https://bugzilla.kernel.org/show_bug.cgi?id=73301 Michael Kerrisk <mtk.manpages@xxxxxxxxx> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mtk.manpages@xxxxxxxxx --- Comment #2 from Michael Kerrisk <mtk.manpages@xxxxxxxxx> --- Steven, (In reply to Steven Stewart-Gallus from comment #0) > The errors printed out by the following code on symlink and symlinkat are > missed by the documentation. > > #include <fcntl.h> > #include <stdio.h> > #include <sys/stat.h> > #include <sys/types.h> > #include <unistd.h> > > int main() { > if (-1 == mkdir("/tmp/temporary", S_IRWXU)) { > perror("mkdir"); > } > > int dir = open("/tmp/temporary", O_RDONLY | O_CLOEXEC); > if (-1 == dir) { > perror("open"); > } > > if (-1 == rmdir("/tmp/temporary")) { > perror("rmdir"); > } > > if (-1 == symlinkat("/", dir, "root")) { > perror("symlinkat"); > } So far, so good. > char template_text[] = "/proc/self/fd/XXXXXXXXXXX/root"; > sprintf(template_text, "/proc/self/fd/%i/root", dir); > if (-1 == symlink("/", template_text)) { > perror("symlink"); > } I'm a little puzzled, why would one want to make a symlink somewhere under /proc? > > return 0; > } > > The calls to symlink and symlinkat in this case give ENOENT errors. For symlinkat(), I can see the logic. You're trying to create a link relative to a directory that does not exist. Could the call reasonably do anything other than fail? > This > might also be a small oversight which is probably impossible to change now. > I wonder if the code thinks this is a dangling symbolic link (a case which > is mentioned by the documentation)? > > The POSIX standard issue 7 also seems to miss this corner case (although it > might simply be an omission of mentioning a system dependant case rather > than a bug for the POSIX standard). The specs in POSIX were driven from the Linux implementation effort, so I don;t think that your hypothesis there would fit. > I'm not sure how exactly one would explain this corner case in the > documentation. I'd be willing to give it a shot, but, first,I'm not sure what if anything to say about the symlink() case. Do you have a more realistic example of that case? -- You are receiving this mail because: You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
