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-rw-r--r--arch/x86/mm/fault.c23
1 files changed, 21 insertions, 2 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 4d09df054e3..9c7378df740 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -17,6 +17,7 @@
#include <asm/traps.h> /* dotraplinkage, ... */
#include <asm/pgalloc.h> /* pgd_*(), ... */
#include <asm/kmemcheck.h> /* kmemcheck_*(), ... */
+#include <asm/vsyscall.h>
/*
* Page fault error code bits:
@@ -105,7 +106,7 @@ check_prefetch_opcode(struct pt_regs *regs, unsigned char *instr,
* but for now it's good enough to assume that long
* mode only uses well known segments or kernel.
*/
- return (!user_mode(regs)) || (regs->cs == __USER_CS);
+ return (!user_mode(regs) || user_64bit_mode(regs));
#endif
case 0x60:
/* 0x64 thru 0x67 are valid prefixes in all modes. */
@@ -419,12 +420,14 @@ static noinline __kprobes int vmalloc_fault(unsigned long address)
return 0;
}
+#ifdef CONFIG_CPU_SUP_AMD
static const char errata93_warning[] =
KERN_ERR
"******* Your BIOS seems to not contain a fix for K8 errata #93\n"
"******* Working around it, but it may cause SEGVs or burn power.\n"
"******* Please consider a BIOS update.\n"
"******* Disabling USB legacy in the BIOS may also help.\n";
+#endif
/*
* No vm86 mode in 64-bit mode:
@@ -504,7 +507,11 @@ bad:
*/
static int is_errata93(struct pt_regs *regs, unsigned long address)
{
-#ifdef CONFIG_X86_64
+#if defined(CONFIG_X86_64) && defined(CONFIG_CPU_SUP_AMD)
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD
+ || boot_cpu_data.x86 != 0xf)
+ return 0;
+
if (address != regs->ip)
return 0;
@@ -720,6 +727,18 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
if (is_errata100(regs, address))
return;
+#ifdef CONFIG_X86_64
+ /*
+ * Instruction fetch faults in the vsyscall page might need
+ * emulation.
+ */
+ if (unlikely((error_code & PF_INSTR) &&
+ ((address & ~0xfff) == VSYSCALL_START))) {
+ if (emulate_vsyscall(regs, address))
+ return;
+ }
+#endif
+
if (unlikely(show_unhandled_signals))
show_signal_msg(regs, error_code, address, tsk);