[PATCH v6 2/5] selftests/mm: unify pkey sighandler selftest assertions and tracing

[Hongfu Li]

Add per-test tracing to the pkey signal-handler selftest and use
pkey_assert() for error handling. Each test enables tracing at start
and disables it at end; on failure, pkey_assert() calls abort_hooks()
to turn tracing off so ftrace is not left enabled.

Signed-off-by: Hongfu Li <lihongfu@xxxxxxxxxx>
---
 .../selftests/mm/pkey_sighandler_tests.c      | 69 ++++++++++---------
 1 file changed, 36 insertions(+), 33 deletions(-)

diff --git a/tools/testing/selftests/mm/pkey_sighandler_tests.c b/tools/testing/selftests/mm/pkey_sighandler_tests.c
index 302fef54049c..085e771227fb 100644
--- a/tools/testing/selftests/mm/pkey_sighandler_tests.c
+++ b/tools/testing/selftests/mm/pkey_sighandler_tests.c
@@ -19,7 +19,6 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <signal.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <sys/mman.h>
 #include <sys/types.h>
@@ -36,6 +35,10 @@ static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
 static siginfo_t siginfo = {0};
 
+int iteration_nr = 1;
+int test_nr;
+int dprint_in_signal;
+
 /*
  * We need to use inline assembly instead of glibc's syscall because glibc's
  * syscall will attempt to access the PLT in order to call a library function
@@ -207,15 +210,14 @@ static void test_sigsegv_handler_with_pkey0_disabled(void)
 	struct sigaction sa;
 	pthread_attr_t attr;
 	pthread_t thr;
+	int ret;
 
 	sa.sa_flags = SA_SIGINFO;
 
 	sa.sa_sigaction = sigsegv_handler;
 	sigemptyset(&sa.sa_mask);
-	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
-		perror("sigaction");
-		exit(EXIT_FAILURE);
-	}
+	ret = sigaction(SIGSEGV, &sa, NULL);
+	pkey_assert(ret == 0);
 
 	memset(&siginfo, 0, sizeof(siginfo));
 
@@ -247,15 +249,14 @@ static void test_sigsegv_handler_cannot_access_stack(void)
 	struct sigaction sa;
 	pthread_attr_t attr;
 	pthread_t thr;
+	int ret;
 
 	sa.sa_flags = SA_SIGINFO;
 
 	sa.sa_sigaction = sigsegv_handler;
 	sigemptyset(&sa.sa_mask);
-	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
-		perror("sigaction");
-		exit(EXIT_FAILURE);
-	}
+	ret = sigaction(SIGSEGV, &sa, NULL);
+	pkey_assert(ret == 0);
 
 	memset(&siginfo, 0, sizeof(siginfo));
 
@@ -288,21 +289,20 @@ static void test_sigsegv_handler_with_different_pkey_for_stack(void)
 	int parent_pid = 0;
 	int child_pid = 0;
 	u64 pkey_reg;
+	long ret;
 
 	sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
 
 	sa.sa_sigaction = sigsegv_handler;
 
 	sigemptyset(&sa.sa_mask);
-	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
-		perror("sigaction");
-		exit(EXIT_FAILURE);
-	}
+	ret = sigaction(SIGSEGV, &sa, NULL);
+	pkey_assert(ret == 0);
 
 	stack = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
-	assert(stack != MAP_FAILED);
+	pkey_assert(stack != MAP_FAILED);
 
 	/* Allow access to MPK 0 and MPK 1 */
 	pkey_reg = pkey_reg_restrictive_default();
@@ -323,7 +323,7 @@ static void test_sigsegv_handler_with_different_pkey_for_stack(void)
 	memset(&siginfo, 0, sizeof(siginfo));
 
 	/* Use clone to avoid newer glibcs using rseq on new threads */
-	long ret = clone_raw(CLONE_VM | CLONE_FS | CLONE_FILES |
+	ret = clone_raw(CLONE_VM | CLONE_FS | CLONE_FILES |
 			     CLONE_SIGHAND | CLONE_THREAD | CLONE_SYSVSEM |
 			     CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID |
 			     CLONE_DETACHED,
@@ -358,6 +358,7 @@ static void test_pkru_preserved_after_sigusr1(void)
 {
 	struct sigaction sa;
 	u64 pkey_reg;
+	int ret;
 
 	/* Allow access to MPK 0 and an arbitrary set of keys */
 	pkey_reg = pkey_reg_restrictive_default();
@@ -369,10 +370,8 @@ static void test_pkru_preserved_after_sigusr1(void)
 
 	sa.sa_sigaction = sigusr1_handler;
 	sigemptyset(&sa.sa_mask);
-	if (sigaction(SIGUSR1, &sa, NULL) == -1) {
-		perror("sigaction");
-		exit(EXIT_FAILURE);
-	}
+	ret = sigaction(SIGUSR1, &sa, NULL);
+	pkey_assert(ret == 0);
 
 	memset(&siginfo, 0, sizeof(siginfo));
 
@@ -444,6 +443,13 @@ static void test_pkru_sigreturn(void)
 	int parent_pid = 0;
 	int child_pid = 0;
 	u64 pkey_reg;
+	long ret;
+
+	/*
+	 * SIGSEGV handler is reset to SIG_DFL below; turn tracing off first
+	 * so a crash does not leave ftrace enabled.
+	 */
+	tracing_off();
 
 	sa.sa_handler = SIG_DFL;
 	sa.sa_flags = 0;
@@ -453,24 +459,20 @@ static void test_pkru_sigreturn(void)
 	 * For this testcase, we do not want to handle SIGSEGV. Reset handler
 	 * to default so that the application can crash if it receives SIGSEGV.
 	 */
-	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
-		perror("sigaction");
-		exit(EXIT_FAILURE);
-	}
+	ret = sigaction(SIGSEGV, &sa, NULL);
+	pkey_assert(ret == 0);
 
 	sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
 	sa.sa_sigaction = sigusr2_handler;
 	sigemptyset(&sa.sa_mask);
 
-	if (sigaction(SIGUSR2, &sa, NULL) == -1) {
-		perror("sigaction");
-		exit(EXIT_FAILURE);
-	}
+	ret = sigaction(SIGUSR2, &sa, NULL);
+	pkey_assert(ret == 0);
 
 	stack = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
-	assert(stack != MAP_FAILED);
+	pkey_assert(stack != MAP_FAILED);
 
 	/*
 	 * Allow access to MPK 0 and MPK 2. The child thread (to be created
@@ -494,7 +496,7 @@ static void test_pkru_sigreturn(void)
 	sigstack.ss_size = STACK_SIZE;
 
 	/* Use clone to avoid newer glibcs using rseq on new threads */
-	long ret = clone_raw(CLONE_VM | CLONE_FS | CLONE_FILES |
+	ret = clone_raw(CLONE_VM | CLONE_FS | CLONE_FILES |
 			     CLONE_SIGHAND | CLONE_THREAD | CLONE_SYSVSEM |
 			     CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID |
 			     CLONE_DETACHED,
@@ -530,16 +532,17 @@ static void (*pkey_tests[])(void) = {
 
 int main(int argc, char *argv[])
 {
-	int i;
-
 	ksft_print_header();
 	ksft_set_plan(ARRAY_SIZE(pkey_tests));
 
 	if (!is_pkeys_supported())
 		ksft_exit_skip("pkeys not supported\n");
 
-	for (i = 0; i < ARRAY_SIZE(pkey_tests); i++)
-		(*pkey_tests[i])();
+	for (test_nr = 0; test_nr < ARRAY_SIZE(pkey_tests); test_nr++) {
+		tracing_on();
+		(*pkey_tests[test_nr])();
+		tracing_off();
+	}
 
 	ksft_finished();
 	return 0;
-- 
2.25.1