From 6aec3ec93ac9e7cbcf75d9ec9b9b45e71cda5ac5 Mon Sep 17 00:00:00 2001 From: Jim Warner Date: Sat, 9 Apr 2022 00:00:00 -0500 Subject: [PATCH] top: ignore the SIGHUP signal if running in batch mode It would appear that openSUSE was the first to release procps-ng version 4.0.0 (in the tumbleweed distro). As a result I checked their source rpm and found a couple of patches I'm porting to newlib for the next release. This particulate commit was a refactor of the openSUSE patch 'procps-ng-3.3.8-bnc634840.patch'. Unfortunately their original patch did not have the intended effect. That was because the amended signal handling logic was performed well before the command line parameters were parsed. So the global 'Batch' flag was in its 0 state. . what follows is the original openSUSE commit message ------------------------------------------------------ Do not setup SIGHUP signal handler if we are in the batch mode Top enables a signal handler for the SIGHUP signal (loss of terminal). While this makes sense for top's default interactive mode, it doesn't make any sense for batch mode. If you run top in nohup just to collect data over time and disconnect top finishes which is not what one would expect. ------------------------------------------------------ Signed-off-by: Jim Warner --- top/top.c | 85 ++++++++++++++++++++++++++++++++----------------------- top/top.h | 1 + 2 files changed, 51 insertions(+), 35 deletions(-) diff --git a/top/top.c b/top/top.c index 110bea8f..40391f68 100644 --- a/top/top.c +++ b/top/top.c @@ -3451,7 +3451,6 @@ static inline int osel_matched (const WIN_t *q, FLG_t enu, const char *str) { * IMPORTANT stuff upon which all those lessor functions depend! */ static void before (char *me) { #define doALL STAT_REAP_NUMA_NODES_TOO - struct sigaction sa; int i, rc; int linux_version_code = procps_linux_version(); @@ -3515,11 +3514,13 @@ static void before (char *me) { error_exit(fmtmk(N_fmt(LIB_errorpid_fmt), __LINE__, strerror(-rc))); #if defined THREADED_CPU || defined THREADED_MEM || defined THREADED_TSK +{ struct sigaction sa; Thread_id_main = pthread_self(); /* in case any of our threads have been enabled, they'll inherit this mask with everything blocked. therefore, signals go to the main thread (us). */ sigfillset(&sa.sa_mask); pthread_sigmask(SIG_BLOCK, &sa.sa_mask, NULL); +} #endif #ifdef THREADED_CPU @@ -3546,38 +3547,6 @@ static void before (char *me) { error_exit(fmtmk(N_fmt(X_THREADINGS_fmt), __LINE__, strerror(errno))); pthread_setname_np(Thread_id_tasks, "update tasks"); #endif - -#ifndef SIGRTMAX // not available on hurd, maybe others too -#define SIGRTMAX 32 -#endif - // lastly, establish a robust signals environment - memset(&sa, 0, sizeof(sa)); - sigemptyset(&sa.sa_mask); - // with user position preserved through SIGWINCH, we must avoid SA_RESTART - sa.sa_flags = 0; - for (i = SIGRTMAX; i; i--) { - switch (i) { - case SIGALRM: case SIGHUP: case SIGINT: - case SIGPIPE: case SIGQUIT: case SIGTERM: - case SIGUSR1: case SIGUSR2: - sa.sa_handler = sig_endpgm; - break; - case SIGTSTP: case SIGTTIN: case SIGTTOU: - sa.sa_handler = sig_paused; - break; - case SIGCONT: case SIGWINCH: - sa.sa_handler = sig_resize; - break; - default: - sa.sa_handler = sig_abexit; - break; - case SIGKILL: case SIGSTOP: - // because uncatchable, fall through - case SIGCHLD: // we can't catch this - continue; // when opening a pipe - } - sigaction(i, &sa, NULL); - } #undef doALL } // end: before @@ -4240,6 +4209,51 @@ static void parse_args (int argc, char **argv) { } // end: parse_args + /* + * Establish a robust signals environment */ +static void signals_set (void) { + #ifndef SIGRTMAX // not available on hurd, maybe others too + #define SIGRTMAX 32 + #endif + int i; + struct sigaction sa; + + memset(&sa, 0, sizeof(sa)); + sigemptyset(&sa.sa_mask); + // with user position preserved through SIGWINCH, we must avoid SA_RESTART + sa.sa_flags = 0; + for (i = SIGRTMAX; i; i--) { + switch (i) { + case SIGHUP: + if (Batch) + sa.sa_handler = SIG_IGN; + else + sa.sa_handler = sig_endpgm; + break; + case SIGALRM: case SIGINT: case SIGPIPE: + case SIGQUIT: case SIGTERM: case SIGUSR1: + case SIGUSR2: + sa.sa_handler = sig_endpgm; + break; + case SIGTSTP: case SIGTTIN: case SIGTTOU: + sa.sa_handler = sig_paused; + break; + case SIGCONT: case SIGWINCH: + sa.sa_handler = sig_resize; + break; + default: + sa.sa_handler = sig_abexit; + break; + case SIGKILL: case SIGSTOP: + // because uncatchable, fall through + case SIGCHLD: // we can't catch this + continue; // when opening a pipe + } + sigaction(i, &sa, NULL); + } +} // end: signals_set + + /* * Set up the terminal attributes */ static void whack_terminal (void) { @@ -6731,8 +6745,9 @@ int main (int argc, char *argv[]) { // +-------------+ wins_stage_1(); // top (sic) slice configs_reads(); // > spread etc, < - parse_args(argc, argv); // > lean stuff, < - whack_terminal(); // > onions etc. < + parse_args(argc, argv); // > onions etc, < + signals_set(); // > lean stuff, < + whack_terminal(); // > more stuff. < wins_stage_2(); // as bottom slice // +-------------+ diff --git a/top/top.h b/top/top.h index 40fe0ecb..bbed7832 100644 --- a/top/top.h +++ b/top/top.h @@ -711,6 +711,7 @@ typedef struct WIN_t { //atic int configs_path (const char *const fmts, ...); //atic void configs_reads (void); //atic void parse_args (int argc, char **argv); +//atic void signals_set (void); //atic void whack_terminal (void); /*------ Windows/Field Groups support ----------------------------------*/ //atic void win_names (WIN_t *q, const char *name); -- 2.40.0