%40intel.com
Stable-dep-of: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Convert IBT selftest to asm to fix objtool warning
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Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 shadow stack support from Dave Hansen:
"This is the long awaited x86 shadow stack support, part of Intel's
Control-flow Enforcement Technology (CET).
CET consists of two related security features: shadow stacks and
indirect branch tracking. This series implements just the shadow stack
part of this feature, and just for userspace.
The main use case for shadow stack is providing protection against
return oriented programming attacks. It works by maintaining a
secondary (shadow) stack using a special memory type that has
protections against modification. When executing a CALL instruction,
the processor pushes the return address to both the normal stack and
to the special permission shadow stack. Upon RET, the processor pops
the shadow stack copy and compares it to the normal stack copy.
For more information, refer to the links below for the earlier
versions of this patch set"
Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/
* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
x86/shstk: Change order of __user in type
x86/ibt: Convert IBT selftest to asm
x86/shstk: Don't retry vm_munmap() on -EINTR
x86/kbuild: Fix Documentation/ reference
x86/shstk: Move arch detail comment out of core mm
x86/shstk: Add ARCH_SHSTK_STATUS
x86/shstk: Add ARCH_SHSTK_UNLOCK
x86: Add PTRACE interface for shadow stack
selftests/x86: Add shadow stack test
x86/cpufeatures: Enable CET CR4 bit for shadow stack
x86/shstk: Wire in shadow stack interface
x86: Expose thread features in /proc/$PID/status
x86/shstk: Support WRSS for userspace
x86/shstk: Introduce map_shadow_stack syscall
x86/shstk: Check that signal frame is shadow stack mem
x86/shstk: Check that SSP is aligned on sigreturn
x86/shstk: Handle signals for shadow stack
x86/shstk: Introduce routines modifying shstk
x86/shstk: Handle thread shadow stack
x86/shstk: Add user-mode shadow stack support
...
Jianping Liu