From 9493892021eac4edf1776d945bcdd3f7a96f6978 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 18 Jul 2019 15:16:20 -0400 Subject: refactor all stat functions in terms of fstatat equivalent logic for fstat+O_PATH fallback and direct use of stat/lstat syscalls where appropriate is kept, now in the fstatat function. this change both improves functionality (now, fstatat forms equivalent to fstat/lstat/stat will work even on kernels too old to have the at functions) and localizes direct interfacing with the kernel stat structure to one file. --- src/stat/fstatat.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-) (limited to 'src/stat/fstatat.c') diff --git a/src/stat/fstatat.c b/src/stat/fstatat.c index 582db442..f5bc3685 100644 --- a/src/stat/fstatat.c +++ b/src/stat/fstatat.c @@ -1,9 +1,40 @@ +#define _BSD_SOURCE #include +#include +#include +#include #include "syscall.h" -int fstatat(int fd, const char *restrict path, struct stat *restrict buf, int flag) +int fstatat(int fd, const char *restrict path, struct stat *restrict st, int flag) { - return syscall(SYS_fstatat, fd, path, buf, flag); + int ret; + + if (flag==AT_EMPTY_PATH && fd>=0 && !*path) { + ret = __syscall(SYS_fstat, fd, st); + if (ret==-EBADF && __syscall(SYS_fcntl, fd, F_GETFD)>=0) { + ret = __syscall(SYS_fstatat, fd, path, st, flag); + if (ret==-EINVAL) { + char buf[15+3*sizeof(int)]; + __procfdname(buf, fd); +#ifdef SYS_stat + ret = __syscall(SYS_stat, buf, st); +#else + ret = __syscall(SYS_fstatat, AT_FDCWD, buf, st, 0); +#endif + } + } + } +#ifdef SYS_lstat + else if ((fd == AT_FDCWD || *path=='/') && flag==AT_SYMLINK_NOFOLLOW) + ret = __syscall(SYS_lstat, path, st); +#endif +#ifdef SYS_stat + else if ((fd == AT_FDCWD || *path=='/') && !flag) + ret = __syscall(SYS_stat, path, st); +#endif + else ret = __syscall(SYS_fstatat, fd, path, st, flag); + + return __syscall_ret(ret); } weak_alias(fstatat, fstatat64); -- cgit v1.2.1