diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2018-01-18 18:28:26 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-03-03 18:51:01 +0300 |
| commit | 24578f5e4c465369b7663873ce7c8bcbc77f7965 (patch) | |
| tree | 808dd07e92bff5a15575ffa311cf74699e3dc3d1 /arch | |
| parent | d84be371195fdd1b80f182c8a953542453ae47f1 (diff) | |
| download | linux-24578f5e4c465369b7663873ce7c8bcbc77f7965.tar.xz | |
x86/mce: Make machine check speculation protected
commit 6f41c34d69eb005e7848716bbcafc979b35037d5 upstream.
The machine check idtentry uses an indirect branch directly from the low
level code. This evades the speculation protection.
Replace it by a direct call into C code and issue the indirect call there
so the compiler can apply the proper speculation protection.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by:Borislav Petkov <bp@alien8.de>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Niced-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801181626290.1847@nanos
[bwh: Backported to 3.2:
- Don't use dotraplinkage
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/traps.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 2 |
3 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 88eae2aec619..e8666d8be9c4 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -69,6 +69,7 @@ dotraplinkage void do_simd_coprocessor_error(struct pt_regs *, long); #ifdef CONFIG_X86_32 dotraplinkage void do_iret_error(struct pt_regs *, long); #endif +void do_mce(struct pt_regs *, long); static inline int get_si_code(unsigned long condition) { diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 3b678770dba5..fc54c3b3df81 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -1407,6 +1407,11 @@ static void unexpected_machine_check(struct pt_regs *regs, long error_code) void (*machine_check_vector)(struct pt_regs *, long error_code) = unexpected_machine_check; +void do_mce(struct pt_regs *regs, long error_code) +{ + machine_check_vector(regs, error_code); +} + /* * Called for each booted CPU to set up machine checks. * Must be called with preempt off: diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index b232bfcf44fb..c13ca52ce42e 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1399,7 +1399,7 @@ errorentry page_fault do_page_fault errorentry async_page_fault do_async_page_fault #endif #ifdef CONFIG_X86_MCE -paranoidzeroentry machine_check *machine_check_vector(%rip) +paranoidzeroentry machine_check do_mce #endif /* |