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Remove abort handler from the backtrace generator

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The abort handler masks the exit status of the backtrace generator by
capturing the abort signal from the backtrace handler and exiting with
zero. Because the output of the backtrace generator is meant to be piped
to `bt_test.py`, its exit status is unimportant and is currently
ignored.

The abort handler calls `exit(3)` which is not asynchronous-signal-safe
and calling it in this context is undefined behavior [0].

Closes ticket 21026.

[0] https://www.securecoding.cert.org/confluence/x/34At
This commit is contained in:
cypherpunks 2016-12-18 15:55:37 +00:00 committed by Nick Mathewson
parent d3c0b137af
commit 04f21f0322
2 changed files with 3 additions and 11 deletions
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3
changes/ticket21026 Normal file
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@ -0,0 +1,3 @@
o Minor bugfixes (testing):
- Remove undefined behavior from the backtrace generator by removing
its signal handler. Fixes bug 21026; bugfix on 0.2.5.2-alpha.

11
src/test/test_bt_cl.c
View File

@ -19,14 +19,12 @@ static int crashtype = 0;
#ifdef __GNUC__ #ifdef __GNUC__
#define NOINLINE __attribute__((noinline)) #define NOINLINE __attribute__((noinline))
#define NORETURN __attribute__((noreturn))
#endif #endif
int crash(int x) NOINLINE; int crash(int x) NOINLINE;
int oh_what(int x) NOINLINE; int oh_what(int x) NOINLINE;
int a_tangled_web(int x) NOINLINE; int a_tangled_web(int x) NOINLINE;
int we_weave(int x) NOINLINE; int we_weave(int x) NOINLINE;
static void abort_handler(int s) NORETURN;
#ifdef HAVE_CFLAG_WNULL_DEREFERENCE #ifdef HAVE_CFLAG_WNULL_DEREFERENCE
DISABLE_GCC_WARNING(null-dereference) DISABLE_GCC_WARNING(null-dereference)
@ -76,13 +74,6 @@ we_weave(int x)
return a_tangled_web(x) + a_tangled_web(x+1); return a_tangled_web(x) + a_tangled_web(x+1);
} }
static void
abort_handler(int s)
{
(void)s;
exit(0);
}
int int
main(int argc, char **argv) main(int argc, char **argv)
{ {
@ -120,8 +111,6 @@ main(int argc, char **argv)
configure_backtrace_handler(NULL); configure_backtrace_handler(NULL);
signal(SIGABRT, abort_handler);
printf("%d\n", we_weave(2)); printf("%d\n", we_weave(2));
clean_up_backtrace_handler(); clean_up_backtrace_handler();