Hi, On 1/2/23 04:47, bugzilla-daemon@xxxxxxxxxx wrote:
https://bugzilla.kernel.org/show_bug.cgi?id=216876 Bug ID: 216876 Summary: prototype for execveat() in the documentation appears wrong Product: Documentation Version: unspecified Hardware: All OS: Linux Status: NEW Severity: low Priority: P1 Component: man-pages Assignee: documentation_man-pages@xxxxxxxxxxxxxxxxxxxx Reporter: markgaleck@xxxxxxxxx Regression: No 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);
Thanks for the report!
This was introduced in commit 71a25d4c79b1ccf538f6b813c834bbc4197f6370
"execveat.2: Fix prototype".
The reason is that the kernel uses the const:
alx@asus5775:~/src/linux/linux$ grepc execveat
./include/linux/compat.h:851:
asmlinkage long compat_sys_execveat(int dfd, const char __user *filename,
const compat_uptr_t __user *argv,
const compat_uptr_t __user *envp, int flags);
./include/linux/syscalls.h:1011:
asmlinkage long sys_execveat(int dfd, const char __user *filename,
const char __user *const __user *argv,
const char __user *const __user *envp, int flags);
./fs/exec.c:2096:
SYSCALL_DEFINE5(execveat,
int, fd, const char __user *, filename,
const char __user *const __user *, argv,
const char __user *const __user *, envp,
int, flags)
{
return do_execveat(fd,
getname_uflags(filename, flags),
argv, envp, flags);
}
./fs/exec.c:2115:
COMPAT_SYSCALL_DEFINE5(execveat, int, fd,
const char __user *, filename,
const compat_uptr_t __user *, argv,
const compat_uptr_t __user *, envp,
int, flags)
{
return compat_do_execveat(fd,
getname_uflags(filename, flags),
argv, envp, flags);
}
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.
Cheers,
Alex
P.S.: There's some problem in bugzilla that it's not receiving my replies, so I
CCed everyone involved so we can keep the discussion in the mailing list.
P.S.2: Ping, Konstantin, please check that. -- <http://www.alejandro-colomar.es/>
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