[PATCH AUTOSEL 6.9 07/11] selftest/timerns: fix clang build failures for abs() calls

[PATCH AUTOSEL 6.9 07/11] selftest/timerns: fix clang build failures for abs() calls

[Sasha Levin]

From: John Hubbard <jhubbard@nvidia.com>

[ Upstream commit f76f9bc616b7320df6789241ca7d26cedcf03cf3 ]

When building with clang, via:

    make LLVM=1 -C tools/testing/selftests

...clang warns about mismatches between the expected and required
integer length being supplied to abs(3).

Fix this by using the correct variant of abs(3): labs(3) or llabs(3), in
these cases.

Reviewed-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Andrei Vagin <avagin@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/timens/exec.c       | 6 +++---
 tools/testing/selftests/timens/timer.c      | 2 +-
 tools/testing/selftests/timens/timerfd.c    | 2 +-
 tools/testing/selftests/timens/vfork_exec.c | 4 ++--
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/timens/exec.c b/tools/testing/selftests/timens/exec.c
index e40dc5be2f668..d12ff955de0d8 100644
--- a/tools/testing/selftests/timens/exec.c
+++ b/tools/testing/selftests/timens/exec.c
@@ -30,7 +30,7 @@ int main(int argc, char *argv[])
 
 		for (i = 0; i < 2; i++) {
 			_gettime(CLOCK_MONOTONIC, &tst, i);
-			if (abs(tst.tv_sec - now.tv_sec) > 5)
+			if (labs(tst.tv_sec - now.tv_sec) > 5)
 				return pr_fail("%ld %ld\n", now.tv_sec, tst.tv_sec);
 		}
 		return 0;
@@ -50,7 +50,7 @@ int main(int argc, char *argv[])
 
 	for (i = 0; i < 2; i++) {
 		_gettime(CLOCK_MONOTONIC, &tst, i);
-		if (abs(tst.tv_sec - now.tv_sec) > 5)
+		if (labs(tst.tv_sec - now.tv_sec) > 5)
 			return pr_fail("%ld %ld\n",
 					now.tv_sec, tst.tv_sec);
 	}
@@ -70,7 +70,7 @@ int main(int argc, char *argv[])
 		/* Check that a child process is in the new timens. */
 		for (i = 0; i < 2; i++) {
 			_gettime(CLOCK_MONOTONIC, &tst, i);
-			if (abs(tst.tv_sec - now.tv_sec - OFFSET) > 5)
+			if (labs(tst.tv_sec - now.tv_sec - OFFSET) > 5)
 				return pr_fail("%ld %ld\n",
 						now.tv_sec + OFFSET, tst.tv_sec);
 		}
diff --git a/tools/testing/selftests/timens/timer.c b/tools/testing/selftests/timens/timer.c
index 5e7f0051bd7be..5b939f59dfa4d 100644
--- a/tools/testing/selftests/timens/timer.c
+++ b/tools/testing/selftests/timens/timer.c
@@ -56,7 +56,7 @@ int run_test(int clockid, struct timespec now)
 			return pr_perror("timerfd_gettime");
 
 		elapsed = new_value.it_value.tv_sec;
-		if (abs(elapsed - 3600) > 60) {
+		if (llabs(elapsed - 3600) > 60) {
 			ksft_test_result_fail("clockid: %d elapsed: %lld\n",
 					      clockid, elapsed);
 			return 1;
diff --git a/tools/testing/selftests/timens/timerfd.c b/tools/testing/selftests/timens/timerfd.c
index 9edd43d6b2c13..a4196bbd6e33f 100644
--- a/tools/testing/selftests/timens/timerfd.c
+++ b/tools/testing/selftests/timens/timerfd.c
@@ -61,7 +61,7 @@ int run_test(int clockid, struct timespec now)
 			return pr_perror("timerfd_gettime(%d)", clockid);
 
 		elapsed = new_value.it_value.tv_sec;
-		if (abs(elapsed - 3600) > 60) {
+		if (llabs(elapsed - 3600) > 60) {
 			ksft_test_result_fail("clockid: %d elapsed: %lld\n",
 					      clockid, elapsed);
 			return 1;
diff --git a/tools/testing/selftests/timens/vfork_exec.c b/tools/testing/selftests/timens/vfork_exec.c
index beb7614941fb1..5b8907bf451dd 100644
--- a/tools/testing/selftests/timens/vfork_exec.c
+++ b/tools/testing/selftests/timens/vfork_exec.c
@@ -32,7 +32,7 @@ static void *tcheck(void *_args)
 
 	for (i = 0; i < 2; i++) {
 		_gettime(CLOCK_MONOTONIC, &tst, i);
-		if (abs(tst.tv_sec - now->tv_sec) > 5) {
+		if (labs(tst.tv_sec - now->tv_sec) > 5) {
 			pr_fail("%s: in-thread: unexpected value: %ld (%ld)\n",
 				args->tst_name, tst.tv_sec, now->tv_sec);
 			return (void *)1UL;
@@ -64,7 +64,7 @@ static int check(char *tst_name, struct timespec *now)
 
 	for (i = 0; i < 2; i++) {
 		_gettime(CLOCK_MONOTONIC, &tst, i);
-		if (abs(tst.tv_sec - now->tv_sec) > 5)
+		if (labs(tst.tv_sec - now->tv_sec) > 5)
 			return pr_fail("%s: unexpected value: %ld (%ld)\n",
 					tst_name, tst.tv_sec, now->tv_sec);
 	}
-- 
2.43.0

[PATCH AUTOSEL 6.9 08/11] selftests/vDSO: fix clang build errors and warnings

[Sasha Levin]

From: John Hubbard <jhubbard@nvidia.com>

[ Upstream commit 73810cd45b99c6c418e1c6a487b52c1e74edb20d ]

When building with clang, via:

    make LLVM=1 -C tools/testing/selftests

...there are several warnings, and an error. This fixes all of those and
allows these tests to run and pass.

1. Fix linker error (undefined reference to memcpy) by providing a local
   version of memcpy.

2. clang complains about using this form:

    if (g = h & 0xf0000000)

...so factor out the assignment into a separate step.

3. The code is passing a signed const char* to elf_hash(), which expects
   a const unsigned char *. There are several callers, so fix this at
   the source by allowing the function to accept a signed argument, and
   then converting to unsigned operations, once inside the function.

4. clang doesn't have __attribute__((externally_visible)) and generates
   a warning to that effect. Fortunately, gcc 12 and gcc 13 do not seem
   to require that attribute in order to build, run and pass tests here,
   so remove it.

Reviewed-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Edward Liaw <edliaw@google.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/vDSO/parse_vdso.c      | 16 +++++++++++-----
 .../selftests/vDSO/vdso_standalone_test_x86.c  | 18 ++++++++++++++++--
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
index 413f75620a35b..4ae417372e9eb 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.c
+++ b/tools/testing/selftests/vDSO/parse_vdso.c
@@ -55,14 +55,20 @@ static struct vdso_info
 	ELF(Verdef) *verdef;
 } vdso_info;
 
-/* Straight from the ELF specification. */
-static unsigned long elf_hash(const unsigned char *name)
+/*
+ * Straight from the ELF specification...and then tweaked slightly, in order to
+ * avoid a few clang warnings.
+ */
+static unsigned long elf_hash(const char *name)
 {
 	unsigned long h = 0, g;
-	while (*name)
+	const unsigned char *uch_name = (const unsigned char *)name;
+
+	while (*uch_name)
 	{
-		h = (h << 4) + *name++;
-		if (g = h & 0xf0000000)
+		h = (h << 4) + *uch_name++;
+		g = h & 0xf0000000;
+		if (g)
 			h ^= g >> 24;
 		h &= ~g;
 	}
diff --git a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
index 8a44ff973ee17..27f6fdf119691 100644
--- a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
+++ b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
@@ -18,7 +18,7 @@
 
 #include "parse_vdso.h"
 
-/* We need a libc functions... */
+/* We need some libc functions... */
 int strcmp(const char *a, const char *b)
 {
 	/* This implementation is buggy: it never returns -1. */
@@ -34,6 +34,20 @@ int strcmp(const char *a, const char *b)
 	return 0;
 }
 
+/*
+ * The clang build needs this, although gcc does not.
+ * Stolen from lib/string.c.
+ */
+void *memcpy(void *dest, const void *src, size_t count)
+{
+	char *tmp = dest;
+	const char *s = src;
+
+	while (count--)
+		*tmp++ = *s++;
+	return dest;
+}
+
 /* ...and two syscalls.  This is x86-specific. */
 static inline long x86_syscall3(long nr, long a0, long a1, long a2)
 {
@@ -70,7 +84,7 @@ void to_base10(char *lastdig, time_t n)
 	}
 }
 
-__attribute__((externally_visible)) void c_main(void **stack)
+void c_main(void **stack)
 {
 	/* Parse the stack */
 	long argc = (long)*stack;
-- 
2.43.0