Jumping to the very next instruction is not very useful:
jmp label
label:
Removing the jump.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-5-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This is a preparatory patch for moving stub32_execve[at]() to this
file. It makes sense to have all execve stubs in one place, so
that they can reuse code.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The rule for 'copy_from_user()' is that it zeroes the remaining kernel
buffer even when the copy fails halfway, just to make sure that we don't
leave uninitialized kernel memory around. Because even if we check for
errors, some kernel buffers stay around after thge copy (think page
cache).
However, the x86-64 logic for user copies uses a copy_user_generic()
function for all the cases, that set the "zerorest" flag for any fault
on the source buffer. Which meant that it didn't just try to clear the
kernel buffer after a failure in copy_from_user(), it also tried to
clear the destination user buffer for the "copy_in_user()" case.
Not only is that pointless, it also means that the clearing code has to
worry about the tail clearing taking page faults for the user buffer
case. Which is just stupid, since that case shouldn't happen in the
first place.
Get rid of the whole "zerorest" thing entirely, and instead just check
if the destination is in kernel space or not. And then just use
memset() to clear the tail of the kernel buffer if necessary.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dirty logging tracks sptes in 4k granularity, meaning that large sptes
have to be split. If live migration is successful, the guest in the
source machine will be destroyed and large sptes will be created in the
destination. However, the guest continues to run in the source machine
(for example if live migration fails), small sptes will remain around
and cause bad performance.
This patch introduce lazy collapsing of small sptes into large sptes.
The rmap will be scanned in ioctl context when dirty logging is stopped,
dropping those sptes which can be collapsed into a single large-page spte.
Later page faults will create the large-page sptes.
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Message-Id: <1428046825-6905-1-git-send-email-wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
CR2 is not cleared as it should after reset. See Intel SDM table named "IA-32
Processor States Following Power-up, Reset, or INIT".
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427933438-12782-5-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
DR0-DR3 are not cleared as they should during reset and when they are set from
userspace. It appears to be caused by c77fb5fe6f ("KVM: x86: Allow the guest
to run with dirty debug registers").
Force their reload on these situations.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427933438-12782-4-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After reset, the CPU can change the BSP, which will be used upon INIT. Reset
should return the BSP which QEMU asked for, and therefore handled accordingly.
To quote: "If the MP protocol has completed and a BSP is chosen, subsequent
INITs (either to a specific processor or system wide) do not cause the MP
protocol to be repeated."
[Intel SDM 8.4.2: MP Initialization Protocol Requirements and Restrictions]
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427933438-12782-3-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
recalculate_apic_map() uses two passes over all VCPUs. This is a relic
from time when we selected a global mode in the first pass and set up
the optimized table in the second pass (to have a consistent mode).
Recent changes made mixed mode unoptimized and we can do it in one pass.
Format of logical MDA is a function of the mode, so we encode it in
apic_logical_id() and drop obsoleted variables from the struct.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1423766494-26150-5-git-send-email-rkrcmar@redhat.com>
[Add lid_bits temporary in apic_logical_id. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We want to support mixed modes and the easiest solution is to avoid
optimizing those weird and unlikely scenarios.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1423766494-26150-4-git-send-email-rkrcmar@redhat.com>
[Add comment above KVM_APIC_MODE_* defines. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Broadcast allowed only one global APIC mode, but mixed modes are
theoretically possible. x2APIC IPI doesn't mean 0xff as broadcast,
the rest does.
x2APIC broadcasts are accepted by xAPIC. If we take SDM to be logical,
even addreses beginning with 0xff should be accepted, but real hardware
disagrees. This patch aims for simple code by considering most of real
behavior as undefined.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1423766494-26150-3-git-send-email-rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In mixed modes, we musn't deliver xAPIC IPIs like x2APIC and vice versa.
Instead of preserving the information in apic_send_ipi(), we regain it
by converting all destinations into correct MDA in the slow path.
This allows easier reasoning about subsequent matching.
Our kvm_apic_broadcast() had an interesting design decision: it didn't
consider IOxAPIC 0xff as broadcast in x2APIC mode ...
everything worked because IOxAPIC can't set that in physical mode and
logical mode considered it as a message for first 8 VCPUs.
This patch interprets IOxAPIC 0xff as x2APIC broadcast.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1423766494-26150-2-git-send-email-rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Drop unused static procedure which doesn't have callers within its
translation unit. It had been already removed independently in QEMU[1]
from the OpenPIC implementation borrowed from the kernel.
[1] https://lists.gnu.org/archive/html/qemu-devel/2014-06/msg01812.html
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Cc: Alexander Graf <agraf@suse.de>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1424768706-23150-3-git-send-email-asolokha@kb.kras.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After speed-up of cpuid_maxphyaddr() it can be called frequently:
instead of heavyweight enumeration of CPUID entries it returns a cached
pre-computed value. It is also inlined now. So caching its result became
unnecessary and can be removed.
Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Message-Id: <20150329205644.GA1258@gnote>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
On each VM-entry CPU should check the following VMCS fields for zero bits
beyond physical address width:
- APIC-access address
- virtual-APIC address
- posted-interrupt descriptor address
This patch adds these checks required by Intel SDM.
Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Message-Id: <20150329205627.GA1244@gnote>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
cpuid_maxphyaddr(), which performs lot of memory accesses is called
extensively across KVM, especially in nVMX code.
This patch adds a cached value of maxphyaddr to vcpu.arch to reduce the
pressure onto CPU cache and simplify the code of cpuid_maxphyaddr()
callers. The cached value is initialized in kvm_arch_vcpu_init() and
reloaded every time CPUID is updated by usermode. It is obvious that
these reloads occur infrequently.
Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Message-Id: <20150329205612.GA1223@gnote>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Exposing the on-stack error code with internal error is cheap and
potentially useful.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1428001865-32280-1-git-send-email-rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If we were migrated right after __getcpu, but before reading the
migration_count, we wouldn't notice that we read TSC of a different
VCPU, nor that KVM's bug made pvti invalid, as only migration_count
on source VCPU is increased.
Change vdso instead of updating migration_count on destination.
Cc: stable@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Fixes: 0a4e6be9ca ("x86: kvm: Revert "remove sched notifier for cross-cpu migrations"")
Message-Id: <1428000263-11892-1-git-send-email-rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The newly-added tracepoint shows the following results on
the tscdeadline_latency test:
qemu-kvm-8387 [002] 6425.558974: kvm_vcpu_wakeup: poll time 10407 ns
qemu-kvm-8387 [002] 6425.558984: kvm_vcpu_wakeup: poll time 0 ns
qemu-kvm-8387 [002] 6425.561242: kvm_vcpu_wakeup: poll time 10477 ns
qemu-kvm-8387 [002] 6425.561251: kvm_vcpu_wakeup: poll time 0 ns
and so on. This is because we need to go through kvm_vcpu_block again
after the timer IRQ is injected. Avoid it by polling once before
entering kvm_vcpu_block.
On my machine (Xeon E5 Sandy Bridge) this removes about 500 cycles (7%)
from the latency of the TSC deadline timer.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rename the old __vcpu_run to vcpu_run, and extract part of it to a new
function vcpu_block.
The next patch will add a new condition in vcpu_block, avoid extra
indentation.
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Guest can't be booted w/ ept=0, there is a message dumped as below:
If you're running a guest on an Intel machine without unrestricted mode
support, the failure can be most likely due to the guest entering an invalid
state for Intel VT. For example, the guest maybe running in big real mode
which is not supported on less recent Intel processors.
EAX=00000011 EBX=f000d2f6 ECX=00006cac EDX=000f8956
ESI=bffbdf62 EDI=00000000 EBP=00006c68 ESP=00006c68
EIP=0000d187 EFL=00000004 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =e000 000e0000 ffffffff 00809300 DPL=0 DS16 [-WA]
CS =f000 000f0000 ffffffff 00809b00 DPL=0 CS16 [-RA]
SS =0000 00000000 ffffffff 00809300 DPL=0 DS16 [-WA]
DS =0000 00000000 ffffffff 00809300 DPL=0 DS16 [-WA]
FS =0000 00000000 ffffffff 00809300 DPL=0 DS16 [-WA]
GS =0000 00000000 ffffffff 00809300 DPL=0 DS16 [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT= 000f6a80 00000037
IDT= 000f6abe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000000
Code=01 1e b8 6a 2e 0f 01 16 74 6a 0f 20 c0 66 83 c8 01 0f 22 c0 <66> ea 8f d1 0f 00 08 00 b8 10 00 00 00 8e d8 8e c0 8e d0 8e e0 8e e8 89 c8 ff e2 89 c1 b8X
X86 eflags bit 1 is fixed set, which means that 1 << 1 is set instead of 1,
this patch fix it.
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Message-Id: <1428473294-6633-1-git-send-email-wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Interrupt entry points are handled with the following code,
each 32-byte code block contains seven entry points:
...
[push][jump 22] // 4 bytes
[push][jump 18] // 4 bytes
[push][jump 14] // 4 bytes
[push][jump 10] // 4 bytes
[push][jump 6] // 4 bytes
[push][jump 2] // 4 bytes
[push][jump common_interrupt][padding] // 8 bytes
[push][jump]
[push][jump]
[push][jump]
[push][jump]
[push][jump]
[push][jump]
[push][jump common_interrupt][padding]
[padding_2]
common_interrupt:
And there is a table which holds pointers to every entry point,
IOW: to every push.
In cold cache, two jumps are still costlier than one, even
though we get the benefit of them residing in the same
cacheline.
This change replaces short jumps with near ones to
'common_interrupt', and pads every push+jump pair to 8 bytes. This
way, each interrupt takes only one jump.
This change replaces ".p2align CONFIG_X86_L1_CACHE_SHIFT" before
dispatch table with ".align 8" - we do not need anything
stronger than that.
The table of entry addresses (the interrupt[] array) is no
longer necessary, the address of entries can be easily
calculated as (irq_entries_start + i*8).
text data bss dec hex filename
12546 0 0 12546 3102 entry_64.o.before
11626 0 0 11626 2d6a entry_64.o
The size decrease is because 1656 bytes of .init.rodata are
gone. That's initdata, though. The resident size does go up a
bit.
Run-tested (32 and 64 bits).
Acked-and-Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428090553-7283-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This change does two things:
Copy-pastes "retint_swapgs:" code into syscall handling code,
the copy is under "syscall_return:" label. The code is unchanged
apart from some label renames.
Removes "opportunistic sysret" code from "retint_swapgs:" code
block, since now it won't be reached by syscall return. This in
fact removes most of the code in question.
text data bss dec hex filename
12530 0 0 12530 30f2 entry_64.o.before
12562 0 0 12562 3112 entry_64.o
Run-tested.
Acked-and-Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427993219-7291-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1. Assorted changes
1.1 allow more feature bits for the guest
1.2 Store breaking event address on program interrupts
2. Interrupt handling rework
2.1 Fix copy_to_user while holding a spinlock (cc stable)
2.2 Rework floating interrupts to follow the priorities
2.3 Allow to inject all local interrupts via new ioctl
2.4 allow to get/set the full local irq state, e.g. for migration
and introspection
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Merge tag 'kvm-s390-next-20150331' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
Features and fixes for 4.1 (kvm/next)
1. Assorted changes
1.1 allow more feature bits for the guest
1.2 Store breaking event address on program interrupts
2. Interrupt handling rework
2.1 Fix copy_to_user while holding a spinlock (cc stable)
2.2 Rework floating interrupts to follow the priorities
2.3 Allow to inject all local interrupts via new ioctl
2.4 allow to get/set the full local irq state, e.g. for migration
and introspection
Fixes page refcounting issues in our Stage-2 page table management code,
fixes a missing unlock in a gicv3 error path, and fixes a race that can
cause lost interrupts if signals are pending just prior to entering the
guest.
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Merge tag 'kvm-arm-fixes-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into 'kvm-next'
Fixes for KVM/ARM for 4.0-rc5.
Fixes page refcounting issues in our Stage-2 page table management code,
fixes a missing unlock in a gicv3 error path, and fixes a race that can
cause lost interrupts if signals are pending just prior to entering the
guest.
I got below kernel panic during kdump test on Thinkpad T420
laptop:
[ 0.000000] No NUMA configuration found
[ 0.000000] Faking a node at [mem 0x0000000000000000-0x0000000037ba4fff]
[ 0.000000] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81d21910
...
[ 0.000000] Call Trace:
[ 0.000000] [<ffffffff817c2a26>] dump_stack+0x45/0x57
[ 0.000000] [<ffffffff817bc8d2>] panic+0xd0/0x204
[ 0.000000] [<ffffffff81d21910>] ? numa_clear_kernel_node_hotplug+0xe6/0xf2
[ 0.000000] [<ffffffff8107741b>] __stack_chk_fail+0x1b/0x20
[ 0.000000] [<ffffffff81d21910>] numa_clear_kernel_node_hotplug+0xe6/0xf2
[ 0.000000] [<ffffffff81d21e5d>] numa_init+0x1a5/0x520
[ 0.000000] [<ffffffff81d222b1>] x86_numa_init+0x19/0x3d
[ 0.000000] [<ffffffff81d22460>] initmem_init+0x9/0xb
[ 0.000000] [<ffffffff81d0d00c>] setup_arch+0x94f/0xc82
[ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
[ 0.000000] [<ffffffff817bd0bb>] ? printk+0x55/0x6b
[ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
[ 0.000000] [<ffffffff81d05d9b>] start_kernel+0xe8/0x4d6
[ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
[ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
[ 0.000000] [<ffffffff81d055ee>] x86_64_start_reservations+0x2a/0x2c
[ 0.000000] [<ffffffff81d05751>] x86_64_start_kernel+0x161/0x184
[ 0.000000] ---[ end Kernel panic - not syncing: stack-protector: Kernel sta
This is caused by writing over the end of numa mask bitmap
in numa_clear_kernel_node().
numa_clear_kernel_node() tries to set the node id in a mask bitmap,
by iterating all reserved regions and assuming that every region
has a valid nid.
This assumption is not true because there's an exception for some
graphic memory quirks. See trim_snb_memory() in arch/x86/kernel/setup.c
It is easily to reproduce the bug in the kdump kernel because kdump
kernel use pre-reserved memory instead of the whole memory, but
kexec pass other reserved memory ranges to 2nd kernel as well.
like below in my test:
kdump kernel ram 0x2d000000 - 0x37bfffff
One of the reserved regions: 0x40000000 - 0x40100000 which
includes 0x40004000, a page excluded in trim_snb_memory(). For
this memblock reserved region the nid is not set, it is still
default value MAX_NUMNODES. later node_set will set bit
MAX_NUMNODES thus stack corruption happen.
This also happens when booting with mem= kernel commandline
during my test.
Fixing it by adding a check, do not call node_set in case nid is
MAX_NUMNODES.
Signed-off-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhe@redhat.com
Cc: qiuxishi@huawei.com
Link: http://lkml.kernel.org/r/20150407134132.GA23522@dhcp-16-198.nay.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Take a look at the first instruction byte before optimizing the NOP -
there might be something else there already, like the ALTERNATIVE_2()
in rdtsc_barrier() which NOPs out on AMD even though we just
patched in an MFENCE.
This happens because the alternatives sees X86_FEATURE_MFENCE_RDTSC,
AMD CPUs set it, we patch in the MFENCE and right afterwards it sees
X86_FEATURE_LFENCE_RDTSC which AMD CPUs don't set and we blindly
optimize the NOP.
Checking whether at least the first byte is 0x90 prevents that.
Signed-off-by: Borislav Petkov <bp@suse.de>
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: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1428181662-18020-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On failure, sys_execve() does not clobber EXTRA_REGS, so we can
just return to userpsace without saving/restoring them.
On success, ELF_PLAT_INIT() in sys_execve() clears all these
registers.
On other executable formats:
- binfmt_flat.c has similar FLAT_PLAT_INIT, but x86 (and everyone
else except sh) doesn't define it.
- binfmt_elf_fdpic.c has ELF_FDPIC_PLAT_INIT, but x86 (and most
others) doesn't define it.
- There are no such hooks in binfmt_aout.c et al. We inherit
EXTRA_REGS from the prior executable.
This inconsistency was not intended.
This change removes SAVE/RESTORE_EXTRA_REGS in stub_execve,
removes register clearing in ELF_PLAT_INIT(),
and instead simply clears them on success in stub_execve.
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428173719-7637-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The 'pax' argument is unnecesary. Instead, store the RAX value
directly in regs.
This pattern goes all the way back to 2.1.106pre1, when restore_sigcontext()
was changed to return an error code instead of EAX directly:
https://git.kernel.org/cgit/linux/kernel/git/history/history.git/diff/arch/i386/kernel/signal.c?id=9a8f8b7ca3f319bd668298d447bdf32730e51174
In 2007 sigaltstack syscall support was added, where the return
value of restore_sigcontext() was changed to carry the memory-copying
failure code.
But instead of putting 'ax' into regs->ax directly, it was carried
in via a pointer and then returned, where the generic syscall return
code copied it to regs->ax.
So there was never any deeper reason for this suboptimal pattern, it
was simply never noticed after being introduced.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1428152303-17154-1-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Quentin caught a corner case with the generation of instruction
padding in the ALTERNATIVE_2 macro: if len(orig_insn) <
len(alt1) < len(alt2), then not enough padding gets added and
that is not good(tm) as we could overwrite the beginning of the
next instruction.
Luckily, at the time of this writing, we don't have
ALTERNATIVE_2() invocations which have that problem and even if
we did, a simple fix would be to prepend the instructions with
enough prefixes so that that corner case doesn't happen.
However, best it would be if we fixed it properly. See below for
a simple, abstracted example of what we're doing.
So what we ended up doing is, we compute the
max(len(alt1), len(alt2)) - len(orig_insn)
and feed that value to the .skip gas directive. The max() cannot
have conditionals due to gas limitations, thus the fancy integer
math.
With this patch, all ALTERNATIVE_2 sites get padded correctly;
generating obscure test cases pass too:
#define alt_max_short(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
#define gen_skip(orig, alt1, alt2, marker) \
.skip -((alt_max_short(alt1, alt2) - (orig)) > 0) * \
(alt_max_short(alt1, alt2) - (orig)),marker
.pushsection .text, "ax"
.globl main
main:
gen_skip(1, 2, 4, 0x09)
gen_skip(4, 1, 2, 0x10)
...
.popsection
Thanks to Quentin for catching it and double-checking the fix!
Reported-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
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: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150404133443.GE21152@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Ingo Molnar:
"Misc fixes: a SYSRET single-stepping fix, a dmi-scan robustization
fix, a reboot quirk and a kgdb fixlet"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kgdb/x86: Fix reporting of 'si' in kgdb on x86_64
x86/asm/entry/64: Disable opportunistic SYSRET if regs->flags has TF set
x86/reboot: Add ASRock Q1900DC-ITX mainboard reboot quirk
MAINTAINERS: Change the x86 microcode loader maintainer
firmware: dmi_scan: Prevent dmi_num integer overflow
Commit:
e2b32e6785 ("x86, kaslr: randomize module base load address")
made module base address randomization unconditional and didn't regard
disabled KKASLR due to CONFIG_HIBERNATION and command line option
"nokaslr". For more info see (now reverted) commit:
f47233c2d3 ("x86/mm/ASLR: Propagate base load address calculation")
In order to propagate KASLR status to kernel proper, we need a single bit
in boot_params.hdr.loadflags and we've chosen bit 1 thus leaving the
top-down allocated bits for bits supposed to be used by the bootloader.
Originally-From: Jiri Kosina <jkosina@suse.cz>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Two static functions are only used if CONFIG_PCI is defined, so only
build them if this is the case. Fixes the build warnings:
arch/x86/kernel/early_printk.c:98:13: warning: ‘mem32_serial_out’ defined but not used [-Wunused-function]
static void mem32_serial_out(unsigned long addr, int offset, int value)
^
arch/x86/kernel/early_printk.c:105:21: warning: ‘mem32_serial_in’ defined but not used [-Wunused-function]
static unsigned int mem32_serial_in(unsigned long addr, int offset)
^
Also convert a few related instances of uintXX_t to kernel specific uXX
defines.
Signed-off-by: Mark Einon <mark.einon@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stuart.r.anderson@intel.com
Link: http://lkml.kernel.org/r/1427923924-22653-1-git-send-email-mark.einon@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Dan reported compiler warnings about missing curly braces in
mce_severity_amd(). Reindent the catch-all "return MCE_AR_SEVERITY"
correctly to single tab.
While at it, chain ctx == IN_KERNEL check with mcgstatus check to make
it cleaner, as suggested by Boris.
No functional changes are introduced by this patch.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1427814281-18192-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now there are generic phy type constants declared in phy.h, migrate over to
using them rather than defining our own. This change has been done as one
atomic commit to be bisectable.
Note: The values of the defines are the same, so there is no ABI breakage
with this patch.
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Commit:
4214a16b02 ("x86/asm/entry/64/compat: Use SYSRETL to return from compat mode SYSENTER")
removed the last user of ENABLE_INTERRUPTS_SYSEXIT32. Kill the
macro now too.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/1428049714-829-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
SYSEXIT is scary on 64-bit kernels -- SYSEXIT must be invoked
with usergs and IRQs on. That means that we rely on STI to
correctly mask interrupts for one instruction. This is okay by
itself, but the semantics with respect to NMIs are unclear.
Avoid the whole issue by using SYSRETL instead. For background,
Intel CPUs don't allow SYSCALL from compat mode, but they do
allow SYSRETL back to compat mode. Go figure.
To avoid doing too much at once, this doesn't revamp the calling
convention. We still return with EBP, EDX, and ECX on the user
stack.
Oddly this seems to be 30 cycles or so faster. Avoiding POPFQ
and STI will account for under half of that, I think, so my best
guess is that Intel just optimizes SYSRET much better than
SYSEXIT.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
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: Denys Vlasenko <vda.linux@googlemail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/57a0bf1b5230b2716a64ebe48e9bc1110f7ab433.1428019097.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Replace the clockevents_notify() call with an explicit function call.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Link: http://lkml.kernel.org/r/2131111.rjxRLX1eZB@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Replace the clockevents_notify() call with an explicit function call.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tony Lindgren <tony@atomide.com>
Link: http://lkml.kernel.org/r/3123047.uVjevtxDV7@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Replace the clockevents_notify() call with an explicit function call.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/8569669.lgxIty9PKW@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Replace the clockevents_notify() call with an explicit function call.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tony Lindgren <tony@atomide.com>
Link: http://lkml.kernel.org/r/2124877.3nbWGILHCV@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Replace the clockevents_notify() call with an explicit function call.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1528188.S1pjqkSL1P@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We write a stack pointer to MSR_IA32_SYSENTER_ESP exactly once,
and we unnecessarily cache the value in tss.sp1. We never
read the cached value.
Remove all of the caching. It serves no purpose.
Suggested-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/05a0163eb33ef5208363f0015496855da7cebadd.1428002830.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
At Denys' request, clean up the comment describing stack padding
in the 32-bit sysenter path.
No code changes.
Signed-off-by: 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: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/41fee7bb8490ae840fe7ef2699f9c2feb932e729.1428002830.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change alpha_rtc_set_mmss() and remote_set_mmss() to use
rtc_class_ops's set_mmss64(), to be y2038 safe.
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Henderson <rth@twiddle.net>
Link: http://lkml.kernel.org/r/1427945681-29972-15-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As part of addressing "y2038 problem" for in-kernel uses, this
patch converts read_boot_clock() to read_boot_clock64() and
read_persistent_clock() to read_persistent_clock64() using
timespec64 by converting clock_access_fn to use timespec64.
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Thierry Reding <treding@nvidia.com> (for tegra part)
Cc: Russell King <rmk@dyn-67.arm.linux.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-7-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As part of addressing "y2038 problem" for in-kernel uses, this
patch adds the y2038-safe omap_read_persistent_clock64() using
timespec64.
Because we rely on some subsequent changes to convert arm
multiarch support, omap_read_persistent_clock() will be removed
then.
Also remove the needless spinlock, because
read_persistent_clock() doesn't run simultaneously.
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-5-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As part of addressing in-kernel y2038 issues, this patch adds
read_persistent_clock64() and replaces all the call sites of
read_persistent_clock() with this function. This is a __weak
implementation, which simply calls the existing y2038 unsafe
read_persistent_clock().
This allows architecture specific implementations to be
converted independently, and eventually the y2038 unsafe
read_persistent_clock() can be removed after all its
architecture specific implementations have been converted to
read_persistent_clock64().
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add support for the new CLWB (cache line write back)
instruction. This instruction was announced in the document
"Intel Architecture Instruction Set Extensions Programming
Reference" with reference number 319433-022.
https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf
The CLWB instruction is used to write back the contents of
dirtied cache lines to memory without evicting the cache lines
from the processor's cache hierarchy. This should be used in
favor of clflushopt or clflush in cases where you require the
cache line to be written to memory but plan to access the data
again in the near future.
One of the main use cases for this is with persistent memory
where CLWB can be used with PCOMMIT to ensure that data has been
accepted to memory and is durable on the DIMM.
This function shows how to properly use CLWB/CLFLUSHOPT/CLFLUSH
and PCOMMIT with appropriate fencing:
void flush_and_commit_buffer(void *vaddr, unsigned int size)
{
void *vend = vaddr + size - 1;
for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
clwb(vaddr);
/* Flush any possible final partial cacheline */
clwb(vend);
/*
* Use SFENCE to order CLWB/CLFLUSHOPT/CLFLUSH cache flushes.
* (MFENCE via mb() also works)
*/
wmb();
/* PCOMMIT and the required SFENCE for ordering */
pcommit_sfence();
}
After this function completes the data pointed to by vaddr is
has been accepted to memory and will be durable if the vaddr
points to persistent memory.
Regarding the details of how the alternatives assembly is set
up, we need one additional byte at the beginning of the CLFLUSH
so that we can flip it into a CLFLUSHOPT by changing that byte
into a 0x66 prefix. Two options are to either insert a 1 byte
ASM_NOP1, or to add a 1 byte NOP_DS_PREFIX. Both have no
functional effect with the plain CLFLUSH, but I've been told
that executing a CLFLUSH + prefix should be faster than
executing a CLFLUSH + NOP.
We had to hard code the assembly for CLWB because, lacking the
ability to assemble the CLWB instruction itself, the next
closest thing is to have an xsaveopt instruction with a 0x66
prefix. Unfortunately XSAVEOPT itself is also relatively new,
and isn't included by all the GCC versions that the kernel needs
to support.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
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: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1422377631-8986-3-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Fix two regressions in the balloon driver's use of memory hotplug
when used in a PV guest.
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Merge tag 'stable/for-linus-4.0-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen regression fixes from David Vrabel:
"Fix two regressions in the balloon driver's use of memory hotplug when
used in a PV guest"
* tag 'stable/for-linus-4.0-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/balloon: before adding hotplugged memory, set frames to invalid
x86/xen: prepare p2m list for memory hotplug
Some of the CYCLE_ACTIVITY.* events can only be scheduled on
counter 2. Due to a typo Haswell matched those with
INTEL_EVENT_CONSTRAINT, which lead to the events never
matching as the comparison does not expect anything
in the umask too. Fix the typo.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1425925222-32361-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For supporting Intel LBR branches filtering, Intel LBR sharing logic
mechanism is introduced from commit b36817e886 ("perf/x86: Add Intel
LBR sharing logic"). It modifies __intel_shared_reg_get_constraints() to
config lbr_sel, which is finally used to set LBR_SELECT.
However, the intel_shared_regs_constraints() function is called after
intel_pebs_constraints(). The PEBS event will return immediately after
intel_pebs_constraints(). So it's impossible to filter branches for PEBS
events.
This patch moves intel_shared_regs_constraints() ahead of
intel_pebs_constraints().
We can safely do that because the intel_shared_regs_constraints() function
only returns empty constraint if its rejecting the event, otherwise it
returns NULL such that we continue calling intel_pebs_constraints() and
x86_get_event_constraint().
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1427467105-9260-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some of x86 bare-metal and Xen CPU initialization code is common
between the two and therefore can be factored out to avoid code
duplication.
As a side effect, doing so will also extend the fix provided by
commit a7fcf28d43 ("x86/asm/entry: Replace this_cpu_sp0() with
current_top_of_stack() to x86_32") to 32-bit Xen PV guests.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
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: Thomas Gleixner <tglx@linutronix.de>
Cc: konrad.wilk@oracle.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1427897534-5086-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch fixes an error in kgdb for x86_64 which would report
the value of dx when asked to give the value of si.
Signed-off-by: Steffen Liebergeld <steffen.liebergeld@kernkonzept.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When I wrote the opportunistic SYSRET code, I missed an important difference
between SYSRET and IRET.
Both instructions are capable of setting EFLAGS.TF, but they behave differently
when doing so:
- IRET will not issue a #DB trap after execution when it sets TF.
This is critical -- otherwise you'd never be able to make forward progress when
returning to userspace.
- SYSRET, on the other hand, will trap with #DB immediately after
returning to CPL3, and the next instruction will never execute.
This breaks anything that opportunistically SYSRETs to a user
context with TF set. For example, running this code with TF set
and a SIGTRAP handler loaded never gets past 'post_nop':
extern unsigned char post_nop[];
asm volatile ("pushfq\n\t"
"popq %%r11\n\t"
"nop\n\t"
"post_nop:"
: : "c" (post_nop) : "r11");
In my defense, I can't find this documented in the AMD or Intel manual.
Fix it by using IRET to restore TF.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.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: Thomas Gleixner <tglx@linutronix.de>
Fixes: 2a23c6b8a9 ("x86_64, entry: Use sysret to return to userspace when possible")
Link: http://lkml.kernel.org/r/9472f1ca4c19a38ecda45bba9c91b7168135fcfa.1427923514.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
* A new efi=debug command line option that enables debug output in the
EFI boot stub and results in less verbose EFI memory map output by
default - Borislav Petkov
* Disable interrupts around EFI calls and use a more standard page
table saving and restoring idiom when making EFI calls - Ingo Molnar
* Reduce the number of memory allocations performed when allocating the
FDT in EFI boot stub by retrieving size from the FDT header in the
EFI config table - Ard Biesheuvel
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Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into core/efi
Pull EFI updates from Matt Fleming:
- Fixes and cleanups for SMBIOS 3.0 DMI code. (Ivan Khoronzhuk)
- A new efi=debug command line option that enables debug output in the
EFI boot stub and results in less verbose EFI memory map output by
default. (Borislav Petkov)
- Disable interrupts around EFI calls and use a more standard page
table saving and restoring idiom when making EFI calls. (Ingo Molnar)
- Reduce the number of memory allocations performed when allocating the
FDT in EFI boot stub by retrieving size from the FDT header in the
EFI config table. (Ard Biesheuvel)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use the new tick_suspend/resume_local() and get rid of the
homebrewn implementation of these in the ARM bL switcher. The
check for the cpumask is completely pointless. There is no harm
to suspend a per cpu tick device unconditionally. If that's a
real issue then we fix it proper at the core level and not with
some completely undocumented hacks in some random core code.
Move the tick internals to the core code, now that this nuisance
is gone.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ rjw: Rebase, changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/1655112.Ws17YsMfN7@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Xen calls on every cpu into tick_resume() which is just wrong.
tick_resume() is for the syscore global suspend/resume
invocation. What XEN really wants is a per cpu local resume
function.
Provide a tick_resume_local() function and use it in XEN.
Also provide a complementary tick_suspend_local() and modify
tick_unfreeze() and tick_freeze(), respectively, to use the
new local tick resume/suspend functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ Combined two patches, rebased, modified subject/changelog. ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1698741.eezk9tnXtG@vostro.rjw.lan
[ Merged to latest timers/core. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
clockevents_notify() is a leftover from the early design of the
clockevents facility. It's really not a notification mechanism,
it's a multiplex call.
We are way better off to have explicit calls instead of this
monstrosity. Split out the suspend/resume() calls and invoke
them directly from the call sites.
No locking required at this point because these calls happen
with interrupts disabled and a single cpu online.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ Rebased on top of 4.0-rc5. ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/713674030.jVm1qaHuPf@vostro.rjw.lan
[ Rebased on top of latest timers/core. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The ASRock Q1900DC-ITX mainboard (Baytrail-D) hangs randomly in
both BIOS and UEFI mode while rebooting unless reboot=pci is
used. Add a quirk to reboot via the pci method.
The problem is very intermittent and hard to debug, it might succeed
rebooting just fine 40 times in a row - but fails half a dozen times
the next day. It seems to be slightly less common in BIOS CSM mode
than native UEFI (with the CSM disabled), but it does happen in either
mode. Since I've started testing this patch in late january, rebooting
has been 100% reliable.
Most of the time it already hangs during POST, but occasionally it
might even make it through the bootloader and the kernel might even
start booting, but then hangs before the mode switch. The same symptoms
occur with grub-efi, gummiboot and grub-pc, just as well as (at least)
kernel 3.16-3.19 and 4.0-rc6 (I haven't tried older kernels than 3.16).
Upgrading to the most current mainboard firmware of the ASRock
Q1900DC-ITX, version 1.20, does not improve the situation.
( Searching the web seems to suggest that other Bay Trail-D mainboards
might be affected as well. )
--
Signed-off-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Cc: <stable@vger.kernel.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/20150330224427.0fb58e42@mir
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently x86-64 efi_call_phys_prolog() saves into a global variable (save_pgd),
and efi_call_phys_epilog() restores the kernel pagetables from that global
variable.
Change this to a cleaner save/restore pattern where the saving function returns
the saved object and the restore function restores that.
Apply the same concept to the 32-bit code as well.
Plus this approach, as an added bonus, allows us to express the
!efi_enabled(EFI_OLD_MEMMAP) situation in a clean fashion as well,
via a 'NULL' return value.
Cc: Tapasweni Pathak <tapaswenipathak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Tapasweni Pathak reported that we do a kmalloc() in efi_call_phys_prolog()
on x86-64 while having interrupts disabled, which is a big no-no, as
kmalloc() can sleep.
Solve this by removing the irq disabling from the prolog/epilog calls
around EFI calls: it's unnecessary, as in this stage we are single
threaded in the boot thread, and we don't ever execute this from
interrupt contexts.
Reported-by: Tapasweni Pathak <tapaswenipathak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
... and hide the memory regions dump behind it. Make it default-off.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20141209095843.GA3990@pd.tnic
Acked-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Logically, we just want to jump around the following instruction
and its prologue/epilogue:
call *sys_call_table(,%rax,8)
if the syscall number is too big - we do not specifically target
the "int_ret_from_sys_call" label.
Use a local, numerical label for this jump, for more clarity.
This also makes the code smaller:
-ffffffff8187756b: 0f 87 0f 00 00 00 ja ffffffff81877580 <int_ret_from_sys_call>
+ffffffff8187756b: 77 0f ja ffffffff8187757c <int_ret_from_sys_call>
because jumps to global labels are never translated to short jump
instructions by GAS.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-9-git-send-email-dvlasenk@redhat.com
[ Improved the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is no reason to use MOVQ to load a non-negative immediate
constant value into a 64-bit register. MOVL does the same, since
the upper 32 bits are zero-extended by the CPU.
This makes the code a bit smaller, while leaving functionality
unchanged.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-8-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
At the 'exit_intr' label we test whether interrupt/exception was in
kernel. If it did, we jump to the preemption check. If preemption
does happen (IOW if we call preempt_schedule_irq()), we go back to
'exit_intr'.
But it's pointless, we already know that the test succeeded last
time, preemption doesn't change the fact that interrupt/exception
was in the kernel.
We can go back directly to checking PER_CPU_VAR(__preempt_count) instead.
This makes the 'exit_intr' label unused, drop it.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-5-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Get rid of #define obfuscation of retint_kernel in
CONFIG_PREEMPT case by defining retint_kernel label always, not
only for CONFIG_PREEMPT.
Strip retint_kernel of .global-ness (ENTRY macro) - it has no
users outside of this file.
This looks like cosmetics, but it is not:
"je LABEL" can be optimized to short jump by assember
only if LABEL is not global, for global labels jump is always
a near one with relocation.
Convert retint_restore_args to a local numeric label, making it
clearer that it is not used elsewhere in the file.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-3-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This mimics the recent similar 64-bit change.
Saves ~110 bytes of code.
Patch was run-tested on 32 and 64 bits, Intel and AMD CPU.
I also looked at the diff of entry_64.o disassembly, to have
a different view of the changes.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
SYSRET code path has a small irq-off block.
On this code path, TRACE_IRQS_ON can't be called right before
interrupts are enabled for real, we can't clobber registers
there. So current code does it earlier, in a safe place.
But with this, TRACE_IRQS_OFF/ON frames just two fast
instructions, which is ridiculous: now most of irq-off block is
_outside_ of the framing.
Do the same thing that we do on SYSCALL entry: do not track this
irq-off block, it is very small to ever cause noticeable irq
latency.
Be careful: make sure that "jnz int_ret_from_sys_call_irqs_off"
now does invoke TRACE_IRQS_OFF - move
int_ret_from_sys_call_irqs_off label before TRACE_IRQS_OFF.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
__verify_local_APIC() is detritus from the early APIC days.
Its return value isn't used anywhere and the information it
prints when debug is enabled is already part of APIC
initialization messages printed to syslog. Off with it!
Signed-off-by: Bandan Das <bsd@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/jpgy4mcsxsq.fsf@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Space allocated for paca is based off nr_cpu_ids,
but pnv_alloc_idle_core_states() iterates paca with
cpu_nr_cores()*threads_per_core, which is using NR_CPUS.
This causes pnv_alloc_idle_core_states() to write over memory,
which is outside of paca array and may later lead to various panics.
Fixes: 7cba160ad7 (powernv/cpuidle: Redesign idle states management)
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds support to migrate vcpu interrupts. Two new vcpu ioctls
are added which get/set the complete status of pending interrupts in one
go. The ioctls are marked as available with the new capability
KVM_CAP_S390_IRQ_STATE.
We can not use a ONEREG, as the number of pending local interrupts is not
constant and depends on the number of CPUs.
To retrieve the interrupt state we add an ioctl KVM_S390_GET_IRQ_STATE.
Its input parameter is a pointer to a struct kvm_s390_irq_state which
has a buffer and length. For all currently pending interrupts, we copy
a struct kvm_s390_irq into the buffer and pass it to userspace.
To store interrupt state into a buffer provided by userspace, we add an
ioctl KVM_S390_SET_IRQ_STATE. It passes a struct kvm_s390_irq_state into
the kernel and injects all interrupts contained in the buffer.
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Let's provide a version of kvm_s390_inject_vcpu() that
does not acquire the local-interrupt lock and skips
waking up the vcpu.
To be used in a later patch for vcpu-local interrupt migration,
where we are already holding the lock.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
We have introduced struct kvm_s390_irq a while ago which allows to
inject all kinds of interrupts as defined in the Principles of
Operation.
Add ioctl to inject interrupts with the extended struct kvm_s390_irq
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
We now have a mechanism for delivering interrupts according to their priority.
Let's inject them using our new infrastructure (instead of letting only hardware
handle them), so we can be sure that the irq priorities are satisfied.
For s390, the cpu timer and the clock comparator are to be checked for common
code kvm_cpu_has_pending_timer(), although the cpu timer is only stepped when
the guest is being executed.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This patch makes interrupt handling compliant to the z/Architecture
Principles of Operation with regard to interrupt priorities.
Add a bitmap for pending floating interrupts. Each bit relates to a
interrupt type and its list. A turned on bit indicates that a list
contains items (interrupts) which need to be delivered. When delivering
interrupts on a cpu we can merge the existing bitmap for cpu-local
interrupts and floating interrupts and have a single mechanism for
delivery.
Currently we have one list for all kinds of floating interrupts and a
corresponding spin lock. This patch adds a separate list per
interrupt type. An exception to this are service signal and machine check
interrupts, as there can be only one pending interrupt at a time.
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This fixes a bug introduced with commit c05c4186bb ("KVM: s390:
add floating irq controller").
get_all_floating_irqs() does copy_to_user() while holding
a spin lock. Let's fix this by filling a temporary buffer
first and copy it to userspace after giving up the lock.
Cc: <stable@vger.kernel.org> # 3.18+: 69a8d45626 KVM: s390: no need to hold...
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Use the normal return values for bool functions
Signed-off-by: Joe Perches <joe@perches.com>
Message-Id: <9f593eb2f43b456851cd73f7ed09654ca58fb570.1427759009.git.joe@perches.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After some review about what these facilities do, the following
facilities will work under KVM and can, therefore, be reported
to the guest if the cpu model and the host cpu provide this bit.
There are plans underway to make the whole bit thing more readable,
but its not yet finished. So here are some last bit changes and
we enhance the KVM mask with:
9 The sense-running-status facility is installed in the
z/Architecture architectural mode.
---> handled by SIE or KVM
10 The conditional-SSKE facility is installed in the
z/Architecture architectural mode.
---> handled by SIE. KVM will retry SIE
13 The IPTE-range facility is installed in the
z/Architecture architectural mode.
---> handled by SIE. KVM will retry SIE
36 The enhanced-monitor facility is installed in the
z/Architecture architectural mode.
---> handled by SIE
47 The CMPSC-enhancement facility is installed in the
z/Architecture architectural mode.
---> handled by SIE
48 The decimal-floating-point zoned-conversion facility
is installed in the z/Architecture architectural mode.
---> handled by SIE
49 The execution-hint, load-and-trap, miscellaneous-
instruction-extensions and processor-assist
---> handled by SIE
51 The local-TLB-clearing facility is installed in the
z/Architecture architectural mode.
---> handled by SIE
52 The interlocked-access facility 2 is installed.
---> handled by SIE
53 The load/store-on-condition facility 2 and load-and-
zero-rightmost-byte facility are installed in the
z/Architecture architectural mode.
---> handled by SIE
57 The message-security-assist-extension-5 facility is
installed in the z/Architecture architectural mode.
---> handled by SIE
66 The reset-reference-bits-multiple facility is installed
in the z/Architecture architectural mode.
---> handled by SIE. KVM will retry SIE
80 The decimal-floating-point packed-conversion
facility is installed in the z/Architecture architectural
mode.
---> handled by SIE
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
If the PER-3 facility is installed, the breaking-event address is to be
stored in the low core.
There is no facility bit for PER-3 in stfl(e) and Linux always uses the
value at address 272 no matter if PER-3 is available or not.
We can't hide its existence from the guest. All program interrupts
injected via the SIE automatically store this information if the PER-3
facility is available in the hypervisor. Also the itdb contains the
address automatically.
As there is no switch to turn this mechanism off, let's simply make it
consistent and also store the breaking event address in case of manual
program interrupt injection.
Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
user_mode_ignore_vm86() can be used instead of user_mode(), in
places where we have already done a v8086_mode() security
check of ptregs.
But doing this check in the wrong place would be a bug that
could result in security problems, and also the naming still
isn't very clear.
Furthermore, it only affects 32-bit kernels, while most
development happens on 64-bit kernels.
If we replace them with user_mode() checks then the cost is only
a very minor increase in various slowpaths:
text data bss dec hex filename
10573391 703562 1753042 13029995 c6d26b vmlinux.o.before
10573423 703562 1753042 13030027 c6d28b vmlinux.o.after
So lets get rid of this distinction once and for all.
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150329090233.GA1963@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The existing clean-files rule was missing vdsox32.so and
vdsox32.so.dbg. We should really rename the intermediates to
allow a single rule to get them all.
Also-reported-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/7fa2ad4a63bc6f52e214125900d54165ef06cc10.1427482099.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
After 'make clean' the following files were left in arch/x86/vdso/:
vdso-image-32-int80.c
vdso-image-32-syscall.c
vdso-image-32-sysenter.c
These file are generated during the build process and are present
in .gitignore, so remove them.
Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/f85bb7ef6f8c6f6aa4bf422348018c84321454f8.1427482099.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Denys Vlasenko