From: "Érico Nogueira via Libc-alpha" <libc-alpha@sourceware.org>
To: libc-alpha@sourceware.org
Cc: "Érico Nogueira" <ericonr@disroot.org>
Subject: [RFC v2] linux: use __fd_to_filename helper function instead of snprintf.
Date: Tue, 27 Apr 2021 10:09:45 -0300 [thread overview]
Message-ID: <20210427130945.917-1-ericonr@disroot.org> (raw)
Change made to fchmodat and fexecve. There are tests using xasprintf
instead of this helper as well, but this commit doesn't touch them.
---
Differences from v1:
- actually builds
- doesn't use an intermediary buf variable
sysdeps/unix/sysv/linux/fchmodat.c | 13 +++----------
sysdeps/unix/sysv/linux/fexecve.c | 10 ++++------
2 files changed, 7 insertions(+), 16 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/fchmodat.c b/sysdeps/unix/sysv/linux/fchmodat.c
index f264f0c09d..5bd1eb96a5 100644
--- a/sysdeps/unix/sysv/linux/fchmodat.c
+++ b/sysdeps/unix/sysv/linux/fchmodat.c
@@ -18,6 +18,7 @@
#include <errno.h>
#include <fcntl.h>
+#include <fd_to_filename.h>
#include <not-cancel.h>
#include <stdio.h>
#include <sys/stat.h>
@@ -69,16 +70,8 @@ fchmodat (int fd, const char *file, mode_t mode, int flag)
/* For most file systems, fchmod does not operate on O_PATH
descriptors, so go through /proc. */
- char buf[32];
- if (__snprintf (buf, sizeof (buf), "/proc/self/fd/%d", pathfd) < 0)
- {
- /* This also may report strange error codes to the caller
- (although snprintf really should not fail). */
- __close_nocancel (pathfd);
- return -1;
- }
-
- int ret = __chmod (buf, mode);
+ struct fd_to_filename filename;
+ int ret = __chmod (__fd_to_filename (pathfd, &filename), mode);
if (ret != 0)
{
if (errno == ENOENT)
diff --git a/sysdeps/unix/sysv/linux/fexecve.c b/sysdeps/unix/sysv/linux/fexecve.c
index f37c245396..df25c2acb8 100644
--- a/sysdeps/unix/sysv/linux/fexecve.c
+++ b/sysdeps/unix/sysv/linux/fexecve.c
@@ -22,6 +22,7 @@
#include <fcntl.h>
#include <sys/stat.h>
+#include <fd_to_filename.h>
#include <sysdep.h>
#include <sys/syscall.h>
#include <kernel-features.h>
@@ -49,12 +50,9 @@ fexecve (int fd, char *const argv[], char *const envp[])
#ifndef __ASSUME_EXECVEAT
/* We use the /proc filesystem to get the information. If it is not
- mounted we fail. */
- char buf[sizeof "/proc/self/fd/" + sizeof (int) * 3];
- __snprintf (buf, sizeof (buf), "/proc/self/fd/%d", fd);
-
- /* We do not need the return value. */
- __execve (buf, argv, envp);
+ mounted we fail. We do not need the return value. */
+ struct fd_to_filename filename;
+ __execve (__fd_to_filename (fd, &filename), argv, envp);
int save = errno;
--
2.31.1
next reply other threads:[~2021-04-27 13:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-27 13:09 Érico Nogueira via Libc-alpha [this message]
2021-05-03 19:26 ` [RFC v2] linux: use __fd_to_filename helper function instead of snprintf Adhemerval Zanella via Libc-alpha
2021-05-03 20:26 ` Érico Nogueira via Libc-alpha
2021-05-03 20:47 ` Adhemerval Zanella via Libc-alpha
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