[PATCH for review] [117/145] i386: error_code is not safe for kprobes

Andi Kleen
2006-08-10T19:54:28Z

r

From: Chuck Ebbert <76306.1226@compuserve.com>

Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.

Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.

Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>

---
arch/i386/kernel/entry.S | 25 +++++++++++++------------
1 files changed, 13 insertions(+), 12 deletions(-)

Index: linux/arch/i386/kernel/entry.S
===================================================================
--- linux.orig/arch/i386/kernel/entry.S
+++ linux/arch/i386/kernel/entry.S
@@ -587,11 +587,9 @@ ENTRY(name) \
/* The include is where all of the SMP etc. interrupts come from */
#include "entry_arch.h"

-ENTRY(divide_error)
- RING0_INT_FRAME
- pushl $0 # no error code
- CFI_ADJUST_CFA_OFFSET 4
- pushl $do_divide_error
+KPROBE_ENTRY(page_fault)
+ RING0_EC_FRAME
+ pushl $do_page_fault
CFI_ADJUST_CFA_OFFSET 4
ALIGN
error_code:
@@ -641,6 +639,7 @@ error_code:
call *%edi
jmp ret_from_exception
CFI_ENDPROC
+.previous

ENTRY(coprocessor_error)
RING0_INT_FRAME
@@ -716,7 +715,8 @@ debug_stack_correct:
call do_debug
jmp ret_from_exception
CFI_ENDPROC
- .previous .text
+.previous
+
/*
* NMI is doubly nasty. It can happen _while_ we're handling
* a debug fault, and the debug fault hasn't yet been able to
@@ -812,7 +812,7 @@ KPROBE_ENTRY(int3)
call do_int3
jmp ret_from_exception
CFI_ENDPROC
- .previous .text
+.previous

ENTRY(overflow)
RING0_INT_FRAME
@@ -877,7 +877,7 @@ KPROBE_ENTRY(general_protection)
CFI_ADJUST_CFA_OFFSET 4
jmp error_code
CFI_ENDPROC
- .previous .text
+.previous

ENTRY(alignment_check)
RING0_EC_FRAME
@@ -886,13 +886,14 @@ ENTRY(alignment_check)
jmp error_code
CFI_ENDPROC

-KPROBE_ENTRY(page_fault)
- RING0_EC_FRAME
- pushl $do_page_fault
+ENTRY(divide_error)
+ RING0_INT_FRAME
+ pushl $0 # no error code
+ CFI_ADJUST_CFA_OFFSET 4
+ pushl $do_divide_error
CFI_ADJUST_CFA_OFFSET 4
jmp error_code
CFI_ENDPROC
- .previous .text

#ifdef CONFIG_X86_MCE
ENTRY(machine_check)