4 files changed, 84 insertions, 3 deletions
diff --git a/tools/testing/selftests/exec/.gitignore b/tools/testing/selftests/exec/.gitignore
index 9e2f00343f15..90c238ba6a4b 100644
--- a/tools/testing/selftests/exec/.gitignore
+++ b/tools/testing/selftests/exec/.gitignore
@@ -7,6 +7,8 @@ execveat.moved
 execveat.path.ephemeral
 execveat.ephemeral
 execveat.denatured
+non-regular
+null-argv
 /load_address_*
 /recursion-depth
 xxxxxxxx*
diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile
index dd61118df66e..a0b8688b0836 100644
--- a/tools/testing/selftests/exec/Makefile
+++ b/tools/testing/selftests/exec/Makefile
@@ -3,13 +3,14 @@ CFLAGS = -Wall
 CFLAGS += -Wno-nonnull
 CFLAGS += -D_GNU_SOURCE
 
-TEST_PROGS := binfmt_script non-regular
-TEST_GEN_PROGS := execveat load_address_4096 load_address_2097152 load_address_16777216
-TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir pipe
+TEST_PROGS := binfmt_script.py
+TEST_GEN_PROGS := execveat load_address_4096 load_address_2097152 load_address_16777216 non-regular
+TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir
 # Makefile is a run-time dependency, since it's accessed by the execveat test
 TEST_FILES := Makefile
 
 TEST_GEN_PROGS += recursion-depth
+TEST_GEN_PROGS += null-argv
 
 EXTRA_CLEAN := $(OUTPUT)/subdir.moved $(OUTPUT)/execveat.moved $(OUTPUT)/xxxxx*	\
 	       $(OUTPUT)/S_I*.test
diff --git a/tools/testing/selftests/exec/binfmt_script b/tools/testing/selftests/exec/binfmt_script.py
index 05f94a741c7a..05f94a741c7a 100755
--- a/tools/testing/selftests/exec/binfmt_script
+++ b/tools/testing/selftests/exec/binfmt_script.py
diff --git a/tools/testing/selftests/exec/null-argv.c b/tools/testing/selftests/exec/null-argv.c
new file mode 100644
index 000000000000..c19726e710d1
--- /dev/null
+++ b/tools/testing/selftests/exec/null-argv.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Test that empty argvs are swapped out for a single empty string. */
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "../kselftest.h"
+
+#define FORK(exec)				\
+do {						\
+	pid = fork();				\
+	if (pid == 0) {				\
+		/* Child */			\
+		exec; /* Some kind of exec */	\
+		perror("# " #exec);		\
+		return 1;			\
+	}					\
+	check_result(pid, #exec);		\
+} while (0)
+
+void check_result(pid_t pid, const char *msg)
+{
+	int wstatus;
+
+	if (pid == (pid_t)-1) {
+		perror("# fork");
+		ksft_test_result_fail("fork failed: %s\n", msg);
+		return;
+	}
+	if (waitpid(pid, &wstatus, 0) < 0) {
+		perror("# waitpid");
+		ksft_test_result_fail("waitpid failed: %s\n", msg);
+		return;
+	}
+	if (!WIFEXITED(wstatus)) {
+		ksft_test_result_fail("child did not exit: %s\n", msg);
+		return;
+	}
+	if (WEXITSTATUS(wstatus) != 0) {
+		ksft_test_result_fail("non-zero exit: %s\n", msg);
+		return;
+	}
+	ksft_test_result_pass("%s\n", msg);
+}
+
+int main(int argc, char *argv[], char *envp[])
+{
+	pid_t pid;
+	static char * const args[] = { NULL };
+	static char * const str[] = { "", NULL };
+
+	/* argc counting checks */
+	if (argc < 1) {
+		fprintf(stderr, "# FAIL: saw argc == 0 (old kernel?)\n");
+		return 1;
+	}
+	if (argc != 1) {
+		fprintf(stderr, "# FAIL: unknown argc (%d)\n", argc);
+		return 1;
+	}
+	if (argv[0][0] == '\0') {
+		/* Good, we found a NULL terminated string at argv[0]! */
+		return 0;
+	}
+
+	/* Test runner. */
+	ksft_print_header();
+	ksft_set_plan(5);
+
+	FORK(execve(argv[0], str, NULL));
+	FORK(execve(argv[0], NULL, NULL));
+	FORK(execve(argv[0], NULL, envp));
+	FORK(execve(argv[0], args, NULL));
+	FORK(execve(argv[0], args, envp));
+
+	ksft_exit(ksft_cnt.ksft_pass == ksft_plan);
+}