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Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linu…
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…x/kernel/git/tip/tip

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86-64: Fix CFI data for interrupt frames
  x86-64: Don't apply destructive erratum workaround on unaffected CPUs
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Linus Torvalds committed Oct 26, 2011
2 parents 0791e98 + eab9e61 commit 7b86572
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Showing 3 changed files with 18 additions and 6 deletions.
2 changes: 2 additions & 0 deletions arch/x86/include/asm/dwarf2.h
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@
#define CFI_REMEMBER_STATE .cfi_remember_state
#define CFI_RESTORE_STATE .cfi_restore_state
#define CFI_UNDEFINED .cfi_undefined
#define CFI_ESCAPE .cfi_escape

#ifdef CONFIG_AS_CFI_SIGNAL_FRAME
#define CFI_SIGNAL_FRAME .cfi_signal_frame
Expand Down Expand Up @@ -68,6 +69,7 @@
#define CFI_REMEMBER_STATE cfi_ignore
#define CFI_RESTORE_STATE cfi_ignore
#define CFI_UNDEFINED cfi_ignore
#define CFI_ESCAPE cfi_ignore
#define CFI_SIGNAL_FRAME cfi_ignore

#endif
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14 changes: 9 additions & 5 deletions arch/x86/kernel/entry_64.S
Original file line number Diff line number Diff line change
Expand Up @@ -331,10 +331,15 @@ ENDPROC(native_usergs_sysret64)
1: incl PER_CPU_VAR(irq_count)
jne 2f
mov PER_CPU_VAR(irq_stack_ptr),%rsp
EMPTY_FRAME 0
CFI_DEF_CFA_REGISTER rsi

2: /* Store previous stack value */
pushq %rsi
CFI_ESCAPE 0x0f /* DW_CFA_def_cfa_expression */, 6, \
0x77 /* DW_OP_breg7 */, 0, \
0x06 /* DW_OP_deref */, \
0x08 /* DW_OP_const1u */, SS+8-RBP, \
0x22 /* DW_OP_plus */
/* We entered an interrupt context - irqs are off: */
TRACE_IRQS_OFF
.endm
Expand Down Expand Up @@ -788,7 +793,6 @@ END(interrupt)
subq $ORIG_RAX-RBP, %rsp
CFI_ADJUST_CFA_OFFSET ORIG_RAX-RBP
SAVE_ARGS_IRQ
PARTIAL_FRAME 0
call \func
.endm

Expand All @@ -813,10 +817,10 @@ ret_from_intr:

/* Restore saved previous stack */
popq %rsi
leaq 16(%rsi), %rsp

CFI_DEF_CFA_REGISTER rsi
leaq ARGOFFSET-RBP(%rsi), %rsp
CFI_DEF_CFA_REGISTER rsp
CFI_ADJUST_CFA_OFFSET -16
CFI_ADJUST_CFA_OFFSET RBP-ARGOFFSET

exit_intr:
GET_THREAD_INFO(%rcx)
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8 changes: 7 additions & 1 deletion arch/x86/mm/fault.c
Original file line number Diff line number Diff line change
Expand Up @@ -420,12 +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:
Expand Down Expand Up @@ -505,7 +507,11 @@ static void dump_pagetable(unsigned long address)
*/
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;

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