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authorBen Cheng <bccheng@android.com>2011-02-24 16:37:52 -0800
committerBen Cheng <bccheng@android.com>2011-02-24 16:37:52 -0800
commitdce4d06b5c92f375bcf2efcb5b2d87d7566d04f2 (patch)
treee2823ada61135b9643624d324942a84ef3864351 /debuggerd/arm
parent0e7c4274c687446dbe30a814278d7a6b99da8c4e (diff)
Fix overflow prevention code in memory dump.
The delta between start and end pointers in memory dump has to be multiples of 4 or 16. Bug: 3486787 Change-Id: Ie34aa79ffb704ca647805dbc6a16f2c35adf849c
Diffstat (limited to 'debuggerd/arm')
-rw-r--r--debuggerd/arm/machine.c42
1 files changed, 23 insertions, 19 deletions
diff --git a/debuggerd/arm/machine.c b/debuggerd/arm/machine.c
index e765c3b72..88bf054ff 100644
--- a/debuggerd/arm/machine.c
+++ b/debuggerd/arm/machine.c
@@ -54,7 +54,7 @@ void dump_stack_and_code(int tfd, int pid, mapinfo *map,
int unwind_depth, unsigned int sp_list[],
bool at_fault)
{
- unsigned int sp, pc, p, end, data;
+ unsigned int sp, pc, lr, p, end, data;
struct pt_regs r;
int sp_depth;
bool only_in_tombstone = !at_fault;
@@ -63,23 +63,25 @@ void dump_stack_and_code(int tfd, int pid, mapinfo *map,
if(ptrace(PTRACE_GETREGS, pid, 0, &r)) return;
sp = r.ARM_sp;
pc = r.ARM_pc;
+ lr = r.ARM_lr;
_LOG(tfd, only_in_tombstone, "\ncode around pc:\n");
- end = p = pc & ~3;
+ p = pc & ~3;
p -= 32;
- if (p > end)
+ if (p > pc)
p = 0;
- end += 32;
- if (end < p)
- end = ~0;
+ end = p + 80;
+ /* 'end - p' has to be multiples of 16 */
+ while (end < p)
+ end -= 16;
/* Dump the code around PC as:
* addr contents
* 00008d34 fffffcd0 4c0eb530 b0934a0e 1c05447c
* 00008d44 f7ff18a0 490ced94 68035860 d0012b00
*/
- while (p <= end) {
+ while (p < end) {
int i;
sprintf(code_buffer, "%08x ", p);
@@ -91,23 +93,24 @@ void dump_stack_and_code(int tfd, int pid, mapinfo *map,
_LOG(tfd, only_in_tombstone, "%s\n", code_buffer);
}
- if ((unsigned) r.ARM_lr != pc) {
+ if (lr != pc) {
_LOG(tfd, only_in_tombstone, "\ncode around lr:\n");
- end = p = r.ARM_lr & ~3;
+ p = lr & ~3;
p -= 32;
- if (p > end)
+ if (p > lr)
p = 0;
- end += 32;
- if (end < p)
- end = ~0;
+ end = p + 80;
+ /* 'end - p' has to be multiples of 16 */
+ while (end < p)
+ end -= 16;
/* Dump the code around LR as:
* addr contents
* 00008d34 fffffcd0 4c0eb530 b0934a0e 1c05447c
* 00008d44 f7ff18a0 490ced94 68035860 d0012b00
*/
- while (p <= end) {
+ while (p < end) {
int i;
sprintf(code_buffer, "%08x ", p);
@@ -133,10 +136,10 @@ void dump_stack_and_code(int tfd, int pid, mapinfo *map,
}
}
else {
- end = sp | 0x000000ff;
- end += 0xff;
- if (end < sp)
- end = ~0;
+ end = p + 256;
+ /* 'end - p' has to be multiples of 4 */
+ if (end < p)
+ end = ~7;
}
_LOG(tfd, only_in_tombstone, "\nstack:\n");
@@ -174,8 +177,9 @@ void dump_stack_and_code(int tfd, int pid, mapinfo *map,
/* print another 64-byte of stack data after the last frame */
end = p+64;
+ /* 'end - p' has to be multiples of 4 */
if (end < p)
- end = ~0;
+ end = ~7;
while (p <= end) {
data = ptrace(PTRACE_PEEKTEXT, pid, (void*)p, NULL);