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| author |  Mark Rutland <mark.rutland@arm.com>
| 2022-09-20 15:00:44 +0100 |
|---|---|---|
| committer |  Catalin Marinas <catalin.marinas@arm.com>
| 2022-09-21 12:41:50 +0100 |
| commit | 0072dc1b53c39fb7c4cfc5c9e5d5a30622198613 (patch) | |
| tree | 7508cd37e59507f88d52883b6e9738f3a37c9253 /arch | |
| parent | arm64: alternatives: add shared NOP callback (diff) | |
| download | linux-0072dc1b53c3.tar.gz linux-0072dc1b53c3.tar.bz2 linux-0072dc1b53c3.zip | |
arm64: avoid BUILD_BUG_ON() in alternative-macros
Nathan reports that the build fails when using clang and LTO:
| In file included from kernel/bounds.c:10:
| In file included from ./include/linux/page-flags.h:10:
| In file included from ./include/linux/bug.h:5:
| In file included from ./arch/arm64/include/asm/bug.h:26:
| In file included from ./include/asm-generic/bug.h:5:
| In file included from ./include/linux/compiler.h:248:
| In file included from ./arch/arm64/include/asm/rwonce.h:11:
| ./arch/arm64/include/asm/alternative-macros.h:224:2: error: call to undeclared function 'BUILD_BUG_ON'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
| BUILD_BUG_ON(feature >= ARM64_NCAPS);
| ^
| ./arch/arm64/include/asm/alternative-macros.h:241:2: error: call to undeclared function 'BUILD_BUG_ON'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
| BUILD_BUG_ON(feature >= ARM64_NCAPS);
| ^
| 2 errors generated.
... the problem being that when LTO is enabled, <asm/rwonce.h> includes
<asm/alternative-macros.h>, and causes a circular include dependency
through <linux/bug.h>. This manifests as BUILD_BUG_ON() not being
defined when used within <asm/alternative-macros.h>.
This patch avoids the problem and simplifies the include dependencies by
using compiletime_assert() instead of BUILD_BUG_ON().
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 21fb26bfb01f ("arm64: alternatives: add alternative_has_feature_*()")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: http://lore.kernel.org/r/YyigTrxhE3IRPzjs@dev-arch.thelio-3990X
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220920140044.1709073-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/alternative-macros.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/alternative-macros.h b/arch/arm64/include/asm/alternative-macros.h index 4a2a98d6d222..966767debaa3 100644 --- a/arch/arm64/include/asm/alternative-macros.h +++ b/arch/arm64/include/asm/alternative-macros.h @@ -215,13 +215,13 @@ alternative_endif #ifndef __ASSEMBLY__ -#include <linux/bug.h> #include <linux/types.h> static __always_inline bool alternative_has_feature_likely(unsigned long feature) { - BUILD_BUG_ON(feature >= ARM64_NCAPS); + compiletime_assert(feature < ARM64_NCAPS, + "feature must be < ARM64_NCAPS"); asm_volatile_goto( ALTERNATIVE_CB("b %l[l_no]", %[feature], alt_cb_patch_nops) @@ -238,7 +238,8 @@ l_no: static __always_inline bool alternative_has_feature_unlikely(unsigned long feature) { - BUILD_BUG_ON(feature >= ARM64_NCAPS); + compiletime_assert(feature < ARM64_NCAPS, + "feature must be < ARM64_NCAPS"); asm_volatile_goto( ALTERNATIVE("nop", "b %l[l_yes]", %[feature]) |