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| author | Brian Gerst <brgerst@gmail.com> | 2009-10-12 10:18:23 -0400 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2014-12-13 15:16:06 +0100 |
| commit | 0d095eeb523a52bfc7a192eb3c688dee14c55408 (patch) | |
| tree | 616c9236ac8f82b804b71f6434cc0eecad110cd5 | |
| parent | 25761523045b78fec26626d85ae44539538bbc6c (diff) | |
| download | lwn-0d095eeb523a52bfc7a192eb3c688dee14c55408.tar.gz lwn-0d095eeb523a52bfc7a192eb3c688dee14c55408.zip | |
x86, 64-bit: Move K8 B step iret fixup to fault entry asm
Move the handling of truncated %rip from an iret fault to the fault
entry path.
This allows x86-64 to use the standard search_extable() function.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <1255357103-5418-1-git-send-email-brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
(cherry picked from commit ae24ffe5ecec17c956ac25371d7c2e12b4b36e53)
[wt: only merged to fix patch context and ease merging of next patches]
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 11 | ||||
| -rw-r--r-- | arch/x86/mm/extable.c | 31 |
3 files changed, 8 insertions, 35 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 61c587484b34..99f0ad753f32 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -570,7 +570,6 @@ extern struct movsl_mask { #ifdef CONFIG_X86_32 # include "uaccess_32.h" #else -# define ARCH_HAS_SEARCH_EXTABLE # include "uaccess_64.h" #endif diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 34a56a9649c5..4f577eb916e0 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1491,12 +1491,17 @@ error_kernelspace: leaq irq_return(%rip),%rcx cmpq %rcx,RIP+8(%rsp) je error_swapgs - movl %ecx,%ecx /* zero extend */ - cmpq %rcx,RIP+8(%rsp) - je error_swapgs + movl %ecx,%eax /* zero extend */ + cmpq %rax,RIP+8(%rsp) + je bstep_iret cmpq $gs_change,RIP+8(%rsp) je error_swapgs jmp error_sti + +bstep_iret: + /* Fix truncated RIP */ + movq %rcx,RIP+8(%rsp) + je error_swapgs END(error_entry) diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 61b41ca3b5a2..d0474ad2a6e5 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -35,34 +35,3 @@ int fixup_exception(struct pt_regs *regs) return 0; } - -#ifdef CONFIG_X86_64 -/* - * Need to defined our own search_extable on X86_64 to work around - * a B stepping K8 bug. - */ -const struct exception_table_entry * -search_extable(const struct exception_table_entry *first, - const struct exception_table_entry *last, - unsigned long value) -{ - /* B stepping K8 bug */ - if ((value >> 32) == 0) - value |= 0xffffffffUL << 32; - - while (first <= last) { - const struct exception_table_entry *mid; - long diff; - - mid = (last - first) / 2 + first; - diff = mid->insn - value; - if (diff == 0) - return mid; - else if (diff < 0) - first = mid+1; - else - last = mid-1; - } - return NULL; -} -#endif |