From: Mark Rutland <mark.rutland@arm.com> mainline inclusion from mainline-v6.16-rc1 commit f699c66691fb7e08a5a631c5baf5f2a19b7a6468 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/8904 CVE: NA Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... ---------------------------------------------------------------------- Historically fpsimd_to_sve() and sve_to_fpsimd() were (conditionally) called by functions which were defined regardless of CONFIG_ARM64_SVE. Hence it was necessary that both fpsimd_to_sve() and sve_to_fpsimd() were always defined and not guarded by ifdeffery. As a result of the removal of fpsimd_signal_preserve_current_state() in commit: 929fa99b1215966f ("arm64/fpsimd: signal: Always save+flush state early") ... sve_to_fpsimd() has no callers when CONFIG_ARM64_SVE=n, resulting in a build-time warnign that it is unused: | arch/arm64/kernel/fpsimd.c:676:13: warning: unused function 'sve_to_fpsimd' [-Wunused-function] | 676 | static void sve_to_fpsimd(struct task_struct *task) | | ^~~~~~~~~~~~~ | 1 warning generated. In contrast, fpsimd_to_sve() still has callers which are defined when CONFIG_ARM64_SVE=n, and it would be awkward to hide this behind ifdeffery and/or to use stub functions. For now, suppress the warning by marking both fpsimd_to_sve() and sve_to_fpsimd() as 'static inline', as we usually do for stub functions. The compiler will no longer warn if either function is unused. Aside from suppressing the warning, there should be no functional change as a result of this patch. Link: https://lore.kernel.org/linux-arm-kernel/20250429194600.GA26883@willie-the-t... Reported-by: Will Deacon <will@kernel.org> Fixes: 929fa99b1215 ("arm64/fpsimd: signal: Always save+flush state early") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20250430173240.4023627-1-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com> Signed-off-by: Hongye Lin <linhongye@h-partners.com> --- arch/arm64/kernel/fpsimd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 4bc5f67bd44e..28dd31f1e3c3 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -682,7 +682,7 @@ static void __fpsimd_to_sve(void *sst, struct user_fpsimd_state const *fst, * task->thread.uw.fpsimd_state must be up to date before calling this * function. */ -static void fpsimd_to_sve(struct task_struct *task) +static inline void fpsimd_to_sve(struct task_struct *task) { unsigned int vq; void *sst = task->thread.sve_state; @@ -706,7 +706,7 @@ static void fpsimd_to_sve(struct task_struct *task) * bytes of allocated kernel memory. * task->thread.sve_state must be up to date before calling this function. */ -static void sve_to_fpsimd(struct task_struct *task) +static inline void sve_to_fpsimd(struct task_struct *task) { unsigned int vq, vl; void const *sst = task->thread.sve_state; -- 2.33.0