popen: stop using _fwalk.

We don't need this now that popen always uses O_CLOEXEC, and it's unsafe
because _fwalk takes a lock. (In <= P, the equivalent code walked the
list without a lock in the child.)

Bug: http://b/129156634
Test: ran tests
Change-Id: Ic9cee7eb59cfc9397f370d1dc47ea3d3326179ca

1 files changed, 0 insertions, 8 deletions

diff --git a/libc/stdio/stdio.cpp b/libc/stdio/stdio.cpp
index d7b69dcb5..8144e5f1d 100644
--- a/libc/stdio/stdio.cpp
+++ b/libc/stdio/stdio.cpp
@@ -1169,11 +1169,6 @@ size_t fwrite_unlocked(const void* buf, size_t size, size_t count, FILE* fp) {
   return (__sfvwrite(fp, &uio) == 0) ? count : ((n - uio.uio_resid) / size);
 }
 
-static int __close_if_popened(FILE* fp) {
-  if (_EXT(fp)->_popen_pid > 0) close(fileno(fp));
-  return 0;
-}
-
 static FILE* __popen_fail(int fds[2]) {
   ErrnoRestorer errno_restorer;
   close(fds[0]);
@@ -1219,9 +1214,6 @@ FILE* popen(const char* cmd, const char* mode) {
 
   if (pid == 0) {
     close(fds[parent]);
-    // POSIX says "The popen() function shall ensure that any streams from previous popen() calls
-    // that remain open in the parent process are closed in the new child process."
-    _fwalk(__close_if_popened);
     // dup2 so that the child fd isn't closed on exec.
     if (dup2(fds[child], desired_child_fd) == -1) _exit(127);
     close(fds[child]);