diff mbox series

tracing/user_events: fix long size check in the ABI selftest

Message ID 20230911160935.10720-1-aleksander.lobakin@intel.com (mailing list archive)
State Accepted
Headers show
Series tracing/user_events: fix long size check in the ABI selftest | expand

Commit Message

Alexander Lobakin Sept. 11, 2023, 4:09 p.m. UTC
The current check for 64-bit architecture is double-bugged.
First of all, %BITS_PER_LONG is not available in the userspace,
the underscored version from <asm/bitsperlong.h> must be used.
The following check:

 #if BITS_PER_LONG == 0
 #error
 #endif

triggers the error in this source file -- the macro is undefined and
thus is implicitly evaluated to 0.
Next, %BITS_PER_LONG means "bits", not "bytes". In the Linux kernel,
it can be 32 or 64, never 8. Given that the tests guarded by that check
are meant to be run on a 64-bit system, the correct value would be 64.

Prefix the macro name and fix the value it's compared to.

Fixes: 60b1af8de8c1 ("tracing/user_events: Add ABI self-test")
Cc: stable@vger.kernel.org # 6.4+
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 tools/testing/selftests/user_events/abi_test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Alexander Lobakin Sept. 13, 2023, 10:07 a.m. UTC | #1
From: Alexander Lobakin <aleksander.lobakin@intel.com>
Date: Mon, 11 Sep 2023 18:09:35 +0200

> The current check for 64-bit architecture is double-bugged.
> First of all, %BITS_PER_LONG is not available in the userspace,
> the underscored version from <asm/bitsperlong.h> must be used.
> The following check:
> 
>  #if BITS_PER_LONG == 0
>  #error
>  #endif
> 
> triggers the error in this source file -- the macro is undefined and
> thus is implicitly evaluated to 0.
> Next, %BITS_PER_LONG means "bits", not "bytes". In the Linux kernel,
> it can be 32 or 64, never 8. Given that the tests guarded by that check
> are meant to be run on a 64-bit system, the correct value would be 64.
> 
> Prefix the macro name and fix the value it's compared to.
> 
> Fixes: 60b1af8de8c1 ("tracing/user_events: Add ABI self-test")
> Cc: stable@vger.kernel.org # 6.4+
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>

Patchwork says "Accepted", but I don't see it anywhere on korg O_o

[...]

Thanks,
Olek
diff mbox series

Patch

diff --git a/tools/testing/selftests/user_events/abi_test.c b/tools/testing/selftests/user_events/abi_test.c
index 5125c42efe65..4b30461fc741 100644
--- a/tools/testing/selftests/user_events/abi_test.c
+++ b/tools/testing/selftests/user_events/abi_test.c
@@ -129,7 +129,7 @@  TEST_F(user, bit_sizes) {
 	ASSERT_EQ(0, reg_disable(&self->check, 0));
 	ASSERT_EQ(0, reg_disable(&self->check, 31));
 
-#if BITS_PER_LONG == 8
+#if __BITS_PER_LONG == 64
 	/* Allow 0-64 bits for 64-bit */
 	ASSERT_EQ(0, reg_enable(&self->check, sizeof(long), 63));
 	ASSERT_NE(0, reg_enable(&self->check, sizeof(long), 64));