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authorDennis Wölfing <denniswoelfing@gmx.de>2017-05-30 18:26:19 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2017-05-30 18:27:57 -0300
commit2e0bbbfbf95fc9e22692e93658a6fbdd2d4554da (patch)
tree662856c19816b2b441dbfda3e15ca771eb303e5f /stdlib
parent4f26ef1b67287d1f2c32865f7d79c13abda81915 (diff)
downloadglibc-2e0bbbfbf95fc9e22692e93658a6fbdd2d4554da.tar.gz
Add reallocarray function
The reallocarray function is an extension from OpenBSD. It is an integer-overflow-safe replacement for realloc(p, X*Y) and malloc(X*Y) (realloc(NULL, X*Y)). It can therefore help in preventing certain security issues in code. This is an updated version of a patch originally submitted by Rüdiger Sonderfeld in May 2014 [1]. Checked on i686-linux-gnu and x86_64-linux-gnu. [1] <https://sourceware.org/ml/libc-alpha/2014-05/msg00481.html>. 2017-05-30 Dennis Wölfing <denniswoelfing@gmx.de> Rüdiger Sonderfeld <ruediger@c-plusplus.de> * include/stdlib.h (__libc_reallocarray): New declaration. * malloc/Makefile (routines): Add reallocarray. (tests): Add tst-reallocarray.c. * malloc/Versions: Add reallocarray and __libc_reallocarray. * malloc/malloc-internal.h (check_mul_overflow_size_t): New inline function. * malloc/malloc.h (reallocarray): New declaration. * stdlib/stdlib.h (reallocarray): Likewise. * malloc/reallocarray.c: New file. * malloc/tst-reallocarray.c: New test file. * manual/memory.texi: Document reallocarray. * sysdeps/unix/sysv/linux/aarch64/libc.abilist: Add reallocarray. * sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tilepro/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
Diffstat (limited to 'stdlib')
-rw-r--r--stdlib/stdlib.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/stdlib/stdlib.h b/stdlib/stdlib.h
index 99125f2d23..428ca2ef68 100644
--- a/stdlib/stdlib.h
+++ b/stdlib/stdlib.h
@@ -422,6 +422,17 @@ extern void *calloc (size_t __nmemb, size_t __size)
between objects pointed by the old and new pointers. */
extern void *realloc (void *__ptr, size_t __size)
__THROW __attribute_warn_unused_result__;
+
+#ifdef __USE_GNU
+/* Re-allocate the previously allocated block in PTR, making the new
+ block large enough for NMEMB elements of SIZE bytes each. */
+/* __attribute_malloc__ is not used, because if reallocarray returns
+ the same pointer that was passed to it, aliasing needs to be allowed
+ between objects pointed by the old and new pointers. */
+extern void *reallocarray (void *__ptr, size_t __nmemb, size_t __size)
+ __THROW __attribute_warn_unused_result__;
+#endif
+
/* Free a block allocated by `malloc', `realloc' or `calloc'. */
extern void free (void *__ptr) __THROW;