summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/entry_32.S
diff options
context:
space:
mode:
authorBrian Gerst <brgerst@gmail.com>2010-03-21 14:00:43 +0100
committerH. Peter Anvin <hpa@zytor.com>2010-05-03 22:39:26 +0200
commit40d2e76315da38993129090dc5d56377e573c312 (patch)
tree8f585daa23780aa0841ac72b34053f9deb00041c /arch/x86/kernel/entry_32.S
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6 (diff)
downloadlinux-40d2e76315da38993129090dc5d56377e573c312.tar.xz
linux-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.S19
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