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| author | Andy Lutomirski <luto@amacapital.net> | 2014-11-23 03:00:32 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-11-23 22:56:19 +0100 |
| commit | 6f442be2fb22be02cafa606f1769fa1e6f894441 (patch) | |
| tree | 1173ca6feb0cdda19b5383e713e2f19152d88940 /arch/x86/include/asm/traps.h | |
| parent | x86_64, traps: Fix the espfix64 #DF fixup and rewrite it in C (diff) | |
| download | linux-6f442be2fb22be02cafa606f1769fa1e6f894441.tar.xz linux-6f442be2fb22be02cafa606f1769fa1e6f894441.zip | |
x86_64, traps: Stop using IST for #SS
On a 32-bit kernel, this has no effect, since there are no IST stacks.
On a 64-bit kernel, #SS can only happen in user code, on a failed iret
to user space, a canonical violation on access via RSP or RBP, or a
genuine stack segment violation in 32-bit kernel code. The first two
cases don't need IST, and the latter two cases are unlikely fatal bugs,
and promoting them to double faults would be fine.
This fixes a bug in which the espfix64 code mishandles a stack segment
violation.
This saves 4k of memory per CPU and a tiny bit of code.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/include/asm/traps.h')
| -rw-r--r-- | arch/x86/include/asm/traps.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index bc8352e7010a..707adc6549d8 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -39,6 +39,7 @@ asmlinkage void simd_coprocessor_error(void); #ifdef CONFIG_TRACING asmlinkage void trace_page_fault(void); +#define trace_stack_segment stack_segment #define trace_divide_error divide_error #define trace_bounds bounds #define trace_invalid_op invalid_op |