diff mbox series

[v2,14/17] selftests: vdso: Make test_vdso_getrandom look for the right vDSO function

Message ID 04d1de23a2ff14e2709edd8b75e27b81d703bc57.1724309198.git.christophe.leroy@csgroup.eu (mailing list archive)
State Handled Elsewhere
Headers show
Series Wire up getrandom() vDSO implementation on powerpc | expand

Commit Message

Christophe Leroy Aug. 22, 2024, 7:13 a.m. UTC
Don't hard-code x86 specific names, use vdso_config definitions
to find the correct function matching the architecture.

Add random VDSO function names in names[][]. Remove the #ifdef
CONFIG_VDSO32, having the name there all the time is harmless
and guaranties a steady index for following strings.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 tools/testing/selftests/vDSO/vdso_config.h         | 8 +++-----
 tools/testing/selftests/vDSO/vdso_test_getrandom.c | 8 ++++++--
 2 files changed, 9 insertions(+), 7 deletions(-)

Comments

Jason A. Donenfeld Aug. 26, 2024, 7:28 a.m. UTC | #1
On Thu, Aug 22, 2024 at 09:13:22AM +0200, Christophe Leroy wrote:
> Don't hard-code x86 specific names, use vdso_config definitions
> to find the correct function matching the architecture.
> 
> Add random VDSO function names in names[][]. Remove the #ifdef
> CONFIG_VDSO32, having the name there all the time is harmless
> and guaranties a steady index for following strings.

This is indeed the right way of doing it. Thanks. I'll take this now,
though with one small fixup:

> +	const char *version = versions[VDSO_VERSION];
> +	const char **name = (const char **)&names[VDSO_NAMES];

I'll just do:

        const char *name = names[VDSO_NAMES][6];

Instead of referring to name[6] everywhere after. Seems more straight
forward.

Jason
LEROY Christophe Aug. 26, 2024, 7:35 a.m. UTC | #2
Le 26/08/2024 à 09:28, Jason A. Donenfeld a écrit :
> On Thu, Aug 22, 2024 at 09:13:22AM +0200, Christophe Leroy wrote:
>> Don't hard-code x86 specific names, use vdso_config definitions
>> to find the correct function matching the architecture.
>>
>> Add random VDSO function names in names[][]. Remove the #ifdef
>> CONFIG_VDSO32, having the name there all the time is harmless
>> and guaranties a steady index for following strings.
> 
> This is indeed the right way of doing it. Thanks. I'll take this now,
> though with one small fixup:
> 
>> +	const char *version = versions[VDSO_VERSION];
>> +	const char **name = (const char **)&names[VDSO_NAMES];
> 
> I'll just do:
> 
>          const char *name = names[VDSO_NAMES][6];
> 
> Instead of referring to name[6] everywhere after. Seems more straight
> forward.

Yes you are right that's more straight forward when using only one of 
the names.
I copy-pasted it from the gettimeofday test which uses several names 
from the table.

Christophe
diff mbox series

Patch

diff --git a/tools/testing/selftests/vDSO/vdso_config.h b/tools/testing/selftests/vDSO/vdso_config.h
index 00bfed6e4922..740ce8c98d2e 100644
--- a/tools/testing/selftests/vDSO/vdso_config.h
+++ b/tools/testing/selftests/vDSO/vdso_config.h
@@ -68,16 +68,15 @@  static const char *versions[7] = {
 	"LINUX_5.10"
 };
 
-static const char *names[2][6] = {
+static const char *names[2][7] = {
 	{
 		"__kernel_gettimeofday",
 		"__kernel_clock_gettime",
 		"__kernel_time",
 		"__kernel_clock_getres",
 		"__kernel_getcpu",
-#if defined(VDSO_32BIT)
 		"__kernel_clock_gettime64",
-#endif
+		"__kernel_getrandom",
 	},
 	{
 		"__vdso_gettimeofday",
@@ -85,9 +84,8 @@  static const char *names[2][6] = {
 		"__vdso_time",
 		"__vdso_clock_getres",
 		"__vdso_getcpu",
-#if defined(VDSO_32BIT)
 		"__vdso_clock_gettime64",
-#endif
+		"__vdso_getrandom",
 	},
 };
 
diff --git a/tools/testing/selftests/vDSO/vdso_test_getrandom.c b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
index 05122425a873..02bcffc23e0c 100644
--- a/tools/testing/selftests/vDSO/vdso_test_getrandom.c
+++ b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
@@ -21,6 +21,7 @@ 
 
 #include "../kselftest.h"
 #include "parse_vdso.h"
+#include "vdso_config.h"
 
 #ifndef timespecsub
 #define	timespecsub(tsp, usp, vsp)					\
@@ -107,6 +108,9 @@  static void vgetrandom_put_state(void *state)
 
 static void vgetrandom_init(void)
 {
+	const char *version = versions[VDSO_VERSION];
+	const char **name = (const char **)&names[VDSO_NAMES];
+
 	if (pthread_key_create(&grnd_ctx.key, vgetrandom_put_state) != 0)
 		return;
 	unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
@@ -115,9 +119,9 @@  static void vgetrandom_init(void)
 		exit(KSFT_SKIP);
 	}
 	vdso_init_from_sysinfo_ehdr(sysinfo_ehdr);
-	grnd_ctx.fn = (__typeof__(grnd_ctx.fn))vdso_sym("LINUX_2.6", "__vdso_getrandom");
+	grnd_ctx.fn = (__typeof__(grnd_ctx.fn))vdso_sym(version, name[6]);
 	if (!grnd_ctx.fn) {
-		printf("__vdso_getrandom is missing!\n");
+		printf("%s is missing!\n", name[6]);
 		exit(KSFT_FAIL);
 	}
 	if (grnd_ctx.fn(NULL, 0, 0, &grnd_ctx.params, ~0UL) != 0) {