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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull binfmt updates from Christian Brauner:
"This contains a bunch of work for binfmt_misc. It fixes a bunch of
old bugs, reworks the locking, and then extends the format registry
so a binary type can be matched programmatically and its interpreter
computed per exec instead of being a fixed string recorded at
registration time.
This allows nixos and other to e.g., implement relocatable binaries
meaning the interpreter/dynamic loader can be determined
programatically, say found relative to the binary. The mechanism is
flexible and can support other policies:
- Handler lookup is now an rcu walk. An exec that matches no
binfmt_misc entry should now never write to a shared cacheline
- remove the VERBOSE_STATUS and USE_DEBUG compile time toggles
- convert the entry file to a seq_file which simplifies things quite
a bit and kills a lot of custom logic
- make flags proper enums
- rename struct Node to binfmt_misc_entry
- allow entries to be removed with unlink(2)
- Add the ability to attach bpf programs to binfmt_misc entries so
it's possible to dynamically choose the execution environment such
as the loader or interpreter on a per binary basis.
A handler is an instance of a binfmt_misc_ops struct_ops with a
->match() and a ->load() program. match() decides from the entry
lookup walk whether the handler applies under the same
registration-order. It can read file content as needed not only the
prefetched 256 bytes in bprm->buf.
load() then selects the interpreter and stages it through the new
bpf_binprm_set_interp(), bpf_binprm_set_interp_arg() and
bpf_binprm_set_flags() kfuncs.
Handlers are published in a registry keyed by the registering
task's user namespace and activated through the existing text
interface with a new 'B' type carrying the handler name:
echo ':origin:B::::nix:' > /proc/sys/fs/binfmt_misc/register
The permission and namespacing model is unchanged. Activating a
handler requires the same write access to an instance as any other
registration. A container mounting its own instance escapes the
host's entries exactly as before. The computed interpreter is
opened with open_exec() under the caller's credentials and goes
through full LSM vetting as the next binprm level. A program can
only ever redirect the caller to something the caller could exec
anyway.
- Two dispatch modes are added. So far the chosen interpreter owns
the whole process identity (argv[0], /proc/pid/cmdline,
/proc/self/exe all name interpreter information). So relocatable
find the dynamic linker instead. Also a binary passed to execveat()
as an inaccessible O_CLOEXEC fd cannot run at all and gdb trips
because AT_ENTRY and AT_PHDR do not match the exe file. So PIE
symbols are unrelocated.
This adds transparent dispatch which allows the interpreter to load
the binary through AT_EXECFD and leaves the argument vector exactly
as the caller built it and labels mm->exe_file and comm with the
binary. It also raises the AT_FLAGS_TRANSPARENT_INTERP aux vector
bit. The interpreter keeps control of mapping the binary.
The second mode is loader substitution. This allows a binary to be
executed natively and only the interpreter to be changed.
- Last, interpreters can be bound at registration time. Each
interpreter is opened by its own write with the credentials the
entry file was opened with. The program picks one per exec with
bpf_binprm_select_interp().
Ucounts are used to properly account for pre-opened interpreters
via /proc/sys/user/max_binfmt_misc_interpreters"
* tag 'vfs-7.3-rc1.binfmt' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (63 commits)
binfmt_misc: document the pre-opened interpreter limit
selftests/exec: test the pre-opened interpreter limit
binfmt_misc: correctly account pre-opened interpreters
binfmt_misc: document interpreters bound by a 'B' entry
selftests/exec: test interpreters bound to a 'B' entry
binfmt_misc: let a 'B' entry bind its interpreters
binfmt_misc: carry pre-opened interpreters in struct binfmt_misc_interp
selftests/exec: share the bpf handler preconditions
binfmt_misc: document registering an entry disabled
selftests/exec: test registering an entry disabled
selftests/exec: let binfmt_flag_supported() return a bool
selftests/exec: check that a binfmt_misc instance cannot be pinned
binfmt_misc: let a register string create an entry disabled
binfmt_misc: document loader substitution
selftests/exec: test binfmt_misc loader substitution
binfmt_misc: let a bpf handler request loader substitution
binfmt_misc: add the 'L' loader substitution flag
binfmt_elf_fdpic: consume a stashed PT_INTERP substitute
binfmt_elf: consume a stashed PT_INTERP substitute
exec: carry a PT_INTERP substitute in struct linux_binprm
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc ipc and core updates from Christian Brauner:
- reject mq_notify() with a zero signal number
- fix coding style in the exit path
* tag 'ipc-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
mqueue: reject mq_notify with signo 0
* tag 'kernel-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
kernel: exit: fix coding style missing spaces
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The dentry_tree_work is not exported, so make it static
to remove the followign sparse warning:
fs/fuse/dir.c:37:21: warning: symbol 'dentry_tree_work' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Each cgroup_iter_memcg subtest touches 1024 pages and expects the matching
memcg counter to be non-zero. On a host with many CPUs it reads zero
instead:
test_anon:FAIL:final anon mapped val: actual 0 <= expected 0
memcg stats are cached per-cpu and only become visible once the periodic
flusher runs (FLUSH_TIME, 2s), or once pending updates cross
MEMCG_CHARGE_BATCH * num_online_cpus(). That threshold is 512 pages at 8
CPUs but 8192 at 128, so a single pass no longer reaches it and
bpf_mem_cgroup_flush_stats() returns without flushing anything.
Retry the stat generation, sleeping in between, so that a flusher cycle is
always covered. Sleep before dropping the mapping, so that a flusher cycle
landing in the sleep observes the mapped state. nr_anon_mapped and
nr_file_mapped are rmap gauges, and unmapping first would post a matching
negative delta for the flusher to aggregate to a net zero.
test_file asserts on both nr_file_pages and nr_file_mapped, which have
different lifetimes, as page cache pages outlive the mapping. Retry
while either one is still zero.
Fixes: 6bce6ddbe634 ("bpf: selftests: selftests for memcg stat kfuncs")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260814232017.2839959-1-andrii@kernel.org
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Add documentation for fuse over io-uring usage of buffer pools and
zero-copy.
Reviewed-by: Bernd Schubert <bernd@bsbernd.com>
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Implement zero-copy in fuse io-uring to eliminate memory copies between
the application, kernel, and server for read/write operations. The
server can directly access client pages or page cache folios without
copying data through an intermediary buffer. When a fuse request arrives,
the kernel registers the relevant pages into a sparse slot in the
server's io_uring registered buffer table. The server can then operate
on these pages directly using io-uring fixed buffer operations (eg
read_fixed/write_fixed) and the kernel unregisters these pages when the
request completes. Non-page-backed args (eg op out headers) will go
through the payload buffer as normal. The server can specify which open
files should have their reads/writes go through zero-copy, by setting
the FOPEN_IO_URING_ZERO_COPY flag when servicing opens.
This requires CAP_SYS_ADMIN and bufpools. This is gated behind
CAP_SYS_ADMIN because zero-copy allows the server direct access to the
client's underlying pages, rather than operating on an intermediary
buffer that the contents of the client's pages were copied into or on
page cache folios.
The request flow for the zero-copy direct-io write path (client writes
data, server reads it) is as follows:
=======================================================================
| Kernel | FUSE server
| |
| "write(fd, buf, 1MB)" |
| |
| >sys_write() |
| >fuse_file_write_iter() |
| >fuse_send_one() |
| [req->args->in_pages = true] |
| [folios hold client write data] |
| |
| >fuse_uring_copy_to_ring() |
| >copy_header_to_ring(IN_OUT) |
| [memcpy fuse_in_header] |
| >copy_header_to_ring(OP) |
| [memcpy write_in header] |
| |
| >fuse_uring_args_to_ring() |
| >setup_fuse_copy_state() |
| [skip_folio_copy = true] |
| |
| >fuse_uring_set_up_zero_copy() |
| [folio_get for each client folio] |
| [build bio_vec array from folios] |
| >io_buffer_register_bvec() |
| [register pages at
ent->zero_copy_index] |
| [ent->zero_copied = true] |
| |
| >fuse_copy_args() |
| [skip_folio_copy => return 0 |
| for page arg, skip data copy] |
| |
| >copy_header_to_ring(RING_ENT) |
| [memcpy ent_in_out] |
| >io_uring_cmd_done() |
| |
| | [CQE received]
| |
| | [issue io_uring READ at
| | ent->zero_copy_index]
| | [reads directly from
| |client's pages (ZERO_COPY)]
| |
| | [write data to backing
| | store]
| | [submit COMMIT AND FETCH]
| |
| >fuse_uring_commit_fetch() |
| >fuse_uring_commit() |
| >fuse_uring_copy_from_ring() |
| >fuse_uring_req_end() |
| >io_buffer_unregister(ent->zero_copy_index) |
| [unregister pages from index] |
| >fuse_zero_copy_release() |
| [folio_put for each folio] |
| [ent->zero_copied = false] |
| >fuse_request_end() |
| [wake up client] |
The zero-copy read path is analogous.
Some requests may have both page-backed args and non-page-backed args.
For these requests, the page-backed args are zero-copied while the
non-page-backed args are copied to the buffer selected from the buffer
pool:
zero-copy: pages registered via io_buffer_register_bvec()
non-page-backed: copied to payload buffer via fuse_copy_args()
For a request whose payload is zero-copied, the
registration/unregistration path looks like:
register: fuse_uring_set_up_zero_copy()
folio_get() for each folio
io_buffer_register_bvec(ent->zero_copy_index)
unregister: fuse_uring_req_end()
io_buffer_unregister(ent->zero_copy_index)
-> fuse_zero_copy_release() callback
folio_put() for each folio
Please note that on abort for in-flight zero-copied requests that have
been sent to userspace, the registered bvec slot remains occupied and
its folios remain pinned until the io-uring ring is destroyed, at which
point io-uring unregisters all buffers and the fuse_zero_copy_release()
callback drops the folio references. Unregistering at teardown would
require operating on the ring context directly, whose validity is hard
to ascertain; this is deemed not worth the complexity for the abort
race, since everything is freed when the ring is torn down.
The throughput improvement from zero-copy depends on how much of the
per-request latency is spent on data copying vs backing I/O. The gain
comes from eliminating the payload-buffer memcpy, but accessing the
zero-copied pages requires the server to issue the read/write as an
IORING_OP_READ/WRITE_FIXED operation. The benefit is largest when the
mempcy is a meaningful fraction of per-request latency while backing i/o
is still noticable enough that the extra io-uring op's overhead doesn't
dominate.
Benchmarked with passthrough_hp (--nopassthrough, q_depth=8) on a
2-socket Intel Xeon Gold 6138 (40 cores / 80 threads), using fio (sync
engine, bs=1M, O_DIRECT, numjobs=2, 30s run + 10s ramp, 3 runs) where
direct-I/O throughput is against a RAM-backed (tmpfs) source (backing
I/O is not the bottleneck):
baseline registered-buf zero-copy (zc vs base)
direct read ~5.1 GB/s ~5.4 GB/s ~8.9 GB/s (+75%)
direct write ~3.4 GB/s ~4.8 GB/s ~5.1 GB/s (+50%)
Reads end up higher than writes because the backing store reads faster
than it writes (the baseline shows the same read>write gap, and the raw
device does too). On a device-bound NVMe (~2 GB/s reads) the read gain
shrinks to ~10-16% (and no measurable gains for writes), as backing I/O
rather than the eliminated copy dominates latency.
The benefit overall scales with how much of the
per-request latency is the data copy versus backing I/O.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Bernd Schubert <bernd@bsbernd.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Allow servers to use a buffer pool that is also registered through
io-uring. When the server registers a buffer pool with io-uring, the
pages backing the pool are pinned upfront. This eliminates the overhead
of pinning/unpinning user pages and translating virtual addresses per
i/o request. This also allows servers to use the same registered memory
for subsequent backing store I/O (eg read_fixed/write_fixed), keeping
data in the same pinned pages without additional pinning or mapping
overhead required.
To use this, the server needs to set the FUSE_URING_REGISTERED_BUFPOOL
flag when adding a bufpool through the FUSE_IO_URING_CMD_ADD_BUFPOOL
cmd. For every sqe submitted (including the one for adding the bufpool),
it should set sqe->uring_cmd_flags to include IORING_URING_CMD_FIXED,
and pass in the index where the registered bufpool resides to
sqe->buf_index.
Benchmarked with passthrough_hp (--nopassthrough, q_depth=8) on a
2-socket Intel Xeon Gold 6138 (40 cores / 80 threads), using fio (sync
engine, bs=1M, O_DIRECT, numjobs=2, 30s run + 10s ramp, 3 runs) where
direct-I/O throughput is against a RAM-backed (tmpfs) source (backing
I/O is not the bottleneck):
baseline registered buffers
direct read ~5.1 GB/s ~5.4 GB/s (+~5%)
direct write ~3.4 GB/s ~4.8 GB/s (+~45%)
Registered buffers bring up the write path speed up closer to speed of
reads. There isn't much improvement for reads because it is already fast
enough where it's at the copy-bound ceiling (surpassing that requires
doing zero-copy). On a device-bound NVMe though, the differences are
within noise, as backing I/O dominates per-request latency.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Bernd Schubert <bernd@bsbernd.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Right now, ents and buffers are tightly coupled in fuse io-uring where
each entry has its own dedicated payload buffer, requiring N buffers for
N entries where each buffer must be large enough to accomodate the
maximum payload size. This is suboptimal as most request types (lookup,
open, release, getattr, etc) require vastly less bytes than the maximum
payload size and some requests (unlink, rmdir, fsync, flush, etc) do not
require payload buffers at all.
Instead of requiring a 1:1 coupling between ents and payload buffers,
allow the server to pass in a buffer pool (a contiguous chunk of memory)
that the kernel will use as it wishes for servicing ents/requests.
Entries only reserve a "buffer" from the pool while actively processing
a request that requires a payload buffer. This decoupling and letting
the kernel delegate memory from the pool for requests allows the kernel to
optimize memory usage and reduces the memory usage requirements needed
to use fuse-over-io-uring.
A pool is registered per queue with the new
FUSE_IO_URING_CMD_ADD_BUFPOOL command. The server passes the pool's base
address and length in fuse_uring_cmd_req.bufpool.{uaddr,len}.
Internally, the kernel splits the region into buffers of
ring->max_payload_sz bytes each (nr_bufs = pool len / max_payload_sz). A
queue commits to a payload mode on first use: registering an entry that
carries its own payload selects the legacy per-entry mode, while
ADD_BUFPOOL selects pool mode. The two are mutually exclusive, so
ADD_BUFPOOL must be issued before any payload-carrying entries are
registered on that queue. The queue must have been created before the
bufpool is added, through the FUSE_IO_URING_CMD_ADD_QUEUE command.
The kernel tracks free buffers with a bitmap (a set bit marks a free
buffer). On dispatch, a request that needs a payload claims a free
buffer (find_first_bit + clear). A request that needs none claims
nothing. The buffer's byte offset within the pool is reported to the
server in the new fuse_uring_ent_in_out.offset field so that the server
can locate the payload. On completion the buffer is returned to the pool
or reused directly if the next request on that entry also has a payload.
The FUSE_HAS_IO_URING_BUFPOOL flag advertises kernel support to the
server for bufpools.
Buffer pool request flow
~~~~~~~~~~~~~~~~~~~~~~~~
| Kernel | FUSE daemon
| |
| [request arrives] |
| [claim a free pool buffer] |
| >fuse_uring_select_buffer() |
| [copy headers to ring] |
| [copy payload to buffer] |
| [report buffer offset in ent_in_out] |
| >io_uring_cmd_done() |
| | [read headers]
| | [read/write payload at offset]
| | [process request]
| | >io_uring_submit()
| | COMMIT_AND_FETCH
| >fuse_uring_commit_fetch() |
| [copy reply from ring] |
| [return buffer to the pool] |
| >fuse_uring_recycle_buffer() |
Reviewed-by: Bernd Schubert <bernd@bsbernd.com>
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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fuse-over-io-uring queues are currently created lazily, as a side effect
of the first FUSE_IO_URING_CMD_REGISTER command for a given qid. This
ties queue creation to entry registration.
Add a FUSE_IO_URING_CMD_ADD_QUEUE command so a server can create a queue
explicitly, decoupling queue setup from entry registration. This is
additionally a prerequisite for FUSE_IO_URING_CMD_ADD_BUFPOOL, which
attaches a buffer pool to an existing queue and therefore needs the
queue to have been created first.
Reviewed-by: Bernd Schubert <bernd@bsbernd.com>
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Currently, the connection's fuse_ring is created lazily on the first
FUSE_IO_URING_CMD_REGISTER command. A server registers entries from one
thread per queue (one per CPU) and those threads issue their first
REGISTER command concurrently. They then race to create the single
per-connection fuse_ring, which required open-coded handling in
fuse_uring_create() to detect and protect against concurrent creations.
Decouple fuse_ring creation from ent registration and move it to
FUSE_INIT reply processing after a server has negotiated and set
FUSE_OVER_IO_URING. The ring is published before the connection is
marked initialized. fuse_uring_register() no longer creates the ring and
it instead uses the ring set up at init time.
Reviewed-by: Bernd Schubert <bernd@bsbernd.com>
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Rename IO_IMU_DEST and IO_IMU_SOURCE to IO_BUF_DEST and IO_BUF_SOURCE
and export it so subsystems may use it.
This is needed by the io_buffer_register_bvec() path for callers who may
need the buffer to be both readable and writable.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Link: https://patch.msgid.link/20260612184840.4058966-5-joannelkoong@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Add io_buffer_register_bvec() for registering a bvec array.
This is a preparatory patch for fuse-over-io-uring zero-copy.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://patch.msgid.link/20260612184840.4058966-4-joannelkoong@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Split the main initialization logic in io_buffer_register_request() into
a helper function.
This is a preparatory patch for supporting kernel-populated buffers in
fuse io-uring, which will be reusing this logic.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://patch.msgid.link/20260612184840.4058966-3-joannelkoong@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Currently, io_buffer_register_bvec() takes in a request. In preparation
for supporting kernel-populated buffers in fuse io-uring (which will
need to register bvecs directly, not through a struct request), rename
this to io_buffer_register_request().
A subsequent patch will commandeer the "io_buffer_register_bvec()"
function name to support registering bvecs directly.
Rename io_buffer_unregister_bvec() to a more generic name,
io_buffer_unregister(), as both io_buffer_register_request() and
io_buffer_register_bvec() callers will use it for unregistration.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://patch.msgid.link/20260612184840.4058966-2-joannelkoong@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Add SoC ID for Qualcomm Snapdragon SDM850.
Signed-off-by: David Heidelberg <david@ixit.cz>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260627-sda850-v2-1-44bf46ade42e@ixit.cz
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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The existing link redirects to a generic page. Update the link to the
specification document.
Signed-off-by: Ninad Naik <ninadnaik07@gmail.com>
Link: https://patch.msgid.link/20260321140212.5026-1-ninadnaik07@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Enable the kptr_xchg_inline functional test on LoongArch64 now that the
BPF JIT can inline bpf_kptr_xchg() with correct memory ordering.
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Acked-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Chenguang Zhao <zhaochenguang@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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Implement arch_bpf_stack_walk() on top of the ORC unwinder within
the LoongArch BPF JIT backend to provide generic BPF stack walking
capabilities.
This function is required by advanced BPF features, including timed
may_goto timeout tracing and BPF exceptions. It will be invoked in
the BPF core subsystem unwinding paths: bpf_prog_find_from_stack(),
bpf_stream_stage_dump_stack(), and bpf_throw().
Co-developed-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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Implement arch_bpf_timed_may_goto() support and advertise it through
bpf_jit_supports_timed_may_goto() so the verifier lowers may_goto into
the timed variant: instead of a fixed iteration counter, the loop is
bounded by a wall-clock timeout maintained in a per-loop stack slot.
arch_bpf_timed_may_goto() uses a custom calling convention: the verifier
passes the count/timestamp stack offset in BPF_REG_AX and expects the
updated count back in the same register. The JIT call path therefore can
skip the usual 'BPF_REG_0 = C return value' move for this helper.
Acked-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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Add support for the internal-only BPF_MOV instruction that resolves the
absolute addresses of the per-CPU data from their per-CPU offsets. This
instruction is used only for internal inlining optimizations between the
BPF verifier and the JITs (e.g. inlining bpf_get_smp_processor_id() and
per-CPU map lookups).
LoongArch keeps the per-CPU offset of the current CPU in $r21 register
(a.k.a. __my_cpu_offset), so resolving a per-CPU address only requires
adding $r21 to the source register holding the per-CPU offset. Advertise
the capability via bpf_jit_supports_percpu_insn().
Acked-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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The BPF verifier can lower bpf_kptr_xchg() to BPF_XCHG when the JIT
advertises ptr xchg support. With ordered amswap_db.* emission from the
previous patch, declare that LoongArch bpf JIT supports this inlining.
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Acked-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Chenguang Zhao <zhaochenguang@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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Per the Linux Kernel Memory Model, value-returning atomic RMW operations
must provide sequentially consistent ordering (a full memory barrier).
On LoongArch, plain AMO instructions and bare ll/sc loops do not satisfy
this requirement by themselves.
Update emit_atomic_rmw() to emit barrier-carrying instructions for all
value-returning BPF atomics:
- BPF_FETCH (ADD/AND/OR/XOR): use am*_db.{b,h,w,d}
- BPF_XCHG: use amswap_db.{b,h,w,d}
- BPF_CMPXCHG: emit dbar 0x700 after the ll/sc loop, matching
__WEAK_LLSC_MB in cmpxchg.h
Add the corresponding instruction encodings and emit helpers to inst.h.
Non-value-returning RMW ops (plain BPF_ADD, BPF_AND, etc.) are left as
weakly ordered, consistent with LKMM.
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Acked-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Chenguang Zhao <zhaochenguang@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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In build_insn(), both 32-bit and 64-bit unconditional branch JA paths
currently share a single case block. It relies on a runtime condition
check to multiplex between the 'off' and 'imm' fields.
Since the instruction classes are already resolved at compile-time via
distinct switch-case labels, this runtime check is redundant.
Split the two paths into individual case blocks to remove the redundant
runtime check.
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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The BPF_NEG operation is a unary operator that performs `dst = -dst`.
The current code unconditionally executes a move_imm() call before the
subtraction, generating useless JITted instructions to load data into
the temporary register `t1`. This `t1` register is never used anywhere
else in the entire BPF_NEG path.
Remove this dead `move_imm()` call to avoid useless instructions.
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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In move_imm(), when an immediate hits the 12-bit unsigned range, an
`ori rd, $zero, imm` instruction is emitted.
According to the manual, the `ori` instruction inherently performs a
logical or with zero-extended immediate operands against $zero, so the
upper 32 bits of the destination register `rd` are already 0.
However, the existing JIT code unconditionally executes `goto zext;`
after `ori`, forcing it to fallthrough into `emit_zext_32()` to clear
the upper 32 bits for 32-bit ALU operations.
Fix this redundancy by directly returning from the function inside the
`is_unsigned_imm12()` block.
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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The current implementation handles combined bpf2bpf and tail calls by
checking at runtime whether REG_TCC holds a scalar count or a pointer
address via a conditional jump. This adds branch prediction overhead
in the hot path of tail call execution.
To implement branchless conditional move, use an unsigned comparison
(sltui) combined with mask instructions (maskeqz/masknez) to achieve
branchless classification and blending of incoming scalar counts and
kernel pointers in REG_TCC.
This optimization refactors the inner logic of the helper function,
unifies the offset decrement at the function entry, and removes all
runtime branching from the prologue hot path completely.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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The old macro-based jmp_offset calculation derives the jump distance
from a stale prior-pass code stride, which can lead to wrong branch
offsets and soft lockups under extra JIT passes.
Fix this by calculating the offset directly on the absolute target:
"ctx->offset[insn + 1] - ctx->idx".
To avoid a false 16-bit range check abort during size estimation, add
a "ctx->image == NULL" guard to inject a safe dummy offset.
Cc: stable@vger.kernel.org
Fixes: cd39d9e6b7e4 ("LoongArch: BPF: Fix jump offset calculation in tailcall")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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Currently, the stack layout places the optional arena register slot
above the tail call counter context. When arena_vm_start is dynamically
enabled, it shifts the relative offset of the tcc_ptr slot within the
stack frame, causing hardcoded tracking macros to mismatch and leading
to memory misalignment or corruption potentially.
To fix this, move the arena register save and restore sequences below
the tail call counter context slots in both build_prologue() and the
epilogue.
Update __build_epilogue() to insert a proper offset decrement to safely
skip the unneeded tcc_ptr reading block while accurately aligning with
the relocated arena slot at the very bottom.
With this patch, the tcc_ptr slot is always positioned at a fixed
distance directly underneath the base callee-saved registers that is
independent of whether the arena features are on.
Cc: stable@vger.kernel.org
Fixes: ef54c517a937 ("LoongArch: BPF: Implement PROBE_MEM32 pseudo instructions")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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The legacy epilogue implementation pops the tail call counter (TCC)
context via a redundant double-load pattern. It first decrements the
load_offset by 2 slots to fetch 'tcc_ptr', and then immediately bumps
it back up by 1 slot to load the original 'tcc' value into REG_TCC,
unnecessarily overwriting the register.
Optimize this sequence by adjusting the load_offset by only 1 slot.
This aligns the offset directly with the higher stack slot containing
the entry TCC counter (or caller state), allowing us to restore the
REG_TCC register safely with a single load.
This removes one redundant instruction from the epilogue hot path,
improves code readability, and ensures the correct TCC register context
is handed back cleanly upon normal return.
Cc: stable@vger.kernel.org
Fixes: c0fcc955ff82 ("LoongArch: BPF: Fix the tailcall hierarchy")
Fixes: ef54c517a937 ("LoongArch: BPF: Implement PROBE_MEM32 pseudo instructions")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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The current implementation of current_pt_regs() relies on the compiler
__builtin_frame_address(0). This introduces an unnecessary dependency
on the frame pointer register, which forces the compiler to generate
redundant prologue and epilogue code, create a larger stack frame, and
perform redundant memory operations to preserve the frame pointer even
in functions where it is otherwise unnecessary.
Optimize this by switching to current_stack_pointer, which explicitly
maps to the hardware stack pointer register. This allows the compiler
to compute the stack alignment directly from the natively maintained
"$sp" register, completely eliminating the overhead of preserving and
restoring the frame pointer on the stack memory.
As a prominent example, this optimization improves the hot-path function
copy_thread(). A disassembly comparison of copy_thread() illustrates the
elimination of the frame pointer, the reduction of stack frame size from
48 bytes down to 32 bytes, and a more compact epilogue path:
Before:
00000000000004f0 <copy_thread>:
4f0: 02ff4063 addi.d $sp, $sp, -48
4f4: 29c08076 st.d $fp, $sp, 32
4f8: 29c06077 st.d $s0, $sp, 24
4fc: 29c0a061 st.d $ra, $sp, 40
500: 02c0c076 addi.d $fp, $sp, 48
...
54c: 1400006e lu12i.w $t2, 3
...
55c: 03bffdce ori $t2, $t2, 0xfff
560: 00153ace or $t2, $fp, $t2
564: 02fb05cd addi.d $t1, $t2, -319
...
628: 28c0a061 ld.d $ra, $sp, 40
62c: 28c08076 ld.d $fp, $sp, 32
630: 28c06077 ld.d $s0, $sp, 24
634: 00150004 move $a0, $zero
638: 02c0c063 addi.d $sp, $sp, 48
63c: 4c000020 ret
After:
00000000000004f0 <copy_thread>:
4f0: 02ff8063 addi.d $sp, $sp, -32
4f4: 29c04077 st.d $s0, $sp, 16
4f8: 29c06061 st.d $ra, $sp, 24
[ prologue st.d and addi.d for $fp are completely eliminated ]
...
544: 1400006e lu12i.w $t2, 3
...
554: 03bffdce ori $t2, $t2, 0xfff
558: 0015386e or $t2, $sp, $t2
55c: 02fb05cd addi.d $t1, $t2, -319
...
620: 28c06061 ld.d $ra, $sp, 24
624: 28c04077 ld.d $s0, $sp, 16
628: 00150004 move $a0, $zero
[ epilogue ld.d for $fp is eliminated; exit path is shortened ]
62c: 02c08063 addi.d $sp, $sp, 32
630: 4c000020 ret
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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Currently, the module-sections.c file defines a custom cmp_3way() macro
to perform a three-way comparison. There is already a generic cmp_int()
macro to do the same thing in linux/sort.h, thus remove the custom macro
and use the generic interface. This is similar with commit 3e17a4b443bb
("riscv: module: Use generic cmp_int() instead of custom cmp_3way()").
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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The current 256MB module virtual address space is easily exhausted when
loading massive graphics drivers such as amdgpu along with the large
unstripped symbol tables, resulting in allocation failures of "execmem:
unable to allocate memory".
Thus, expand the module virtual address space to 2GB while keeping
the current normal code model '-mcmodel=normal', rather than using the
medium code model '-mcmodel=medium'. This approach avoids the extra
performance overhead and larger binary size of forcing every function
call into a 2-instruction sequence of 'pcaddu18i + jirl'.
Given that individual module code segments rarely exceed 128MB, most
jumps remain fast direct calls by using the bl instruction. For the
long-distance jumps exceeding the +/-128MB limit, apply_r_larch_b26()
emits PLT entries, while signed_imm_check() guarantees the run-time
safety by rejecting any out-of-bound instruction offsets.
There is still a risk that the distance between .init.text and .text of
the same module exceeds 128MB. So we divide the 2GB virtual space to be
two sub-regions: the first 256MB is for module text, and the rest is for
module data.
Cc: stable@vger.kernel.org
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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get_free_mem_region() and mhp_get_pluggable_range() bound their search
to DIRECT_MAP_PHYSMEM_END. LoongArch does not define it, so the fallback
in include/linux/mm.h applies: under CONFIG_SPARSEMEM_VMEMMAP it is
(1ULL << MAX_PHYSMEM_BITS) - 1, a compile-time constant that does not
adapt to the CPU's physical address space bits (cpu_pabits, probed from
CPUCFG1).
The vmemmap window only covers physical space below 2^(cpu_pabits+1)
(i.e. VMEMMAP_SIZE), so on CPUs with fewer physical address bits than
MAX_PHYSMEM_BITS the fallback allows get_free_mem_region() to return
a ZONE_DEVICE region outside the vmemmap window; vmemmap_populate() then
wraps the memmap range around and maps it into low memory, silently
corrupting the page tables. The same search also picked the top-of-
address-space region that crashed memmap_init_zone_device() with amdkfd
on Loongson-3C6000 in 6.16 [1]; the commit 2969b42c8f99 ("LoongArch/mm:
align vmemmap to maximal folio size") keeps that region in bounds on
current Loongson-3C6000 configs, but CPUs with smaller cpu_pabits (e.g.
the Loongson-2K series) are still affected.
Define DIRECT_MAP_PHYSMEM_END as the vmemmap-covered physical range,
(1ULL << (cpu_pabits + 1)) - 1, capped at (1ULL << MAX_PHYSMEM_BITS) - 1
under CONFIG_SPARSEMEM, similar to the commit f3336b48cf9d ("riscv: mm:
Define DIRECT_MAP_PHYSMEM_END").
[1] https://lore.kernel.org/amd-gfx/20250814032153.227285-1-jeffbai@aosc.io/
Cc: stable@vger.kernel.org # v6.13+
Signed-off-by: Han Gao <gaohan@iscas.ac.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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With LoongArch virt machine, a typical setting is one core per socket,
there will max 256 sockets (packages) on one VM. With PPTT acpi table,
array acpi_package_ids[] will be overflowed.
Here change the array size of acpi_package_ids[] with the max value of
MAX_PACKAGES and KVM_MAX_VCPUS.
Cc: stable@vger.kernel.org # 6.7+
Fixes: 4e8f58620f67 ("LoongArch: Retrieve CPU package ID from PPTT when available")
Reviewed-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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See the procedure below:
smb2_sess_setup
ksmbd_smb2_session_create
__session_create
hash_add(sessions_table, &sess->hlist, sess->id)
ksmbd_counter_inc(KSMBD_COUNTER_SESSIONS)
ksmbd_conn_handler_loop
ksmbd_server_terminate_conn
ksmbd_sessions_deregister
hash_del(&sess->hlist)
// do not decrement KSMBD_COUNTER_SESSIONS
KSMBD_COUNTER_SESSIONS tracks sessions published in sessions_table, but
session removal does not decrement it. The value therefore keeps growing
after sessions are expired, rejected during registration, or removed on
the last channel disconnect.
Fixes: b38f99c1217a ("ksmbd: add procfs interface for runtime monitoring and statistics")
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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KSMBD_COUNTER_SESSIONS tracks sessions published in sessions_table.
Increment it while holding sessions_table_lock so publishing a session and
updating the counter happen together.
Fixes: b38f99c1217a ("ksmbd: add procfs interface for runtime monitoring and statistics")
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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See the procedure below:
smb2_sess_setup
ksmbd_smb2_session_create
__session_create
atomic_set(&sess->refcnt, 2)
hash_add(sessions_table, &sess->hlist, sess->id)
ksmbd_session_register
xa_store(&conn->sessions, sess->id, sess) // fail
ksmbd_user_session_put
atomic_dec(&sess->refcnt) // refcnt is 1, session is not freed
Remove the session from sessions_table and drop its table reference if
xa_store() fails.
Fixes: f5c779b7ddbd ("ksmbd: fix racy issue from session setup and logoff")
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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Print a warning if the sessions procfs entry cannot be created.
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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smb_check_perm_dacl() validates that the DACL fits inside the NT
security descriptor, but then bounds its two ACE walks by the
remaining NTSD length (acl_size) rather than the DACL's declared
size (pdacl_size).
When pdacl->size is smaller than the trailing NTSD buffer, bytes
after the declared DACL boundary - still inside the stored security
descriptor - are parsed as ACEs during access checks. A crafted
DACL can place an access-granting ACE beyond pdacl->size, and the
current code accepts it during SMB2_CREATE access validation, while
parse_dacl() and smb_inherit_dacl() stop at pdacl_size.
Bound both ACE walks by pdacl_size to match the DACL boundary
semantics used elsewhere in the server.
Validation:
- semantic KUnit harness shows the post-boundary ACE is selected
before the fix and rejected (EACCES) after it
- linux master (7.2-rc6), x86_64
Fixes: 8f0541186e9a ("ksmbd: fix heap-based overflow in set_ntacl_dacl()")
Signed-off-by: Hang Nan <2122295973@qq.com>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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The temporary RDMA encryption diagnostics logged every SMB3 request
and successful payload operation with pr_err(), which made normal
traffic too noisy.
Keep only negotiation, RDMA READ preparation, RDMA WRITE transform
metadata, crypto completion, and final transfer completion messages as
KSMBD_DEBUG_RDMA diagnostics. Keep error reports for malformed metadata,
crypto, RDMA transfer, and file write failures at error level.
This preserves the diagnostics needed to verify RDMA transform
operation without flooding the kernel error log during normal I/O.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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Port SMB Direct RDMA payload encryption support to the current ksmbd tree.
The current tree already supports all-state lookup for encrypted expired
sessions, so the overlapping lookup hunk from the original patch is
intentionally omitted.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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SMB3 permits a message to be compressed before it is encrypted. After
decrypting such a request, ksmbd must trim the AEAD tag using
OriginalMessageSize, decompress the nested compression transform, and
validate the resulting SMB2 PDU.
Share the decompression helper between the connection receive path and
the post-decryption work path so unencrypted and encrypted compressed
requests follow the same validation.
Fixes: a08de24c2b85 ("ksmbd: negotiate and decode SMB2 compression")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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Previous-session replacement marks the old session expired but retains its
SMB3 encryption key. An in-flight encrypted request can still arrive on
that connection. Rejecting the expired session before decryption made ksmbd
treat the request as a key failure and abort the transport, causing
reconnect failures.
Allow key lookup for expired sessions that have encryption enabled. Keep
the session reference during validation so the normal
STATUS_USER_SESSION_DELETED response is encrypted with the old key. The
session remains expired and no command is executed.
Fixes: fa9415d4024f ("ksmbd: mark SMB2_SESSION_EXPIRED to session when destroying previous session")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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MS-SMB2 requires the server to disconnect a connection when an
encrypted transform cannot be associated with a session or fails
authenticated decryption. This includes an encrypted request that
still carries a SessionId invalidated through PreviousSessionId.
Move the connection to EXITING and shut down its transport when
decrypt_req() fails. Add the missing TCP shutdown callback so a receive
blocked in kernel_recvmsg() is released; SMB Direct already provides
the corresponding callback.
Plaintext requests using an invalidated SessionId do not take this
path and continue to receive STATUS_USER_SESSION_DELETED.
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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The normal response path applies an SMB3 transform when the request was
encrypted. Async interim responses, completed compound prefixes and two
CHANGE_NOTIFY cleanup paths write their synthetic response work directly,
bypassing that encryption step.
A packet capture shows FE SMB2 STATUS_PENDING, CREATE and CHANGE_NOTIFY
responses following FD SMB3 requests. The client resets the connection
immediately after receiving those plaintext responses.
Send synthetic interim work through a common helper that applies the
session encryption transform first. A compound prefix shares the original
work's response iov, which encryption would replace in place, so flatten it
into an independently owned work before encrypting and sending it.
Fixes: 64bfa9d49026 ("smb/server: use MSG_EOR for async interim response")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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ksmbd_all_conn_set_status() treats every connection whose transient
binding flag is set as belonging to the target SessionId. A logoff or
session replacement can consequently move an unrelated connection to
NEED_RECONNECT or NEED_SETUP.
Pass the target session itself and select connections using either the
connection-local session xarray or the session's permanent channel list.
Use the same association test while waiting for requests to drain.
Serialize session-wide status changes under request_lock and do not
overwrite EXITING or RELEASING. Protect the shutdown transition with the
same lock so a concurrent session update cannot revive a closing
connection.
Fixes: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel")
Fixes: abcc506a9a71 ("ksmbd: fix racy issue from smb2 close and logoff with multichannel")
Fixes: c444139cb747 ("ksmbd: rewrite stop_sessions() with restartable iteration")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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An SMB3 multichannel binding registers the secondary connection in the
session channel list, but does not insert the session into the secondary
connection's session xarray.
The decryption path only searches the connection-local xarray. As a
result, every encrypted request received on a bound channel fails with
"Could not get decryption key".
Use the channel-aware session lookup for decryption. Also stop using the
temporary conn->binding flag to decide whether the global lookup is
allowed. Validate the permanent channel association under chann_lock
instead.
Fixes: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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Add a share flag for requiring SMB3 encryption on an individual share.
Advertise SMB2_SHAREFLAG_ENCRYPT_DATA in TREE_CONNECT responses and
reject both unencrypted TREE_CONNECT attempts and plaintext requests for
shares carrying the flag.
Keep BIT(19) reserved for the existing ksmbd-tools WIDE_LINKS flag and
use BIT(20) for the new netlink ABI flag.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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BVT_DirectoryLeasing_ReadWriteHandleCaching requires a parent directory
lease break notification when another client creates a child in the
leased directory. A child CREATE without a lease context did not notify
the parent lease holders because the notification path expected a
non-NULL lease context.
Allow the parent lease notification helper to handle a NULL child lease
context and notify matching parent leases. Invoke it after a child is
created without a lease context while preserving the existing lease-key
filtering for requests that provide one.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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BVT_AppInstanceVersion_SMB311_GreaterVersion,
BVT_AppInstanceVersion_SMB311_SameVersion,
BVT_AppInstanceVersion_SMB311_LowerAppInstanceVersionHigh, and
BVT_AppInstanceVersion_SMB311_LowerAppInstanceVersionLow exercise
ordered opens using the same AppInstanceId. ksmbd tracked the
AppInstanceId, but did not parse the version context or enforce the
version ordering, so versioned opens returned incorrect sharing
violations.
Parse and retain the 24-byte AppInstanceVersion context with each open.
Reject a version that is lower than or equal to the active version with
STATUS_FILE_FORCED_CLOSED, reject an unversioned open against a versioned
handle, and close the previous handle for a newer takeover. Do not apply
the takeover check to durable reconnect or replay requests.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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