This is a note to let you know that I've just added the patch titled
selftests:resctrl: Fix build failure on archs without __cpuid_count()
to the 6.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-resctrl-fix-build-failure-on-archs-without.patch
and it can be found in the queue-6.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bb327a26431b7b4942b97d6cca8026c3073556ce
Author: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Date: Thu Sep 5 12:02:31 2024 -0600
selftests:resctrl: Fix build failure on archs without __cpuid_count()
[ Upstream commit 7beaf1da074f7ea25454d6c11da142c3892d3c4e ]
When resctrl is built on architectures without __cpuid_count()
support, build fails. resctrl uses __cpuid_count() defined in
kselftest.h.
Even though the problem is seen while building resctrl on aarch64,
this error can be seen on any platform that doesn't support CPUID.
CPUID is a x86/x86-64 feature and code paths with CPUID asm commands
will fail to build on all other architectures.
All others tests call __cpuid_count() do so from x86/x86_64 code paths
when _i386__ or __x86_64__ are defined. resctrl is an exception.
Fix the problem by defining __cpuid_count() only when __i386__ or
__x86_64__ are defined in kselftest.h and changing resctrl to call
__cpuid_count() only when __i386__ or __x86_64__ are defined.
In file included from resctrl.h:24,
from cat_test.c:11:
In function ‘arch_supports_noncont_cat’,
inlined from ‘noncont_cat_run_test’ at cat_test.c:326:6:
../kselftest.h:74:9: error: impossible constraint in ‘asm’
74 | __asm__ __volatile__ ("cpuid\n\t" \
| ^~~~~~~
cat_test.c:304:17: note: in expansion of macro ‘__cpuid_count’
304 | __cpuid_count(0x10, 1, eax, ebx, ecx, edx);
| ^~~~~~~~~~~~~
../kselftest.h:74:9: error: impossible constraint in ‘asm’
74 | __asm__ __volatile__ ("cpuid\n\t" \
| ^~~~~~~
cat_test.c:306:17: note: in expansion of macro ‘__cpuid_count’
306 | __cpuid_count(0x10, 2, eax, ebx, ecx, edx);
Fixes: ae638551ab64 ("selftests/resctrl: Add non-contiguous CBMs CAT test")
Reported-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Closes: https://lore.kernel.org/lkml/20240809071059.265914-1-usama.anjum@xxxxxxxxxxxxx/
Reported-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Acked-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index 76c2a6945d3e8..f9214e7cdd134 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -61,6 +61,7 @@
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
#endif
+#if defined(__i386__) || defined(__x86_64__) /* arch */
/*
* gcc cpuid.h provides __cpuid_count() since v4.4.
* Clang/LLVM cpuid.h provides __cpuid_count() since v3.4.0.
@@ -75,6 +76,7 @@
: "=a" (a), "=b" (b), "=c" (c), "=d" (d) \
: "0" (level), "2" (count))
#endif
+#endif /* end arch */
/* define kselftest exit codes */
#define KSFT_PASS 0
diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 55315ed695f47..18565f02163e7 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -293,12 +293,12 @@ static int cat_run_test(const struct resctrl_test *test, const struct user_param
static bool arch_supports_noncont_cat(const struct resctrl_test *test)
{
- unsigned int eax, ebx, ecx, edx;
-
/* AMD always supports non-contiguous CBM. */
if (get_vendor() == ARCH_AMD)
return true;
+#if defined(__i386__) || defined(__x86_64__) /* arch */
+ unsigned int eax, ebx, ecx, edx;
/* Intel support for non-contiguous CBM needs to be discovered. */
if (!strcmp(test->resource, "L3"))
__cpuid_count(0x10, 1, eax, ebx, ecx, edx);
@@ -308,6 +308,9 @@ static bool arch_supports_noncont_cat(const struct resctrl_test *test)
return false;
return ((ecx >> 3) & 1);
+#endif /* end arch */
+
+ return false;
}
static int noncont_cat_run_test(const struct resctrl_test *test,
