linux-stable.git/arch/mips/kernel/syscalls, branch master

arch: hookup fchroot() system call

2026-07-27T15:18:00+00:00

Wire up the fchroot() system call as number 472 on (nearly) all
architectures and sync the mirrored copies of the syscall tables and
the asm-generic unistd.h under tools/.

Link: https://patch.msgid.link/20260724-work-failfs-v2-5-485dabbae185@kernel.org
Signed-off-by: Christian Brauner (Amutable)

rseq: Implement sys_rseq_slice_yield()

2026-01-22T10:11:17+00:00

Provide a new syscall which has the only purpose to yield the CPU after the
kernel granted a time slice extension.

sched_yield() is not suitable for that because it unconditionally
schedules, but the end of the time slice extension is not required to
schedule when the task was already preempted. This also allows to have a
strict check for termination to catch user space invoking random syscalls
including sched_yield() from a time slice extension region.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Mathieu Desnoyers 
Acked-by: Arnd Bergmann 
Link: https://patch.msgid.link/20251215155708.929634896@linutronix.de

arch: hookup listns() system call

2025-11-03T16:41:18+00:00

Add the listns() system call to all architectures.

Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-20-2e6f823ebdc0@kernel.org
Tested-by: syzbot@syzkaller.appspotmail.com
Reviewed-by: Arnd Bergmann 
Reviewed-by: Jeff Layton 
Signed-off-by: Christian Brauner

fs: introduce file_getattr and file_setattr syscalls

2025-07-02T15:05:17+00:00

Introduce file_getattr() and file_setattr() syscalls to manipulate inode
extended attributes. The syscalls takes pair of file descriptor and
pathname. Then it operates on inode opened accroding to openat()
semantics. The struct file_attr is passed to obtain/change extended
attributes.

This is an alternative to FS_IOC_FSSETXATTR ioctl with a difference
that file don't need to be open as we can reference it with a path
instead of fd. By having this we can manipulated inode extended
attributes not only on regular files but also on special ones. This
is not possible with FS_IOC_FSSETXATTR ioctl as with special files
we can not call ioctl() directly on the filesystem inode using fd.

This patch adds two new syscalls which allows userspace to get/set
extended inode attributes on special files by using parent directory
and a path - *at() like syscall.

CC: linux-api@vger.kernel.org
CC: linux-fsdevel@vger.kernel.org
CC: linux-xfs@vger.kernel.org
Signed-off-by: Andrey Albershteyn 
Link: https://lore.kernel.org/20250630-xattrat-syscall-v6-6-c4e3bc35227b@kernel.org
Acked-by: Arnd Bergmann 
Signed-off-by: Christian Brauner

fs: add open_tree_attr()

2025-02-12T11:12:28+00:00

Add open_tree_attr() which allow to atomically create a detached mount
tree and set mount options on it. If OPEN_TREE_CLONE is used this will
allow the creation of a detached mount with a new set of mount options
without it ever being exposed to userspace without that set of mount
options applied.

Link: https://lore.kernel.org/r/20250128-work-mnt_idmap-update-v2-v1-3-c25feb0d2eb3@kernel.org
Reviewed-by: "Seth Forshee (DigitalOcean)" 
Signed-off-by: Christian Brauner

Revert "mips: fix shmctl/semctl/msgctl syscall for o32"

2025-01-31T08:28:38+00:00

This reverts commit bc7584e009c39375294794f7ca751a6b2622c425.

The split IPC system calls for o32 have been introduced with modern
version only. Changing this breaks ABI.

Signed-off-by: Thomas Bogendoerfer

mips: fix shmctl/semctl/msgctl syscall for o32

2025-01-11T11:55:47+00:00

The commit 275f22148e87 ("ipc: rename old-style shmctl/semctl/msgctl
syscalls") switched various architectures to use sys_old_*ctl() with
ipc_parse_version, including mips n32/n64. However, for mips o32, commit
0d6040d46817 ("arch: add split IPC system calls where needed") added
separate IPC syscalls without properly using the old-style handlers.

This causes applications using uClibc-ng to fail with -EINVAL when
calling semctl/shmctl/msgctl with IPC_64 flag, as uClibc-ng uses the
syscall numbers from kernel headers to determine whether to use the IPC
multiplexer or split syscalls. In contrast, glibc is unaffected as it
uses a unified feature test macro __ASSUME_DIRECT_SYSVIPC_SYSCALLS
(disabled for mips-o32) to make this decision.

Fix this by switching the o32 ABI entries for semctl, shmctl and msgctl
to use the old-style handlers, matching the behavior of other
architectures and fixing compatibility with uClibc-ng.

Signed-off-by: Ism Hong 
Signed-off-by: Thomas Bogendoerfer

fs/xattr: add *at family syscalls

2024-11-06T17:59:44+00:00

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//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 
Link: https://lore.kernel.org/r/20240426162042.191916-1-cgoettsche@seltendoof.de
Reviewed-by: Arnd Bergmann 
Reviewed-by: Christian Brauner 
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 
Signed-off-by: Al Viro

syscalls: fix compat_sys_io_pgetevents_time64 usage

2024-06-25T13:57:20+00:00

Using sys_io_pgetevents() as the entry point for compat mode tasks
works almost correctly, but misses the sign extension for the min_nr
and nr arguments.

This was addressed on parisc by switching to
compat_sys_io_pgetevents_time64() in commit 6431e92fc827 ("parisc:
io_pgetevents_time64() needs compat syscall in 32-bit compat mode"),
as well as by using more sophisticated system call wrappers on x86 and
s390. However, arm64, mips, powerpc, sparc and riscv still have the
same bug.

Change all of them over to use compat_sys_io_pgetevents_time64()
like parisc already does. This was clearly the intention when the
function was originally added, but it got hooked up incorrectly in
the tables.

Cc: stable@vger.kernel.org
Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit architectures")
Acked-by: Heiko Carstens  # s390
Signed-off-by: Arnd Bergmann

mips: fix compat_sys_lseek syscall

2024-06-21T08:16:34+00:00

This is almost compatible, but passing a negative offset should result
in a EINVAL error, but on mips o32 compat mode would seek to a large
32-bit byte offset.

Use compat_sys_lseek() to correctly sign-extend the argument.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Thomas Bogendoerfer