2020-11-23 22:01:26

by Alejandro Colomar

Subject: [PATCH] set_tid_address.2: SYNOPSIS: Fix set_tid_address() return type

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 <[email protected]>
---
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 :
--
2.29.2

2020-11-25 02:00:18

by Michael Kerrisk (man-pages)

Subject: Re: [PATCH] set_tid_address.2: SYNOPSIS: Fix set_tid_address() return type

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 <[email protected]>

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/