From: Hyeonggon Yoo <42.hyeyoo@gmail.com>
To: Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Stephen Rothwell <sfr@canb.auug.org.au>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
clang-built-linux@googlegroups.com,
Naresh Kamboju <naresh.kamboju@linaro.org>
Subject: [PATCH] mm, slub: Fix support for clang 10
Date: Wed, 19 May 2021 03:12:47 +0900 [thread overview]
Message-ID: <20210518181247.GA10062@hyeyoo> (raw)
Previously in 'commit ff3daafe3fd3 ("mm, slub: change run-time assertion
in kmalloc_index() to compile-time")', changed kmalloc_index's run-time
assertion to compile-time assertion.
But clang 10 has a bug misevaluating __builtin_constant_p() as true,
making it unable to compile. This bug was fixed in clang 11.
To support clang 10, introduce a macro to do run-time assertion if clang
version is less than 11, even if the size is constant. Might revert this
commit later if we choose not to support clang 10.
Fixes: ff3daafe3fd3 ("mm, slub: change run-time assertion in kmalloc_index() to compile-time")
Link: https://lore.kernel.org/r/CA+G9fYvYxqVhUTkertjZjcrUq8LWPnO7qC==Wum3gYCwWF9D6Q@mail.gmail.com/
Link: https://lkml.org/lkml/2021/5/11/872
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
---
include/linux/slab.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 9d316aac0aba..8d8dd8571261 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -413,7 +413,7 @@ static __always_inline unsigned int __kmalloc_index(size_t size,
if (size <= 16 * 1024 * 1024) return 24;
if (size <= 32 * 1024 * 1024) return 25;
- if (size_is_constant)
+ if ((IS_ENABLED(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 110000) && size_is_constant)
BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
else
BUG();
--
2.25.1
next reply other threads:[~2021-05-18 18:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-18 18:12 Hyeonggon Yoo [this message]
2021-05-18 18:16 ` [PATCH] mm, slub: Fix support for clang 10 Hyeonggon Yoo
2021-05-18 18:21 ` Hyeonggon Yoo
2021-05-18 20:30 ` Nick Desaulniers
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