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ccb7735a1e
Currently WARN_ON_FPU evaluates its argument even if
CONFIG_X86_DEBUG_FPU is disabled, which adds unnecessary instructions to
several functions, for example kernel_fpu_begin(). Fix this by using
BUILD_BUG_ON_INVALID(x) in the no-debug case rather than (void)(x).
Fixes: 83242c5158 ("x86/fpu: Make WARN_ON_FPU() more robust in the !CONFIG_X86_DEBUG_FPU case")
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20250127224523.94300-1-ebiggers%40kernel.org
28 lines
657 B
C
28 lines
657 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __X86_KERNEL_FPU_INTERNAL_H
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#define __X86_KERNEL_FPU_INTERNAL_H
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extern struct fpstate init_fpstate;
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/* CPU feature check wrappers */
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static __always_inline __pure bool use_xsave(void)
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{
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return cpu_feature_enabled(X86_FEATURE_XSAVE);
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}
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static __always_inline __pure bool use_fxsr(void)
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{
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return cpu_feature_enabled(X86_FEATURE_FXSR);
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}
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#ifdef CONFIG_X86_DEBUG_FPU
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# define WARN_ON_FPU(x) WARN_ON_ONCE(x)
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#else
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# define WARN_ON_FPU(x) ({ BUILD_BUG_ON_INVALID(x); 0; })
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#endif
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/* Used in init.c */
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extern void fpstate_init_user(struct fpstate *fpstate);
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extern void fpstate_reset(struct fpu *fpu);
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#endif
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