From d37f85c269fbb6e905802ffdbce0ba4173ba21a9 Mon Sep 17 00:00:00 2001 From: Jim Warner Date: Tue, 6 Aug 2019 00:00:00 -0500 Subject: [PATCH] top: avoid a potential SEGV during program termination The backtrace shown in the bug report referenced below illustrates a 'normal' program termination interrupted with some signal, ultimately then causing a top crash. So this commit just rearranges a little code such that all signals will be blocked during that rather lengthy end of program processing regardless of how initiated. [ in that report, ignore the assertion regarding the ] [ '-n' option. it obviously was not '1' since do_key ] [ had been called, which otherwise wouldn't be true. ] [ and when it is '1' the -d option would be ignored. ] Reference(s): https://bugzilla.redhat.com/show_bug.cgi?id=1737552 Signed-off-by: Jim Warner --- top/top.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/top/top.c b/top/top.c index b01907a3..73598e26 100644 --- a/top/top.c +++ b/top/top.c @@ -404,6 +404,11 @@ static void at_eoj (void) { * The real program end */ static void bye_bye (const char *str) NORETURN; static void bye_bye (const char *str) { + sigset_t ss; + +// POSIX.1-2004 async-signal-safe: sigfillset, sigprocmask + sigfillset(&ss); + sigprocmask(SIG_BLOCK, &ss, NULL); at_eoj(); // restore tty in preparation for exit #ifdef ATEOJ_RPTSTD { proc_t *p; @@ -595,12 +600,6 @@ static void sig_abexit (int sig) { * SIGUSR1 and SIGUSR2 */ static void sig_endpgm (int dont_care_sig) NORETURN; static void sig_endpgm (int dont_care_sig) { - sigset_t ss; - -// POSIX.1-2004 async-signal-safe: sigfillset, sigprocmask - sigfillset(&ss); - sigprocmask(SIG_BLOCK, &ss, NULL); - Frames_signal = BREAK_sig; bye_bye(NULL); (void)dont_care_sig; } // end: sig_endpgm -- 2.40.0