Re: [PATCH v2 10/14] loongarch: Handle KCOV __init vs inline mismatches

Huacai Chen
2025-06-19T08:56:01Z

Hi, Kees,

On Fri, May 23, 2025 at 12:39 PM Kees Cook <kees@kernel.org> wrote:
>
> When KCOV is enabled all functions get instrumented, unless
> the __no_sanitize_coverage attribute is used. To prepare for
> __no_sanitize_coverage being applied to __init functions, we have to
> handle differences in how GCC's inline optimizations get resolved. For
> loongarch this exposed several places where __init annotations were
> missing but ended up being "accidentally correct". Fix these cases and
> force one function to be inline with __always_inline.
>
> Signed-off-by: Kees Cook <kees@kernel.org>
> ---
> Cc: Huacai Chen <chenhuacai@kernel.org>
> Cc: WANG Xuerui <kernel@xen0n.name>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Tianyang Zhang <zhangtianyang@loongson.cn>
> Cc: Bibo Mao <maobibo@loongson.cn>
> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
> Cc: <loongarch@lists.linux.dev>
> ---
> arch/loongarch/include/asm/smp.h | 2 +-
> arch/loongarch/kernel/time.c | 2 +-
> arch/loongarch/mm/ioremap.c | 4 ++--
> 3 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/loongarch/include/asm/smp.h b/arch/loongarch/include/asm/smp.h
> index ad0bd234a0f1..88e19d8a11f4 100644
> --- a/arch/loongarch/include/asm/smp.h
> +++ b/arch/loongarch/include/asm/smp.h
> @@ -39,7 +39,7 @@ int loongson_cpu_disable(void);
> void loongson_cpu_die(unsigned int cpu);
> #endif
>
> -static inline void plat_smp_setup(void)
> +static __always_inline void plat_smp_setup(void)
Similar to x86 and arm, I prefer to mark it as __init rather than
__always_inline.

Huacai

> {
> loongson_smp_setup();
> }
> diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c
> index bc75a3a69fc8..367906b10f81 100644
> --- a/arch/loongarch/kernel/time.c
> +++ b/arch/loongarch/kernel/time.c
> @@ -102,7 +102,7 @@ static int constant_timer_next_event(unsigned long delta, struct clock_event_dev
> return 0;
> }
>
> -static unsigned long __init get_loops_per_jiffy(void)
> +static unsigned long get_loops_per_jiffy(void)
> {
> unsigned long lpj = (unsigned long)const_clock_freq;
>
> diff --git a/arch/loongarch/mm/ioremap.c b/arch/loongarch/mm/ioremap.c
> index 70ca73019811..df949a3d0f34 100644
> --- a/arch/loongarch/mm/ioremap.c
> +++ b/arch/loongarch/mm/ioremap.c
> @@ -16,12 +16,12 @@ void __init early_iounmap(void __iomem *addr, unsigned long size)
>
> }
>
> -void *early_memremap_ro(resource_size_t phys_addr, unsigned long size)
> +void * __init early_memremap_ro(resource_size_t phys_addr, unsigned long size)
> {
> return early_memremap(phys_addr, size);
> }
>
> -void *early_memremap_prot(resource_size_t phys_addr, unsigned long size,
> +void * __init early_memremap_prot(resource_size_t phys_addr, unsigned long size,
> unsigned long prot_val)
> {
> return early_memremap(phys_addr, size);
> --
> 2.34.1
>