[PATCH 6/8] tools/nolibc: tests: add test for -fstack-protector

Willy Tarreau
2023-03-25T15:46:00Z

From: Thomas Weißschuh <linux@weissschuh.net>

Test the previously introduce stack protector functionality in nolibc.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
tools/testing/selftests/nolibc/Makefile | 3 +
tools/testing/selftests/nolibc/nolibc-test.c | 62 +++++++++++++++++++-
2 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 4469dcb0c9d7..e516e53775d4 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -76,6 +76,9 @@ else
Q=@
endif

+CFLAGS_STACKPROTECTOR = -DNOLIBC_STACKPROTECTOR \
+ $(call cc-option,-mstack-protector-guard=global) \
+ $(call cc-option,-fstack-protector-all)
CFLAGS_s390 = -m64
CFLAGS ?= -Os -fno-ident -fno-asynchronous-unwind-tables \
$(call cc-option,-fno-stack-protector) \
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index fb2d4872fac9..21bacc928bf7 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -667,6 +667,63 @@ int run_stdlib(int min, int max)
return ret;
}

+#if defined(__clang__)
+__attribute__((optnone))
+#elif defined(__GNUC__)
+__attribute__((optimize("O0")))
+#endif
+static int smash_stack(void)
+{
+ char buf[100];
+
+ for (size_t i = 0; i < 200; i++)
+ buf[i] = 'P';
+
+ return 1;
+}
+
+static int run_protection(int min, int max)
+{
+ pid_t pid;
+ int llen = 0, status;
+
+ llen += printf("0 -fstackprotector ");
+
+#if !defined(NOLIBC_STACKPROTECTOR)
+ llen += printf("not supported");
+ pad_spc(llen, 64, "[SKIPPED]\n");
+ return 0;
+#endif
+
+ pid = -1;
+ pid = fork();
+
+ switch (pid) {
+ case -1:
+ llen += printf("fork()");
+ pad_spc(llen, 64, "[FAIL]\n");
+ return 1;
+
+ case 0:
+ close(STDOUT_FILENO);
+ close(STDERR_FILENO);
+
+ smash_stack();
+ return 1;
+
+ default:
+ pid = waitpid(pid, &status, 0);
+
+ if (pid == -1 || !WIFSIGNALED(status) || WTERMSIG(status) != SIGABRT) {
+ llen += printf("waitpid()");
+ pad_spc(llen, 64, "[FAIL]\n");
+ return 1;
+ }
+ pad_spc(llen, 64, " [OK]\n");
+ return 0;
+ }
+}
+
/* prepare what needs to be prepared for pid 1 (stdio, /dev, /proc, etc) */
int prepare(void)
{
@@ -719,8 +776,9 @@ int prepare(void)
/* This is the definition of known test names, with their functions */
static const struct test test_names[] = {
/* add new tests here */
- { .name = "syscall", .func = run_syscall },
- { .name = "stdlib", .func = run_stdlib },
+ { .name = "syscall", .func = run_syscall },
+ { .name = "stdlib", .func = run_stdlib },
+ { .name = "protection", .func = run_protection },
{ 0 }
};

--
2.17.5