[newlib-cygwin] Cygwin: signal: Revert _cygtls::inside_kernel() change

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=9c3e1e9ea9d2d930fef1ae6a62e61b101c1e047c

commit 9c3e1e9ea9d2d930fef1ae6a62e61b101c1e047c
Author: Takashi Yano <[email protected]>
Date:   Wed May 28 15:31:23 2025 +0900

    Cygwin: signal: Revert _cygtls::inside_kernel() change
    
    This patch partially reverts the commit b7097ab39ed0 because it
    seems to cause issues when longjmp is used within a signal handler.
    The problem that the commit addressed no longer occurs even if this
    change is reverted.
    
    Fixes: b7097ab39ed0 ("Cygwin: signal: Revive toggling incyg flag in call_signal_handler()")
    Reviewed-by: Corinna Vinschen <[email protected]>
    Signed-off-by: Takashi Yano <[email protected]>

Diff:
---
 winsup/cygwin/exceptions.cc           | 6 +++---
 winsup/cygwin/local_includes/cygtls.h | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
index 804adc92b..bcc7fe6f8 100644
--- a/winsup/cygwin/exceptions.cc
+++ b/winsup/cygwin/exceptions.cc
@@ -932,7 +932,7 @@ _cygtls::interrupt_now (CONTEXT *cx, siginfo_t& si, void *handler,
   /* Delay the interrupt if we are
      1) somehow inside the DLL
      2) in a Windows DLL.  */
-  if (incyg || inside_kernel (cx, true))
+  if (incyg || inside_kernel (cx))
     interrupted = false;
   else
     {
@@ -1797,7 +1797,7 @@ _cygtls::call_signal_handler ()
 
       int this_errno = saved_errno;
       reset_signal_arrived ();
-      incyg = false;
+      incyg = 0;
       current_sig = 0;	/* Flag that we can accept another signal */
 
       /* We have to fetch the original return address from the signal stack
@@ -1910,7 +1910,7 @@ _cygtls::call_signal_handler ()
 	}
       unlock ();
 
-      incyg = true;
+      incyg = 1;
 
       set_signal_mask (_my_tls.sigmask, (this_sa_flags & SA_SIGINFO)
 					? context1.uc_sigmask : this_oldmask);
diff --git a/winsup/cygwin/local_includes/cygtls.h b/winsup/cygwin/local_includes/cygtls.h
index 1b3bf65f1..615361d3f 100644
--- a/winsup/cygwin/local_includes/cygtls.h
+++ b/winsup/cygwin/local_includes/cygtls.h
@@ -198,7 +198,7 @@ public: /* Do NOT remove this public: line, it's a marker for gentls_offsets. */
   class san *andreas;
   waitq wq;
   volatile int current_sig;
-  unsigned incyg;
+  volatile unsigned incyg;
   volatile unsigned stacklock;
   __tlsstack_t *stackptr;
   __tlsstack_t stack[TLS_STACK_SIZE];