* exceptions.cc (sig_handle_tty_stop): Avoid races by waiting for bothcvs/cr-0x9ecr-0x9e

signal_arrived and for sigCONT.
(sigpacket::process): Enforce sending of both signal_arrived and sigCONT, where
appropriate.
* gendef (sigreturn): Save tls pointer in ebx so that it can jump into
sigdelayed and use the same register.

3 files changed, 254 insertions, 6 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index a2d027861c0..54b7cb0efaf 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,5 +1,14 @@
 2004-01-26  Christopher Faylor  <cgf@redhat.com>
 
+	* exceptions.cc (sig_handle_tty_stop): Avoid races by waiting for both
+	signal_arrived and for sigCONT.
+	(sigpacket::process): Enforce sending of both signal_arrived and
+	sigCONT, where appropriate.
+	* gendef (sigreturn): Save tls pointer in ebx so that it can jump into
+	sigdelayed and use the same register.
+
+2004-01-26  Christopher Faylor  <cgf@redhat.com>
+
 	* cygtls.cc (_threadinfo::init_thread): Add more local reent stdio
 	initialization.
 	* dcrt0.cc (initial_env): Can it really be true that XP doesn't allow
diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
index 9889d4d260b..49b04c7c87d 100644
--- a/winsup/cygwin/exceptions.cc
+++ b/winsup/cygwin/exceptions.cc
@@ -610,8 +610,19 @@ sig_handle_tty_stop (int sig)
     }
   sigproc_printf ("process %d stopped by signal %d, myself->ppid_handle %p",
 		  myself->pid, sig, myself->ppid_handle);
-  if (WaitForSingleObject (sigCONT, INFINITE) != WAIT_OBJECT_0)
-    api_fatal ("WaitSingleObject failed, %E");
+  HANDLE w4[2];
+  w4[0] = sigCONT;
+  w4[1] = signal_arrived;
+  switch (WaitForMultipleObjects (2, w4, TRUE, INFINITE))
+    {
+    case WAIT_OBJECT_0:
+    case WAIT_OBJECT_0 + 1:
+      reset_signal_arrived ();
+      break;
+    default:
+      api_fatal ("WaitSingleObject failed, %E");
+      break;
+    }
   return;
 }
 }
@@ -891,9 +902,12 @@ set_signal_mask (sigset_t newmask, sigset_t oldmask)
 int __stdcall
 sig_handle (int sig, sigset_t mask, int pid, _threadinfo *tls)
 {
-  if (sig == SIGCONT)
+  DWORD continue_now;
+  if (sig != SIGCONT)
+    continue_now = false;
+  else
     {
-      DWORD stopped = myself->process_state & PID_STOPPED;
+      continue_now = myself->process_state & PID_STOPPED;
       myself->stopsig = 0;
       myself->process_state &= ~PID_STOPPED;
       /* Clear pending stop signals */
@@ -901,8 +915,6 @@ sig_handle (int sig, sigset_t mask, int pid, _threadinfo *tls)
       sig_clear (SIGTSTP);
       sig_clear (SIGTTIN);
       sig_clear (SIGTTOU);
-      if (stopped)
-	SetEvent (sigCONT);
     }
 
   int rc = 1;
@@ -952,6 +964,8 @@ sig_handle (int sig, sigset_t mask, int pid, _threadinfo *tls)
 	  || sig == SIGURG)
 	{
 	  sigproc_printf ("default signal %d ignored", sig);
+	  if (continue_now)
+	    SetEvent (signal_arrived);
 	  goto done;
 	}
 
@@ -985,6 +999,8 @@ dosig:
   rc = setup_handler (sig, handler, thissig, tls ?: _main_tls);
 
 done:
+  if (continue_now)
+    SetEvent (sigCONT);
   sigproc_printf ("returning %d", rc);
   return rc;
 
diff --git a/winsup/cygwin/gendef b/winsup/cygwin/gendef
new file mode 100755
index 00000000000..7e3a4aef996
--- /dev/null
+++ b/winsup/cygwin/gendef
@@ -0,0 +1,223 @@
+#!/usr/bin/perl
+use strict;
+my $in = shift;
+my $tls_offsets = shift;
+my $out = shift;
+my $sigfe = shift;
+
+$main::first = 0;
+if (!defined($in) || !defined($out) || !defined($sigfe)) {
+    die "usage: $0 deffile.in cygtls.h deffile.def sigfe.s\n";
+}
+
+require $tls_offsets;
+
+open(IN, $in) or die "$0: couldn't open \"$in\" - $!\n";
+my @top = ();
+while (<IN>) {
+    push(@top, $_);
+    last if /^\s*exports\s*$/i;
+}
+my $libline = <IN>;
+my @in = <IN>;
+close(IN);
+
+my %sigfe = ();
+my @data = ();
+my @nosigfuncs = ();
+my @out = ();
+for (@in) {
+    /\sDATA$/o and do {
+	push(@data, $_);
+	next;
+    };
+    chomp;
+    if (/=/o) {
+	if (s/\s+NOSIGFE\s*$//) {
+	} elsif (s/ SIGFE$//) {
+	  my $func = (split(' '))[2];
+	  $sigfe{$func} = '_sigfe_' . $func;
+	}
+    } else {
+	my ($func, $sigfe) = m%^\s*(\S+)(?:\s+((?:NO)?SIGR?FE))?$%o;
+	if (defined($sigfe) && $sigfe =~ /^NO/o) {
+	    $_ = $func;
+	} else {
+	    $sigfe ||= 'sigfe';
+	    $_ = '_' . lc($sigfe) . '_' . $func;
+	    $sigfe{$func} = $_;
+	    $_ = $func . ' = ' . $_;
+	}
+    }
+    s/(\S)\s+(\S)/$1 $2/go;
+    s/(\S)\s+$/$1/o;
+    s/^\s+(\S)/$1/o;
+    push(@out, $_ . "\n");
+}
+
+for (@out) {
+    my ($alias, $func) = /^(\S+) = (\S+)\s*$/o;
+    $_ = $alias . ' = ' . $sigfe{$func} . "\n"
+      if defined($func) && $sigfe{$func};
+}
+open(OUT, '>', $out) or die "$0: couldn't open \"$out\" - $!\n";
+print OUT @top, @data, @out;
+close OUT;
+
+open(SIGFE, '>', $sigfe) or die "$0: couldn't open sigfe file \"$sigfe\" - $!\n";
+
+for my $k (sort keys %sigfe) {
+    print SIGFE fefunc($k, $sigfe{$k});
+}
+close SIGFE;
+
+sub fefunc {
+    my $func = '_' . shift;
+    my $fe = '_' . shift;
+    my $extra;
+    my $res = <<EOF;
+	.extern	_siglist_index
+	.extern	_siglist
+	.extern	$func
+	.global	$fe
+$fe:
+	pushl	\$$func
+	jmp	__sigfe
+
+EOF
+    if (!$main::first++) {
+	$res = <<EOF . longjmp () . $res;
+	.text
+	.global	__sigbe
+	.global	_sigreturn
+	.global	_sigdelayed
+
+	.stabs	"_sigfe:F(0,1)",36,0,0,__sigbe
+__sigfe:
+	pushl	%edx
+	movl	%fs:4,%eax
+	movl	\$4,%edx
+	xadd	%edx,$tls::stackptr(%eax)
+	leal	__sigbe,%eax
+	xchg	%eax,8(%esp)
+	movl	%eax,(%edx)
+	popl	%edx
+	ret
+
+	.stabs	"_sigbe:F(0,1)",36,0,0,__sigbe
+__sigbe:
+	pushl	%eax
+	pushl	%edx
+	movl	\$-4,%edx
+1:	movl	%fs:4,%eax
+	xadd	%edx,$tls::stackptr(%eax)
+	xorl	%eax,%eax
+	lock    xchg %eax,-4(%edx)
+	testl	%eax,%eax
+	jnz	2f
+	call	_low_priority_sleep
+	xorl	%edx,%edx
+	jmp	1b
+2:	xchg	%eax,4(%esp)
+	popl	%edx
+	ret
+
+	.stabs	"sigreturn:F(0,1)",36,0,0,_sigreturn
+_sigreturn:
+	addl	\$4,%esp			# Remove argument
+	call	_set_process_mask\@4
+
+	movl	%fs:4,%ebx
+
+	cmpl	\$0,$tls::sig(%ebx)	# Did a signal come in?
+	jnz	3f			# Yes, if non-zero
+
+1:	popl	%edx			# saved errno
+	testl	%edx,%edx		# Is it < 0
+	jl	2f			# yup.  ignore it
+	movl	$tls::errno_addr(%ebx),%eax
+	movl	%edx,(%eax)
+2:	popl	%eax
+	popl	%ebx
+	popl	%ecx
+	popl	%edx
+	popl	%edi
+	popl	%esi
+	popf
+	popl	%ebp
+	jmp	__sigbe
+
+	.stabs	"sigdelayed:F(0,1)",36,0,0,_sigdelayed
+_sigdelayed:
+	pushl	%ebp
+	movl	%esp,%ebp
+	pushf
+	pushl	%esi
+	pushl	%edi
+	pushl	%edx
+	pushl	%ecx
+	pushl	%ebx
+	pushl	%eax
+	movl	%fs:4,%ebx
+	pushl	$tls::saved_errno(%ebx)	# saved errno
+3:	pushl	$tls::oldmask(%ebx)	# oldmask
+	pushl	$tls::sig(%ebx)		# signal argument
+	pushl	\$_sigreturn
+
+	call	_reset_signal_arrived\@0
+	pushl	$tls::func(%ebx)	# signal func
+	pushl	$tls::newmask(%ebx)	# newmask - eaten by set_process_mask
+
+	call	_set_process_mask\@4
+	movl	\$0,$tls::sig(%ebx)	# zero the signal number as a
+					# flag to the signal handler thread
+					# that it is ok to set up sigsave
+	popl	%ebx
+	jmp	*%ebx
+
+EOF
+    }
+    return $res;
+}
+
+sub longjmp {
+    return <<EOF;
+
+	.globl	_longjmp
+
+_longjmp:
+	pushl	%ebp
+	movl	%esp,%ebp
+	movl	8(%ebp),%edi
+	movl	12(%ebp),%eax
+	testl	%eax,%eax
+	jne	0f
+	incl	%eax
+0:
+	movl	%eax,0(%edi)
+	movl	24(%edi),%ebp
+	pushfl
+	popl	%ebx
+	movw	42(%edi),%ax
+	movw	%ax,%ss
+	movl	28(%edi),%esp
+	pushl	32(%edi)
+	pushl	%ebx
+	movw	36(%edi),%ax
+	movw	%ax,%es
+	movw	40(%edi),%ax
+	movw	%ax,%gs
+	movl	%fs:4,%eax
+	leal	($tls::stack)(%eax),%edx
+	movl	%edx,($tls::stackptr)(%eax)
+	movl	0(%edi),%eax
+	movl	4(%edi),%ebx
+	movl	8(%edi),%ecx
+	movl	12(%edi),%edx
+	movl	16(%edi),%esi
+	movl	20(%edi),%edi
+	popfl
+	ret
+
+EOF
+}