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author | Frank Ch. Eigler <fche@elastic.org> | 2008-04-13 17:50:45 -0400 |
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committer | Frank Ch. Eigler <fche@elastic.org> | 2008-04-13 17:50:45 -0400 |
commit | f7e07777e033e580351dc6886ab7dbdddd9839fe (patch) | |
tree | 07c4878e3eaf77801d5104c2f6c498cfff9e3bbd /runtime/stack-i386.c | |
parent | a9f3ab125303a2e89dd3c17b39f26e1d2c428fa5 (diff) | |
download | systemtap-steved-f7e07777e033e580351dc6886ab7dbdddd9839fe.tar.gz systemtap-steved-f7e07777e033e580351dc6886ab7dbdddd9839fe.tar.xz systemtap-steved-f7e07777e033e580351dc6886ab7dbdddd9839fe.zip |
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.c | 9 |
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) { |