fs: add open_tree_attr()

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 detache

fs: add open_tree_attr()

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/[email protected]
Reviewed-by: "Seth Forshee (DigitalOcean)" <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

show more ...

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 relat

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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Arnd Bergmann <[email protected]>
Reviewed-by: Christian Brauner <[email protected]>
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
[brauner: slight tweaks]
Signed-off-by: Christian Brauner <[email protected]>
Signed-off-by: Al Viro <[email protected]>

show more ...

powerpc: restore some missing spu syscalls

A couple of system calls were inadventently removed from the table during
a bugfix for 32-bit powerpc entry. Restore the original behavior.

Fixes: e237506

powerpc: restore some missing spu syscalls

A couple of system calls were inadventently removed from the table during
a bugfix for 32-bit powerpc entry. Restore the original behavior.

Fixes: e23750623835 ("powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs")
Acked-by: Michael Ellerman <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>

show more ...

syscalls: fix compat_sys_io_pgetevents_time64 usage

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 arg

syscalls: fix compat_sys_io_pgetevents_time64 usage

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: [email protected]
Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit architectures")
Acked-by: Heiko Carstens <[email protected]> # s390
Signed-off-by: Arnd Bergmann <[email protected]>

show more ...

mseal: wire up mseal syscall

Patch series "Introduce mseal", v10.

This patchset proposes a new mseal() syscall for the Linux kernel.

In a nutshell, mseal() protects the VMAs of a given virtual mem

mseal: wire up mseal syscall

Patch series "Introduce mseal", v10.

This patchset proposes a new mseal() syscall for the Linux kernel.

In a nutshell, mseal() protects the VMAs of a given virtual memory range
against modifications, such as changes to their permission bits.

Modern CPUs support memory permissions, such as the read/write (RW) and
no-execute (NX) bits. Linux has supported NX since the release of kernel
version 2.6.8 in August 2004 [1]. The memory permission feature improves
the security stance on memory corruption bugs, as an attacker cannot
simply write to arbitrary memory and point the code to it. The memory
must be marked with the X bit, or else an exception will occur.
Internally, the kernel maintains the memory permissions in a data
structure called VMA (vm_area_struct). mseal() additionally protects the
VMA itself against modifications of the selected seal type.

Memory sealing is useful to mitigate memory corruption issues where a
corrupted pointer is passed to a memory management system. For example,
such an attacker primitive can break control-flow integrity guarantees
since read-only memory that is supposed to be trusted can become writable
or .text pages can get remapped. Memory sealing can automatically be
applied by the runtime loader to seal .text and .rodata pages and
applications can additionally seal security critical data at runtime. A
similar feature already exists in the XNU kernel with the
VM_FLAGS_PERMANENT [3] flag and on OpenBSD with the mimmutable syscall
[4]. Also, Chrome wants to adopt this feature for their CFI work [2] and
this patchset has been designed to be compatible with the Chrome use case.

Two system calls are involved in sealing the map: mmap() and mseal().

The new mseal() is an syscall on 64 bit CPU, and with following signature:

int mseal(void addr, size_t len, unsigned long flags)
addr/len: memory range.
flags: reserved.

mseal() blocks following operations for the given memory range.

1> Unmapping, moving to another location, and shrinking the size,
via munmap() and mremap(), can leave an empty space, therefore can
be replaced with a VMA with a new set of attributes.

2> Moving or expanding a different VMA into the current location,
via mremap().

3> Modifying a VMA via mmap(MAP_FIXED).

4> Size expansion, via mremap(), does not appear to pose any specific
risks to sealed VMAs. It is included anyway because the use case is
unclear. In any case, users can rely on merging to expand a sealed VMA.

5> mprotect() and pkey_mprotect().

6> Some destructive madvice() behaviors (e.g. MADV_DONTNEED) for anonymous
memory, when users don't have write permission to the memory. Those
behaviors can alter region contents by discarding pages, effectively a
memset(0) for anonymous memory.

The idea that inspired this patch comes from Stephen Röttger’s work in
V8 CFI [5]. Chrome browser in ChromeOS will be the first user of this
API.

Indeed, the Chrome browser has very specific requirements for sealing,
which are distinct from those of most applications. For example, in the
case of libc, sealing is only applied to read-only (RO) or read-execute
(RX) memory segments (such as .text and .RELRO) to prevent them from
becoming writable, the lifetime of those mappings are tied to the lifetime
of the process.

Chrome wants to seal two large address space reservations that are managed
by different allocators. The memory is mapped RW- and RWX respectively
but write access to it is restricted using pkeys (or in the future ARM
permission overlay extensions). The lifetime of those mappings are not
tied to the lifetime of the process, therefore, while the memory is
sealed, the allocators still need to free or discard the unused memory.
For example, with madvise(DONTNEED).

However, always allowing madvise(DONTNEED) on this range poses a security
risk. For example if a jump instruction crosses a page boundary and the
second page gets discarded, it will overwrite the target bytes with zeros
and change the control flow. Checking write-permission before the discard
operation allows us to control when the operation is valid. In this case,
the madvise will only succeed if the executing thread has PKEY write
permissions and PKRU changes are protected in software by control-flow
integrity.

Although the initial version of this patch series is targeting the Chrome
browser as its first user, it became evident during upstream discussions
that we would also want to ensure that the patch set eventually is a
complete solution for memory sealing and compatible with other use cases.
The specific scenario currently in mind is glibc's use case of loading and
sealing ELF executables. To this end, Stephen is working on a change to
glibc to add sealing support to the dynamic linker, which will seal all
non-writable segments at startup. Once this work is completed, all
applications will be able to automatically benefit from these new
protections.

In closing, I would like to formally acknowledge the valuable
contributions received during the RFC process, which were instrumental in
shaping this patch:

Jann Horn: raising awareness and providing valuable insights on the
destructive madvise operations.
Liam R. Howlett: perf optimization.
Linus Torvalds: assisting in defining system call signature and scope.
Theo de Raadt: sharing the experiences and insight gained from
implementing mimmutable() in OpenBSD.

MM perf benchmarks
==================
This patch adds a loop in the mprotect/munmap/madvise(DONTNEED) to
check the VMAs’ sealing flag, so that no partial update can be made,
when any segment within the given memory range is sealed.

To measure the performance impact of this loop, two tests are developed.
[8]

The first is measuring the time taken for a particular system call,
by using clock_gettime(CLOCK_MONOTONIC). The second is using
PERF_COUNT_HW_REF_CPU_CYCLES (exclude user space). Both tests have
similar results.

The tests have roughly below sequence:
for (i = 0; i < 1000, i++)
create 1000 mappings (1 page per VMA)
start the sampling
for (j = 0; j < 1000, j++)
mprotect one mapping
stop and save the sample
delete 1000 mappings
calculates all samples.

Below tests are performed on Intel(R) Pentium(R) Gold 7505 @ 2.00GHz,
4G memory, Chromebook.

Based on the latest upstream code:
The first test (measuring time)
syscall__ vmas t t_mseal delta_ns per_vma %
munmap__ 1 909 944 35 35 104%
munmap__ 2 1398 1502 104 52 107%
munmap__ 4 2444 2594 149 37 106%
munmap__ 8 4029 4323 293 37 107%
munmap__ 16 6647 6935 288 18 104%
munmap__ 32 11811 12398 587 18 105%
mprotect 1 439 465 26 26 106%
mprotect 2 1659 1745 86 43 105%
mprotect 4 3747 3889 142 36 104%
mprotect 8 6755 6969 215 27 103%
mprotect 16 13748 14144 396 25 103%
mprotect 32 27827 28969 1142 36 104%
madvise_ 1 240 262 22 22 109%
madvise_ 2 366 442 76 38 121%
madvise_ 4 623 751 128 32 121%
madvise_ 8 1110 1324 215 27 119%
madvise_ 16 2127 2451 324 20 115%
madvise_ 32 4109 4642 534 17 113%

The second test (measuring cpu cycle)
syscall__ vmas cpu cmseal delta_cpu per_vma %
munmap__ 1 1790 1890 100 100 106%
munmap__ 2 2819 3033 214 107 108%
munmap__ 4 4959 5271 312 78 106%
munmap__ 8 8262 8745 483 60 106%
munmap__ 16 13099 14116 1017 64 108%
munmap__ 32 23221 24785 1565 49 107%
mprotect 1 906 967 62 62 107%
mprotect 2 3019 3203 184 92 106%
mprotect 4 6149 6569 420 105 107%
mprotect 8 9978 10524 545 68 105%
mprotect 16 20448 21427 979 61 105%
mprotect 32 40972 42935 1963 61 105%
madvise_ 1 434 497 63 63 115%
madvise_ 2 752 899 147 74 120%
madvise_ 4 1313 1513 200 50 115%
madvise_ 8 2271 2627 356 44 116%
madvise_ 16 4312 4883 571 36 113%
madvise_ 32 8376 9319 943 29 111%

Based on the result, for 6.8 kernel, sealing check adds
20-40 nano seconds, or around 50-100 CPU cycles, per VMA.

In addition, I applied the sealing to 5.10 kernel:
The first test (measuring time)
syscall__ vmas t tmseal delta_ns per_vma %
munmap__ 1 357 390 33 33 109%
munmap__ 2 442 463 21 11 105%
munmap__ 4 614 634 20 5 103%
munmap__ 8 1017 1137 120 15 112%
munmap__ 16 1889 2153 263 16 114%
munmap__ 32 4109 4088 -21 -1 99%
mprotect 1 235 227 -7 -7 97%
mprotect 2 495 464 -30 -15 94%
mprotect 4 741 764 24 6 103%
mprotect 8 1434 1437 2 0 100%
mprotect 16 2958 2991 33 2 101%
mprotect 32 6431 6608 177 6 103%
madvise_ 1 191 208 16 16 109%
madvise_ 2 300 324 24 12 108%
madvise_ 4 450 473 23 6 105%
madvise_ 8 753 806 53 7 107%
madvise_ 16 1467 1592 125 8 108%
madvise_ 32 2795 3405 610 19 122%

The second test (measuring cpu cycle)
syscall__ nbr_vma cpu cmseal delta_cpu per_vma %
munmap__ 1 684 715 31 31 105%
munmap__ 2 861 898 38 19 104%
munmap__ 4 1183 1235 51 13 104%
munmap__ 8 1999 2045 46 6 102%
munmap__ 16 3839 3816 -23 -1 99%
munmap__ 32 7672 7887 216 7 103%
mprotect 1 397 443 46 46 112%
mprotect 2 738 788 50 25 107%
mprotect 4 1221 1256 35 9 103%
mprotect 8 2356 2429 72 9 103%
mprotect 16 4961 4935 -26 -2 99%
mprotect 32 9882 10172 291 9 103%
madvise_ 1 351 380 29 29 108%
madvise_ 2 565 615 49 25 109%
madvise_ 4 872 933 61 15 107%
madvise_ 8 1508 1640 132 16 109%
madvise_ 16 3078 3323 245 15 108%
madvise_ 32 5893 6704 811 25 114%

For 5.10 kernel, sealing check adds 0-15 ns in time, or 10-30
CPU cycles, there is even decrease in some cases.

It might be interesting to compare 5.10 and 6.8 kernel
The first test (measuring time)
syscall__ vmas t_5_10 t_6_8 delta_ns per_vma %
munmap__ 1 357 909 552 552 254%
munmap__ 2 442 1398 956 478 316%
munmap__ 4 614 2444 1830 458 398%
munmap__ 8 1017 4029 3012 377 396%
munmap__ 16 1889 6647 4758 297 352%
munmap__ 32 4109 11811 7702 241 287%
mprotect 1 235 439 204 204 187%
mprotect 2 495 1659 1164 582 335%
mprotect 4 741 3747 3006 752 506%
mprotect 8 1434 6755 5320 665 471%
mprotect 16 2958 13748 10790 674 465%
mprotect 32 6431 27827 21397 669 433%
madvise_ 1 191 240 49 49 125%
madvise_ 2 300 366 67 33 122%
madvise_ 4 450 623 173 43 138%
madvise_ 8 753 1110 357 45 147%
madvise_ 16 1467 2127 660 41 145%
madvise_ 32 2795 4109 1314 41 147%

The second test (measuring cpu cycle)
syscall__ vmas cpu_5_10 c_6_8 delta_cpu per_vma %
munmap__ 1 684 1790 1106 1106 262%
munmap__ 2 861 2819 1958 979 327%
munmap__ 4 1183 4959 3776 944 419%
munmap__ 8 1999 8262 6263 783 413%
munmap__ 16 3839 13099 9260 579 341%
munmap__ 32 7672 23221 15549 486 303%
mprotect 1 397 906 509 509 228%
mprotect 2 738 3019 2281 1140 409%
mprotect 4 1221 6149 4929 1232 504%
mprotect 8 2356 9978 7622 953 423%
mprotect 16 4961 20448 15487 968 412%
mprotect 32 9882 40972 31091 972 415%
madvise_ 1 351 434 82 82 123%
madvise_ 2 565 752 186 93 133%
madvise_ 4 872 1313 442 110 151%
madvise_ 8 1508 2271 763 95 151%
madvise_ 16 3078 4312 1234 77 140%
madvise_ 32 5893 8376 2483 78 142%

From 5.10 to 6.8
munmap: added 250-550 ns in time, or 500-1100 in cpu cycle, per vma.
mprotect: added 200-750 ns in time, or 500-1200 in cpu cycle, per vma.
madvise: added 33-50 ns in time, or 70-110 in cpu cycle, per vma.

In comparison to mseal, which adds 20-40 ns or 50-100 CPU cycles, the
increase from 5.10 to 6.8 is significantly larger, approximately ten times
greater for munmap and mprotect.

When I discuss the mm performance with Brian Makin, an engineer who worked
on performance, it was brought to my attention that such performance
benchmarks, which measuring millions of mm syscall in a tight loop, may
not accurately reflect real-world scenarios, such as that of a database
service. Also this is tested using a single HW and ChromeOS, the data
from another HW or distribution might be different. It might be best to
take this data with a grain of salt.


This patch (of 5):

Wire up mseal syscall for all architectures.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jeff Xu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jann Horn <[email protected]> [Bug #2]
Cc: Jeff Xu <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Jorge Lucangeli Obes <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Muhammad Usama Anjum <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: Stephen Röttger <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Amer Al Shanawany <[email protected]>
Cc: Javier Carrasco <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

wire up syscalls for statmount/listmount

Wire up all archs.

Signed-off-by: Miklos Szeredi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed

wire up syscalls for statmount/listmount

Wire up all archs.

Signed-off-by: Miklos Szeredi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Ian Kent <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

show more ...

LSM: wireup Linux Security Module syscalls

Wireup lsm_get_self_attr, lsm_set_self_attr and lsm_list_modules
system calls.

Signed-off-by: Casey Schaufler <[email protected]>
Reviewed-by: Kees C

LSM: wireup Linux Security Module syscalls

Wireup lsm_get_self_attr, lsm_set_self_attr and lsm_list_modules
system calls.

Signed-off-by: Casey Schaufler <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Cc: [email protected]
Reviewed-by: Mickaël Salaün <[email protected]>
[PM: forward ported beyond v6.6 due merge window changes]
Signed-off-by: Paul Moore <[email protected]>

show more ...

arch: Reserve map_shadow_stack() syscall number for all architectures

commit c35559f94ebc ("x86/shstk: Introduce map_shadow_stack syscall")
recently added support for map_shadow_stack() but it is li

arch: Reserve map_shadow_stack() syscall number for all architectures

commit c35559f94ebc ("x86/shstk: Introduce map_shadow_stack syscall")
recently added support for map_shadow_stack() but it is limited to x86
only for now. There is a possibility that other architectures (namely,
arm64 and RISC-V), that are implementing equivalent support for shadow
stacks, might need to add support for it.

Independent of that, reserving arch-specific syscall numbers in the
syscall tables of all architectures is good practice and would help
avoid future conflicts. map_shadow_stack() is marked as a conditional
syscall in sys_ni.c. Adding it to the syscall tables of other
architectures is harmless and would return ENOSYS when exercised.

Note, map_shadow_stack() was assigned #453 during the merge process
since #452 was taken by fchmodat2().

For Powerpc, map it to sys_ni_syscall() as is the norm for Powerpc
syscall tables.

For Alpha, map_shadow_stack() takes up #563 as Alpha still diverges from
the common syscall numbering system in the other architectures.

Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lore.kernel.org/lkml/[email protected]/

Signed-off-by: Sohil Mehta <[email protected]>
Reviewed-by: Rick Edgecombe <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Acked-by: Michael Ellerman <[email protected]> (powerpc)
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>

show more ...

syscalls: Cleanup references to sys_lookup_dcookie()

commit 'be65de6b03aa ("fs: Remove dcookies support")' removed the
syscall definition for lookup_dcookie. However, syscall tables still
point to

syscalls: Cleanup references to sys_lookup_dcookie()

commit 'be65de6b03aa ("fs: Remove dcookies support")' removed the
syscall definition for lookup_dcookie. However, syscall tables still
point to the old sys_lookup_dcookie() definition. Update syscall tables
of all architectures to directly point to sys_ni_syscall() instead.

Signed-off-by: Sohil Mehta <[email protected]>
Reviewed-by: Randy Dunlap <[email protected]>
Acked-by: Namhyung Kim <[email protected]> # for perf
Acked-by: Russell King (Oracle) <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>

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futex: Add sys_futex_requeue()

Finish off the 'simple' futex2 syscall group by adding
sys_futex_requeue(). Unlike sys_futex_{wait,wake}() its arguments are
too numerous to fit into a regular syscall

futex: Add sys_futex_requeue()

Finish off the 'simple' futex2 syscall group by adding
sys_futex_requeue(). Unlike sys_futex_{wait,wake}() its arguments are
too numerous to fit into a regular syscall. As such, use struct
futex_waitv to pass the 'source' and 'destination' futexes to the
syscall.

This syscall implements what was previously known as FUTEX_CMP_REQUEUE
and uses {val, uaddr, flags} for source and {uaddr, flags} for
destination.

This design explicitly allows requeueing between different types of
futex by having a different flags word per uaddr.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

futex: Add sys_futex_wait()

To complement sys_futex_waitv()/wake(), add sys_futex_wait(). This
syscall implements what was previously known as FUTEX_WAIT_BITSET
except it uses 'unsigned long' for th

futex: Add sys_futex_wait()

To complement sys_futex_waitv()/wake(), add sys_futex_wait(). This
syscall implements what was previously known as FUTEX_WAIT_BITSET
except it uses 'unsigned long' for the value and bitmask arguments,
takes timespec and clockid_t arguments for the absolute timeout and
uses FUTEX2 flags.

The 'unsigned long' allows FUTEX2_SIZE_U64 on 64bit platforms.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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futex: Add sys_futex_wake()

To complement sys_futex_waitv() add sys_futex_wake(). This syscall
implements what was previously known as FUTEX_WAKE_BITSET except it
uses 'unsigned long' for the bitmas

futex: Add sys_futex_wake()

To complement sys_futex_waitv() add sys_futex_wake(). This syscall
implements what was previously known as FUTEX_WAKE_BITSET except it
uses 'unsigned long' for the bitmask and takes FUTEX2 flags.

The 'unsigned long' allows FUTEX2_SIZE_U64 on 64bit platforms.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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arch: Register fchmodat2, usually as syscall 452

This registers the new fchmodat2 syscall in most places as nuber 452,
with alpha being the exception where it's 562. I found all these sites
by grep

arch: Register fchmodat2, usually as syscall 452

This registers the new fchmodat2 syscall in most places as nuber 452,
with alpha being the exception where it's 562. I found all these sites
by grepping for fspick, which I assume has found me everything.

Signed-off-by: Palmer Dabbelt <[email protected]>
Signed-off-by: Alexey Gladkov <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Message-Id: <a677d521f048e4ca439e7080a5328f21eb8e960e.1689092120.git.legion@kernel.org>
Signed-off-by: Christian Brauner <[email protected]>

show more ...

cachestat: wire up cachestat for other architectures

cachestat is previously only wired in for x86 (and architectures using
the generic unistd.h table):

https://lore.kernel.org/lkml/20230503013608.

cachestat: wire up cachestat for other architectures

cachestat is previously only wired in for x86 (and architectures using
the generic unistd.h table):

https://lore.kernel.org/lkml/[email protected]/

This patch wires cachestat in for all the other architectures.

[[email protected]: wire up cachestat for arm64]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Nhat Pham <[email protected]>
Tested-by: Michael Ellerman <[email protected]> [powerpc]
Acked-by: Geert Uytterhoeven <[email protected]> [m68k]
Reviewed-by: Arnd Bergmann <[email protected]>
Acked-by: Heiko Carstens <[email protected]> [s390]
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: John Paul Adrian Glaubitz <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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powerpc/32: fix syscall wrappers with 64-bit arguments

With the introduction of syscall wrappers all wrappers for syscalls with
64-bit arguments must be handled specially, not only those that have
u

powerpc/32: fix syscall wrappers with 64-bit arguments

With the introduction of syscall wrappers all wrappers for syscalls with
64-bit arguments must be handled specially, not only those that have
unaligned 64-bit arguments. This left out the fallocate() and
sync_file_range2() syscalls.

Fixes: 7e92e01b7245 ("powerpc: Provide syscall wrapper")
Fixes: e23750623835 ("powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs")
Signed-off-by: Andreas Schwab <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs

powerpc 32-bit system call (and function) calling convention for 64-bit
arguments requires the next available odd-p

powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs

powerpc 32-bit system call (and function) calling convention for 64-bit
arguments requires the next available odd-pair (two sequential registers
with the first being odd-numbered) from the standard register argument
allocation.

The first argument register is r3, so a 64-bit argument that appears at
an even position in the argument list must skip a register (unless there
were preceding 64-bit arguments, which might throw things off). This
requires non-standard compat definitions to deal with the holes in the
argument register allocation.

With pt_regs syscall wrappers which use a standard mapper to map pt_regs
GPRs to function arguments, 32-bit kernels hit the same basic problem,
the standard definitions don't cope with the unused argument registers.

Fix this by having 32-bit kernels share those syscall definitions with
compat.

Thanks to Jason for spending a lot of time finding and bisecting this
and developing a trivial reproducer. The perfect bug report.

Reported-by: Jason A. Donenfeld <[email protected]>
Signed-off-by: Nicholas Piggin <[email protected]>
Fixes: 7e92e01b72452 ("powerpc: Provide syscall wrapper")
Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc: Adopt SYSCALL_DEFINE for arch-specific syscall handlers

Arch-specific implementations of syscall handlers are currently used
over generic implementations for the following reasons:

1. Sema

powerpc: Adopt SYSCALL_DEFINE for arch-specific syscall handlers

Arch-specific implementations of syscall handlers are currently used
over generic implementations for the following reasons:

1. Semantics unique to powerpc
2. Compatibility syscalls require 'argument padding' to comply with
64-bit argument convention in ELF32 abi.
3. Parameter types or order is different in other architectures.

These syscall handlers have been defined prior to this patch series
without invoking the SYSCALL_DEFINE or COMPAT_SYSCALL_DEFINE macros with
custom input and output types. We remove every such direct definition in
favour of the aforementioned macros.

Also update syscalls.tbl in order to refer to the symbol names generated
by each of these macros. Since ppc64_personality can be called by both
64 bit and 32 bit binaries through compatibility, we must generate both
both compat_sys_ and sys_ symbols for this handler.

As an aside:
A number of architectures including arm and powerpc agree on an
alternative argument order and numbering for most of these arch-specific
handlers. A future patch series may allow for asm/unistd.h to signal
through its defines that a generic implementation of these syscall
handlers with the correct calling convention be emitted, through the
__ARCH_WANT_COMPAT_SYS_... convention.

Signed-off-by: Rohan McLure <[email protected]>
Reviewed-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/32: Remove powerpc select specialisation

Syscall #82 has been implemented for 32-bit platforms in a unique way on
powerpc systems. This hack will in effect guess whether the caller is
expect

powerpc/32: Remove powerpc select specialisation

Syscall #82 has been implemented for 32-bit platforms in a unique way on
powerpc systems. This hack will in effect guess whether the caller is
expecting new select semantics or old select semantics. It does so via a
guess, based off the first parameter. In new select, this parameter
represents the length of a user-memory array of file descriptors, and in
old select this is a pointer to an arguments structure.

The heuristic simply interprets sufficiently large values of its first
parameter as being a call to old select. The following is a discussion
on how this syscall should be handled.


As discussed in this thread, the existence of such a hack suggests that for
whatever powerpc binaries may predate glibc, it is most likely that they
would have taken use of the old select semantics. x86 and arm64 both
implement this syscall with oldselect semantics.

Remove the powerpc implementation, and update syscall.tbl to refer to emit
a reference to sys_old_select and compat_sys_old_select
for 32-bit binaries, in keeping with how other architectures support
syscall #82.

Signed-off-by: Rohan McLure <[email protected]>
Reviewed-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lore.kernel.org/r/[email protected]

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mm/mempolicy: wire up syscall set_mempolicy_home_node

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>

mm/mempolicy: wire up syscall set_mempolicy_home_node

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Ben Widawsky <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Feng Tang <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Huang Ying <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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futex: Wireup futex_waitv syscall

Wireup futex_waitv syscall for all remaining archs.

Signed-off-by: André Almeida <[email protected]>
Acked-by: Max Filippov <[email protected]>
Acked-by:

futex: Wireup futex_waitv syscall

Wireup futex_waitv syscall for all remaining archs.

Signed-off-by: André Almeida <[email protected]>
Acked-by: Max Filippov <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Tested-by: Michael Ellerman <[email protected]> (powerpc)
Signed-off-by: Arnd Bergmann <[email protected]>

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compat: remove some compat entry points

These are all handled correctly when calling the native system call entry
point, so remove the special cases.

Link: https://lkml.kernel.org/r/20210727144859.

compat: remove some compat entry points

These are all handled correctly when calling the native system call entry
point, so remove the special cases.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Feng Tang <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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mm: wire up syscall process_mrelease

Split off from prev patch in the series that implements the syscall.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Su

mm: wire up syscall process_mrelease

Split off from prev patch in the series that implements the syscall.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Suren Baghdasaryan <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Florian Weimer <[email protected]>
Cc: Jan Engelhardt <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Tim Murray <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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exit/bdflush: Remove the deprecated bdflush system call

The bdflush system call has been deprecated for a very long time.
Recently Michael Schmitz tested[1] and found that the last known
caller of o

exit/bdflush: Remove the deprecated bdflush system call

The bdflush system call has been deprecated for a very long time.
Recently Michael Schmitz tested[1] and found that the last known
caller of of the bdflush system call is unaffected by it's removal.

Since the code is not needed delete it.

[1] https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/87sg10quue.fsf_-_@disp2133
Tested-by: Michael Schmitz <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Acked-by: Cyril Hrubis <[email protected]>
Signed-off-by: "Eric W. Biederman" <[email protected]>

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quota: Wire up quotactl_fd syscall

Wire up the quotactl_fd syscall.

Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Jan Kara <[email protected]>

quota: Disable quotactl_path syscall

In commit fa8b90070a80 ("quota: wire up quotactl_path") we have wired up
new quotactl_path syscall. However some people in LWN discussion have
objected that the

quota: Disable quotactl_path syscall

In commit fa8b90070a80 ("quota: wire up quotactl_path") we have wired up
new quotactl_path syscall. However some people in LWN discussion have
objected that the path based syscall is missing dirfd and flags argument
which is mostly standard for contemporary path based syscalls. Indeed
they have a point and after a discussion with Christian Brauner and
Sascha Hauer I've decided to disable the syscall for now and update its
API. Since there is no userspace currently using that syscall and it
hasn't been released in any major release, we should be fine.

CC: Christian Brauner <[email protected]>
CC: Sascha Hauer <[email protected]>
Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein
Signed-off-by: Jan Kara <[email protected]>

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