selftests/nolibc: disable coredump via setrlimit

qemu-user does has its own implementation of coredumping.
That implementation does not respect the call to
prctl(PR_SET_DUMPABLE, 0) in run_protection().
This leads to a coredump for every test run under qemu-user.

Use also setrlimit() to inhibit coredump creation which is respected by
qemu-user.

Link: https://lore.kernel.org/qemu-devel/20231115-qemu-user-dumpable-v1-2-edbe7f0fbb02@t-8ch.de/
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/20231123-nolibc-rlimit-v1-3-a428b131de2a@weissschuh.net/
Acked-by: Willy Tarreau <w@1wt.eu>

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index a0271ac313ee376503c8dae2f3de768c131460f6..6ba4f8275ac47899a1c5d622ffc81444b06e49d7 100644 (file)
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1166,6 +1166,7 @@ static int run_protection(int min __attribute__((unused)),
 {
        pid_t pid;
        int llen = 0, status;
+       struct rlimit rlimit = { 0, 0 };
 
        llen += printf("0 -fstackprotector ");
 
@@ -1197,6 +1198,7 @@ static int run_protection(int min __attribute__((unused)),
                close(STDERR_FILENO);
 
                prctl(PR_SET_DUMPABLE, 0, 0, 0, 0);
+               setrlimit(RLIMIT_CORE, &rlimit);
                smash_stack();
                return 1;