diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/getcwd.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/getcwd.c | 169 |
1 files changed, 33 insertions, 136 deletions
diff --git a/sysdeps/unix/sysv/linux/getcwd.c b/sysdeps/unix/sysv/linux/getcwd.c index 6e3c5e0644..8f884808c3 100644 --- a/sysdeps/unix/sysv/linux/getcwd.c +++ b/sysdeps/unix/sysv/linux/getcwd.c @@ -38,27 +38,6 @@ #endif -#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. */ -# define no_syscall_getcwd 0 -# define have_new_dcache 1 -#else -# 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. - An additional problem is that the system call does not return - the path of directories longer than one page. */ -static int no_syscall_getcwd; -static int have_new_dcache; -# else -# define no_syscall_getcwd 1 -static int have_new_dcache = 1; -# endif -#endif - /* 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 @@ -73,9 +52,6 @@ __getcwd (char *buf, size_t size) int n; char *result; - if (no_syscall_getcwd && !have_new_dcache) - return generic_getcwd (buf, size); - #ifndef NO_ALLOCATION size_t alloc_size = size; if (size == 0) @@ -101,138 +77,59 @@ __getcwd (char *buf, size_t size) #endif path = buf; -#if defined __NR_getcwd || __LINUX_GETCWD_SYSCALL > 0 - if (!no_syscall_getcwd) - { - int retval; - - retval = INLINE_SYSCALL (getcwd, 2, CHECK_STRING (path), alloc_size); - if (retval >= 0) - { -# ifndef NO_ALLOCATION - if (buf == NULL && size == 0) - /* Ensure that the buffer is only as large as necessary. */ - buf = realloc (path, (size_t) retval); - - if (buf == NULL) - /* Either buf was NULL all along, or `realloc' failed but - we still have the original string. */ - buf = path; -# endif - - return buf; - } - - /* The system call cannot handle paths longer than a page. - Neither can the magic symlink in /proc/self. Just use the - generic implementation right away. */ - if (errno == ENAMETOOLONG) - { -# ifndef NO_ALLOCATION - if (buf == NULL && size == 0) - { - free (path); - path = NULL; - } -# endif - - result = generic_getcwd (path, size); - -# ifndef NO_ALLOCATION - if (result == NULL && buf == NULL && size != 0) - free (path); -# endif - - return result; - } + int retval; -# if __ASSUME_GETCWD_SYSCALL - /* It should never happen that the `getcwd' syscall failed because - the buffer is too small if we allocated the buffer ourselves - large enough. */ - assert (errno != ERANGE || buf != NULL || size != 0); + retval = INLINE_SYSCALL (getcwd, 2, CHECK_STRING (path), alloc_size); + if (retval >= 0) + { +#ifndef NO_ALLOCATION + if (buf == NULL && size == 0) + /* Ensure that the buffer is only as large as necessary. */ + buf = realloc (path, (size_t) retval); -# ifndef NO_ALLOCATION if (buf == NULL) - free (path); -# endif + /* Either buf was NULL all along, or `realloc' failed but + we still have the original string. */ + buf = path; +#endif - return NULL; -# else - if (errno == ENOSYS) - { - no_syscall_getcwd = 1; - have_new_dcache = 1; /* Now we will try the /proc method. */ - } - else if (errno != ERANGE || buf != NULL) - { -# ifndef NO_ALLOCATION - if (buf == NULL) - free (path); -# endif - return NULL; - } -# endif + return buf; } -#endif - n = __readlink ("/proc/self/cwd", path, alloc_size - 1); - if (n != -1) + /* The system call cannot handle paths longer than a page. + Neither can the magic symlink in /proc/self. Just use the + generic implementation right away. */ + if (errno == ENAMETOOLONG) { - if (path[0] == '/') - { - if ((size_t) n >= alloc_size - 1) - { #ifndef NO_ALLOCATION - if (buf == NULL) - free (path); -#endif - return NULL; - } - - path[n] = '\0'; -#ifndef NO_ALLOCATION - if (buf == NULL && size == 0) - /* Ensure that the buffer is only as large as necessary. */ - buf = realloc (path, (size_t) n + 1); - if (buf == NULL) - /* Either buf was NULL all along, or `realloc' failed but - we still have the original string. */ - buf = path; -#endif - - return buf; + if (buf == NULL && size == 0) + { + free (path); + path = NULL; } -#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 + result = generic_getcwd (path, size); #ifndef NO_ALLOCATION - /* Don't put restrictions on the length of the path unless the user does. */ - if (buf == NULL && size == 0) - { - free (path); - path = NULL; - } + if (result == NULL && buf == NULL && size != 0) + free (path); #endif - result = generic_getcwd (path, size); + return result; + } + + /* It should never happen that the `getcwd' syscall failed because + the buffer is too small if we allocated the buffer ourselves + large enough. */ + assert (errno != ERANGE || buf != NULL || size != 0); #ifndef NO_ALLOCATION - if (result == NULL && buf == NULL && size != 0) + if (buf == NULL) free (path); #endif - return result; + return NULL; } weak_alias (__getcwd, getcwd) |