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| author |   Mike Gilbert <floppym@gentoo.org> | 2023-07-17 11:03:13 -0400 |
|---|---|---|
| committer | Mike Gilbert <floppym@gentoo.org> | 2023-08-03 20:20:37 -0400 |
| commit | 0317bbe09fe23e4bd972ee254f14817def701731 (patch) | |
| tree | 2a20bfab92c5aef7d090a7aac364a195b263f6a9 /libsbutil | |
| parent | libsandbox: skip checking access() without W_OK or R_OK mode (diff) | |
| download | sandbox-0317bbe09fe23e4bd972ee254f14817def701731.tar.gz sandbox-0317bbe09fe23e4bd972ee254f14817def701731.tar.bz2 sandbox-0317bbe09fe23e4bd972ee254f14817def701731.zip | |
libsbutil: add sbio_faccessat and use it in sb_exists
sbio_faccessat allows libsbutil to access the unwrapped version of
faccessat when called from libsandbox.
Using faccessat in place of fstatat seems to give a small boost in
performance.
Pass AT_EACCESS faccessat to enable a faster path if uid != euid.
Bug: https://bugs.gentoo.org/910273
Signed-off-by: Mike Gilbert <floppym@gentoo.org>
Diffstat (limited to 'libsbutil')
| -rw-r--r-- | libsbutil/sb_exists.c | 10 | ||||
| -rw-r--r-- | libsbutil/sbutil.h | 1 |
2 files changed, 11 insertions, 0 deletions
diff --git a/libsbutil/sb_exists.c b/libsbutil/sb_exists.c index d34f0cc..c2171fe 100644 --- a/libsbutil/sb_exists.c +++ b/libsbutil/sb_exists.c @@ -10,5 +10,15 @@ int sb_exists(int dirfd, const char *pathname, int flags) { struct stat64 buf; + + if (sbio_faccessat(dirfd, pathname, F_OK, flags|AT_EACCESS) == 0) + return 0; + + /* musl's faccessat gives EINVAL when the kernel does not support + * faccessat2 and AT_SYMLINK_NOFOLLOW is set. + * https://www.openwall.com/lists/musl/2023/06/19/1 */ + if (errno != EINVAL) + return -1; + return fstatat64(dirfd, pathname, &buf, flags); } diff --git a/libsbutil/sbutil.h b/libsbutil/sbutil.h index 4061dd3..6d284f1 100644 --- a/libsbutil/sbutil.h +++ b/libsbutil/sbutil.h @@ -100,6 +100,7 @@ extern const char sb_fd_dir[]; const char *sb_get_cmdline(pid_t pid); /* libsandbox need to use a wrapper for open */ +attribute_hidden extern int (*sbio_faccessat)(int, const char *, int, int); attribute_hidden extern int (*sbio_open)(const char *, int, mode_t); attribute_hidden extern FILE *(*sbio_popen)(const char *, const char *); extern const char *sbio_message_path; |