As of f22054c94d (Modify strnstr.c., 2017-08-30), the strnstr() implementation was replaced by a version that segfaults (at least sometimes) on 64-bit systems.
The reason: the new implementation uses memmem(), and the prototype of memmem() is missing because the _GNU_SOURCE constant is not defined before including <string.h>. As a consequence its return type defaults to int (and GCC spits out a warning). On 64-bit systems, the int data type is too small, though, to hold a full char *, hence the upper 32-bit are cut off and bad things happen due to a bogus pointer being used to access memory. Reported as https://github.com/Alexpux/MINGW-packages/issues/2879 in the MSYS2 project. Cc: Sichen Zhao <1473996...@qq.com> Signed-off-by: Johannes Schindelin <johannes.schinde...@gmx.de> --- Published-As: https://github.com/dscho/msys2-runtime/releases/tag/fix-strnstr-segfault-v1 Fetch-It-Via: git fetch https://github.com/dscho/msys2-runtime fix-strnstr-segfault-v1 newlib/libc/string/strnstr.c | 1 + 1 file changed, 1 insertion(+) diff --git a/newlib/libc/string/strnstr.c b/newlib/libc/string/strnstr.c index ce32d0f73e..f6b007813f 100644 --- a/newlib/libc/string/strnstr.c +++ b/newlib/libc/string/strnstr.c @@ -31,6 +31,7 @@ QUICKREF */ #undef __STRICT_ANSI__ +#define _GNU_SOURCE #include <_ansi.h> #include <string.h> base-commit: 05cfd1aed8b262e82f62acc2de2858d2d2b6679c -- 2.14.1.windows.1.521.g18481b3d404
