[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1257270936-5496-1-git-send-email-brgerst@gmail.com>
Date: Tue, 3 Nov 2009 12:55:36 -0500
From: Brian Gerst <brgerst@...il.com>
To: Ingo Molnar <mingo@...e.hu>
Cc: x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] x86, 64-bit: Move K8 B step iret fixup to fault entry asm (v2)
Move the handling of truncated %rip from an iret fault to the fault
entry path.
This allows x86-64 to use the standard search_extable() function.
v2: Fixed jump to error_swapgs to be unconditional.
Signed-off-by: Brian Gerst <brgerst@...il.com>
---
arch/x86/include/asm/uaccess.h | 1 -
arch/x86/kernel/entry_64.S | 11 ++++++++---
arch/x86/mm/extable.c | 31 -------------------------------
3 files changed, 8 insertions(+), 35 deletions(-)
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index d2c6c93..abd3e0e 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -570,7 +570,6 @@ extern struct movsl_mask {
#ifdef CONFIG_X86_32
# include "uaccess_32.h"
#else
-# define ARCH_HAS_SEARCH_EXTABLE
# include "uaccess_64.h"
#endif
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index b5c061f..1579a6c 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1491,12 +1491,17 @@ error_kernelspace:
leaq irq_return(%rip),%rcx
cmpq %rcx,RIP+8(%rsp)
je error_swapgs
- movl %ecx,%ecx /* zero extend */
- cmpq %rcx,RIP+8(%rsp)
- je error_swapgs
+ movl %ecx,%eax /* zero extend */
+ cmpq %rax,RIP+8(%rsp)
+ je bstep_iret
cmpq $gs_change,RIP+8(%rsp)
je error_swapgs
jmp error_sti
+
+bstep_iret:
+ /* Fix truncated RIP */
+ movq %rcx,RIP+8(%rsp)
+ jmp error_swapgs
END(error_entry)
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 61b41ca..d0474ad 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -35,34 +35,3 @@ int fixup_exception(struct pt_regs *regs)
return 0;
}
-
-#ifdef CONFIG_X86_64
-/*
- * Need to defined our own search_extable on X86_64 to work around
- * a B stepping K8 bug.
- */
-const struct exception_table_entry *
-search_extable(const struct exception_table_entry *first,
- const struct exception_table_entry *last,
- unsigned long value)
-{
- /* B stepping K8 bug */
- if ((value >> 32) == 0)
- value |= 0xffffffffUL << 32;
-
- while (first <= last) {
- const struct exception_table_entry *mid;
- long diff;
-
- mid = (last - first) / 2 + first;
- diff = mid->insn - value;
- if (diff == 0)
- return mid;
- else if (diff < 0)
- first = mid+1;
- else
- last = mid-1;
- }
- return NULL;
-}
-#endif
--
1.6.2.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists