diff options
Diffstat (limited to 'sysdeps/generic/sbrk.c')
| -rw-r--r-- | sysdeps/generic/sbrk.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/sysdeps/generic/sbrk.c b/sysdeps/generic/sbrk.c index 698f814..92ad8c4 100644 --- a/sysdeps/generic/sbrk.c +++ b/sysdeps/generic/sbrk.c @@ -22,6 +22,11 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ extern void *__curbrk; extern int __brk (void *addr); +#ifdef PIC +extern int __libc_is_static; +weak_extern (__libc_is_static) +#endif + /* Extend the process's data space by INCREMENT. If INCREMENT is negative, shrink data space by - INCREMENT. Return start of new space allocated, or -1 for errors. */ @@ -30,12 +35,16 @@ __sbrk (ptrdiff_t increment) { void *oldbrk; - /* Always update __curbrk from the kernel's brk value. That way two - separate instances of __brk and __sbrk can share the heap, returning - interleaved pieces of it. This happens when libc.so is loaded by - dlopen in a statically-linked program that already uses __brk. */ - if (__brk (0) < 0) - return (void *) -1; + /* If this is not part of the dynamic library or the library is used + via dynamic loading in a statically linked program update + __curbrk from the kernel's brk value. That way two separate + instances of __brk and __sbrk can share the heap, returning + interleaved pieces of it. */ +#ifdef PIC + if (__curbrk == NULL || &__libc_is_static == NULL) +#endif + if (__brk (0) < 0) + return (void *) -1; if (increment == 0) return __curbrk; |