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| author | Andy Lutomirski <luto@amacapital.net> | 2014-11-22 18:00:32 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-12-06 15:05:46 -0800 |
| commit | fd5683d05ef451c15c24b30050bcd7d14bc50a1d (patch) | |
| tree | 4a1cb821c4db247c11a1fe591135a01d2bd0a72f /arch/x86/ia32 | |
| parent | ea21cb1f6b15abb6f6c039654412ff460175cb0f (diff) | |
x86_64, traps: Stop using IST for #SS
commit 6f442be2fb22be02cafa606f1769fa1e6f894441 upstream.
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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/ia32')
0 files changed, 0 insertions, 0 deletions