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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 17:39:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 17:39:29 +0000 |
commit | 8ffec2a3aba6f114784e11f89ef1d57a096ae540 (patch) | |
tree | ccebcbad06203e8241a8e7249f8e6c478a3682ea /lib/openat-priv.h | |
parent | Initial commit. (diff) | |
download | coreutils-upstream.tar.xz coreutils-upstream.zip |
Adding upstream version 8.32.upstream/8.32upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/openat-priv.h')
-rw-r--r-- | lib/openat-priv.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/lib/openat-priv.h b/lib/openat-priv.h new file mode 100644 index 0000000..5b824f7 --- /dev/null +++ b/lib/openat-priv.h @@ -0,0 +1,64 @@ +/* Internals for openat-like functions. + + Copyright (C) 2005-2006, 2009-2020 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 + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* written by Jim Meyering */ + +#ifndef _GL_HEADER_OPENAT_PRIV +#define _GL_HEADER_OPENAT_PRIV + +#include <errno.h> +#include <limits.h> +#include <stdlib.h> + +/* 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 + /proc support, and even on systems *with* ProcFS support. Return + nonzero if the failure may be legitimate, e.g., because /proc is not + readable, or the particular .../fd/N directory is not present. */ +#define EXPECTED_ERRNO(Errno) \ + ((Errno) == ENOTDIR || (Errno) == ENOENT \ + || (Errno) == EPERM || (Errno) == EACCES \ + || (Errno) == ENOSYS /* Solaris 8 */ \ + || (Errno) == EOPNOTSUPP /* FreeBSD */) + +/* Wrapper function shared among linkat and renameat. */ +int at_func2 (int fd1, char const *file1, + int fd2, char const *file2, + int (*func) (char const *file1, char const *file2)); + +#endif /* _GL_HEADER_OPENAT_PRIV */ |