[PATCH v6 07/19] arm64: introduce is_a32_task and is_a32_thread (for AArch32 compat)

Catalin Marinas
2015-12-03T12:13:03Z

On Wed, Nov 18, 2015 at 12:16:47AM +0300, Yury Norov wrote:
> diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
> index 7fbed69..9700e5e 100644
> --- a/arch/arm64/include/asm/compat.h
> +++ b/arch/arm64/include/asm/compat.h
> @@ -299,19 +299,44 @@ struct compat_shmid64_ds {
> compat_ulong_t __unused5;
> };
>
> -static inline int is_compat_task(void)
> +#ifdef CONFIG_AARCH32_EL0
> +
> +static inline int is_a32_compat_task(void)
> {
> return test_thread_flag(TIF_32BIT);
> }
>
> -static inline int is_compat_thread(struct thread_info *thread)
> +static inline int is_a32_compat_thread(struct thread_info *thread)
> {
> return test_ti_thread_flag(thread, TIF_32BIT);
> }
>
> +#else
> +
> +static inline int is_a32_compat_task(void)
> +{
> + return 0;
> +}
> +
> +static inline int is_a32_compat_thread(struct thread_info *thread)
> +{
> + return 0;
> +}
> +#endif
> +
> +static inline int is_compat_task(void)
> +{
> + return is_a32_compat_task();
> +}
> +
> #else /* !CONFIG_COMPAT */
>
> -static inline int is_compat_thread(struct thread_info *thread)
> +static inline int is_a32_compat_thread(struct thread_info *thread)
> +{
> + return 0;
> +}
> +
> +static inline int is_a32_compat_task(void)
> {
> return 0;
> }

My main worry with this patch is a potential #include mess. I can see
that you already had to include asm/compat.h explicitly in
hw_breakpoint.c even though linux/compat.h was already included. In
subsequent files (asm/elf.h, asm/memory.h) you check is_compat_task()
without explicitly including asm/compat.h and hope that it won't break.

A solution would be to add these functions in a separate header file
that gets included where needed (also by asm/compat.h).

--
Catalin