Cygwin 3.4.3 and 3.5.0... hangs in make, top, procps, ls /proc/PID/...

[Takashi Yano]

On Thu, 29 Dec 2022 21:59:45 -0700
Brian Inglis wrote:
> I got some hangs (deadlock?) between (parallel?) make jobs, top, procps, and 
> even ls /proc/*/ when trying to cygport all check curl or look at the process 
> statuses when builds hung under Cygwin 3.4.3 and 3.5.0-0.69...
> 
> Had to revert to a Cygwin 3.4.0-344 test build from Dec 16 sources to build and 
> check curl etc.
> 
> Only external differences seems to be recent dll sizes are *MUCH* smaller:
> 
> $ ls -glort /bin/cygwin1*.dll
> -rwxr-xr-x 1 3588124 Sep  5 05:17 /bin/cygwin1-prev.dll
> -rwxr-xr-x 1 3561202 Dec 16 00:33 /bin/cygwin1-test.dll
> -rwxr-xr-x 1 3561202 Dec 16 00:33 /bin/cygwin1.dll
> -rwxr-xr-x 1 2951221 Dec 16 05:50 /bin/cygwin1-save.dll
> -rwxr-xr-x 1 2951221 Dec 16 05:50 /bin/cygwin1-curr.dll
> -rwxr-xr-x 1 2940981 Dec 23 03:03 /bin/cygwin1-69.dll
> 
> and tars:
> -rwxr-xr-x 1 3563651 2022-12-04 06:09 usr/bin/cygwin1.dll cygwin-3.4.0-1
> -rwxr-xr-x 1 3563526 2022-12-10 13:12 usr/bin/cygwin1.dll cygwin-3.4.1-1
> -rwxr-xr-x 1 3564074 2022-12-11 05:06 usr/bin/cygwin1.dll cygwin-3.4.2-1
> -rwxr-xr-x 1 2951221 2022-12-16 05:50 usr/bin/cygwin1.dll cygwin-3.4.3-1
> -rwxr-xr-x 1 2940981 2022-12-23 03:03 usr/bin/cygwin1.dll cygwin-3.5.0-0.69...
> 
> Anyone seen this issue or anything come to mind to cause or help diagnose this?
> 
> Running MS Win 10.0.19044.2364 21H2 patched to date.

I have looked into this issue a bit, and found that
q->sigtls becomes sometimes NULL and access violation
occurs at the following code.

winsup/cygwin/sigproc.cc: 1378
		if (q->sigtls->sigmask & (bit = SIGTOMASK (q->si.si_signo)))
		  {
		    tl_entry = cygheap->find_tls (q->si.si_signo, issig_wait);

I'm not sure why this happens, however it seems that
the following patch fixes the issue.

diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index ce36c8be3..90eaa2a47 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -1375,6 +1375,8 @@ wait_sig (VOID *)
 	    *pack.mask = 0;
 	    while ((q = q->next))
 	      {
+		if (q->sigtls == NULL)
+		  continue;
 		if (q->sigtls->sigmask & (bit = SIGTOMASK (q->si.si_signo)))
 		  {
 		    tl_entry = cygheap->find_tls (q->si.si_signo, issig_wait);

Corinna, could you please have a look?

On Sat, 31 Dec 2022 13:01:29 -0700
Brian Inglis wrote:
> was also getting the messages below locally and still on GitHub scallywag:
> 
> 	cygcheck (6936) child_copy: cygheap read copy failed,
> 
> ../curl/scallywag/1_x86_64  build.log:2022-12-26T00:39:35.6163236Z       0 
> [main] cygcheck (6936) child_copy: cygheap read copy failed, 0x0..0x80003B5F0, 
> done 0, windows pid 6936, Win32 error 299
> ../curl/scallywag/1_x86_64  build.log:2022-12-26T00:48:03.4525278Z       0 
> [main] cygcheck (568) child_copy: cygheap read copy failed, 0x0..0x80003BA48, 
> done 0, windows pid 568, Win32 error 299
> ../dialog/scallywag/1_x86_64  build.log:2022-12-31T18:42:37.0939902Z       0 
> [main] cygcheck (6992) child_copy: cygheap read copy failed, 0x0..0x80003CB38, 
> done 0, windows pid 6992, Win32 error 299

I guess this is another problem.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>