From 98f9e35befe5c11e3da448cbe015969ed91730a4 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 17 Feb 2014 14:45:55 +0100 Subject: [PATCH 1/3] qtest: drop unused child_pid field Signed-off-by: Stefan Hajnoczi Reviewed-by: Markus Armbruster --- tests/libqtest.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/tests/libqtest.c b/tests/libqtest.c index c9a4f89451..2876ce47d8 100644 --- a/tests/libqtest.c +++ b/tests/libqtest.c @@ -43,7 +43,6 @@ struct QTestState int qmp_fd; bool irq_level[MAX_IRQ]; GString *rx; - int child_pid; /* Child process created to execute QEMU */ pid_t qemu_pid; /* QEMU process spawned by our child */ }; @@ -152,7 +151,6 @@ QTestState *qtest_init(const char *extra_args) g_free(qmp_socket_path); s->rx = g_string_new(""); - s->child_pid = pid; for (i = 0; i < MAX_IRQ; i++) { s->irq_level[i] = false; } From cef60c925c41563721dc73b1ace7b2f399f72a5b Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 17 Feb 2014 14:54:17 +0100 Subject: [PATCH 2/3] qtest: make QEMU our direct child process qtest_init() cannot use exec*p() to launch QEMU since the exec*p() functions take an argument array while qtest_init() takes char *extra_args. Therefore we execute /bin/sh -c and let the shell parse the argument string. This left /bin/sh as our child process and our child's child was QEMU. We still want QEMU's pid so the -pidfile option was used to let QEMU report its pid. The pidfile needs to be unlinked when the test case exits or fails. In other words, the pidfile creates a new problem for us! Simplify all this using the shell 'exec' command. It allows us to replace the /bin/sh process with QEMU. Then we no longer need to use -pidfile because we already know our fork child's pid. Note: Yes, it seems silly to exec /bin/sh when we could just exec QEMU directly. But remember qtest_init() takes a single char *extra_args command-line fragment instead of a real argv[] array, so we need /bin/sh's argument parsing behavior. Signed-off-by: Stefan Hajnoczi Reviewed-by: Markus Armbruster --- tests/libqtest.c | 34 +++++----------------------------- 1 file changed, 5 insertions(+), 29 deletions(-) diff --git a/tests/libqtest.c b/tests/libqtest.c index 2876ce47d8..8b2b2d7fa4 100644 --- a/tests/libqtest.c +++ b/tests/libqtest.c @@ -43,7 +43,7 @@ struct QTestState int qmp_fd; bool irq_level[MAX_IRQ]; GString *rx; - pid_t qemu_pid; /* QEMU process spawned by our child */ + pid_t qemu_pid; /* our child QEMU process */ }; #define g_assert_no_errno(ret) do { \ @@ -88,32 +88,14 @@ static int socket_accept(int sock) return ret; } -static pid_t read_pid_file(const char *pid_file) -{ - FILE *f; - char buffer[1024]; - pid_t pid = -1; - - f = fopen(pid_file, "r"); - if (f) { - if (fgets(buffer, sizeof(buffer), f)) { - pid = atoi(buffer); - } - fclose(f); - } - return pid; -} - QTestState *qtest_init(const char *extra_args) { QTestState *s; int sock, qmpsock, i; gchar *socket_path; gchar *qmp_socket_path; - gchar *pid_file; gchar *command; const char *qemu_binary; - pid_t pid; qemu_binary = getenv("QTEST_QEMU_BINARY"); g_assert(qemu_binary != NULL); @@ -122,22 +104,20 @@ QTestState *qtest_init(const char *extra_args) socket_path = g_strdup_printf("/tmp/qtest-%d.sock", getpid()); qmp_socket_path = g_strdup_printf("/tmp/qtest-%d.qmp", getpid()); - pid_file = g_strdup_printf("/tmp/qtest-%d.pid", getpid()); sock = init_socket(socket_path); qmpsock = init_socket(qmp_socket_path); - pid = fork(); - if (pid == 0) { - command = g_strdup_printf("%s " + s->qemu_pid = fork(); + if (s->qemu_pid == 0) { + command = g_strdup_printf("exec %s " "-qtest unix:%s,nowait " "-qtest-log /dev/null " "-qmp unix:%s,nowait " - "-pidfile %s " "-machine accel=qtest " "-display none " "%s", qemu_binary, socket_path, - qmp_socket_path, pid_file, + qmp_socket_path, extra_args ?: ""); execlp("/bin/sh", "sh", "-c", command, NULL); exit(1); @@ -159,10 +139,6 @@ QTestState *qtest_init(const char *extra_args) qtest_qmp_discard_response(s, ""); qtest_qmp_discard_response(s, "{ 'execute': 'qmp_capabilities' }"); - s->qemu_pid = read_pid_file(pid_file); - unlink(pid_file); - g_free(pid_file); - if (getenv("QTEST_STOP")) { kill(s->qemu_pid, SIGSTOP); } From b15d422a23a3e4cf1b4195af209211eccdb88d51 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 17 Feb 2014 16:33:35 +0100 Subject: [PATCH 3/3] qtest: kill QEMU process on g_assert() failure The QEMU process stays running if the test case fails. This patch fixes the leak by installing a SIGABRT signal handler which invokes qtest_end(). Signed-off-by: Stefan Hajnoczi Reviewed-by: Markus Armbruster Reviewed-by: Paolo Bonzini --- tests/libqtest.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/tests/libqtest.c b/tests/libqtest.c index 8b2b2d7fa4..f587d36176 100644 --- a/tests/libqtest.c +++ b/tests/libqtest.c @@ -44,6 +44,7 @@ struct QTestState bool irq_level[MAX_IRQ]; GString *rx; pid_t qemu_pid; /* our child QEMU process */ + struct sigaction sigact_old; /* restored on exit */ }; #define g_assert_no_errno(ret) do { \ @@ -88,6 +89,19 @@ static int socket_accept(int sock) return ret; } +static void kill_qemu(QTestState *s) +{ + if (s->qemu_pid != -1) { + kill(s->qemu_pid, SIGTERM); + waitpid(s->qemu_pid, NULL, 0); + } +} + +static void sigabrt_handler(int signo) +{ + kill_qemu(global_qtest); +} + QTestState *qtest_init(const char *extra_args) { QTestState *s; @@ -96,6 +110,7 @@ QTestState *qtest_init(const char *extra_args) gchar *qmp_socket_path; gchar *command; const char *qemu_binary; + struct sigaction sigact; qemu_binary = getenv("QTEST_QEMU_BINARY"); g_assert(qemu_binary != NULL); @@ -108,6 +123,14 @@ QTestState *qtest_init(const char *extra_args) sock = init_socket(socket_path); qmpsock = init_socket(qmp_socket_path); + /* Catch SIGABRT to clean up on g_assert() failure */ + sigact = (struct sigaction){ + .sa_handler = sigabrt_handler, + .sa_flags = SA_RESETHAND, + }; + sigemptyset(&sigact.sa_mask); + sigaction(SIGABRT, &sigact, &s->sigact_old); + s->qemu_pid = fork(); if (s->qemu_pid == 0) { command = g_strdup_printf("exec %s " @@ -148,13 +171,9 @@ QTestState *qtest_init(const char *extra_args) void qtest_quit(QTestState *s) { - int status; - - if (s->qemu_pid != -1) { - kill(s->qemu_pid, SIGTERM); - waitpid(s->qemu_pid, &status, 0); - } + sigaction(SIGABRT, &s->sigact_old, NULL); + kill_qemu(s); close(s->fd); close(s->qmp_fd); g_string_free(s->rx, true);