Commit Graph

12 Commits

Author SHA1 Message Date
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
Arnd Bergmann
b82c1d235a syscalls: add back legacy __NR_nfsservctl macro
The conversion from the old unistd.h file to syscall.tbl dropped the
nfsservctl macro. This one was handled inconsistently across architectures
in the original introduction of the syscall.tbl format, and I went the
other way on this.

The syscall was already gone in linux-3.1 before the current users
of the generic table (other than openrisc) first appeared, so nobody
could actally use it, but putting the number back helps for consistency
since there are build scripts that check the presence of all these
macros.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=2301919
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-08-06 08:57:02 +02:00
Arnd Bergmann
26fef9d0bb syscalls: fix fstat() entry again
The previous patch to fix the newfstatat() syscall entry ended up breaking
fstat() instead. Unfortunately these two are not handled the same way, so
I messed this one up the exact opposite way.

Fixes: 343416f0c1 ("syscalls: fix syscall macros for newfstat/newfstatat")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-08-05 22:35:43 +02:00
Arnd Bergmann
343416f0c1 syscalls: fix syscall macros for newfstat/newfstatat
The __NR_newfstat and __NR_newfstatat macros accidentally got renamed
in the conversion to the syscall.tbl format, dropping the 'new' portion
of the name.

In an unrelated change, the two syscalls are no longer architecture
specific but are once more defined on all 64-bit architectures, so the
'newstat' ABI keyword can be dropped from the table as a simplification.

Fixes: Fixes: 4fe53bf2ba ("syscalls: add generic scripts/syscall.tbl")
Closes: https://lore.kernel.org/lkml/838053e0-b186-4e9f-9668-9a3384a71f23@app.fastmail.com/T/#t
Reported-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-08-02 15:20:47 +02:00
Arnd Bergmann
54233a4254 uretprobe: change syscall number, again
Despite multiple attempts to get the syscall number assignment right
for the newly added uretprobe syscall, we ended up with a bit of a mess:

 - The number is defined as 467 based on the assumption that the
   xattrat family of syscalls would use 463 through 466, but those
   did not make it into 6.11.

 - The include/uapi/asm-generic/unistd.h file still lists the number
   463, but the new scripts/syscall.tbl that was supposed to have the
   same data lists 467 instead as the number for arc, arm64, csky,
   hexagon, loongarch, nios2, openrisc and riscv. None of these
   architectures actually provide a uretprobe syscall.

 - All the other architectures (powerpc, arm, mips, ...) don't list
   this syscall at all.

There are two ways to make it consistent again: either list it with
the same syscall number on all architectures, or only list it on x86
but not in scripts/syscall.tbl and asm-generic/unistd.h.

Based on the most recent discussion, it seems like we won't need it
anywhere else, so just remove the inconsistent assignment and instead
move the x86 number to the next available one in the architecture
specific range, which is 335.

Fixes: 5c28424e9a ("syscalls: Fix to add sys_uretprobe to syscall.tbl")
Fixes: 190fec72df ("uprobe: Wire up uretprobe system call")
Fixes: 63ded11097 ("uprobe: Change uretprobe syscall scope and number")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-08-02 15:18:49 +02:00
Masami Hiramatsu (Google)
5c28424e9a syscalls: Fix to add sys_uretprobe to syscall.tbl
Add sys_uretprobe entry to scripts/syscall.tbl as same as
arch/x86/entry/syscalls/syscall_64.tbl.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/all/20240719102824.1e086a40@canb.auug.org.au/
Fixes: 63ded11097 ("uprobe: Change uretprobe syscall scope and number")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-07-19 14:35:51 +09:00
Arnd Bergmann
3db80c999d riscv: convert to generic syscall table
The uapi/asm/unistd_{32,64}.h and asm/syscall_table_{32,64}.h headers can
now be generated from scripts/syscall.tbl, which makes this consistent
with the other architectures that have their own syscall.tbl.

riscv has two extra system call that gets added to scripts/syscall.tbl.

The newstat and rlimit entries in the syscall_abis_64 line are for system
calls that were part of the generic ABI when riscv64 got added but are
no longer enabled by default for new architectures. Both riscv32 and
riscv64 also implement memfd_secret, which is optional for all
architectures.

Unlike all the other 32-bit architectures, the time32 and stat64
sets of syscalls are not enabled on riscv32.

Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-07-10 14:23:38 +02:00
Arnd Bergmann
77122bf9e3 openrisc: convert to generic syscall table
The uapi/asm/unistd_32.h and asm/syscall_table_32.h headers can now be
generated from scripts/syscall.tbl, which makes this consistent with
the other architectures that have their own syscall.tbl.

openrisc has one extra system call that gets added to scripts/syscall.tbl.

The time32, stat64, rlimit and renameat entries in the syscall_abis_32
line are for system calls that were part of the generic ABI when
arch/nios2 got added but are no longer enabled by default for new
architectures.

Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.

When asm/syscalls.h is included in kernel/fork.c for the purpose of
type checking, the redirection macros cause problems.  Move these so
only the references get redirected.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-07-10 14:23:38 +02:00
Arnd Bergmann
ef608c5767 nios2: convert to generic syscall table
The uapi/asm/unistd_32.h and asm/syscall_table_32.h headers can now be
generated from scripts/syscall.tbl, which makes this consistent with
the other architectures that have their own syscall.tbl.

nios2 has one extra system call that gets added to scripts/syscall.tbl.

The time32, stat64, and rlimit entries in the syscall_abis_32
line are for system calls that were part of the generic ABI when
arch/nios2 got added but are no longer enabled by default for new
architectures.

Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-07-10 14:23:38 +02:00
Arnd Bergmann
f840cab63e csky: convert to generic syscall table
The uapi/asm/unistd_32.h and asm/syscall_table_32.h headers can now be
generated from scripts/syscall.tbl, which makes this consistent with
the other architectures that have their own syscall.tbl.

csky has two architecture specific system calls, which I add to
the generic table.  The time32, stat64 and rlimit entries in the
syscall_abis_32 line are for system calls that were part of the generic
ABI when arch/csky got added but are no longer enabled by default for
new architectures.

Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-07-10 14:23:38 +02:00
Arnd Bergmann
4414ad8eb4 arc: convert to generic syscall table
The uapi/asm/unistd_32.h and asm/syscall_table_32.h headers can now be
generated from scripts/syscall.tbl, which makes this consistent with
the other architectures that have their own syscall.tbl.

arc has a couple of architecture specific system calls, which I add to the
generic table. This for some reason includes the deprecated sys_sysfs()
syscall that was presumably added by accident.

The time32, renameat, stat64 and rlimit entries in the syscall_abis_32
entry are for system calls that were part of the generic ABI when arch/arc
got added but are no longer enabled by default for new architectures.

Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-07-10 14:23:38 +02:00
Arnd Bergmann
4fe53bf2ba syscalls: add generic scripts/syscall.tbl
The asm-generic/unistd.h header still follows the old style of defining
system call numbers and the table. Most architectures got the new
syscall.tbl format as part of the y2038 conversion back in 2018, but
the newer architectures that share a single table never did.

I did a semi-automated conversion of the asm-generic/unistd.h contents
into a syscall.tbl format, using the ABI field to take care of all
the relevant differences that are encoded using #ifdef checks in the
existing header.

Conversion of the architectures is done one at a time in order to
be able to review or revert them as needed.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-07-04 16:00:29 +02:00