Small optimization to avoid coredump writing during the stack protector tests. Adds prctl() as prerequisite.
This series is based on nolibc/20230524-nolibc-rv32+stkp4
Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- Changes in v2: - Fix compilation warning in prctl() testcase - Link to v1: https://lore.kernel.org/r/20230526-nolibc-test-no-dump-v1-0-62e724a96db2@wei...
--- Thomas Weißschuh (2): tools/nolibc: add support for prctl() selftests/nolibc: prevent coredumps during test execution
tools/include/nolibc/sys.h | 27 +++++++++++++++++++++++++++ tools/testing/selftests/nolibc/nolibc-test.c | 3 +++ 2 files changed, 30 insertions(+) --- base-commit: 1974a2b5fd434812b32952b09df7b79fdee8104d change-id: 20230526-nolibc-test-no-dump-a1b1d9557df8
Best regards,
It will be used to disable core dumps from the child spawned to validate the stack protector functionality.
Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- tools/include/nolibc/sys.h | 27 +++++++++++++++++++++++++++ tools/testing/selftests/nolibc/nolibc-test.c | 2 ++ 2 files changed, 29 insertions(+)
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index 7874062bea95..3d521feffad6 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -22,6 +22,7 @@ #include <linux/fcntl.h> /* for O_* and AT_* */ #include <linux/stat.h> /* for statx() */ #include <linux/reboot.h> /* for LINUX_REBOOT_* */ +#include <linux/prctl.h>
#include "arch.h" #include "errno.h" @@ -894,6 +895,32 @@ int open(const char *path, int flags, ...) }
+/* + * int prctl(int option, unsigned long arg2, unsigned long arg3, + * unsigned long arg4, unsigned long arg5); + */ + +static __attribute__((unused)) +int sys_prctl(int option, unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5) +{ + return my_syscall5(__NR_prctl, option, arg2, arg3, arg4, arg5); +} + +static __attribute__((unused)) +int prctl(int option, unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5) +{ + int ret = sys_prctl(option, arg2, arg3, arg4, arg5); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + + /* * int pivot_root(const char *new, const char *old); */ diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 6e0a4dbe321e..95ff2867a91d 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -22,6 +22,7 @@ #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/mount.h> +#include <sys/prctl.h> #include <sys/reboot.h> #include <sys/stat.h> #include <sys/syscall.h> @@ -580,6 +581,7 @@ int run_syscall(int min, int max) CASE_TEST(poll_null); EXPECT_SYSZR(1, poll(NULL, 0, 0)); break; CASE_TEST(poll_stdout); EXPECT_SYSNE(1, ({ struct pollfd fds = { 1, POLLOUT, 0}; poll(&fds, 1, 0); }), -1); break; CASE_TEST(poll_fault); EXPECT_SYSER(1, poll((void *)1, 1, 0), -1, EFAULT); break; + CASE_TEST(prctl); EXPECT_SYSER(1, prctl(PR_SET_NAME, (unsigned long)NULL, 0, 0, 0), -1, EFAULT); break; CASE_TEST(read_badf); EXPECT_SYSER(1, read(-1, &tmp, 1), -1, EBADF); break; CASE_TEST(sched_yield); EXPECT_SYSZR(1, sched_yield()); break; CASE_TEST(select_null); EXPECT_SYSZR(1, ({ struct timeval tv = { 0 }; select(0, NULL, NULL, NULL, &tv); })); break;
The child process forked during stackprotector tests intentionally gets killed with SIGABRT. By default this will trigger writing a coredump. The writing of the coredump can spam the systems coredump machinery and take some time.
Timings for the full run of nolibc-test: Before: 200ms After: 20ms
This is on a desktop x86 system with systemd-coredumpd enabled.
Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- tools/testing/selftests/nolibc/nolibc-test.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 95ff2867a91d..3296e8567fa5 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -831,6 +831,7 @@ static int run_protection(int min, int max) close(STDOUT_FILENO); close(STDERR_FILENO);
+ prctl(PR_SET_DUMPABLE, 0, 0, 0, 0); smash_stack(); return 1;
On Fri, May 26, 2023 at 09:51:18AM +0200, Thomas Weißschuh wrote:
Small optimization to avoid coredump writing during the stack protector tests. Adds prctl() as prerequisite.
This series is based on nolibc/20230524-nolibc-rv32+stkp4
Signed-off-by: Thomas Weißschuh linux@weissschuh.net
Changes in v2:
- Fix compilation warning in prctl() testcase
- Link to v1: https://lore.kernel.org/r/20230526-nolibc-test-no-dump-v1-0-62e724a96db2@wei...
I just noticed the warning as well when testing the whole branch, applied this one instead.
thanks, Willy
linux-kselftest-mirror@lists.linaro.org
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Thomas Weißschuh -
Willy Tarreau