[GIT PULL] x86/asm changes for v3.2

From: Ingo Molnar
Date: Wed Oct 26 2011 - 11:14:04 EST


Linus,

Please pull the latest x86-asm-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-asm-for-linus

Thanks,

Ingo

------------------>
Jan Beulich (2):
x86-64: Don't apply destructive erratum workaround on unaffected CPUs
x86-64: Fix CFI data for interrupt frames


arch/x86/include/asm/dwarf2.h | 2 ++
arch/x86/kernel/entry_64.S | 14 +++++++++-----
arch/x86/mm/fault.c | 8 +++++++-
3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/dwarf2.h b/arch/x86/include/asm/dwarf2.h
index 3260991..f6f1598 100644
--- a/arch/x86/include/asm/dwarf2.h
+++ b/arch/x86/include/asm/dwarf2.h
@@ -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
@@ -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
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 6419bb0..faf8d5e 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -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
@@ -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

@@ -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)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 0d17c8c..9c7378d 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -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:
@@ -505,7 +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;

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