https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=a5f96c196e71c7df4cac2575db7be97e95a39df4
commit a5f96c196e71c7df4cac2575db7be97e95a39df4
Author: Takashi Yano <takashi.y...@nifty.ne.jp>
Date: Sat Aug 16 05:57:06 2025 +0900
Cygwin: spawn: Make ch_spwan_local be initialized properly
The class child_info_spawn has two constructors: one without arguments
and one with two arguments. The former does not initialize any members.
Commit 1f836c5f7394 used the latter to ensure that the local ch_spawn
(i.e., ch_spawn_local) would be properly initialized. However, this was
insufficient - it initialized only the base child_info members, not the
fields specific to child_info_spawn. This led to the issue reported in
https://cygwin.com/pipermail/cygwin/2025-August/258660.html.
This patch introduces a new constructor to properly initialize member
variable 'ev', etc., which were referred without initialization, and
switches ch_spawn_local to use it. 'subproc_ready', which may not be
initialized, is also initialized in the constructor of the base class
child_info.
Addresses: https://cygwin.com/pipermail/cygwin/2025-August/258660.html
Fixes: 1f836c5f7394 ("Cygwin: spawn: Make system() thread-safe")
Reported-by: Denis Excoffier <cyg...@denis-excoffier.org>
Reviewed-by: Jeremy Drake <cyg...@jdrake.com>
Signed-off-by: Takashi Yano <takashi.y...@nifty.ne.jp>
(cherry picked from commit 880c96576b2423d1e77e25a3a2da7fc761377728)
Diff:
---
winsup/cygwin/local_includes/child_info.h | 3 ++-
winsup/cygwin/sigproc.cc | 9 ++++++++-
winsup/cygwin/spawn.cc | 2 +-
winsup/cygwin/syscalls.cc | 2 +-
4 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/winsup/cygwin/local_includes/child_info.h
b/winsup/cygwin/local_includes/child_info.h
index 2da62ffaa..25d99fa7d 100644
--- a/winsup/cygwin/local_includes/child_info.h
+++ b/winsup/cygwin/local_includes/child_info.h
@@ -33,7 +33,7 @@ enum child_status
#define EXEC_MAGIC_SIZE sizeof(child_info)
/* Change this value if you get a message indicating that it is out-of-sync. */
-#define CURR_CHILD_INFO_MAGIC 0xacbf4682U
+#define CURR_CHILD_INFO_MAGIC 0x77f25a01U
#include "pinfo.h"
struct cchildren
@@ -149,6 +149,7 @@ public:
void cleanup ();
child_info_spawn () {};
+ child_info_spawn (child_info_types);
child_info_spawn (child_info_types, bool);
void record_children ();
void reattach_children ();
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index 361887981..30779cf8e 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -895,7 +895,8 @@ child_info::child_info (unsigned in_cb, child_info_types
chtype,
msv_count (0), cb (in_cb), intro (PROC_MAGIC_GENERIC),
magic (CHILD_INFO_MAGIC), type (chtype), cygheap (::cygheap),
cygheap_max (::cygheap_max), flag (0), retry (child_info::retry_count),
- rd_proc_pipe (NULL), wr_proc_pipe (NULL), sigmask (_my_tls.sigmask)
+ rd_proc_pipe (NULL), wr_proc_pipe (NULL), subproc_ready (NULL),
+ sigmask (_my_tls.sigmask)
{
fhandler_union_cb = sizeof (fhandler_union);
user_h = cygwin_user_h;
@@ -946,6 +947,12 @@ child_info_fork::child_info_fork () :
{
}
+child_info_spawn::child_info_spawn (child_info_types chtype) :
+ child_info (sizeof *this, chtype, false), hExeced (NULL), ev (NULL),
+ sem (NULL), moreinfo (NULL)
+{
+}
+
child_info_spawn::child_info_spawn (child_info_types chtype, bool
need_subproc_ready) :
child_info (sizeof *this, chtype, need_subproc_ready)
{
diff --git a/winsup/cygwin/spawn.cc b/winsup/cygwin/spawn.cc
index 680f0fefd..71add8755 100644
--- a/winsup/cygwin/spawn.cc
+++ b/winsup/cygwin/spawn.cc
@@ -950,7 +950,7 @@ spawnve (int mode, const char *path, const char *const
*argv,
if (!envp)
envp = empty_env;
- child_info_spawn ch_spawn_local (_CH_NADA, false);
+ child_info_spawn ch_spawn_local (_CH_NADA);
switch (_P_MODE (mode))
{
case _P_OVERLAY:
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 863f8f23c..1b1ff17b0 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -4535,7 +4535,7 @@ popen (const char *command, const char *in_type)
fcntl (stdchild, F_SETFD, stdchild_state | FD_CLOEXEC);
/* Start a shell process to run the given command without forking. */
- child_info_spawn ch_spawn_local (_CH_NADA, false);
+ child_info_spawn ch_spawn_local (_CH_NADA);
pid_t pid = ch_spawn_local.worker ("/bin/sh", argv, environ, _P_NOWAIT,
__std[0], __std[1]);
