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Subject: Re: [PATCH] set_tid_address.2: SYNOPSIS: Fix set_tid_address() return
 type
To:     Alejandro Colomar <alx.manpages@gmail.com>
References: <20201123215911.7576-1-alx.manpages@gmail.com>
From:   "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Message-ID: <b8c3ee44-91f7-ee0c-b39a-044459f3b456@gmail.com>
Date:   Tue, 24 Nov 2020 10:50:29 +0100
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Hi Alex,

On 11/23/20 10:59 PM, Alejandro Colomar wrote:
> The Linux kernel uses 'pid_t' instead of 'long' for the return type.
> As glibc provides no wrapper, use the same types the kernel uses.
> 
> $ sed -n 34,36p man-pages/man2/set_tid_address.2
> .PP
> .IR Note :
> There is no glibc wrapper for this system call; see NOTES.
> 
> $ grep -rn 'SYSCALL_DEFINE.*set_tid_address' linux/
> linux/kernel/fork.c:1632:
> SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
> 
> $ sed -n 1632,1638p linux/kernel/fork.c
> SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
> {
> 	current->clear_child_tid = tidptr;
> 
> 	return task_pid_vnr(current);
> }
> 
> $ grep -rn 'task_pid_vnr(struct' linux/
> linux/include/linux/sched.h:1374:
> static inline pid_t task_pid_vnr(struct task_struct *tsk)
>
> Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>

Thanks! Patch applied.

Cheers,

Michael

> ---
>  man2/set_tid_address.2 | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/man2/set_tid_address.2 b/man2/set_tid_address.2
> index 380efcdd8..b18b8efef 100644
> --- a/man2/set_tid_address.2
> +++ b/man2/set_tid_address.2
> @@ -29,7 +29,7 @@ set_tid_address \- set pointer to thread ID
>  .nf
>  .B #include <linux/unistd.h>
>  .PP
> -.BI "long set_tid_address(int *" tidptr );
> +.BI "pid_t set_tid_address(int *" tidptr );
>  .fi
>  .PP
>  .IR Note :
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/