From 4e8b0938d90793d6e1e200d6b25e6581b72bd4d0 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 20 Jun 2012 22:16:47 -0400 Subject: proper error handling for fcntl F_GETOWN on modern kernels on old kernels, there's no way to detect errors; we must assume negative syscall return values are pgrp ids. but if the F_GETOWN_EX fcntl works, we can get a reliable answer. --- src/fcntl/fcntl.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'src/fcntl') diff --git a/src/fcntl/fcntl.c b/src/fcntl/fcntl.c index fa5ad32f..fb7806a3 100644 --- a/src/fcntl/fcntl.c +++ b/src/fcntl/fcntl.c @@ -1,6 +1,8 @@ +#define _GNU_SOURCE #include #include #include +#include #include "syscall.h" #include "libc.h" @@ -13,6 +15,12 @@ int fcntl(int fd, int cmd, ...) va_end(ap); if (cmd == F_SETFL) arg |= O_LARGEFILE; if (cmd == F_SETLKW) return syscall_cp(SYS_fcntl, fd, cmd, arg); - if (cmd == F_GETOWN) return __syscall(SYS_fcntl, fd, cmd, arg); + if (cmd == F_GETOWN) { + struct f_owner_ex ex; + int ret = __syscall(SYS_fcntl, fd, F_GETOWN_EX, &ex); + if (ret == -EINVAL) return __syscall(SYS_fcntl, fd, cmd, arg); + if (ret) return __syscall_ret(ret); + return ex.type == F_OWNER_PGRP ? -ex.pid : ex.pid; + } return syscall(SYS_fcntl, fd, cmd, arg); } -- cgit v1.2.1