seccomp: test -- Add seccomp_filter_threads

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

test/zdtm/static/Makefile

@@ -182,6 +182,7 @@ TST_NOFILE	:=				\
 		seccomp_strict			\
 		seccomp_filter			\
 		seccomp_filter_tsync			\
+		seccomp_filter_threads			\
 		seccomp_filter_inheritance		\
 		different_creds			\
 		vsx				\
@@ -458,6 +459,7 @@ different_creds:	LDLIBS += -pthread
 sigpending:		LDLIBS += -pthread
 sigaltstack:		LDLIBS += -pthread
 seccomp_filter_tsync:	LDLIBS += -pthread
+seccomp_filter_threads:	LDLIBS += -pthread
 shm:			CFLAGS += -DNEW_IPC_NS
 msgque:			CFLAGS += -DNEW_IPC_NS
 sem:			CFLAGS += -DNEW_IPC_NS

test/zdtm/static/seccomp_filter_threads.c

+#include <unistd.h>
+#include <stdbool.h>
+#include <signal.h>
+#include <stddef.h>
+#include <sys/prctl.h>
+#include <sys/ptrace.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/syscall.h>
+
+#ifdef __NR_seccomp
+# include <linux/seccomp.h>
+# include <linux/filter.h>
+# include <linux/limits.h>
+# include <pthread.h>
+#endif
+
+#include "zdtmtst.h"
+
+#ifndef SECCOMP_SET_MODE_FILTER
+#define SECCOMP_SET_MODE_FILTER 1
+#endif
+
+#ifndef SECCOMP_FILTER_FLAG_TSYNC
+#define SECCOMP_FILTER_FLAG_TSYNC 1
+#endif
+
+const char *test_doc	= "Check threads to carry different seccomps";
+const char *test_author	= "Cyrill Gorcunov <gorcunov@openvz.org>";
+
+#ifdef __NR_seccomp
+
+static task_waiter_t tw;
+
+int get_seccomp_mode(pid_t pid)
+{
+	FILE *f;
+	char buf[PATH_MAX];
+
+	sprintf(buf, "/proc/%d/status", pid);
+	f = fopen(buf, "r+");
+	if (!f) {
+		pr_perror("fopen failed");
+		return -1;
+	}
+
+	while (NULL != fgets(buf, sizeof(buf), f)) {
+		int mode;
+
+		if (sscanf(buf, "Seccomp:\t%d", &mode) != 1)
+			continue;
+
+		fclose(f);
+		return mode;
+	}
+	fclose(f);
+
+	return -1;
+}
+
+int filter_syscall(int syscall_nr, unsigned int flags)
+{
+	struct sock_filter filter[] = {
+		BPF_STMT(BPF_LD+BPF_W+BPF_ABS, offsetof(struct seccomp_data, nr)),
+		BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, syscall_nr, 0, 1),
+		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_KILL),
+		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
+	};
+
+	struct sock_fprog bpf_prog = {
+		.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
+		.filter = filter,
+	};
+
+	if (syscall(__NR_seccomp, SECCOMP_SET_MODE_FILTER, flags, &bpf_prog) < 0) {
+		pr_perror("seccomp failed");
+		return -1;
+	}
+
+	return 0;
+}
+
+void *thread_main(void *arg)
+{
+	if (filter_syscall(__NR_ptrace, 0) < 0)
+		pthread_exit((void *)1);
+
+	test_msg("__NR_ptrace filtered inside a sole thread\n");
+
+	task_waiter_complete(&tw, 1);
+	task_waiter_wait4(&tw, 2);
+
+	ptrace(PTRACE_TRACEME);
+	pthread_exit((void *)1);
+}
+
+int main(int argc, char ** argv)
+{
+	int ret, mode, status;
+	pid_t pid;
+
+	test_init(argc, argv);
+	task_waiter_init(&tw);
+
+	pid = fork();
+	if (pid < 0) {
+		pr_perror("fork");
+		return -1;
+	}
+
+	if (pid == 0) {
+		pthread_t thread;
+		void *p = NULL;
+
+		zdtm_seccomp = 1;
+
+		pthread_create(&thread, NULL, thread_main, NULL);
+		if (pthread_join(thread, &p) != 0) {
+			pr_perror("pthread_join");
+			exit(1);
+		}
+
+		syscall(__NR_exit, p);
+	}
+
+	task_waiter_wait4(&tw, 1);
+
+	test_daemon();
+	test_waitsig();
+
+	task_waiter_complete(&tw, 2);
+	mode = get_seccomp_mode(pid);
+
+	if (mode != SECCOMP_MODE_DISABLED) {
+		fail("seccomp mode mismatch %d\n", mode);
+		return 1;
+	}
+
+	ret = waitpid(pid, &status, 0);
+	if (ret != pid) {
+		fail("waitpid: %d != %d", ret, pid);
+		exit(1);
+	}
+
+	if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+		fail("expected 0 exit, got %d\n", WEXITSTATUS(status));
+		exit(1);
+	}
+
+	pass();
+	return 0;
+}
+
+#else /* __NR_seccomp */
+
+#define TEST_SKIP_REASON "incompatible kernel (no seccomp)"
+#include "skip-me.c"
+
+#endif /* __NR_seccomp */

test/zdtm/static/seccomp_filter_threads.desc

+{'flags': 'suid', 'feature': 'seccomp_filters'}