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Date:   Fri, 4 Aug 2023 17:38:03 +0200
From:   Thomas =?utf-8?Q?Wei=C3=9Fschuh?= <thomas@t-8ch.de>
To:     Zhangjin Wu <falcon@tinylab.org>
Cc:     w@1wt.eu, arnd@arndb.de, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, tanyuan@tinylab.org
Subject: Re: [PATCH v1 3/3] tools/nolibc: stackprotector.h: make
 __stack_chk_init static
Message-ID: <34bf8710-0571-4f69-87bc-b3776264744b@t-8ch.de>
References: <cover.1691073180.git.falcon@tinylab.org>
 <d5eb12e6b9238dcb85935cf6af3ed12ff043f900.1691073180.git.falcon@tinylab.org>
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On 2023-08-03 22:47:01+0800, Zhangjin Wu wrote:
> This allows to generate smaller text/data/dec size.
> 
> As the _start_c() function added by crt.h, __stack_chk_init() is called
> from _start_c() instead of the assembly _start. So, it is able to mark
> it with static now.
> 
> Signed-off-by: Zhangjin Wu <falcon@tinylab.org>

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>

> ---
>  tools/include/nolibc/crt.h            | 2 +-
>  tools/include/nolibc/stackprotector.h | 5 ++---
>  2 files changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/include/nolibc/crt.h b/tools/include/nolibc/crt.h
> index 32e128b0fb62..a5f33fef1672 100644
> --- a/tools/include/nolibc/crt.h
> +++ b/tools/include/nolibc/crt.h
> @@ -10,7 +10,7 @@
>  char **environ __attribute__((weak));
>  const unsigned long *_auxv __attribute__((weak));
>  
> -void __stack_chk_init(void);
> +static void __stack_chk_init(void);
>  static void exit(int);
>  
>  void _start_c(long *sp)
> diff --git a/tools/include/nolibc/stackprotector.h b/tools/include/nolibc/stackprotector.h
> index b620f2b9578d..13f1d0e60387 100644
> --- a/tools/include/nolibc/stackprotector.h
> +++ b/tools/include/nolibc/stackprotector.h
> @@ -37,8 +37,7 @@ void __stack_chk_fail_local(void)
>  __attribute__((weak,section(".data.nolibc_stack_chk")))
>  uintptr_t __stack_chk_guard;
>  
> -__attribute__((weak,section(".text.nolibc_stack_chk"))) __no_stack_protector
> -void __stack_chk_init(void)
> +static __no_stack_protector void __stack_chk_init(void)
>  {
>  	my_syscall3(__NR_getrandom, &__stack_chk_guard, sizeof(__stack_chk_guard), 0);
>  	/* a bit more randomness in case getrandom() fails, ensure the guard is never 0 */
> @@ -46,7 +45,7 @@ void __stack_chk_init(void)
>  		__stack_chk_guard ^= (uintptr_t) &__stack_chk_guard;
>  }
>  #else /* !defined(_NOLIBC_STACKPROTECTOR) */
> -__inline__ void __stack_chk_init(void) {}
> +static void __stack_chk_init(void) {}
>  #endif /* defined(_NOLIBC_STACKPROTECTOR) */
>  
>  #endif /* _NOLIBC_STACKPROTECTOR_H */
> -- 
> 2.25.1
>