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| author | Brian Gerst <brgerst@gmail.com> | 2010-03-21 09:00:43 -0400 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-05-03 13:39:26 -0700 |
| commit | 40d2e76315da38993129090dc5d56377e573c312 (patch) | |
| tree | 8f585daa23780aa0841ac72b34053f9deb00041c /arch/x86/kernel/entry_32.S | |
| parent | be1066bbcd443a65df312fdecea7e4959adedb45 (diff) | |
| download | lwn-40d2e76315da38993129090dc5d56377e573c312.tar.gz lwn-40d2e76315da38993129090dc5d56377e573c312.zip | |
x86-32: Rework cache flush denied handler
The cache flush denied error is an erratum on some AMD 486 clones. If an invd
instruction is executed in userspace, the processor calls exception 19 (13 hex)
instead of #GP (13 decimal). On cpus where XMM is not supported, redirect
exception 19 to do_general_protection(). Also, remove die_if_kernel(), since
this was the last user.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1269176446-2489-2-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kernel/entry_32.S')
| -rw-r--r-- | arch/x86/kernel/entry_32.S | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 44a8e0dc6737..cd49141cf153 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -53,6 +53,7 @@ #include <asm/processor-flags.h> #include <asm/ftrace.h> #include <asm/irq_vectors.h> +#include <asm/cpufeature.h> /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ #include <linux/elf-em.h> @@ -905,7 +906,25 @@ ENTRY(simd_coprocessor_error) RING0_INT_FRAME pushl $0 CFI_ADJUST_CFA_OFFSET 4 +#ifdef CONFIG_X86_INVD_BUG + /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */ +661: pushl $do_general_protection +662: +.section .altinstructions,"a" + .balign 4 + .long 661b + .long 663f + .byte X86_FEATURE_XMM + .byte 662b-661b + .byte 664f-663f +.previous +.section .altinstr_replacement,"ax" +663: pushl $do_simd_coprocessor_error +664: +.previous +#else pushl $do_simd_coprocessor_error +#endif CFI_ADJUST_CFA_OFFSET 4 jmp error_code CFI_ENDPROC |