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authorFrank Ch. Eigler <fche@elastic.org>2008-04-13 17:50:45 -0400
committerFrank Ch. Eigler <fche@elastic.org>2008-04-13 17:50:45 -0400
commitf7e07777e033e580351dc6886ab7dbdddd9839fe (patch)
tree07c4878e3eaf77801d5104c2f6c498cfff9e3bbd /runtime/stack-i386.c
parenta9f3ab125303a2e89dd3c17b39f26e1d2c428fa5 (diff)
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runtime backtrace: stop infinite loops by checking for full print buffer
2008-04-13 Frank Ch. Eigler <fche@elastic.org> * print.c (_stp_pbuf_full): New function to note full print buffer. * stack-{i386,x86_64}.c: Use it in all stack-searching loops, to impose another limit against unbounded iteration.
Diffstat (limited to 'runtime/stack-i386.c')
-rw-r--r--runtime/stack-i386.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/runtime/stack-i386.c b/runtime/stack-i386.c
index 20c8eda5..78f89b0d 100644
--- a/runtime/stack-i386.c
+++ b/runtime/stack-i386.c
@@ -17,7 +17,8 @@ static int _stp_valid_stack_ptr(unsigned long context, unsigned long p)
static void _stp_stack_print_fallback(unsigned long context, unsigned long stack, int verbose)
{
unsigned long addr;
- while (_stp_valid_stack_ptr(context, stack)) {
+ while (_stp_valid_stack_ptr(context, stack) &&
+ !_stp_pbuf_full()) {
if (unlikely(_stp_read_address(addr, (unsigned long *)stack, KERNEL_DS))) {
/* cannot access stack. give up. */
return;
@@ -42,7 +43,8 @@ static void __stp_stack_print (struct pt_regs *regs, int verbose, int levels)
unsigned long ebp = regs->ebp;
#endif /* STAPCONF_X86_UNIREGS */
- while (_stp_valid_stack_ptr(context, (unsigned long)ebp)) {
+ while (_stp_valid_stack_ptr(context, (unsigned long)ebp) &&
+ !_stp_pbuf_full()) {
if (unlikely(_stp_read_address(addr, (unsigned long *)(ebp + 4), KERNEL_DS))) {
/* cannot access stack. give up. */
return;
@@ -59,7 +61,8 @@ static void __stp_stack_print (struct pt_regs *regs, int verbose, int levels)
struct unwind_frame_info info;
arch_unw_init_frame_info(&info, regs);
- while (!arch_unw_user_mode(&info)) {
+ while (!arch_unw_user_mode(&info) &&
+ !_stp_pbuf_full ()) {
int ret = unwind(&info);
dbug_unwind(1, "ret=%d PC=%lx SP=%lx\n", ret, UNW_PC(&info), UNW_SP(&info));
if (ret == 0) {