diff mbox

[uclibc-ng-devel] valloc declaration in stdlib.h

Message ID CAPmKWpH7x5QVTnehjOTx9SnZD0HqQ5zA=t8BuCmeQK2JPfft=Q@mail.gmail.com
State Accepted
Headers show

Commit Message

Eugene Yudin July 24, 2017, 2:04 p.m. UTC 
Hi,

Current uClibc-ng have issue with several different valloc declarations.

malloc.h:
#ifdef __UCLIBC_SUSV2_LEGACY__
/* Allocate SIZE bytes on a page boundary.  */
extern __malloc_ptr_t valloc __MALLOC_P ((size_t __size))
__attribute_malloc__;
#endif

stdlib.h:
 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 /* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.
 */
 extern void *valloc (size_t __size) __THROW __attribute_malloc__ __wur;
 #endif

The second declaration doesn't use the define __UCLIBC_SUSV2_LEGACY__.
That leads to compile time problems.

The attached patch fixes this diffrence.

Comments

Waldemar Brodkorb July 24, 2017, 8:29 p.m. UTC | #1 
Hi Eugene,
Eugene Yudin wrote,

> Hi,
> 
> Current uClibc-ng have issue with several different valloc declarations.
> 
> malloc.h:
> #ifdef __UCLIBC_SUSV2_LEGACY__
> /* Allocate SIZE bytes on a page boundary.  */
> extern __malloc_ptr_t valloc __MALLOC_P ((size_t __size)) __attribute_malloc__;
> #endif
> 
> stdlib.h:
>  #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
>  /* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.  */
>  extern void *valloc (size_t __size) __THROW __attribute_malloc__ __wur;
>  #endif
> 
> The second declaration doesn't use the define __UCLIBC_SUSV2_LEGACY__.
> That leads to compile time problems.

Can you explain in which situations this leads to compile time
problems?

best regards
 Waldemar
Eugene Yudin July 25, 2017, 9:11 a.m. UTC | #2 
Sorry. I made a typo. Of course It's a runtime error.

Requirements:
 * uClibc-ng with disabled option "Enable SuSv2 LEGACY functions"
(UCLIBC_SUSV2_LEGACY symbol).

Test progam:
$ cat test_valloc.c
#include <stdlib.h>

int main(int argc, char *argv[])
{
void *p;

p = valloc(1);
if (p == NULL)
return EXIT_FAILURE;

free(p);

return EXIT_SUCCESS;
}

The program above compiles without problems because of declaration in
"stdio.h", but it segfaults in runtime:
$ ./test_valloc
Segmentation fault

Definition of valloc also depends from UCLIBC_SUSV2_LEGACY
(libc/stdlib/Makefile.in):
CSRC-$(UCLIBC_SUSV2_LEGACY) += valloc.c

The patch transforms the issue to compile time error.

On Mon, Jul 24, 2017 at 11:29 PM, Waldemar Brodkorb <wbx@uclibc-ng.org>
wrote:

> Hi Eugene,
> Eugene Yudin wrote,
>
> > Hi,
> >
> > Current uClibc-ng have issue with several different valloc declarations.
> >
> > malloc.h:
> > #ifdef __UCLIBC_SUSV2_LEGACY__
> > /* Allocate SIZE bytes on a page boundary.  */
> > extern __malloc_ptr_t valloc __MALLOC_P ((size_t __size))
> __attribute_malloc__;
> > #endif
> >
> > stdlib.h:
> >  #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
> >  /* Allocate SIZE bytes on a page boundary.  The storage cannot be
> freed.  */
> >  extern void *valloc (size_t __size) __THROW __attribute_malloc__ __wur;
> >  #endif
> >
> > The second declaration doesn't use the define __UCLIBC_SUSV2_LEGACY__.
> > That leads to compile time problems.
>
> Can you explain in which situations this leads to compile time
> problems?
>
> best regards
>  Waldemar
>
Waldemar Brodkorb July 29, 2017, 4:34 p.m. UTC | #3 
Hi,
Eugene Yudin wrote,

> Sorry. I made a typo. Of course It's a runtime error.
> 
> Requirements:
>  * uClibc-ng with disabled option "Enable SuSv2 LEGACY functions"
> (UCLIBC_SUSV2_LEGACY symbol).

Applied and pushed,
 Thanks
  Waldemar
diff mbox

Patch

commit 3990f36e0ba7177cb36effe24ef72dca04c762c0
Author: Eugene Yudin <e.yudin@ndmsystems.com>
Date:   Wed May 4 14:56:57 2016 +0300

    stdlib.h: Fix valloc declaration.

diff --git a/include/stdlib.h b/include/stdlib.h
index cbc0473..8947796 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -518,9 +518,11 @@  extern void cfree (void *__ptr) __THROW;
 # include <alloca.h>
 #endif /* Use GNU, BSD, or misc.  */
 
-#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
+#ifdef __UCLIBC_SUSV2_LEGACY__
+# if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 /* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.  */
 extern void *valloc (size_t __size) __THROW __attribute_malloc__ __wur;
+# endif
 #endif
 
 #if defined __USE_XOPEN2K && defined __UCLIBC_HAS_ADVANCED_REALTIME__