From 9af9997449c5e66cd431cb0c46371eade3ecd35a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Mariusz=20Koz=C5=82owski?= Date: Sun, 17 Dec 2023 10:45:05 +0100 Subject: [PATCH] Cleanup pthread code --- Makefile | 2 ++ memcr.c | 65 +++++++++++++++++++++++++++++++++----------------------- 2 files changed, 40 insertions(+), 27 deletions(-) diff --git a/Makefile b/Makefile index 5fb5223..a0ba536 100644 --- a/Makefile +++ b/Makefile @@ -62,6 +62,8 @@ else MCFLAGS += -fstack-protector-all -fstack-protector-strong endif +#MCFLAGS += -fsanitize=thread + CC ?= $(CROSS_COMPILE)gcc LD ?= $(CROSS_COMPILE)ld.bfd OBJCOPY ?= $(CROSS_COMPILE)objcopy diff --git a/memcr.c b/memcr.c index 2d7ffff..8325878 100644 --- a/memcr.c +++ b/memcr.c @@ -155,10 +155,16 @@ static struct target_context ctx; static int interrupted; -static pthread_mutex_t parasite_status_lock = PTHREAD_MUTEX_INITIALIZER; -static pthread_cond_t parasite_status_cond = PTHREAD_COND_INITIALIZER; -static unsigned long parasite_status; -static unsigned long parasite_status_changed; +static struct { + pthread_t thread_id; + pthread_mutex_t lock; + pthread_cond_t cond; + int changed; + int status; +} parasite_watch = { + .lock = PTHREAD_MUTEX_INITIALIZER, + .cond = PTHREAD_COND_INITIALIZER, +}; /* * man sigaction: For a ptrace(2) event, si_code will contain SIG‐TRAP and have the ptrace event in the high byte: @@ -257,7 +263,7 @@ static int service_cmds_wait_and_pop_front(struct service_command_ctx *ctx) } else if (service_cmds_ctx.interrupt == TRUE) ret = 1; else - fprintf(stderr, "[-] %s: pthread_cond_wait(): %m\n", __func__); + fprintf(stderr, "[-] %s: pthread_cond_wait() failed: %d\n", __func__, ret); pthread_mutex_unlock(&service_cmds_ctx.lock); return ret; @@ -345,11 +351,11 @@ static void md5_final(unsigned char *md, unsigned int *len, void *ctx) static void parasite_status_signal(pid_t pid, int status) { - pthread_mutex_lock(¶site_status_lock); - parasite_status = status; - parasite_status_changed = 1; - pthread_cond_signal(¶site_status_cond); - pthread_mutex_unlock(¶site_status_lock); + pthread_mutex_lock(¶site_watch.lock); + parasite_watch.changed = 1; + parasite_watch.status = status; + pthread_cond_signal(¶site_watch.cond); + pthread_mutex_unlock(¶site_watch.lock); if (WIFEXITED(status)) ; /* normal exit */ @@ -371,12 +377,12 @@ static int parasite_status_wait(int *status) clock_gettime(CLOCK_REALTIME, &ts); ts.tv_sec += 1; - pthread_mutex_lock(¶site_status_lock); - while (!parasite_status_changed && (ret == 0 || ret == ETIMEDOUT)) - ret = pthread_cond_timedwait(¶site_status_cond, ¶site_status_lock, &ts); + pthread_mutex_lock(¶site_watch.lock); + while (!parasite_watch.changed && (ret == 0 || ret == ETIMEDOUT)) + ret = pthread_cond_timedwait(¶site_watch.cond, ¶site_watch.lock, &ts); if (!ret) - *status = parasite_status; - pthread_mutex_unlock(¶site_status_lock); + *status = parasite_watch.status; + pthread_mutex_unlock(¶site_watch.lock); if (ret != ETIMEDOUT) break; @@ -385,7 +391,9 @@ static int parasite_status_wait(int *status) } if (ret) - fprintf(stdout, "[-] parasite status cond timedwait failed: %s\n", strerror(ret)); + fprintf(stderr, "[-] parasite status cond timedwait failed: %d\n", ret); + + pthread_join(parasite_watch.thread_id, NULL); return ret; } @@ -394,9 +402,9 @@ static int parasite_status_ok(void) { int ret; - pthread_mutex_lock(¶site_status_lock); - ret = !parasite_status_changed; - pthread_mutex_unlock(¶site_status_lock); + pthread_mutex_lock(¶site_watch.lock); + ret = !parasite_watch.changed; + pthread_mutex_unlock(¶site_watch.lock); return ret; } @@ -2000,14 +2008,13 @@ static void *parasite_watch_thread(void *ptr) return NULL; } -static int parasite_watch(pid_t pid) +static int parasite_watch_start(pid_t pid) { int ret; - pthread_t id; - ret = pthread_create(&id, NULL, parasite_watch_thread, (void *)(unsigned long)pid); + ret = pthread_create(¶site_watch.thread_id, NULL, parasite_watch_thread, (void *)(unsigned long)pid); if (ret) - printf("[-] pthread_create() failed: %s\n", strerror(ret)); + fprintf(stderr, "[-] pthread_create() failed: %d\n", ret); return ret; } @@ -2138,7 +2145,7 @@ static int execute_parasite_checkpoint(pid_t pid) /* translate lxc ns pid to global one */ iterate_pstree(pid, 0, MAX_THREADS, update_parasite_pid); - parasite_watch(parasite_pid); + parasite_watch_start(parasite_pid); ret = cmd_checkpoint(pid); return ret; @@ -2177,13 +2184,17 @@ static void sigint_handler(int signal) fprintf(stdout, "%s() got SIGINT\n", __func__); } -static void sigchld_handler_service (int sig, siginfo_t *sip, void *notused) +static void sigchld_handler_service(int sig, siginfo_t *sip, void *notused) { int status; + int _errno; + + _errno = errno; if (sip->si_pid == waitpid(sip->si_pid, &status, WNOHANG)) { fprintf(stdout, "[+] Worker %d exit.\n", sip->si_pid); clear_pid_on_worker_exit_non_blocking(sip->si_pid); } + errno = _errno; } static void sigchld_handler_worker(int signal) @@ -2629,7 +2640,7 @@ static int service_mode(const char *listen_location) ret = pthread_create(&svc_cmd_thread_id, NULL, service_command_thread, NULL); if (ret) { - printf("[-] pthread_create() failed: %s\n", strerror(ret)); + fprintf(stderr, "[-] pthread_create() failed: %d\n", ret); goto err; } @@ -2705,7 +2716,7 @@ static int user_interactive_mode(pid_t pid) ret = pthread_create(&user_abort_thread_id, NULL, user_abort_thread, NULL); if (ret) { - printf("[-] pthread_create() failed: %s\n", strerror(ret)); + fprintf(stderr, "[-] pthread_create() failed: %d\n", ret); return ret; }