[LTP] [PATCH v2] syscalls/getrandom05: add test variants

[Jan Stancek]

And skip EFAULT for glibc as it can segfault in VDSO:
  #0  __arch_chacha20_blocks_nostack () at arch/x86/entry/vdso/vgetrandom-chacha.S:146
  146             movups          state0,0x00(output)

  (gdb) bt
  #0  __arch_chacha20_blocks_nostack () at arch/x86/entry/vdso/vgetrandom-chacha.S:146
  #1  0x00007fcd3ce6417a in __cvdso_getrandom_data (rng_info=0x7fcd3ce5f280, buffer=0xffffffffffffffff, len=64, flags=1, opaque_state=0x7fcd3ce5df00,
      opaque_len=<optimized out>) at arch/x86/entry/vdso/../../../../lib/vdso/getrandom.c:237
  #2  __cvdso_getrandom (buffer=<optimized out>, len=64, flags=1, opaque_state=0x7fcd3ce5df00, opaque_len=<optimized out>)
      at arch/x86/entry/vdso/../../../../lib/vdso/getrandom.c:259
  #3  __vdso_getrandom (buffer=0xffffffffffffffff, len=64, flags=1, opaque_state=0x7fcd3ce5df00, opaque_len=<optimized out>)
      at arch/x86/entry/vdso/vgetrandom.c:11
  #4  0x00007fcd3cc7faf3 in getrandom_vdso (buffer=0xffffffffffffffff, length=64, flags=0, cancel=<optimized out>)
      at ../sysdeps/unix/sysv/linux/getrandom.c:204
  #5  0x0000000000401ff7 in verify_getrandom (i=0) at getrandom05.c:40

Signed-off-by: Jan Stancek <jstancek@redhat.com>
---
 .../kernel/syscalls/getrandom/getrandom05.c   | 16 +++++++-
 .../kernel/syscalls/getrandom/getrandom_var.h | 41 +++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 testcases/kernel/syscalls/getrandom/getrandom_var.h

diff --git a/testcases/kernel/syscalls/getrandom/getrandom05.c b/testcases/kernel/syscalls/getrandom/getrandom05.c
index 92098deb723d..c4886b886f80 100644
--- a/testcases/kernel/syscalls/getrandom/getrandom05.c
+++ b/testcases/kernel/syscalls/getrandom/getrandom05.c
@@ -16,6 +16,7 @@
 
 #include "tst_test.h"
 #include "lapi/getrandom.h"
+#include "getrandom_var.h"
 
 static char buff_efault[64];
 static char buff_einval[64];
@@ -32,15 +33,28 @@ static struct test_case_t {
 	{buff_einval, sizeof(buff_einval), -1, EINVAL, "flag is invalid"},
 };
 
+static void setup(void)
+{
+	getrandom_info();
+}
+
 static void verify_getrandom(unsigned int i)
 {
 	struct test_case_t *tc = &tcases[i];
 
-	TST_EXP_FAIL2(getrandom(tc->buff, tc->size, tc->flag),
+	/* EFAULT test can segfault on recent glibc, skip it */
+	if (tst_variant == 1 && tc->expected_errno == EFAULT) {
+		tst_res(TCONF, "Skipping EFAULT test for libc getrandom()");
+		return;
+	}
+
+	TST_EXP_FAIL2(do_getrandom(tc->buff, tc->size, tc->flag),
 		tc->expected_errno, "%s", tc->desc);
 }
 
 static struct tst_test test = {
 	.tcnt = ARRAY_SIZE(tcases),
 	.test = verify_getrandom,
+	.test_variants = TEST_VARIANTS,
+	.setup = setup,
 };
diff --git a/testcases/kernel/syscalls/getrandom/getrandom_var.h b/testcases/kernel/syscalls/getrandom/getrandom_var.h
new file mode 100644
index 000000000000..b19b0ebc0120
--- /dev/null
+++ b/testcases/kernel/syscalls/getrandom/getrandom_var.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2024 Jan Stancek <jstancek@redhat.com>
+ */
+
+#ifndef GETRANDOM_VAR__
+#define GETRANDOM_VAR__
+
+#include "lapi/syscalls.h"
+
+static inline int do_getrandom(void *buf, size_t buflen, unsigned int flags)
+{
+	switch (tst_variant) {
+	case 0:
+		return tst_syscall(__NR_getrandom, buf, buflen, flags);
+	case 1:
+		return getrandom(buf, buflen, flags);
+	}
+	return -1;
+}
+
+static void getrandom_info(void)
+{
+	switch (tst_variant) {
+	case 0:
+		tst_res(TINFO, "Testing SYS_getrandom syscall");
+		break;
+	case 1:
+		tst_res(TINFO, "Testing libc getrandom()");
+		break;
+	}
+}
+
+/* if we don't have libc getrandom() test only syscall version */
+#ifdef HAVE_SYS_RANDOM_H
+# define TEST_VARIANTS 2
+#else
+# define TEST_VARIANTS 1
+#endif
+
+#endif /* GETRANDOM_VAR__ */
-- 
2.43.0