From 122002f0ddf267977282f05066a0794e31661501 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Mon, 15 Mar 2021 10:26:21 -0400 Subject: remove no-longer-needed special case handling in popen popen was special-casing the possibility (only possible when the parent closed stdin and/or stdout) that the child's end of the pipe was already on the final desired fd number, in which case there was no way to get rid of its close-on-exec flag in the child. commit 6fc6ca1a323bc0b6b9e9cdc8fa72221ae18fe206 made this unnecessary by implementing the POSIX-future requirement that dup2 file actions with equal source and destination fd values remove the close-on-exec flag. --- src/stdio/popen.c | 16 ---------------- 1 file changed, 16 deletions(-) (limited to 'src') diff --git a/src/stdio/popen.c b/src/stdio/popen.c index 92cb57ee..b53a5572 100644 --- a/src/stdio/popen.c +++ b/src/stdio/popen.c @@ -33,21 +33,6 @@ FILE *popen(const char *cmd, const char *mode) } FLOCK(f); - /* If the child's end of the pipe happens to already be on the final - * fd number to which it will be assigned (either 0 or 1), it must - * be moved to a different fd. Otherwise, there is no safe way to - * remove the close-on-exec flag in the child without also creating - * a file descriptor leak race condition in the parent. */ - if (p[1-op] == 1-op) { - int tmp = fcntl(1-op, F_DUPFD_CLOEXEC, 0); - if (tmp < 0) { - e = errno; - goto fail; - } - __syscall(SYS_close, p[1-op]); - p[1-op] = tmp; - } - e = ENOMEM; if (!posix_spawn_file_actions_init(&fa)) { if (!posix_spawn_file_actions_adddup2(&fa, p[1-op], 1-op)) { @@ -64,7 +49,6 @@ FILE *popen(const char *cmd, const char *mode) } posix_spawn_file_actions_destroy(&fa); } -fail: fclose(f); __syscall(SYS_close, p[1-op]); -- cgit v1.2.1