From f33cbe72e6166b97d6fa2400cb00a885b47999d7 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 2 Jan 2014 15:11:25 -0300 Subject: [PATCH] perf evlist: Send the errno in the signal when workload fails When a tool uses perf_evlist__start_workload and the supplied workload fails (e.g.: its binary wasn't found), perror was being used to print the error reason. This is undesirable, as the caller may be a GUI, when it wants to have total control of the error reporting process. So move to using sigaction(SA_SIGINFO) + siginfo_t->sa_value->sival_int to communicate to the caller the errno and let it print it using the UI of its choosing. Cc: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-epgcv7kjq8ll2udqfken92pz@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 39 +++++++++++++++++++++++++++++++++++++-- tools/perf/builtin-stat.c | 21 +++++++++++++++------ tools/perf/util/evlist.c | 11 ++++++++--- 3 files changed, 60 insertions(+), 11 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 6ec0cbc..f987d38 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -341,6 +341,22 @@ static void record__init_features(struct record *rec) perf_header__clear_feat(&session->header, HEADER_BRANCH_STACK); } +static volatile int workload_exec_errno; + +/* + * perf_evlist__prepare_workload will send a SIGUSR1 + * if the fork fails, since we asked by setting its + * want_signal to true. + */ +static void workload_exec_failed_signal(int signo, siginfo_t *info, + void *ucontext __maybe_unused) +{ + workload_exec_errno = info->si_value.sival_int; + done = 1; + signr = signo; + child_finished = 1; +} + static int __cmd_record(struct record *rec, int argc, const char **argv) { int err; @@ -359,7 +375,6 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) on_exit(record__sig_exit, rec); signal(SIGCHLD, sig_handler); signal(SIGINT, sig_handler); - signal(SIGUSR1, sig_handler); signal(SIGTERM, sig_handler); session = perf_session__new(file, false, NULL); @@ -492,8 +507,20 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) /* * Let the child rip */ - if (forks) + if (forks) { + struct sigaction act = { + .sa_flags = SA_SIGINFO, + .sa_sigaction = workload_exec_failed_signal, + }; + /* + * perf_evlist__prepare_workload will, after we call + * perf_evlist__start_Workload, send a SIGUSR1 if the exec call + * fails, that we will catch in workload_signal to flip + * workload_exec_errno. + */ + sigaction(SIGUSR1, &act, NULL); perf_evlist__start_workload(evsel_list); + } for (;;) { int hits = rec->samples; @@ -521,6 +548,14 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) } } + if (forks && workload_exec_errno) { + char msg[512]; + const char *emsg = strerror_r(workload_exec_errno, msg, sizeof(msg)); + pr_err("Workload failed: %s\n", emsg); + err = -1; + goto out_delete_session; + } + if (quiet || signr == SIGUSR1) return 0; diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 1c76c7a..9d0d52d 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -58,6 +58,7 @@ #include "util/thread.h" #include "util/thread_map.h" +#include #include #include #include @@ -509,16 +510,17 @@ static void handle_initial_delay(void) } } -static volatile bool workload_exec_failed; +static volatile int workload_exec_errno; /* * perf_evlist__prepare_workload will send a SIGUSR1 * if the fork fails, since we asked by setting its * want_signal to true. */ -static void workload_exec_failed_signal(int signo __maybe_unused) +static void workload_exec_failed_signal(int signo __maybe_unused, siginfo_t *info, + void *ucontext __maybe_unused) { - workload_exec_failed = true; + workload_exec_errno = info->si_value.sival_int; } static int __run_perf_stat(int argc, const char **argv) @@ -596,13 +598,17 @@ static int __run_perf_stat(int argc, const char **argv) clock_gettime(CLOCK_MONOTONIC, &ref_time); if (forks) { + struct sigaction act = { + .sa_flags = SA_SIGINFO, + .sa_sigaction = workload_exec_failed_signal, + }; /* * perf_evlist__prepare_workload will, after we call * perf_evlist__start_Workload, send a SIGUSR1 if the exec call * fails, that we will catch in workload_signal to flip - * workload_exec_failed. + * workload_exec_errno. */ - signal(SIGUSR1, workload_exec_failed_signal); + sigaction(SIGUSR1, &act, NULL); perf_evlist__start_workload(evsel_list); handle_initial_delay(); @@ -615,8 +621,11 @@ static int __run_perf_stat(int argc, const char **argv) } wait(&status); - if (workload_exec_failed) + if (workload_exec_errno) { + const char *emsg = strerror_r(workload_exec_errno, msg, sizeof(msg)); + pr_err("Workload failed: %s\n", emsg); return -1; + } if (WIFSIGNALED(status)) psignal(WTERMSIG(status), argv[0]); diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index b08a7ec..4a30c87 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1073,9 +1073,14 @@ int perf_evlist__prepare_workload(struct perf_evlist *evlist, struct target *tar execvp(argv[0], (char **)argv); - perror(argv[0]); - if (want_signal) - kill(getppid(), SIGUSR1); + if (want_signal) { + union sigval val; + + val.sival_int = errno; + if (sigqueue(getppid(), SIGUSR1, val)) + perror(argv[0]); + } else + perror(argv[0]); exit(-1); } -- 2.7.4