[PATCH] unwinder: Use probe_kernel_address instead of __get_user in kernel/unwind.c
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>
diff --git a/kernel/unwind.c b/kernel/unwind.c
index ed0a21d..af48168 100644
--- a/kernel/unwind.c
+++ b/kernel/unwind.c
@@ -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 @@
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 @@
& (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 @@
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