// SPDX-License-Identifier: GPL-2.0 #include <assert.h>#include <fcntl.h>#include <inttypes.h>#include <libgen.h>#include <limits.h>#include <linux/coredump.h>#include <linux/fs.h>#include <linux/limits.h>#include <pthread.h>#include <string.h>#include <sys/mount.h>#include <poll.h>#include <sys/epoll.h>#include <sys/resource.h>#include <sys/stat.h>#include <sys/socket.h>#include <sys/un.h>#include <unistd.h> #include "kselftest_harness.h"#include "../filesystems/wrappers.h"#include "../pidfd/pidfd.h" #include "coredump_test.h" #define STACKDUMP_FILE "stack_values"#define STACKDUMP_SCRIPT "stackdump" #ifndef PAGE_SIZE#define PAGE_SIZE 4096#endif FIXTURE_SETUP(coredump){	FILE *file;	int ret; 	self->pid_coredump_server = -ESRCH;	self->fd_tmpfs_detached = -1;	file = fopen("/proc/sys/kernel/core_pattern", "r");	ASSERT_NE(NULL, file); 	ret = fread(self->original_core_pattern, 1, sizeof(self->original_core_pattern), file);	ASSERT_TRUE(ret || feof(file));	ASSERT_LT(ret, sizeof(self->original_core_pattern)); 	self->original_core_pattern[ret] = '\0';	self->fd_tmpfs_detached = create_detached_tmpfs();	ASSERT_GE(self->fd_tmpfs_detached, 0); 	ret = fclose(file);	ASSERT_EQ(0, ret);} FIXTURE_TEARDOWN(coredump){	const char *reason;	FILE *file;	int ret, status; 	unlink(STACKDUMP_FILE); 	if (self->pid_coredump_server > 0) {		kill(self->pid_coredump_server, SIGTERM);		waitpid(self->pid_coredump_server, &status, 0);	}	unlink("/tmp/coredump.file");	unlink("/tmp/coredump.socket"); 	file = fopen("/proc/sys/kernel/core_pattern", "w");	if (!file) {		reason = "Unable to open core_pattern";		goto fail;	} 	ret = fprintf(file, "%s", self->original_core_pattern);	if (ret < 0) {		reason = "Unable to write to core_pattern";		goto fail;	} 	ret = fclose(file);	if (ret) {		reason = "Unable to close core_pattern";		goto fail;	} 	if (self->fd_tmpfs_detached >= 0) {		ret = close(self->fd_tmpfs_detached);		if (ret < 0) {			reason = "Unable to close detached tmpfs";			goto fail;		}		self->fd_tmpfs_detached = -1;	} 	return;fail:	/* This should never happen */	fprintf(stderr, "Failed to cleanup stackdump test: %s\n", reason);} TEST_F_TIMEOUT(coredump, stackdump, 120){	unsigned long long stack;	char *test_dir, *line;	size_t line_length;	char buf[PAGE_SIZE];	int ret, i, status;	FILE *file;	pid_t pid; 	/*	 * Step 1: Setup core_pattern so that the stackdump script is executed when the child	 * process crashes	 */	ret = readlink("/proc/self/exe", buf, sizeof(buf));	ASSERT_NE(-1, ret);	ASSERT_LT(ret, sizeof(buf));	buf[ret] = '\0'; 	test_dir = dirname(buf); 	file = fopen("/proc/sys/kernel/core_pattern", "w");	ASSERT_NE(NULL, file); 	ret = fprintf(file, "|%1$s/%2$s %%P %1$s/%3$s", test_dir, STACKDUMP_SCRIPT, STACKDUMP_FILE);	ASSERT_LT(0, ret); 	ret = fclose(file);	ASSERT_EQ(0, ret); 	/* Step 2: Create a process who spawns some threads then crashes */	pid = fork();	ASSERT_TRUE(pid >= 0);	if (pid == 0)		crashing_child(); 	/*	 * Step 3: Wait for the stackdump script to write the stack pointers to the stackdump file	 */	waitpid(pid, &status, 0);	ASSERT_TRUE(WIFSIGNALED(status));	ASSERT_TRUE(WCOREDUMP(status)); 	for (i = 0; i < 10; ++i) {		file = fopen(STACKDUMP_FILE, "r");		if (file)			break;		sleep(1);	}	ASSERT_NE(file, NULL); 	/* Step 4: Make sure all stack pointer values are non-zero */	line = NULL;	for (i = 0; -1 != getline(&line, &line_length, file); ++i) {		stack = strtoull(line, NULL, 10);		ASSERT_NE(stack, 0);	}	free(line); 	ASSERT_EQ(i, 1 + NUM_THREAD_SPAWN); 	fclose(file);} TEST_HARNESS_MAIN