Stefan Hansson
b1236ce38b
On musl, O_ACCMODE is defined as (03|O_SEARCH), unlike glibc which defines it as (O_RDONLY|O_WRONLY|O_RDWR). Additionally, O_SEARCH is simply defined as O_PATH. This causes problems for systemd on musl, as it changes the behaviour of open_mkdir_at_full() to return -EINVAL if O_PATH is included in flags due to the fact that O_ACCMODE includes O_SEARCH (i.e. O_PATH). Consequently, this makes the test-fs-util test fail. Upstream musl seems content with this behaviour and doesn't seem interested in matching glibc's behaviour due to that defining it this way allows for O_SEARCH to match POSIX better by allowing it to open directories where read permission is missing. Apparently musl does some emulation in other places to make this work more consistently as well. Initially I took the approach of working around this by redefining O_SEARCH as O_RDONLY if O_SEARCH == O_PATH. This fixes the test and is the approach taken by both XZ[1] and Gzip[2][3], but was not taken as redefining system headers potentially could be problematic. Instead, introduce O_ACCMODE_STRICT which just is a copy of glibc's O_ACCMODE and use it everywhere. This way we don't have to deal with unusual definitions of O_ACCMODE from C standard libraries other than glibc. [1]: https://git.tukaani.org/?p=xz.git;a=blob;f=src/xz/file_io.c;h=8c83269b13fa31284f7ea5f3627a1dfbce7d6e14;hb=HEAD#l72 [2]: https://git.savannah.gnu.org/cgit/gnulib.git/tree/lib/fcntl.in.h (lines 380 and 396, commit d7f551b30f3f2a0fa57c1b10c12f4eea41a9b89e) [3]: https://lists.gnu.org/archive/html/bug-gzip/2025-01/msg00000.html
52 lines
1.9 KiB
C
52 lines
1.9 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
|
|
#pragma once
|
|
|
|
#include <fcntl.h>
|
|
|
|
/* This is defined since glibc-2.41. */
|
|
#ifndef F_DUPFD_QUERY
|
|
#define F_DUPFD_QUERY 1027
|
|
#endif
|
|
|
|
/* This is defined since glibc-2.39. */
|
|
#ifndef F_SEAL_EXEC
|
|
#define F_SEAL_EXEC 0x0020 /* prevent chmod modifying exec bits */
|
|
#endif
|
|
|
|
/* So O_LARGEFILE is generally implied by glibc, and defined to zero hence, because we only build in LFS
|
|
* mode. However, when invoking fcntl(F_GETFL) the flag is ORed into the result anyway — glibc does not mask
|
|
* it away. Which sucks. Let's define the actual value here, so that we can mask it ourselves.
|
|
*
|
|
* The precise definition is arch specific, so we use the values defined in the kernel (note that some
|
|
* are hexa and others are octal; duplicated as-is from the kernel definitions):
|
|
* - alpha, arm, arm64, m68k, mips, parisc, powerpc, sparc: each has a specific value;
|
|
* - others: they use the "generic" value (defined in include/uapi/asm-generic/fcntl.h) */
|
|
#if O_LARGEFILE != 0
|
|
#define RAW_O_LARGEFILE O_LARGEFILE
|
|
#else
|
|
#if defined(__alpha__) || defined(__arm__) || defined(__aarch64__) || defined(__m68k__)
|
|
#define RAW_O_LARGEFILE 0400000
|
|
#elif defined(__mips__)
|
|
#define RAW_O_LARGEFILE 0x2000
|
|
#elif defined(__parisc__) || defined(__hppa__)
|
|
#define RAW_O_LARGEFILE 000004000
|
|
#elif defined(__powerpc__)
|
|
#define RAW_O_LARGEFILE 0200000
|
|
#elif defined(__sparc__)
|
|
#define RAW_O_LARGEFILE 0x40000
|
|
#else
|
|
#define RAW_O_LARGEFILE 00100000
|
|
#endif
|
|
#endif
|
|
|
|
/* This is defined since glibc-2.39. */
|
|
#ifndef AT_HANDLE_FID
|
|
#define AT_HANDLE_FID AT_REMOVEDIR
|
|
#endif
|
|
|
|
/* On musl, O_ACCMODE is defined as (03|O_SEARCH), unlike glibc which defines it as
|
|
* (O_RDONLY|O_WRONLY|O_RDWR). Additionally, O_SEARCH is simply defined as O_PATH. This changes the behaviour
|
|
* of O_ACCMODE in certain situations, which we don't want. This definition is copied from glibc and works
|
|
* around the problems with musl's definition. */
|
|
#define O_ACCMODE_STRICT (O_RDONLY|O_WRONLY|O_RDWR)
|