Instead of putting io_uring's registered files in unix_gc() we want it
to be done by io_uring itself. The trick here is to consider io_uring
registered files for cycle detection but not actually putting them down.
Because io_uring can't register other ring instances, this will remove
all refs to the ring file triggering the ->release path and clean up
with io_ring_ctx_free().
Cc: stable@vger.kernel.org
Fixes: 6b06314c47 ("io_uring: add file set registration")
Reported-and-tested-by: David Bouman <dbouman03@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
[axboe: add kerneldoc comment to skb, fold in skb leak fix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
pskb_may_pull already contains all of the checks performed by
pskb_pull.
Use pskb_may_pull for validation in pskb_pull, eliminating the
duplication and making __pskb_pull obsolete.
Replace __pskb_pull with pskb_pull where applicable.
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can benefit from a smaller struct ubuf_info, so leave only mandatory
fields and let users to decide how they want to extend it. Convert
MSG_ZEROCOPY to struct ubuf_info_msgzc and remove duplicated fields.
This reduces the size from 48 bytes to just 16.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We're going to split struct ubuf_info and leave there only
mandatory fields. Users are free to extend it. Add struct
ubuf_info_msgzc, which will be an extended version for MSG_ZEROCOPY and
some other users. It duplicates of struct ubuf_info for now and will be
removed in a couple of patches.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/ethernet/freescale/fec.h
7d650df99d ("net: fec: add pm_qos support on imx6q platform")
40c79ce13b ("net: fec: add stop mode support for imx8 platform")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Daniel Borkmann says:
====================
pull-request: bpf-next 2022-09-05
The following pull-request contains BPF updates for your *net-next* tree.
We've added 106 non-merge commits during the last 18 day(s) which contain
a total of 159 files changed, 5225 insertions(+), 1358 deletions(-).
There are two small merge conflicts, resolve them as follows:
1) tools/testing/selftests/bpf/DENYLIST.s390x
Commit 27e23836ce ("selftests/bpf: Add lru_bug to s390x deny list") in
bpf tree was needed to get BPF CI green on s390x, but it conflicted with
newly added tests on bpf-next. Resolve by adding both hunks, result:
[...]
lru_bug # prog 'printk': failed to auto-attach: -524
setget_sockopt # attach unexpected error: -524 (trampoline)
cb_refs # expected error message unexpected error: -524 (trampoline)
cgroup_hierarchical_stats # JIT does not support calling kernel function (kfunc)
htab_update # failed to attach: ERROR: strerror_r(-524)=22 (trampoline)
[...]
2) net/core/filter.c
Commit 1227c1771d ("net: Fix data-races around sysctl_[rw]mem_(max|default).")
from net tree conflicts with commit 29003875bd ("bpf: Change bpf_setsockopt(SOL_SOCKET)
to reuse sk_setsockopt()") from bpf-next tree. Take the code as it is from
bpf-next tree, result:
[...]
if (getopt) {
if (optname == SO_BINDTODEVICE)
return -EINVAL;
return sk_getsockopt(sk, SOL_SOCKET, optname,
KERNEL_SOCKPTR(optval),
KERNEL_SOCKPTR(optlen));
}
return sk_setsockopt(sk, SOL_SOCKET, optname,
KERNEL_SOCKPTR(optval), *optlen);
[...]
The main changes are:
1) Add any-context BPF specific memory allocator which is useful in particular for BPF
tracing with bonus of performance equal to full prealloc, from Alexei Starovoitov.
2) Big batch to remove duplicated code from bpf_{get,set}sockopt() helpers as an effort
to reuse the existing core socket code as much as possible, from Martin KaFai Lau.
3) Extend BPF flow dissector for BPF programs to just augment the in-kernel dissector
with custom logic. In other words, allow for partial replacement, from Shmulik Ladkani.
4) Add a new cgroup iterator to BPF with different traversal options, from Hao Luo.
5) Support for BPF to collect hierarchical cgroup statistics efficiently through BPF
integration with the rstat framework, from Yosry Ahmed.
6) Support bpf_{g,s}et_retval() under more BPF cgroup hooks, from Stanislav Fomichev.
7) BPF hash table and local storages fixes under fully preemptible kernel, from Hou Tao.
8) Add various improvements to BPF selftests and libbpf for compilation with gcc BPF
backend, from James Hilliard.
9) Fix verifier helper permissions and reference state management for synchronous
callbacks, from Kumar Kartikeya Dwivedi.
10) Add support for BPF selftest's xskxceiver to also be used against real devices that
support MAC loopback, from Maciej Fijalkowski.
11) Various fixes to the bpf-helpers(7) man page generation script, from Quentin Monnet.
12) Document BPF verifier's tnum_in(tnum_range(), ...) gotchas, from Shung-Hsi Yu.
13) Various minor misc improvements all over the place.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (106 commits)
bpf: Optimize rcu_barrier usage between hash map and bpf_mem_alloc.
bpf: Remove usage of kmem_cache from bpf_mem_cache.
bpf: Remove prealloc-only restriction for sleepable bpf programs.
bpf: Prepare bpf_mem_alloc to be used by sleepable bpf programs.
bpf: Remove tracing program restriction on map types
bpf: Convert percpu hash map to per-cpu bpf_mem_alloc.
bpf: Add percpu allocation support to bpf_mem_alloc.
bpf: Batch call_rcu callbacks instead of SLAB_TYPESAFE_BY_RCU.
bpf: Adjust low/high watermarks in bpf_mem_cache
bpf: Optimize call_rcu in non-preallocated hash map.
bpf: Optimize element count in non-preallocated hash map.
bpf: Relax the requirement to use preallocated hash maps in tracing progs.
samples/bpf: Reduce syscall overhead in map_perf_test.
selftests/bpf: Improve test coverage of test_maps
bpf: Convert hash map to bpf_mem_alloc.
bpf: Introduce any context BPF specific memory allocator.
selftest/bpf: Add test for bpf_getsockopt()
bpf: Change bpf_getsockopt(SOL_IPV6) to reuse do_ipv6_getsockopt()
bpf: Change bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt()
bpf: Change bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt()
...
====================
Link: https://lore.kernel.org/r/20220905161136.9150-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
We got a recent syzbot report [1] showing a possible misuse
of pfmemalloc page status in TCP zerocopy paths.
Indeed, for pages coming from user space or other layers,
using page_is_pfmemalloc() is moot, and possibly could give
false positives.
There has been attempts to make page_is_pfmemalloc() more robust,
but not using it in the first place in this context is probably better,
removing cpu cycles.
Note to stable teams :
You need to backport 84ce071e38 ("net: introduce
__skb_fill_page_desc_noacc") as a prereq.
Race is more probable after commit c07aea3ef4
("mm: add a signature in struct page") because page_is_pfmemalloc()
is now using low order bit from page->lru.next, which can change
more often than page->index.
Low order bit should never be set for lru.next (when used as an anchor
in LRU list), so KCSAN report is mostly a false positive.
Backporting to older kernel versions seems not necessary.
[1]
BUG: KCSAN: data-race in lru_add_fn / tcp_build_frag
write to 0xffffea0004a1d2c8 of 8 bytes by task 18600 on cpu 0:
__list_add include/linux/list.h:73 [inline]
list_add include/linux/list.h:88 [inline]
lruvec_add_folio include/linux/mm_inline.h:105 [inline]
lru_add_fn+0x440/0x520 mm/swap.c:228
folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246
folio_batch_add_and_move mm/swap.c:263 [inline]
folio_add_lru+0xf1/0x140 mm/swap.c:490
filemap_add_folio+0xf8/0x150 mm/filemap.c:948
__filemap_get_folio+0x510/0x6d0 mm/filemap.c:1981
pagecache_get_page+0x26/0x190 mm/folio-compat.c:104
grab_cache_page_write_begin+0x2a/0x30 mm/folio-compat.c:116
ext4_da_write_begin+0x2dd/0x5f0 fs/ext4/inode.c:2988
generic_perform_write+0x1d4/0x3f0 mm/filemap.c:3738
ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:270
ext4_file_write_iter+0x2e3/0x1210
call_write_iter include/linux/fs.h:2187 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x468/0x760 fs/read_write.c:578
ksys_write+0xe8/0x1a0 fs/read_write.c:631
__do_sys_write fs/read_write.c:643 [inline]
__se_sys_write fs/read_write.c:640 [inline]
__x64_sys_write+0x3e/0x50 fs/read_write.c:640
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
read to 0xffffea0004a1d2c8 of 8 bytes by task 18611 on cpu 1:
page_is_pfmemalloc include/linux/mm.h:1740 [inline]
__skb_fill_page_desc include/linux/skbuff.h:2422 [inline]
skb_fill_page_desc include/linux/skbuff.h:2443 [inline]
tcp_build_frag+0x613/0xb20 net/ipv4/tcp.c:1018
do_tcp_sendpages+0x3e8/0xaf0 net/ipv4/tcp.c:1075
tcp_sendpage_locked net/ipv4/tcp.c:1140 [inline]
tcp_sendpage+0x89/0xb0 net/ipv4/tcp.c:1150
inet_sendpage+0x7f/0xc0 net/ipv4/af_inet.c:833
kernel_sendpage+0x184/0x300 net/socket.c:3561
sock_sendpage+0x5a/0x70 net/socket.c:1054
pipe_to_sendpage+0x128/0x160 fs/splice.c:361
splice_from_pipe_feed fs/splice.c:415 [inline]
__splice_from_pipe+0x222/0x4d0 fs/splice.c:559
splice_from_pipe fs/splice.c:594 [inline]
generic_splice_sendpage+0x89/0xc0 fs/splice.c:743
do_splice_from fs/splice.c:764 [inline]
direct_splice_actor+0x80/0xa0 fs/splice.c:931
splice_direct_to_actor+0x305/0x620 fs/splice.c:886
do_splice_direct+0xfb/0x180 fs/splice.c:974
do_sendfile+0x3bf/0x910 fs/read_write.c:1249
__do_sys_sendfile64 fs/read_write.c:1317 [inline]
__se_sys_sendfile64 fs/read_write.c:1303 [inline]
__x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1303
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
value changed: 0x0000000000000000 -> 0xffffea0004a1d288
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18611 Comm: syz-executor.4 Not tainted 6.0.0-rc2-syzkaller-00248-ge022620b5d05-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Fixes: c07aea3ef4 ("mm: add a signature in struct page")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sometimes, gcc will optimize the function by spliting it to two or
more functions. In this case, kfree_skb_reason() is splited to
kfree_skb_reason and kfree_skb_reason.part.0. However, the
function/tracepoint trace_kfree_skb() in it needs the return address
of kfree_skb_reason().
This split makes the call chains becomes:
kfree_skb_reason() -> kfree_skb_reason.part.0 -> trace_kfree_skb()
which makes the return address that passed to trace_kfree_skb() be
kfree_skb().
Therefore, introduce '__fix_address', which is the combination of
'__noclone' and 'noinline', and apply it to kfree_skb_reason() to
prevent to from being splited or made inline.
(Is it better to simply apply '__noclone oninline' to kfree_skb_reason?
I'm thinking maybe other functions have the same problems)
Meanwhile, wrap 'skb_unref()' with 'unlikely()', as the compiler thinks
it is likely return true and splits kfree_skb_reason().
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
bpf-next 2022-07-22
We've added 73 non-merge commits during the last 12 day(s) which contain
a total of 88 files changed, 3458 insertions(+), 860 deletions(-).
The main changes are:
1) Implement BPF trampoline for arm64 JIT, from Xu Kuohai.
2) Add ksyscall/kretsyscall section support to libbpf to simplify tracing kernel
syscalls through kprobe mechanism, from Andrii Nakryiko.
3) Allow for livepatch (KLP) and BPF trampolines to attach to the same kernel
function, from Song Liu & Jiri Olsa.
4) Add new kfunc infrastructure for netfilter's CT e.g. to insert and change
entries, from Kumar Kartikeya Dwivedi & Lorenzo Bianconi.
5) Add a ksym BPF iterator to allow for more flexible and efficient interactions
with kernel symbols, from Alan Maguire.
6) Bug fixes in libbpf e.g. for uprobe binary path resolution, from Dan Carpenter.
7) Fix BPF subprog function names in stack traces, from Alexei Starovoitov.
8) libbpf support for writing custom perf event readers, from Jon Doron.
9) Switch to use SPDX tag for BPF helper man page, from Alejandro Colomar.
10) Fix xsk send-only sockets when in busy poll mode, from Maciej Fijalkowski.
11) Reparent BPF maps and their charging on memcg offlining, from Roman Gushchin.
12) Multiple follow-up fixes around BPF lsm cgroup infra, from Stanislav Fomichev.
13) Use bootstrap version of bpftool where possible to speed up builds, from Pu Lehui.
14) Cleanup BPF verifier's check_func_arg() handling, from Joanne Koong.
15) Make non-prealloced BPF map allocations low priority to play better with
memcg limits, from Yafang Shao.
16) Fix BPF test runner to reject zero-length data for skbs, from Zhengchao Shao.
17) Various smaller cleanups and improvements all over the place.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (73 commits)
bpf: Simplify bpf_prog_pack_[size|mask]
bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)
bpf, x64: Allow to use caller address from stack
ftrace: Allow IPMODIFY and DIRECT ops on the same function
ftrace: Add modify_ftrace_direct_multi_nolock
bpf/selftests: Fix couldn't retrieve pinned program in xdp veth test
bpf: Fix build error in case of !CONFIG_DEBUG_INFO_BTF
selftests/bpf: Fix test_verifier failed test in unprivileged mode
selftests/bpf: Add negative tests for new nf_conntrack kfuncs
selftests/bpf: Add tests for new nf_conntrack kfuncs
selftests/bpf: Add verifier tests for trusted kfunc args
net: netfilter: Add kfuncs to set and change CT status
net: netfilter: Add kfuncs to set and change CT timeout
net: netfilter: Add kfuncs to allocate and insert CT
net: netfilter: Deduplicate code in bpf_{xdp,skb}_ct_lookup
bpf: Add documentation for kfuncs
bpf: Add support for forcing kfunc args to be trusted
bpf: Switch to new kfunc flags infrastructure
tools/resolve_btfids: Add support for 8-byte BTF sets
bpf: Introduce 8-byte BTF set
...
====================
Link: https://lore.kernel.org/r/20220722221218.29943-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pavel Begunkov says:
====================
io_uring zerocopy send
The patchset implements io_uring zerocopy send. It works with both registered
and normal buffers, mixing is allowed but not recommended. Apart from usual
request completions, just as with MSG_ZEROCOPY, io_uring separately notifies
the userspace when buffers are freed and can be reused (see API design below),
which is delivered into io_uring's Completion Queue. Those "buffer-free"
notifications are not necessarily per request, but the userspace has control
over it and should explicitly attaching a number of requests to a single
notification. The series also adds some internal optimisations when used with
registered buffers like removing page referencing.
From the kernel networking perspective there are two main changes. The first
one is passing ubuf_info into the network layer from io_uring (inside of an
in kernel struct msghdr). This allows extra optimisations, e.g. ubuf_info
caching on the io_uring side, but also helps to avoid cross-referencing
and synchronisation problems. The second part is an optional optimisation
removing page referencing for requests with registered buffers.
Benchmarking UDP with an optimised version of the selftest (see [1]), which
sends a bunch of requests, waits for completions and repeats. "+ flush" column
posts one additional "buffer-free" notification per request, and just "zc"
doesn't post buffer notifications at all.
NIC (requests / second):
IO size | non-zc | zc | zc + flush
4000 | 495134 | 606420 (+22%) | 558971 (+12%)
1500 | 551808 | 577116 (+4.5%) | 565803 (+2.5%)
1000 | 584677 | 592088 (+1.2%) | 560885 (-4%)
600 | 596292 | 598550 (+0.4%) | 555366 (-6.7%)
dummy (requests / second):
IO size | non-zc | zc | zc + flush
8000 | 1299916 | 2396600 (+84%) | 2224219 (+71%)
4000 | 1869230 | 2344146 (+25%) | 2170069 (+16%)
1200 | 2071617 | 2361960 (+14%) | 2203052 (+6%)
600 | 2106794 | 2381527 (+13%) | 2195295 (+4%)
Previously it also brought a massive performance speedup compared to the
msg_zerocopy tool (see [3]), which is probably not super interesting. There
is also an additional bunch of refcounting optimisations that was omitted from
the series for simplicity and as they don't change the picture drastically,
they will be sent as follow up, as well as flushing optimisations closing the
performance gap b/w two last columns.
For TCP on localhost (with hacks enabling localhost zerocopy) and including
additional overhead for receive:
IO size | non-zc | zc
1200 | 4174 | 4148
4096 | 7597 | 11228
Using a real NIC 1200 bytes, zc is worse than non-zc ~5-10%, maybe the
omitted optimisations will somewhat help, should look better for 4000,
but couldn't test properly because of setup problems.
Links:
liburing (benchmark + tests):
[1] https://github.com/isilence/liburing/tree/zc_v4
kernel repo:
[2] https://github.com/isilence/linux/tree/zc_v4
RFC v1:
[3] https://lore.kernel.org/io-uring/cover.1638282789.git.asml.silence@gmail.com/
RFC v2:
https://lore.kernel.org/io-uring/cover.1640029579.git.asml.silence@gmail.com/
Net patches based:
git@github.com:isilence/linux.git zc_v4-net-base
or
https://github.com/isilence/linux/tree/zc_v4-net-base
API design overview:
The series introduces an io_uring concept of notifactors. From the userspace
perspective it's an entity to which it can bind one or more requests and then
requesting to flush it. Flushing a notifier makes it impossible to attach new
requests to it, and instructs the notifier to post a completion once all
requests attached to it are completed and the kernel doesn't need the buffers
anymore.
Notifications are stored in notification slots, which should be registered as
an array in io_uring. Each slot stores only one notifier at any particular
moment. Flushing removes it from the slot and the slot automatically replaces
it with a new notifier. All operations with notifiers are done by specifying
an index of a slot it's currently in.
When registering a notification the userspace specifies a u64 tag for each
slot, which will be copied in notification completion entries as
cqe::user_data. cqe::res is 0 and cqe::flags is equal to wrap around u32
sequence number counting notifiers of a slot.
====================
Link: https://lore.kernel.org/r/cover.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Managed pages contain pinned userspace pages and controlled by upper
layers, there is no need in tracking skb->pfmemalloc for them. Introduce
a helper for filling frags but ignoring page tracking, it'll be needed
later.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some users like io_uring can do page pinning more efficiently, so we
want a way to delegate referencing to other subsystems. For that add
a new flag called SKBFL_MANAGED_FRAG_REFS. When set, skb doesn't hold
page references and upper layers are responsivle to managing page
lifetime.
It's allowed to convert skbs from managed to normal by calling
skb_zcopy_downgrade_managed(). The function will take all needed
page references and clear the flag. It's needed, for instance,
to avoid mixing managed modes.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add support for custom iov_iter handling to msghdr. The idea is that
in-kernel subsystems want control over how an SG is split.
Signed-off-by: David Ahern <dsahern@kernel.org>
[pavel: move callback into msghdr]
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We don't want to list every single ubuf_info callback in
skb_orphan_frags(), add a flag controlling the behaviour.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move the len fields manipulation in the skbs to a helper function.
There is a comment specifically requesting this and there are several
other areas in the code displaying the same pattern which can be
refactored.
This improves code readability.
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Link: https://lore.kernel.org/r/20220622160853.GA6478@debian
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As the skb drop reasons are getting more and more, move the enum
'skb_drop_reason' and related function to the standalone header
'dropreason.h', as Jakub Kicinski suggested.
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
While analyzing yet another syzbot report, I found the following
patch very useful. It allows to better understand what went wrong.
This debug info is only enabled if CONFIG_DEBUG_NET=y,
which is the case for syzbot builds.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The SKB_DR_OR() is used to set the drop reason to a value when it is
not set or specified yet. SKB_NOT_DROPPED_YET should also be considered
as not set.
Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make sure skb_transport_header() and skb_transport_offset() uses
are not fooled if the transport header has not been set.
This change will likely expose existing bugs in linux networking stacks.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Long time ago Tom added a giant comment to skbuff.h explaining
checksums. Now that we have a place in Documentation for skbuff
docs we should render it. Sprinkle some markup while at it.
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
