Re: signals and _REENT

[Jeff Johnston <jjohnstn at redhat dot com>]

Here is patch as mentioned.  Did I miss anything?

-- Jeff J.

----- Original Message -----
From: "Jeff Johnston" <jjohnstn@redhat.com>
To: "Freddie Chopin" <freddie_chopin@op.pl>
Cc: newlib@sourceware.org
Sent: Wednesday, February 25, 2015 12:34:13 PM
Subject: Re: signals and _REENT

Agreed.  I will post a patch.

----- Original Message -----
From: "Freddie Chopin" <freddie_chopin@op.pl>
To: newlib@sourceware.org
Sent: Tuesday, February 24, 2015 4:06:58 PM
Subject: Re: signals and _REENT

On 02/24/2015 07:07 PM, Jeff Johnston wrote:
> These functions set errno for the caller when an error has occurred.
> This would mean a user would have to check the global errno value (not using
> the dynamic reentrancy errno macro) which in turn could be changed by
> another thread making similar calls and therefore unreliable.

If errno is the only reason for using _REENT instead of _GLOBAL_REENT 
then this can be easily solved. The functions may still get pointer to 
current _REENT (for errno), but signal actions should be taken/set with 
_GLOBAL_REENT.

Regards,
FCh

Index: signal.c
===================================================================
RCS file: /cvs/src/src/newlib/libc/signal/signal.c,v
retrieving revision 1.6
diff -u -p -r1.6 signal.c
--- signal.c	31 Oct 2007 22:22:31 -0000	1.6
+++ signal.c	26 Feb 2015 19:36:27 -0000
@@ -105,14 +105,14 @@ _DEFUN (_init_signal_r, (ptr),
 {
   int i;
 
-  if (ptr->_sig_func == NULL)
+  if (_GLOBAL_REENT->_sig_func == NULL)
     {
-      ptr->_sig_func = (_sig_func_ptr *)_malloc_r (ptr, sizeof (_sig_func_ptr) * NSIG);
-      if (ptr->_sig_func == NULL)
+      _GLOBAL_REENT->_sig_func = (_sig_func_ptr *)_malloc_r (ptr, sizeof (_sig_func_ptr) * NSIG);
+      if (_GLOBAL_REENT->_sig_func == NULL)
 	return -1;
 
       for (i = 0; i < NSIG; i++)
-	ptr->_sig_func[i] = SIG_DFL;
+	_GLOBAL_REENT->_sig_func[i] = SIG_DFL;
     }
 
   return 0;
@@ -132,11 +132,11 @@ _DEFUN (_signal_r, (ptr, sig, func),
       return SIG_ERR;
     }
 
-  if (ptr->_sig_func == NULL && _init_signal_r (ptr) != 0)
+  if (_GLOBAL_REENT->_sig_func == NULL && _init_signal_r (ptr) != 0)
     return SIG_ERR;
   
-  old_func = ptr->_sig_func[sig];
-  ptr->_sig_func[sig] = func;
+  old_func = _GLOBAL_REENT->_sig_func[sig];
+  _GLOBAL_REENT->_sig_func[sig] = func;
 
   return old_func;
 }
@@ -154,10 +154,10 @@ _DEFUN (_raise_r, (ptr, sig),
       return -1;
     }
 
-  if (ptr->_sig_func == NULL)
+  if (_GLOBAL_REENT->_sig_func == NULL)
     func = SIG_DFL;
   else
-    func = ptr->_sig_func[sig];
+    func = _GLOBAL_REENT->_sig_func[sig];
 
   if (func == SIG_DFL)
     return _kill_r (ptr, _getpid_r (ptr), sig);
@@ -170,7 +170,7 @@ _DEFUN (_raise_r, (ptr, sig),
     }
   else
     {
-      ptr->_sig_func[sig] = SIG_DFL;
+      _GLOBAL_REENT->_sig_func[sig] = SIG_DFL;
       func (sig);
       return 0;
     }
@@ -188,10 +188,10 @@ _DEFUN (__sigtramp_r, (ptr, sig),
       return -1;
     }
 
-  if (ptr->_sig_func == NULL && _init_signal_r (ptr) != 0)
+  if (_GLOBAL_REENT->_sig_func == NULL && _init_signal_r (ptr) != 0)
     return -1;
 
-  func = ptr->_sig_func[sig];
+  func = _GLOBAL_REENT->_sig_func[sig];
   if (func == SIG_DFL)
     return 1;
   else if (func == SIG_ERR)
@@ -200,7 +200,7 @@ _DEFUN (__sigtramp_r, (ptr, sig),
     return 3;
   else
     {
-      ptr->_sig_func[sig] = SIG_DFL;
+      _GLOBAL_REENT->_sig_func[sig] = SIG_DFL;
       func (sig);
       return 0;
     }