X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=gnu%2Fopenat-priv.h;h=26983e1853ce3af597cc21ad4a6292343920c0bf;hb=daa269958ad8d50ef8154ccb65e58acaf7a6dd99;hp=ca4fa50f84924a12843a29405f3237fbfbd6aed0;hpb=22f1eb8bc17e5be72dd23d42d6aaa60196ac22e6;p=debian%2Ftar diff --git a/gnu/openat-priv.h b/gnu/openat-priv.h index ca4fa50f..26983e18 100644 --- a/gnu/openat-priv.h +++ b/gnu/openat-priv.h @@ -2,7 +2,7 @@ /* DO NOT EDIT! GENERATED AUTOMATICALLY! */ /* Internals for openat-like functions. - Copyright (C) 2005-2006, 2009-2010 Free Software Foundation, Inc. + Copyright (C) 2005-2006, 2009-2013 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -23,9 +23,29 @@ #define _GL_HEADER_OPENAT_PRIV #include +#include #include -#define OPENAT_BUFFER_SIZE 512 +/* Maximum number of bytes that it is safe to allocate as a single + array on the stack, and that is known as a compile-time constant. + The assumption is that we'll touch the array very quickly, or a + temporary very near the array, provoking an out-of-memory trap. On + some operating systems, there is only one guard page for the stack, + and a page size can be as small as 4096 bytes. Subtract 64 in the + hope that this will let the compiler touch a nearby temporary and + provoke a trap. */ +#define SAFER_ALLOCA_MAX (4096 - 64) + +#define SAFER_ALLOCA(m) ((m) < SAFER_ALLOCA_MAX ? (m) : SAFER_ALLOCA_MAX) + +#if defined PATH_MAX +# define OPENAT_BUFFER_SIZE SAFER_ALLOCA (PATH_MAX) +#elif defined _XOPEN_PATH_MAX +# define OPENAT_BUFFER_SIZE SAFER_ALLOCA (_XOPEN_PATH_MAX) +#else +# define OPENAT_BUFFER_SIZE SAFER_ALLOCA (1024) +#endif + char *openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file); /* Trying to access a BUILD_PROC_NAME file will fail on systems without