v1 -> v2: - Use current_umask() instead of current->fs->umask. - Retested it. ---------------------------------------------------------------------- It's not possible to read the process umask without also modifying it, which is what umask(2) does. A library cannot read umask safely, especially if the main program might be multithreaded. This patch series adds a trivial system call "getumask" which returns the umask of the current process. Another approach to this has been attempted before, adding something to /proc, although it didn't go anywhere. See: http://comments.gmane.org/gmane.linux.kernel/1292109 Another way to solve this would be to add a thread-safe getumask to glibc. Since glibc could own the mutex, this would permit libraries linked to this glibc to read umask safely. I should also note that man-pages documents getumask(3), but no version of glibc has ever implemented it. Typical test script: #include <stdio.h> #include <stdlib.h> #include <linux/unistd.h> #include <sys/syscall.h> int main(int argc, char *argv[]) { int r = syscall(329); if (r == -1) { perror("getumask"); exit(1); } printf("umask = %o\n", r); exit(0); } $ ./getumask umask = 22 Rich. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
