From 0c8bc102f287d3993751d80ba2dffb01e0c8bc7f Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sun, 3 Jul 2016 17:42:05 -0400 Subject: [PATCH] improve abort fallback behavior when raising SIGABRT fails to terminate these changes still do not yield a fully-conforming abort, but they fix two known issues: - per POSIX, termination via SIGKILL is not "abnormal", but both ISO C and POSIX require abort to yield abnormal termination. - raising SIGKILL fails to do anything to pid 1 in some containers. now, the trapping instruction produced by a_crash() is expected to produce abnormal termination, without the risk of invoking a signal handler since SIGILL and SIGSEGV are blocked, and _Exit, which contains an infinite loop analogous to the one being removed from abort itself, is used as a last resort. this implementation still fails to produce an exit status as if the process terminated via SIGABRT in cases where SIGABRT is blocked or ignored, but fixing that is not easy; the obvious pseudo-solutions all have subtle race conditions where a concurrent fork or exec can expose incorrect signal state. --- src/exit/abort.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/exit/abort.c b/src/exit/abort.c index 203dd35c..ecc0f735 100644 --- a/src/exit/abort.c +++ b/src/exit/abort.c @@ -1,10 +1,14 @@ #include #include #include "syscall.h" +#include "pthread_impl.h" +#include "atomic.h" _Noreturn void abort(void) { raise(SIGABRT); + __block_all_sigs(0); + a_crash(); raise(SIGKILL); - for (;;); + _Exit(127); } -- 2.25.1