Bug 216876

Summary: prototype for execveat() in the documentation appears wrong
Product: Documentation Reporter: Mark Galeck (markgaleck)
Component: man-pagesAssignee: documentation_man-pages (documentation_man-pages)
Status: RESOLVED DOCUMENTED    
Severity: low    
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: Subsystem:
Regression: No Bisected commit-id:

Description Mark Galeck 2023-01-02 03:47:47 UTC 
prototype for execveat() in the documentation is:

int execveat(int dirfd, const char *pathname,
                    const char *const argv[], const char *const envp[],
                    int flags);


This appears to be inconsistent with similar functions, other documentation, and my sources (latest Ubuntu distribution). 


I think two of the "const" should be dropped so that we should have:

int execveat(int dirfd, const char *pathname,
                    char *const argv[], char *const envp[],
                    int flags);
Comment 1 Florian Weimer 2023-01-02 15:26:40 UTC 
* Alejandro Colomar via Libc-alpha:

> It seems that glibc added a wrapper recently, and I didn't check that
> the prototype changed:
>
> alx@asus5775:~/src/gnu/glibc$ grepc execveat
> ./posix/unistd.h:300:
> extern int execveat (int __fd, const char *__path, char *const __argv[],
>                      char *const __envp[], int __flags)
>     __THROW __nonnull ((2, 3));
>
>
> ./sysdeps/unix/sysv/linux/execveat.c:25:
> int
> execveat (int dirfd, const char *path, char *const argv[], char *const
> envp[],
>           int flags)
> {
>   /* Avoid implicit array coercion in syscall macros.  */
>   return INLINE_SYSCALL_CALL (execveat, dirfd, path, &argv[0], &envp[0],
>                             flags);
> }
>
>
> I CCd glibc so that they can comment.

POSIX uses these types for fexecve and execve, and it seemed right to be
consistent with that.

There are several more manual pages which do not specify the correct
prototype: open, openat, prctl.  I have received compiler bug reports
when people used function pointers modeled after the declarations of
open and prctl in the manual pages because of the ABI mismatch with the
glibc implementations.  The execveat difference is harmless in
comparison.

Thanks,
Florian