Dependency: [PATCH] kernel/signal: Signal-based pre-coredump notification Signed-off-by: Enke Chen <enkechen@xxxxxxxxx> --- tools/testing/selftests/prctl/Makefile | 2 +- tools/testing/selftests/prctl/predump-sig-test.c | 160 +++++++++++++++++++++++ 2 files changed, 161 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/prctl/predump-sig-test.c diff --git a/tools/testing/selftests/prctl/Makefile b/tools/testing/selftests/prctl/Makefile index c7923b2..f8d60d5 100644 --- a/tools/testing/selftests/prctl/Makefile +++ b/tools/testing/selftests/prctl/Makefile @@ -5,7 +5,7 @@ ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/) ifeq ($(ARCH),x86) TEST_PROGS := disable-tsc-ctxt-sw-stress-test disable-tsc-on-off-stress-test \ - disable-tsc-test + disable-tsc-test predump-sig-test all: $(TEST_PROGS) include ../lib.mk diff --git a/tools/testing/selftests/prctl/predump-sig-test.c b/tools/testing/selftests/prctl/predump-sig-test.c new file mode 100644 index 0000000..15d62691 --- /dev/null +++ b/tools/testing/selftests/prctl/predump-sig-test.c @@ -0,0 +1,160 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018, Enke Chen, Cisco Systems, Inc. + * + * Tests for prctl(PR_SET_PREDUMP_SIG, ...) / prctl(PR_GET_PREDUMP_SIG, ...) + * + * When set with prctl(), the specified signal is sent to the parent process + * prior to the coredump of a child process. + * + * Usage: ./predump-sig-test {SIGUSR1 | SIGRT2} + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/wait.h> +#include <sys/prctl.h> +#include <signal.h> +#include <errno.h> + +#ifndef PR_SET_PREDUMP_SIG +#define PR_SET_PREDUMP_SIG 54 +#define PR_GET_PREDUMP_SIG 55 +#endif + +#define SIGRT2 (SIGRTMIN + 1) + +#define handle_error(msg) \ + do { perror(msg); exit(EXIT_FAILURE); } while (0) + +static sig_idx; +static siginfo_t siginfo_rcv[2]; + +static void sigaction_func(int sig, siginfo_t *siginfo, void *arg) +{ + memcpy(&siginfo_rcv[sig_idx], siginfo, sizeof(siginfo_t)); + sig_idx++; +} + +static int set_sigaction(int sig) +{ + struct sigaction new_action; + int rc; + + memset(&new_action, 0, sizeof(struct sigaction)); + new_action.sa_sigaction = sigaction_func; + new_action.sa_flags = SA_SIGINFO; + sigemptyset(&new_action.sa_mask); + + return sigaction(sig, &new_action, NULL); +} + +static int test_prctl(int sig) +{ + int sig2, rc; + + rc = prctl(PR_SET_PREDUMP_SIG, sig, 0, 0, 0); + if (rc < 0) + handle_error("prctl: setting"); + + rc = prctl(PR_GET_PREDUMP_SIG, &sig2, 0, 0, 0); + if (rc < 0) + handle_error("prctl: getting"); + + if (sig2 != sig) { + printf("prctl: sig %d, post %d\n", sig, sig2); + return -1; + } + return 0; +} + +static void child_fn(void) +{ + int rc, sig; + + printf("\nChild pid: %ld\n", (long)getpid()); + + /* Test: Child should not inherit the predump_signal */ + rc = prctl(PR_GET_PREDUMP_SIG, &sig, 0, 0, 0); + if (rc < 0) + handle_error("prctl: child"); + + printf("child: predump_signal %d\n", sig); + + /* Force coredump here */ + printf("child: calling abort()\n"); + fflush(stdout); + abort(); +} + +static int parent_fn(pid_t child_pid) +{ + int i, status, count; + siginfo_t *si; + pid_t w; + + for (count = 0; count < 2; count++) { + w = waitpid(child_pid, &status, 0); + printf("\nwaitpid: %d\n", w); + if (w < 0) + perror("waitpid"); + + si = &siginfo_rcv[count]; + printf("signal: si_signo %d, si_pid %ld, si_uid %d\n", + si->si_signo, si->si_pid, si->si_uid); + printf("siginfo: si_errno %d, si_code %d, si_status %d\n", + si->si_errno, si->si_code, si->si_status); + } + fflush(stdout); +} + +int main(int argc, char *argv[]) +{ + pid_t child_pid; + int rc, signo; + + if (argc != 2) { + printf("invalid number of arguments\n"); + exit(EXIT_FAILURE); + } + + if (strcmp(argv[1], "SIGUSR1") == 0) + signo = SIGUSR1; + else if (strcmp(argv[1], "SIGRT2") == 0) + signo = SIGRT2; + else { + printf("invalid argument for signal\n"); + fflush(stdout); + exit(EXIT_FAILURE); + } + + rc = set_sigaction(SIGCHLD); + if (rc < 0) + handle_error("set_sigaction: SIGCHLD"); + + if (signo != SIGCHLD) { + rc = set_sigaction(signo); + if (rc < 0) + handle_error("set_sigaction: SIGCHLD"); + } + + /* Test: prctl() setting */ + rc = test_prctl(0); + printf("prctl: sig %d %s\n", 0, (rc == 0) ? "PASS" : "FAIL"); + + rc = test_prctl(signo); + printf("prctl: sig %d %s\n", signo, (rc == 0) ? "PASS" : "FAIL"); + + child_pid = fork(); + if (child_pid == -1) + handle_error("fork"); + + if (child_pid == 0) { /* Code executed by child */ + child_fn(); + } else { /* Code executed by parent */ + parent_fn(child_pid); + exit(EXIT_SUCCESS); + } +} -- 1.8.3.1