diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/getcwd.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/getcwd.c | 45 |
1 files changed, 38 insertions, 7 deletions
diff --git a/sysdeps/unix/sysv/linux/getcwd.c b/sysdeps/unix/sysv/linux/getcwd.c index fe28e2d894..cc7b987f9b 100644 --- a/sysdeps/unix/sysv/linux/getcwd.c +++ b/sysdeps/unix/sysv/linux/getcwd.c @@ -18,6 +18,7 @@ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ +#include <assert.h> #include <errno.h> #include <limits.h> #include <stdlib.h> @@ -26,7 +27,19 @@ #include <sysdep.h> #include <sys/syscall.h> +#include "kernel-features.h" + +#if __ASSUME_GETCWD_SYSCALL > 0 +/* Kernel 2.1.92 introduced a third way to get the current working + directory: a syscall. We've got to be careful that even when + compiling under 2.1.92+ the libc still runs under older kernels. */ +extern int __syscall_getcwd (char *buf, unsigned long size); +# define no_syscall_getcwd 0 +# define have_new_dcache 1 +/* This is a trick since we don't define generic_getcwd. */ +# define generic_getcwd getcwd +#else /* The "proc" filesystem provides an easy method to retrieve the value. For each process, the corresponding directory contains a symbolic link named `cwd'. Reading the content of this link immediate gives us the @@ -34,16 +47,17 @@ the proc filesystem mounted. Use the POSIX implementation in this case. */ static char *generic_getcwd (char *buf, size_t size) internal_function; -#ifdef __NR_getcwd +# if __NR_getcwd /* Kernel 2.1.92 introduced a third way to get the current working directory: a syscall. We've got to be careful that even when compiling under 2.1.92+ the libc still runs under older kernels. */ extern int __syscall_getcwd (char *buf, unsigned long size); static int no_syscall_getcwd; static int have_new_dcache; -#else -# define no_syscall_getcwd 1 +# else +# define no_syscall_getcwd 1 static int have_new_dcache = 1; +# endif #endif char * @@ -80,7 +94,7 @@ __getcwd (char *buf, size_t size) save_errno = errno; -#ifdef __NR_getcwd +#if defined __NR_getcwd || __LINUX_GETCWD_SYSCALL > 0 if (!no_syscall_getcwd) { int retval; @@ -98,6 +112,16 @@ __getcwd (char *buf, size_t size) return buf; } +# if __ASSUME_GETCWD_SYSCALL + /* It should never happen that the `getcwd' syscall failed because + the buffer is too small if we allocated the buffer outself. */ + assert (errno != ERANGE || buf != NULL); + + if (buf == NULL) + free (path); + + return NULL; +# else if (errno == ENOSYS) { no_syscall_getcwd = 1; @@ -111,6 +135,7 @@ __getcwd (char *buf, size_t size) } __set_errno (save_errno); +# endif } #endif @@ -136,14 +161,18 @@ __getcwd (char *buf, size_t size) } return buf; } +#ifndef have_new_dcache else have_new_dcache = 0; +#endif } +#if __ASSUME_GETCWD_SYSCALL == 0 /* Set to have_new_dcache only if error indicates that proc doesn't exist. */ if (errno != EACCES && errno != ENAMETOOLONG) have_new_dcache = 0; +#endif /* Something went wrong. Restore the error number and use the generic version. */ @@ -165,7 +194,9 @@ __getcwd (char *buf, size_t size) } weak_alias (__getcwd, getcwd) +#if __ASSUME_GETCWD_SYSCALL == 0 /* Get the code for the generic version. */ -#define GETCWD_RETURN_TYPE static char * internal_function -#define __getcwd generic_getcwd -#include <sysdeps/posix/getcwd.c> +# define GETCWD_RETURN_TYPE static char * internal_function +# define __getcwd generic_getcwd +# include <sysdeps/posix/getcwd.c> +#endif |