Christian Göttsche 6140be90ec fs/xattr: add *at family syscalls ... Add the four syscalls setxattrat(), getxattrat(), listxattrat() and removexattrat(). Those can be used to operate on extended attributes, especially security related ones, either relative to a pinned directory or on a file descriptor without read access, avoiding a /proc/<pid>/fd/<fd> detour, requiring a mounted procfs. One use case will be setfiles(8) setting SELinux file contexts ("security.selinux") without race conditions and without a file descriptor opened with read access requiring SELinux read permission. Use the do_{name}at() pattern from fs/open.c. Pass the value of the extended attribute, its length, and for setxattrat(2) the command (XATTR_CREATE or XATTR_REPLACE) via an added struct xattr_args to not exceed six syscall arguments and not merging the AT_* and XATTR_* flags. [AV: fixes by Christian Brauner folded in, the entire thing rebased on top of {filename,file}_...xattr() primitives, treatment of empty pathnames regularized. As the result, AT_EMPTY_PATH+NULL handling is cheap, so f...(2) can use it] Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Link: https://lore.kernel.org/r/20240426162042.191916-1-cgoettsche@seltendoof.de Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christian Brauner <brauner@kernel.org> CC: x86@kernel.org CC: linux-alpha@vger.kernel.org CC: linux-kernel@vger.kernel.org CC: linux-arm-kernel@lists.infradead.org CC: linux-ia64@vger.kernel.org CC: linux-m68k@lists.linux-m68k.org CC: linux-mips@vger.kernel.org CC: linux-parisc@vger.kernel.org CC: linuxppc-dev@lists.ozlabs.org CC: linux-s390@vger.kernel.org CC: linux-sh@vger.kernel.org CC: sparclinux@vger.kernel.org CC: linux-fsdevel@vger.kernel.org CC: audit@vger.kernel.org CC: linux-arch@vger.kernel.org CC: linux-api@vger.kernel.org CC: linux-security-module@vger.kernel.org CC: selinux@vger.kernel.org [brauner: slight tweaks] Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>		2024-11-06 12:59:44 -05:00
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Kbuild	…
auxvec.h	…
bitsperlong.h	uapi: introduce uapi-friendly macros for GENMASK	2024-02-08 08:41:03 -05:00
bpf_perf_event.h	…
errno-base.h	…
errno.h	…
fcntl.h	open: return EINVAL for O_DIRECTORY | O_CREAT	2023-03-22 11:06:55 +01:00
hugetlb_encode.h	hugetlb_encode.h: fix undefined behaviour (34 << 26)	2022-10-03 14:02:55 -07:00
int-l64.h	…
int-ll64.h	…
ioctl.h	…
ioctls.h	…
ipcbuf.h	arch: ipcbuf.h: make uapi asm/ipcbuf.h self-contained	2019-12-04 19:44:14 -08:00
kvm_para.h	…
mman-common.h	mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse	2022-09-11 20:25:46 -07:00
mman.h	…
msgbuf.h	arch: msgbuf.h: make uapi asm/msgbuf.h self-contained	2019-12-04 19:44:14 -08:00
param.h	…
poll.h	aio: fix use-after-free due to missing POLLFREE handling	2021-12-09 10:49:56 -08:00
posix_types.h	y2038: hide timeval/timespec/itimerval/itimerspec types	2020-02-21 11:22:15 -08:00
resource.h	…
sembuf.h	asm-generic/sembuf: Update architecture related information in comment	2020-10-26 16:48:22 +01:00
setup.h	…
shmbuf.h	shmbuf.h: add asm/shmbuf.h to UAPI compile-test coverage	2022-02-17 09:09:37 +01:00
siginfo.h	kernel: Drop IA64 support from sig_fault handlers	2023-09-11 08:13:18 +00:00
signal-defs.h	signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed	2021-11-03 14:09:26 -05:00
signal.h	signal.h: add linux/signal.h and asm/signal.h to UAPI compile-test coverage	2022-02-17 09:09:36 +01:00
socket.h	net: add SO_DEVMEM_DONTNEED setsockopt to release RX frags	2024-09-11 20:44:32 -07:00
sockios.h	…
stat.h	…
statfs.h	…
swab.h	…
termbits-common.h	serial: Support for RS-485 multipoint addresses	2022-06-27 14:44:20 +02:00
termbits.h	termbits.h: Remove posix_types.h include	2022-05-19 18:25:26 +02:00
termios.h	…
types.h	uapi: Add missing _UAPI prefix to <asm-generic/types.h> include guard	2022-12-01 16:22:06 +01:00
ucontext.h	…
unistd.h	fs/xattr: add *at family syscalls	2024-11-06 12:59:44 -05:00