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authorAndy Lutomirski <luto@amacapital.net>2014-11-23 05:00:32 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2014-11-24 00:56:19 +0300
commit6f442be2fb22be02cafa606f1769fa1e6f894441 (patch)
tree1173ca6feb0cdda19b5383e713e2f19152d88940 /arch/x86/kernel/dumpstack_64.c
parentaf726f21ed8af2cdaa4e93098dc211521218ae65 (diff)
downloadlinux-6f442be2fb22be02cafa606f1769fa1e6f894441.tar.xz
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/kernel/dumpstack_64.c')
-rw-r--r--arch/x86/kernel/dumpstack_64.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 1abcb50b48ae..ff86f19b5758 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -24,7 +24,6 @@ static char x86_stack_ids[][8] = {
[ DEBUG_STACK-1 ] = "#DB",
[ NMI_STACK-1 ] = "NMI",
[ DOUBLEFAULT_STACK-1 ] = "#DF",
- [ STACKFAULT_STACK-1 ] = "#SS",
[ MCE_STACK-1 ] = "#MC",
#if DEBUG_STKSZ > EXCEPTION_STKSZ
[ N_EXCEPTION_STACKS ...