Add sigaltstack() prototype - Round 2

[Joel Sherrill]

On 8/15/2014 8:46 AM, Corinna Vinschen wrote:
> Hi Joel,
>
> On Aug 15 08:26, Joel Sherrill wrote:
>> Hi
>>
>> The RTEMS Project has been porting more and more FreeBSD code
>> for capabilities like IPV6, USB, and user level commands. We are
>> trying very hard not to have to modify the source code as we
>> move it over. Some of the kernel code we have brought over
>> resulted in this needing to be added.
>>
>> I first proposed v1 of this patch 2 years ago and dropped it.
>> I attempted address those comments though. See the other
>> recent thread.
>>
>> This method is defined here:
>>
>> http://pubs.opengroup.org/onlinepubs/009695399/functions/sigaltstack.html
>>
>> One odd thing is that newlib uses <sys/signal.h> for <signal.h> prototypes
>> so I followed the pattern.   Not much really to the patch. It adds:
>>
>> + typedef struct  sigaltstack {...} stack_t
>> + sigaltstack() prototype protected
>>
>> The big question (as always) is whether or not the guards on the methods
>> are correct.
>>
>> 2014-08-15 Joel Sherrill <...>
>>
>>     * libc/include/sys/signal.h: Add sigaltstack() support.
> Shouldn't this patch define the available flags, too?
You are correct. It should. Obviously the code we were compiling didn't
use them. :)

Attached is v3. Values follow those in glibc. Same ChangeLog.

Built sparc-rtems
>
> Corinna
>

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill@OARcorp.com        On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
Support Available                (256) 722-9985

-------------- next part --------------
Index: newlib/libc/include/sys/signal.h
===================================================================
RCS file: /cvs/src/src/newlib/libc/include/sys/signal.h,v
retrieving revision 1.22
diff -u -r1.22 signal.h
--- newlib/libc/include/sys/signal.h	26 Oct 2012 09:23:46 -0000	1.22
+++ newlib/libc/include/sys/signal.h	15 Aug 2014 14:20:10 -0000
@@ -104,6 +104,23 @@
 #define sa_sigaction  _signal_handlers._sigaction
 #endif
 
+#if __BSD_VISIBLE || __XSI_VISIBLE || __POSIX_VISIBLE >= 200112
+/*
+ * Possible values for ss_flags in stack_t below.
+ */
+#define SS_ONSTACK 0x1
+#define SS_ONSTACK 0x2
+
+/*
+ * Structure used in sigaltstack call.
+ */
+typedef struct sigaltstack {
+  void     *ss_sp;    /* Stack base or pointer.  */
+  int       ss_flags; /* Flags.  */
+  size_t    ss_size;  /* Stack size.  */
+} stack_t;
+#endif
+
 #elif defined(__CYGWIN__)
 #include <cygwin/signal.h>
 #else
@@ -161,6 +178,11 @@
 int _EXFUN(sigsuspend, (const sigset_t *));
 int _EXFUN(sigpause, (int));
 
+
+#if __BSD_VISIBLE || __XSI_VISIBLE || __POSIX_VISIBLE >= 200112
+int _EXFUN(sigaltstack, (const stack_t *__restrict, stack_t *__restrict));
+#endif
+
 #if defined(_POSIX_THREADS)
 #ifdef __CYGWIN__
 #  ifndef _CYGWIN_TYPES_H