https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=96d856320a1d740546eaf8a6c0ddb3d489e10492
commit 96d856320a1d740546eaf8a6c0ddb3d489e10492
Author: Corinna Vinschen <cori...@vinschen.de>
AuthorDate: Thu Dec 5 18:34:02 2024 +0100
Commit: Corinna Vinschen <cori...@vinschen.de>
CommitDate: Thu Dec 5 21:16:34 2024 +0100
Cygwin: setjmp/longjmp: drop setting spinning flag
Per the comment in _cygtls::interrupt_now(), the spinning flag
is supposed to guard that the targeted thread is about to enter
the Cygwin DLL. Setting spinning has then been added to _sigfe,
_sigbe, sigdelayed and stabilize_sig_stack, the latter being called
from setjmp/longjmp.
However, setjmp/longjmp only enter the DLL in case of a pending
signal, calling _cygtls::call_signal_handler(). This in turn is
already guarded by setting the incyg flag, and there's no other
action in stabilize_sig_stack which might interfere with the
signal setup. All the rest of setjmp/longjmp is plain userspace.
Therefore, drop setting the spinning flag from stabilize_sig_stack,
because it results in dropped signals in tight longjmp loops.
Fixes: edc4f86ad2827 ("* Makefile.in (clean): Remove sigfe.s.")
Signed-off-by: Corinna Vinschen <cori...@vinschen.de>
Diff:
---
winsup/cygwin/scripts/gendef | 1 -
1 file changed, 1 deletion(-)
diff --git a/winsup/cygwin/scripts/gendef b/winsup/cygwin/scripts/gendef
index 377ceb59b2c8..11cdf584abae 100755
--- a/winsup/cygwin/scripts/gendef
+++ b/winsup/cygwin/scripts/gendef
@@ -332,7 +332,6 @@ stabilize_sig_stack:
movq %gs:8,%r12
1: movl \$1,%r10d
xchgl %r10d,_cygtls.stacklock(%r12) # try to acquire lock
- movl %r10d,_cygtls.spinning(%r12) # flag if we are waiting for
lock
testl %r10d,%r10d
jz 2f
pause
