linux-kernel - Re: next-20250909: selftests/arm64/gcs/basic-gcs.c:390:30: error: use of undeclared identifier 'HWCAP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1e331ebb-3315-4cbe-b194-ccbeeaded4da@t-8ch.de>
Date: Fri, 12 Sep 2025 08:30:08 +0200
From: Thomas Weißschuh <linux@...ssschuh.net>
To: Naresh Kamboju <naresh.kamboju@...aro.org>
Cc: open list <linux-kernel@...r.kernel.org>, 
	Linux ARM <linux-arm-kernel@...ts.infradead.org>, 
	"open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest@...r.kernel.org>, lkft-triage@...ts.linaro.org, 
	Linux Regressions <regressions@...ts.linux.dev>, Mark Brown <broonie@...nel.org>, 
	Catalin Marinas <catalin.marinas@....com>, Will Deacon <will@...nel.org>, Arnd Bergmann <arnd@...db.de>, 
	Dan Carpenter <dan.carpenter@...aro.org>, Anders Roxell <anders.roxell@...aro.org>, 
	Ben Copeland <benjamin.copeland@...aro.org>, Shuah Khan <shuah@...nel.org>
Subject: Re: next-20250909: selftests/arm64/gcs/basic-gcs.c:390:30: error:
 use of undeclared identifier 'HWCAP_GCS'

Hi Naresh,

On 2025-09-12 00:48:47+0530, Naresh Kamboju wrote:
> The following build warnings / errors noticed on arm64 defconfig
> with clang-20 and gcc-13 toolchains on the Linux next-20250909
> till next-20250911 tag while building selftests/arm64.
> 
> Regression Analysis:
> - New regression? Yes
> - Reproducibility? yes
> 
> First seen on  next-20250909
>  Good: next-20250908
>  Bad: next-20250909 till next-20250911
> 
> Test regression: next-20250909:
> selftests/arm64/gcs/basic-gcs.c:390:30: error: use of undeclared
> identifier 'HWCAP_GCS'
> 
> Reported-by: Linux Kernel Functional Testing <lkft@...aro.org>
> 
> ## Build log
> selftests/arm64/gcs/basic-gcs.c:390:30: error: use of undeclared
> identifier 'HWCAP_GCS'
>   390 |         if (!(getauxval(AT_HWCAP) & HWCAP_GCS))
>       |                                     ^
> 1 error generated.
> 
> The suspected commit pointing to,
>   kselftest/arm64/gcs: Use nolibc's getauxval()
>   a985fe638344492727528e52416211dda1c391d5

That suspicion looks correct. I am wondering a bit how this works for
the other selftests which use this symbol.

Can you give this one a try:

diff --git a/tools/testing/selftests/arm64/gcs/gcs-util.h b/tools/testing/selftests/arm64/gcs/gcs-util.h
index c99a6b39ac14..816b497634d6 100644
--- a/tools/testing/selftests/arm64/gcs/gcs-util.h
+++ b/tools/testing/selftests/arm64/gcs/gcs-util.h
@@ -26,6 +26,10 @@ struct user_gcs {
 };
 #endif

+#ifndef HWCAP_GCS
+#define HWCAP_GCS (1UL << 32)
+#endif
+
 /* Shadow Stack/Guarded Control Stack interface */
 #define PR_GET_SHADOW_STACK_STATUS     74
 #define PR_SET_SHADOW_STACK_STATUS      75