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[PATCH] unwinder: Use probe_kernel_address instead of __get_user in kernel/unwind.c

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This avoids trouble with the page fault handler if the fault
happens inside an interrupt context.

Suggested by Linus

Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Andi Kleen 2006-12-07 02:14:12 +01:00 committed by Andi Kleen
parent f3d73707a1
commit e2124bb8d3
1 changed files with 8 additions and 6 deletions
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14
kernel/unwind.c
View file

@ -14,6 +14,7 @@
#include <linux/bootmem.h>
#include <linux/sort.h>
#include <linux/stop_machine.h>
#include <linux/uaccess.h>
#include <asm/sections.h>
#include <asm/uaccess.h>
#include <asm/unaligned.h>
@ -550,7 +551,7 @@ static unsigned long read_pointer(const u8 **pLoc,
return 0;
}
if ((ptrType & DW_EH_PE_indirect)
&& __get_user(value, (unsigned long *)value))
&& probe_kernel_address((unsigned long *)value, value))
return 0;
*pLoc = ptr.p8;
@ -982,18 +983,19 @@ int unwind(struct unwind_frame_info *frame)
& (sizeof(unsigned long) - 1))) {
unsigned long link;
if (!__get_user(link,
if (!probe_kernel_address(
(unsigned long *)(UNW_FP(frame)
+ FRAME_LINK_OFFSET))
+ FRAME_LINK_OFFSET),
link)
# if FRAME_RETADDR_OFFSET < 0
&& link > bottom && link < UNW_FP(frame)
# else
&& link > UNW_FP(frame) && link < bottom
# endif
&& !(link & (sizeof(link) - 1))
&& !__get_user(UNW_PC(frame),
&& !probe_kernel_address(
(unsigned long *)(UNW_FP(frame)
+ FRAME_RETADDR_OFFSET))) {
+ FRAME_RETADDR_OFFSET), UNW_PC(frame))) {
UNW_SP(frame) = UNW_FP(frame) + FRAME_RETADDR_OFFSET
# if FRAME_RETADDR_OFFSET < 0
-
@ -1104,7 +1106,7 @@ int unwind(struct unwind_frame_info *frame)
return -EIO;
switch(reg_info[i].width) {
#define CASE(n) case sizeof(u##n): \
__get_user(FRAME_REG(i, u##n), (u##n *)addr); \
probe_kernel_address((u##n *)addr, FRAME_REG(i, u##n)); \
break
CASES;
#undef CASE