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git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from bpf and netfilter.
Current release - regressions:
- gro: initialize network_offset in network layer
- tcp: reduce accepted window in NEW_SYN_RECV state
Current release - new code bugs:
- eth: mlx5e: do not use ptp structure for tx ts stats when not
initialized
- eth: ice: check for unregistering correct number of devlink params
Previous releases - regressions:
- bpf: Allow delete from sockmap/sockhash only if update is allowed
- sched: taprio: extend minimum interval restriction to entire cycle
too
- netfilter: ipset: add list flush to cancel_gc
- ipv4: fix address dump when IPv4 is disabled on an interface
- sock_map: avoid race between sock_map_close and sk_psock_put
- eth: mlx5: use mlx5_ipsec_rx_status_destroy to correctly delete
status rules
Previous releases - always broken:
- core: fix __dst_negative_advice() race
- bpf:
- fix multi-uprobe PID filtering logic
- fix pkt_type override upon netkit pass verdict
- netfilter: tproxy: bail out if IP has been disabled on the device
- af_unix: annotate data-race around unix_sk(sk)->addr
- eth: mlx5e: fix UDP GSO for encapsulated packets
- eth: idpf: don't enable NAPI and interrupts prior to allocating Rx
buffers
- eth: i40e: fully suspend and resume IO operations in EEH case
- eth: octeontx2-pf: free send queue buffers incase of leaf to inner
- eth: ipvlan: dont Use skb->sk in ipvlan_process_v{4,6}_outbound"
* tag 'net-6.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits)
netdev: add qstat for csum complete
ipvlan: Dont Use skb->sk in ipvlan_process_v{4,6}_outbound
net: ena: Fix redundant device NUMA node override
ice: check for unregistering correct number of devlink params
ice: fix 200G PHY types to link speed mapping
i40e: Fully suspend and resume IO operations in EEH case
i40e: factoring out i40e_suspend/i40e_resume
e1000e: move force SMBUS near the end of enable_ulp function
net: dsa: microchip: fix RGMII error in KSZ DSA driver
ipv4: correctly iterate over the target netns in inet_dump_ifaddr()
net: fix __dst_negative_advice() race
nfc/nci: Add the inconsistency check between the input data length and count
MAINTAINERS: dwmac: starfive: update Maintainer
net/sched: taprio: extend minimum interval restriction to entire cycle too
net/sched: taprio: make q->picos_per_byte available to fill_sched_entry()
netfilter: nft_fib: allow from forward/input without iif selector
netfilter: tproxy: bail out if IP has been disabled on the device
netfilter: nft_payload: skbuff vlan metadata mangle support
net: ti: icssg-prueth: Fix start counter for ft1 filter
sock_map: avoid race between sock_map_close and sk_psock_put
...
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Add three new kfuncs for the bits iterator:
- bpf_iter_bits_new
Initialize a new bits iterator for a given memory area. Due to the
limitation of bpf memalloc, the max number of words (8-byte units) that
can be iterated over is limited to (4096 / 8).
- bpf_iter_bits_next
Get the next bit in a bpf_iter_bits
- bpf_iter_bits_destroy
Destroy a bpf_iter_bits
The bits iterator facilitates the iteration of the bits of a memory area,
such as cpumask. It can be used in any context and on any address.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240517023034.48138-2-laoar.shao@gmail.com
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Commit 13e1df09284d ("kheaders: explicitly validate existence of cpio
command") added an explicit check for `cpio` using `type`.
However, `type` in `dash` (which is used in some popular distributions
and base images as the shell script runner) prints the missing message
to standard output, and thus no error is printed:
$ bash -c 'type missing >/dev/null'
bash: line 1: type: missing: not found
$ dash -c 'type missing >/dev/null'
$
For instance, this issue may be seen by loongarch builders, given its
defconfig enables CONFIG_IKHEADERS since commit 9cc1df421f00 ("LoongArch:
Update Loongson-3 default config file").
Therefore, use `command -v` instead to have consistent behavior, and
take the chance to provide a more explicit error.
Fixes: 13e1df09284d ("kheaders: explicitly validate existence of cpio command")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Build environments might be running with different umask settings
resulting in indeterministic file modes for the files contained in
kheaders.tar.xz. The file itself is served with 444, i.e. world
readable. Archive the files explicitly with 744,a+X to improve
reproducibility across build environments.
--mode=0444 is not suitable as directories need to be executable. Also,
444 makes it hard to delete all the readonly files after extraction.
Cc: stable@vger.kernel.org
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixes from Masami Hiramatsu:
- uprobes: prevent mutex_lock() under rcu_read_lock().
Recent changes moved uprobe_cpu_buffer preparation which involves
mutex_lock(), under __uprobe_trace_func() which is called inside
rcu_read_lock().
Fix it by moving uprobe_cpu_buffer preparation outside of
__uprobe_trace_func()
- kprobe-events: handle the error case of btf_find_struct_member()
* tag 'probes-fixes-v6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/probes: fix error check in parse_btf_field()
uprobes: prevent mutex_lock() under rcu_read_lock()
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PCI bridge window logic needs to find out in advance to the actual
allocation if there is an empty space big enough to fit the window.
Export find_resource_space() for the purpose. Also move the struct
resource_constraint into generic header to be able to use the new
interface.
Link: https://lore.kernel.org/r/20240507102523.57320-7-ilpo.jarvinen@linux.intel.com
Tested-by: Lidong Wang <lidong.wang@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
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allocate_resource() accepts ->alignf() callback to perform custom alignment
beyond constraint->align. If alignf is NULL, simple_align_resource() is
used which only returns avail->start (no change).
Using avail->start directly is natural and can be done with a conditional
in __find_resource_space() instead which avoids unnecessarily using
callback. It makes the code inside __find_resource_space() more obvious and
removes the need for the caller to provide constraint->alignf
unnecessarily.
This is preparation for exporting find_resource_space().
Link: https://lore.kernel.org/r/20240507102523.57320-6-ilpo.jarvinen@linux.intel.com
Tested-by: Lidong Wang <lidong.wang@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
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To make it simpler to declare resource constraint alignf callbacks, add
typedef for it and document it.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240507102523.57320-5-ilpo.jarvinen@linux.intel.com
Tested-by: Lidong Wang <lidong.wang@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
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Document find_resource_space() and the struct resource_constraint as they
are going to be exposed outside of resource.c.
Link: https://lore.kernel.org/r/20240507102523.57320-4-ilpo.jarvinen@linux.intel.com
Tested-by: Lidong Wang <lidong.wang@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
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Rename find_resource() to find_resource_space() to better describe what the
function does. This is a preparation for exposing it beyond resource.c,
which is needed by PCI core. Also rename the __ variant to match the names.
Link: https://lore.kernel.org/r/20240507102523.57320-3-ilpo.jarvinen@linux.intel.com
Tested-by: Lidong Wang <lidong.wang@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-05-28
We've added 23 non-merge commits during the last 11 day(s) which contain
a total of 45 files changed, 696 insertions(+), 277 deletions(-).
The main changes are:
1) Rename skb's mono_delivery_time to tstamp_type for extensibility
and add SKB_CLOCK_TAI type support to bpf_skb_set_tstamp(),
from Abhishek Chauhan.
2) Add netfilter CT zone ID and direction to bpf_ct_opts so that arbitrary
CT zones can be used from XDP/tc BPF netfilter CT helper functions,
from Brad Cowie.
3) Several tweaks to the instruction-set.rst IETF doc to address
the Last Call review comments, from Dave Thaler.
4) Small batch of riscv64 BPF JIT optimizations in order to emit more
compressed instructions to the JITed image for better icache efficiency,
from Xiao Wang.
5) Sort bpftool C dump output from BTF, aiming to simplify vmlinux.h
diffing and forcing more natural type definitions ordering,
from Mykyta Yatsenko.
6) Use DEV_STATS_INC() macro in BPF redirect helpers to silence
a syzbot/KCSAN race report for the tx_errors counter,
from Jiang Yunshui.
7) Un-constify bpf_func_info in bpftool to fix compilation with LLVM 17+
which started treating const structs as constants and thus breaking
full BTF program name resolution, from Ivan Babrou.
8) Fix up BPF program numbers in test_sockmap selftest in order to reduce
some of the test-internal array sizes, from Geliang Tang.
9) Small cleanup in Makefile.btf script to use test-ge check for v1.25-only
pahole, from Alan Maguire.
10) Fix bpftool's make dependencies for vmlinux.h in order to avoid needless
rebuilds in some corner cases, from Artem Savkov.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (23 commits)
bpf, net: Use DEV_STAT_INC()
bpf, docs: Fix instruction.rst indentation
bpf, docs: Clarify call local offset
bpf, docs: Add table captions
bpf, docs: clarify sign extension of 64-bit use of 32-bit imm
bpf, docs: Use RFC 2119 language for ISA requirements
bpf, docs: Move sentence about returning R0 to abi.rst
bpf: constify member bpf_sysctl_kern:: Table
riscv, bpf: Try RVC for reg move within BPF_CMPXCHG JIT
riscv, bpf: Use STACK_ALIGN macro for size rounding up
riscv, bpf: Optimize zextw insn with Zba extension
selftests/bpf: Handle forwarding of UDP CLOCK_TAI packets
net: Add additional bit to support clockid_t timestamp type
net: Rename mono_delivery_time to tstamp_type for scalabilty
selftests/bpf: Update tests for new ct zone opts for nf_conntrack kfuncs
net: netfilter: Make ct zone opts configurable for bpf ct helpers
selftests/bpf: Fix prog numbers in test_sockmap
bpf: Remove unused variable "prev_state"
bpftool: Un-const bpf_func_info to fix it for llvm 17 and newer
bpf: Fix order of args in call to bpf_map_kvcalloc
...
====================
Link: https://lore.kernel.org/r/20240528105924.30905-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:
====================
pull-request: bpf 2024-05-27
We've added 15 non-merge commits during the last 7 day(s) which contain
a total of 18 files changed, 583 insertions(+), 55 deletions(-).
The main changes are:
1) Fix broken BPF multi-uprobe PID filtering logic which filtered by thread
while the promise was to filter by process, from Andrii Nakryiko.
2) Fix the recent influx of syzkaller reports to sockmap which triggered
a locking rule violation by performing a map_delete, from Jakub Sitnicki.
3) Fixes to netkit driver in particular on skb->pkt_type override upon pass
verdict, from Daniel Borkmann.
4) Fix an integer overflow in resolve_btfids which can wrongly trigger build
failures, from Friedrich Vock.
5) Follow-up fixes for ARC JIT reported by static analyzers,
from Shahab Vahedi.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
selftests/bpf: Cover verifier checks for mutating sockmap/sockhash
Revert "bpf, sockmap: Prevent lock inversion deadlock in map delete elem"
bpf: Allow delete from sockmap/sockhash only if update is allowed
selftests/bpf: Add netkit test for pkt_type
selftests/bpf: Add netkit tests for mac address
netkit: Fix pkt_type override upon netkit pass verdict
netkit: Fix setting mac address in l2 mode
ARC, bpf: Fix issues reported by the static analyzers
selftests/bpf: extend multi-uprobe tests with USDTs
selftests/bpf: extend multi-uprobe tests with child thread case
libbpf: detect broken PID filtering logic for multi-uprobe
bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic
bpf: fix multi-uprobe PID filtering logic
bpf: Fix potential integer overflow in resolve_btfids
MAINTAINERS: Add myself as reviewer of ARM64 BPF JIT
====================
Link: https://lore.kernel.org/r/20240527203551.29712-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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We have seen an influx of syzkaller reports where a BPF program attached to
a tracepoint triggers a locking rule violation by performing a map_delete
on a sockmap/sockhash.
We don't intend to support this artificial use scenario. Extend the
existing verifier allowed-program-type check for updating sockmap/sockhash
to also cover deleting from a map.
From now on only BPF programs which were previously allowed to update
sockmap/sockhash can delete from these map types.
Fixes: ff9105993240 ("bpf, sockmap: Prevent lock inversion deadlock in map delete elem")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzbot+ec941d6e24f633a59172@syzkaller.appspotmail.com
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+ec941d6e24f633a59172@syzkaller.appspotmail.com
Acked-by: John Fastabend <john.fastabend@gmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=ec941d6e24f633a59172
Link: https://lore.kernel.org/bpf/20240527-sockmap-verify-deletes-v1-1-944b372f2101@cloudflare.com
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- Fix io_uring based write-through after converting cifs to use the
netfs library
- Fix aio error handling when doing write-through via netfs library
- Fix performance regression in iomap when used with non-large folio
mappings
- Fix signalfd error code
- Remove obsolete comment in signalfd code
- Fix async request indication in netfs_perform_write() by raising
BDP_ASYNC when IOCB_NOWAIT is set
- Yield swap device immediately to prevent spurious EBUSY errors
- Don't cross a .backup mountpoint from backup volumes in afs to avoid
infinite loops
- Fix a race between umount and async request completion in 9p after 9p
was converted to use the netfs library
* tag 'vfs-6.10-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
netfs, 9p: Fix race between umount and async request completion
afs: Don't cross .backup mountpoint from backup volume
swap: yield device immediately
netfs: Fix setting of BDP_ASYNC from iocb flags
signalfd: drop an obsolete comment
signalfd: fix error return code
iomap: fault in smaller chunks for non-large folio mappings
filemap: add helper mapping_max_folio_size()
netfs: Fix AIO error handling when doing write-through
netfs: Fix io_uring based write-through
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Do a spell-checking pass.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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btf_find_struct_member() might return NULL or an error via the
ERR_PTR() macro. However, its caller in parse_btf_field() only checks
for the NULL condition. Fix this by using IS_ERR() and returning the
error up the stack.
Link: https://lore.kernel.org/all/20240527094351.15687-1-clopez@suse.de/
Fixes: c440adfbe3025 ("tracing/probes: Support BTF based data structure field access")
Signed-off-by: Carlos López <clopez@suse.de>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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core.c has become rather large, move most scheduler syscall
related functionality into a separate file, syscalls.c.
This is about ~15% of core.c's raw linecount.
Move the alloc_user_cpus_ptr(), __rt_effective_prio(),
rt_effective_prio(), uclamp_none(), uclamp_se_set()
and uclamp_bucket_id() inlines to kernel/sched/sched.h.
Internally export the __sched_setscheduler(), __sched_setaffinity(),
__setscheduler_prio(), set_load_weight(), enqueue_task(), dequeue_task(),
check_class_changed(), splice_balance_callbacks() and balance_callbacks()
methods to better facilitate this.
Move the new file's build to sched_policy.c, because it fits there
semantically, but also because it's the smallest of the 4 build units
under an allmodconfig build:
-rw-rw-r-- 1 mingo mingo 7.3M May 27 12:35 kernel/sched/core.i
-rw-rw-r-- 1 mingo mingo 6.4M May 27 12:36 kernel/sched/build_utility.i
-rw-rw-r-- 1 mingo mingo 6.3M May 27 12:36 kernel/sched/fair.i
-rw-rw-r-- 1 mingo mingo 5.8M May 27 12:36 kernel/sched/build_policy.i
This better balances build time for scheduler subsystem rebuilds.
I build-tested this new file as a standalone syscalls.o file for a bit,
to make sure all the encapsulations & abstractions are robust.
Also update/add my copyright notices to these files.
Build time measurements:
# -Before/+After:
kepler:~/tip> perf stat -e 'cycles,instructions,duration_time' --sync --repeat 5 --pre 'rm -f kernel/sched/*.o' m kernel/sched/built-in.a >/dev/null
Performance counter stats for 'm kernel/sched/built-in.a' (5 runs):
- 71,938,508,607 cycles ( +- 0.17% )
+ 71,992,916,493 cycles ( +- 0.22% )
- 106,214,780,964 instructions # 1.48 insn per cycle ( +- 0.01% )
+ 105,450,231,154 instructions # 1.46 insn per cycle ( +- 0.01% )
- 5,878,232,620 ns duration_time ( +- 0.38% )
+ 5,290,085,069 ns duration_time ( +- 0.21% )
- 5.8782 +- 0.0221 seconds time elapsed ( +- 0.38% )
+ 5.2901 +- 0.0111 seconds time elapsed ( +- 0.21% )
Build time improvement of -11.1% (duration_time) is expected: the
parallel build time of the scheduler subsystem is determined by the
largest, slowest to build object file, which is kernel/sched/core.o.
By moving ~15% of its complexity into another build unit, we reduced
build time by -11%.
Measured cycles spent on building is within its ~0.2% stddev noise envelope.
The -0.7% reduction in instructions spent on building the scheduler is
statistically reliable and somewhat surprising - I can only speculate:
maybe compilers aren't that efficient at building & optimizing 10+ KLOC files
(core.c), and it's an overall win to balance the linecount a bit.
Anyway, this might be a data point that suggests that reducing the linecount
of our largest files will improve not just code readability and maintainability,
but might also improve build times a bit.
Code generation got a bit worse, by 0.5kb text on an x86 defconfig build:
# -Before/+After:
kepler:~/tip> size vmlinux
text data bss dec hex filename
-26475475 10439178 1740804 38655457 24dd5e1 vmlinux
+26476003 10439178 1740804 38655985 24dd7f1 vmlinux
kepler:~/tip> size kernel/sched/built-in.a
text data bss dec hex filename
- 76056 30025 489 106570 1a04a kernel/sched/core.o (ex kernel/sched/built-in.a)
+ 63452 29453 489 93394 16cd2 kernel/sched/core.o (ex kernel/sched/built-in.a)
44299 2181 104 46584 b5f8 kernel/sched/fair.o (ex kernel/sched/built-in.a)
- 42764 3424 120 46308 b4e4 kernel/sched/build_policy.o (ex kernel/sched/built-in.a)
+ 55651 4044 120 59815 e9a7 kernel/sched/build_policy.o (ex kernel/sched/built-in.a)
44866 12655 2192 59713 e941 kernel/sched/build_utility.o (ex kernel/sched/built-in.a)
44866 12655 2192 59713 e941 kernel/sched/build_utility.o (ex kernel/sched/built-in.a)
This is primarily due to the extra functions exported, and the size
gets exaggerated somewhat by __pfx CFI function padding:
ffffffff810cc710 <__pfx_enqueue_task>:
ffffffff810cc710: 90 nop
ffffffff810cc711: 90 nop
ffffffff810cc712: 90 nop
ffffffff810cc713: 90 nop
ffffffff810cc714: 90 nop
ffffffff810cc715: 90 nop
ffffffff810cc716: 90 nop
ffffffff810cc717: 90 nop
ffffffff810cc718: 90 nop
ffffffff810cc719: 90 nop
ffffffff810cc71a: 90 nop
ffffffff810cc71b: 90 nop
ffffffff810cc71c: 90 nop
ffffffff810cc71d: 90 nop
ffffffff810cc71e: 90 nop
ffffffff810cc71f: 90 nop
AFAICS the cost is primarily not to core.o and fair.o though (which contain
most performance sensitive scheduler functions), only to syscalls.o
that get called with much lower frequency - so I think this is an acceptable
trade-off for better code separation.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: https://lore.kernel.org/r/20240407084319.1462211-2-mingo@kernel.org
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Even though css_clear_dir would be called to cleanup
all existing cgroup files when css_populate_dir failed,
reclaiming newly created cgroup files before
css_populate_dir returns with failure makes code more
consistent.
Signed-off-by: David Wang <00107082@163.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Hierarchical counting of events is not practical for watching when a
particular pids.max is being hit. Therefore introduce .local flavor of
events file (akin to memory controller) that collects only events
relevant to given cgroup.
The file is only added to the default hierarchy.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The pids.events file should honor the hierarchy, so make the events
propagate from their origin up to the root on the unified hierarchy. The
legacy behavior remains non-hierarchical.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Currently, when pids.max limit is breached in the hierarchy, the event
is counted and reported in the cgroup where the forking task resides.
This decouples the limit and the notification caused by the limit making
it hard to detect when the actual limit was effected.
Redefine the pids.events:max as: the number of times the limit of the
cgroup was hit.
(Implementation differentiates also "forkfail" event but this is
currently not exposed as it would better fit into pids.stat. It also
differs from pids.events:max only when pids.max is configured on
non-leaf cgroups.)
Since it changes semantics of the original "max" event, introduce this
change only in the v2 API of the controller and add a cgroup2 mount
option to revert to the legacy behavior.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Since commit 51ffe41178c4 ("cpuset: convert away from cftype->read()"),
cpuset_common_file_read() has been renamed.
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The struct cpuset is kzalloc'd, all the members are zeroed already,
so don't need nodes_clear() here.
No functional changes intended.
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Ingo Molnar:
- Fix x86 IRQ vector leak caused by a CPU offlining race
- Fix build failure in the riscv-imsic irqchip driver
caused by an API-change semantic conflict
- Fix use-after-free in irq_find_at_or_after()
* tag 'irq-urgent-2024-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after()
genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline
irqchip/riscv-imsic: Fixup riscv_ipi_set_virq_range() conflict
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get_pid_task() internally already calls rcu_read_lock() and
rcu_read_unlock(), so there is no point to do this one extra time.
This is a drive-by improvement and has no correctness implications.
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Current implementation of PID filtering logic for multi-uprobes in
uprobe_prog_run() is filtering down to exact *thread*, while the intent
for PID filtering it to filter by *process* instead. The check in
uprobe_prog_run() also differs from the analogous one in
uprobe_multi_link_filter() for some reason. The latter is correct,
checking task->mm, not the task itself.
Fix the check in uprobe_prog_run() to perform the same task->mm check.
While doing this, we also update get_pid_task() use to use PIDTYPE_TGID
type of lookup, given the intent is to get a representative task of an
entire process. This doesn't change behavior, but seems more logical. It
would hold task group leader task now, not any random thread task.
Last but not least, given multi-uprobe support is half-broken due to
this PID filtering logic (depending on whether PID filtering is
important or not), we need to make it easy for user space consumers
(including libbpf) to easily detect whether PID filtering logic was
already fixed.
We do it here by adding an early check on passed pid parameter. If it's
negative (and so has no chance of being a valid PID), we return -EINVAL.
Previous behavior would eventually return -ESRCH ("No process found"),
given there can't be any process with negative PID. This subtle change
won't make any practical change in behavior, but will allow applications
to detect PID filtering fixes easily. Libbpf fixes take advantage of
this in the next patch.
Cc: stable@vger.kernel.org
Acked-by: Jiri Olsa <jolsa@kernel.org>
Fixes: b733eeade420 ("bpf: Add pid filter support for uprobe_multi link")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more mm updates from Andrew Morton:
"Jeff Xu's implementation of the mseal() syscall"
* tag 'mm-stable-2024-05-24-11-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
selftest mm/mseal read-only elf memory segment
mseal: add documentation
selftest mm/mseal memory sealing
mseal: add mseal syscall
mseal: wire up mseal syscall
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Otherwise we can cause spurious EBUSY issues when trying to mount the
rootfs later on.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218845
Reported-by: Petri Kaukasoina <petri.kaukasoina@tuni.fi>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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irq_find_at_or_after() dereferences the interrupt descriptor which is
returned by mt_find() while neither holding sparse_irq_lock nor RCU read
lock, which means the descriptor can be freed between mt_find() and the
dereference:
CPU0 CPU1
desc = mt_find()
delayed_free_desc(desc)
irq_desc_get_irq(desc)
The use-after-free is reported by KASAN:
Call trace:
irq_get_next_irq+0x58/0x84
show_stat+0x638/0x824
seq_read_iter+0x158/0x4ec
proc_reg_read_iter+0x94/0x12c
vfs_read+0x1e0/0x2c8
Freed by task 4471:
slab_free_freelist_hook+0x174/0x1e0
__kmem_cache_free+0xa4/0x1dc
kfree+0x64/0x128
irq_kobj_release+0x28/0x3c
kobject_put+0xcc/0x1e0
delayed_free_desc+0x14/0x2c
rcu_do_batch+0x214/0x720
Guard the access with a RCU read lock section.
Fixes: 721255b9826b ("genirq: Use a maple tree for interrupt descriptor management")
Signed-off-by: dicken.ding <dicken.ding@mediatek.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240524091739.31611-1-dicken.ding@mediatek.com
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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/20240415163527.626541-1-jeffxu@chromium.org
Link: https://lkml.kernel.org/r/20240415163527.626541-2-jeffxu@chromium.org
Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jann Horn <jannh@google.com> [Bug #2]
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Amer Al Shanawany <amer.shanawany@gmail.com>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Recent changes made uprobe_cpu_buffer preparation lazy, and moved it
deeper into __uprobe_trace_func(). This is problematic because
__uprobe_trace_func() is called inside rcu_read_lock()/rcu_read_unlock()
block, which then calls prepare_uprobe_buffer() -> uprobe_buffer_get() ->
mutex_lock(&ucb->mutex), leading to a splat about using mutex under
non-sleepable RCU:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 98231, name: stress-ng-sigq
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
...
Call Trace:
<TASK>
dump_stack_lvl+0x3d/0xe0
__might_resched+0x24c/0x270
? prepare_uprobe_buffer+0xd5/0x1d0
__mutex_lock+0x41/0x820
? ___perf_sw_event+0x206/0x290
? __perf_event_task_sched_in+0x54/0x660
? __perf_event_task_sched_in+0x54/0x660
prepare_uprobe_buffer+0xd5/0x1d0
__uprobe_trace_func+0x4a/0x140
uprobe_dispatcher+0x135/0x280
? uprobe_dispatcher+0x94/0x280
uprobe_notify_resume+0x650/0xec0
? atomic_notifier_call_chain+0x21/0x110
? atomic_notifier_call_chain+0xf8/0x110
irqentry_exit_to_user_mode+0xe2/0x1e0
asm_exc_int3+0x35/0x40
RIP: 0033:0x7f7e1d4da390
Code: 33 04 00 0f 1f 80 00 00 00 00 f3 0f 1e fa b9 01 00 00 00 e9 b2 fc ff ff 66 90 f3 0f 1e fa 31 c9 e9 a5 fc ff ff 0f 1f 44 00 00 <cc> 0f 1e fa b8 27 00 00 00 0f 05 c3 0f 1f 40 00 f3 0f 1e fa b8 6e
RSP: 002b:00007ffd2abc3608 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000076d325f1 RCX: 0000000000000000
RDX: 0000000076d325f1 RSI: 000000000000000a RDI: 00007ffd2abc3690
RBP: 000000000000000a R08: 00017fb700000000 R09: 00017fb700000000
R10: 00017fb700000000 R11: 0000000000000246 R12: 0000000000017ff2
R13: 00007ffd2abc3610 R14: 0000000000000000 R15: 00007ffd2abc3780
</TASK>
Luckily, it's easy to fix by moving prepare_uprobe_buffer() to be called
slightly earlier: into uprobe_trace_func() and uretprobe_trace_func(), outside
of RCU locked section. This still keeps this buffer preparation lazy and helps
avoid the overhead when it's not needed. E.g., if there is only BPF uprobe
handler installed on a given uprobe, buffer won't be initialized.
Note, the other user of prepare_uprobe_buffer(), __uprobe_perf_func(), is not
affected, as it doesn't prepare buffer under RCU read lock.
Link: https://lore.kernel.org/all/20240521053017.3708530-1-andrii@kernel.org/
Fixes: 1b8f85defbc8 ("uprobes: prepare uprobe args buffer lazily")
Reported-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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|
The absence of IRQD_MOVE_PCNTXT prevents immediate effectiveness of
interrupt affinity reconfiguration via procfs. Instead, the change is
deferred until the next instance of the interrupt being triggered on the
original CPU.
When the interrupt next triggers on the original CPU, the new affinity is
enforced within __irq_move_irq(). A vector is allocated from the new CPU,
but the old vector on the original CPU remains and is not immediately
reclaimed. Instead, apicd->move_in_progress is flagged, and the reclaiming
process is delayed until the next trigger of the interrupt on the new CPU.
Upon the subsequent triggering of the interrupt on the new CPU,
irq_complete_move() adds a task to the old CPU's vector_cleanup list if it
remains online. Subsequently, the timer on the old CPU iterates over its
vector_cleanup list, reclaiming old vectors.
However, a rare scenario arises if the old CPU is outgoing before the
interrupt triggers again on the new CPU.
In that case irq_force_complete_move() is not invoked on the outgoing CPU
to reclaim the old apicd->prev_vector because the interrupt isn't currently
affine to the outgoing CPU, and irq_needs_fixup() returns false. Even
though __vector_schedule_cleanup() is later called on the new CPU, it
doesn't reclaim apicd->prev_vector; instead, it simply resets both
apicd->move_in_progress and apicd->prev_vector to 0.
As a result, the vector remains unreclaimed in vector_matrix, leading to a
CPU vector leak.
To address this issue, move the invocation of irq_force_complete_move()
before the irq_needs_fixup() call to reclaim apicd->prev_vector, if the
interrupt is currently or used to be affine to the outgoing CPU.
Additionally, reclaim the vector in __vector_schedule_cleanup() as well,
following a warning message, although theoretically it should never see
apicd->move_in_progress with apicd->prev_cpu pointing to an offline CPU.
Fixes: f0383c24b485 ("genirq/cpuhotplug: Add support for cleaning up move in progress")
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240522220218.162423-1-dongli.zhang@oracle.com
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|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
"Minor last minute fixes:
- Fix a very tight race between the ring buffer readers and resizing
the ring buffer
- Correct some stale comments in the ring buffer code
- Fix kernel-doc in the rv code
- Add a MODULE_DESCRIPTION to preemptirq_delay_test"
* tag 'trace-fixes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rv: Update rv_en(dis)able_monitor doc to match kernel-doc
tracing: Add MODULE_DESCRIPTION() to preemptirq_delay_test
ring-buffer: Fix a race between readers and resize checks
ring-buffer: Correct stale comments related to non-consuming readers
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|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing cleanup from Steven Rostedt:
"Remove second argument of __assign_str()
The __assign_str() macro logic of the TRACE_EVENT() macro was
optimized so that it no longer needs the second argument. The
__assign_str() is always matched with __string() field that takes a
field name and the source for that field:
__string(field, source)
The TRACE_EVENT() macro logic will save off the source value and then
use that value to copy into the ring buffer via the __assign_str().
Before commit c1fa617caeb0 ("tracing: Rework __assign_str() and
__string() to not duplicate getting the string"), the __assign_str()
needed the second argument which would perform the same logic as the
__string() source parameter did. Not only would this add overhead, but
it was error prone as if the __assign_str() source produced something
different, it may not have allocated enough for the string in the ring
buffer (as the __string() source was used to determine how much to
allocate)
Now that the __assign_str() just uses the same string that was used in
__string() it no longer needs the source parameter. It can now be
removed"
* tag 'trace-assign-str-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/treewide: Remove second parameter of __assign_str()
|
|
Pull virtio updates from Michael Tsirkin:
"Several new features here:
- virtio-net is finally supported in vduse
- virtio (balloon and mem) interaction with suspend is improved
- vhost-scsi now handles signals better/faster
And fixes, cleanups all over the place"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (48 commits)
virtio-pci: Check if is_avq is NULL
virtio: delete vq in vp_find_vqs_msix() when request_irq() fails
MAINTAINERS: add Eugenio Pérez as reviewer
vhost-vdpa: Remove usage of the deprecated ida_simple_xx() API
vp_vdpa: don't allocate unused msix vectors
sound: virtio: drop owner assignment
fuse: virtio: drop owner assignment
scsi: virtio: drop owner assignment
rpmsg: virtio: drop owner assignment
nvdimm: virtio_pmem: drop owner assignment
wifi: mac80211_hwsim: drop owner assignment
vsock/virtio: drop owner assignment
net: 9p: virtio: drop owner assignment
net: virtio: drop owner assignment
net: caif: virtio: drop owner assignment
misc: nsm: drop owner assignment
iommu: virtio: drop owner assignment
drm/virtio: drop owner assignment
gpio: virtio: drop owner assignment
firmware: arm_scmi: virtio: drop owner assignment
...
|
|
cpumask_of_node() can be called for NUMA_NO_NODE inside do_map_benchmark()
resulting in the following sanitizer report:
UBSAN: array-index-out-of-bounds in ./arch/x86/include/asm/topology.h:72:28
index -1 is out of range for type 'cpumask [64][1]'
CPU: 1 PID: 990 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #29
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:117)
ubsan_epilogue (lib/ubsan.c:232)
__ubsan_handle_out_of_bounds (lib/ubsan.c:429)
cpumask_of_node (arch/x86/include/asm/topology.h:72) [inline]
do_map_benchmark (kernel/dma/map_benchmark.c:104)
map_benchmark_ioctl (kernel/dma/map_benchmark.c:246)
full_proxy_unlocked_ioctl (fs/debugfs/file.c:333)
__x64_sys_ioctl (fs/ioctl.c:890)
do_syscall_64 (arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Use cpumask_of_node() in place when binding a kernel thread to a cpuset
of a particular node.
Note that the provided node id is checked inside map_benchmark_ioctl().
It's just a NUMA_NO_NODE case which is not handled properly later.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 65789daa8087 ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
|
|
While validating node ids in map_benchmark_ioctl(), node_possible() may
be provided with invalid argument outside of [0,MAX_NUMNODES-1] range
leading to:
BUG: KASAN: wild-memory-access in map_benchmark_ioctl (kernel/dma/map_benchmark.c:214)
Read of size 8 at addr 1fffffff8ccb6398 by task dma_map_benchma/971
CPU: 7 PID: 971 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #37
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:117)
kasan_report (mm/kasan/report.c:603)
kasan_check_range (mm/kasan/generic.c:189)
variable_test_bit (arch/x86/include/asm/bitops.h:227) [inline]
arch_test_bit (arch/x86/include/asm/bitops.h:239) [inline]
_test_bit at (include/asm-generic/bitops/instrumented-non-atomic.h:142) [inline]
node_state (include/linux/nodemask.h:423) [inline]
map_benchmark_ioctl (kernel/dma/map_benchmark.c:214)
full_proxy_unlocked_ioctl (fs/debugfs/file.c:333)
__x64_sys_ioctl (fs/ioctl.c:890)
do_syscall_64 (arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Compare node ids with sane bounds first. NUMA_NO_NODE is considered a
special valid case meaning that benchmarking kthreads won't be bound to a
cpuset of a given node.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 65789daa8087 ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
|
|
If do_map_benchmark() has failed, there is nothing useful to copy back
to userspace.
Suggested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
|
|
kthread creation failure is invalidly handled inside do_map_benchmark().
The put_task_struct() calls on the error path are supposed to balance the
get_task_struct() calls which only happen after all the kthreads are
successfully created. Rollback using kthread_stop() for already created
kthreads in case of such failure.
In normal situation call kthread_stop_put() to gracefully stop kthreads
and put their task refcounts. This should be done for all started
kthreads.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 65789daa8087 ("dma-mapping: add benchmark support for streaming DMA APIs")
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
|
|
With the rework of how the __string() handles dynamic strings where it
saves off the source string in field in the helper structure[1], the
assignment of that value to the trace event field is stored in the helper
value and does not need to be passed in again.
This means that with:
__string(field, mystring)
Which use to be assigned with __assign_str(field, mystring), no longer
needs the second parameter and it is unused. With this, __assign_str()
will now only get a single parameter.
There's over 700 users of __assign_str() and because coccinelle does not
handle the TRACE_EVENT() macro I ended up using the following sed script:
git grep -l __assign_str | while read a ; do
sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file;
mv /tmp/test-file $a;
done
I then searched for __assign_str() that did not end with ';' as those
were multi line assignments that the sed script above would fail to catch.
Note, the same updates will need to be done for:
__assign_str_len()
__assign_rel_str()
__assign_rel_str_len()
I tested this with both an allmodconfig and an allyesconfig (build only for both).
[1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts.
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org> # xfs
Tested-by: Guenter Roeck <linux@roeck-us.net>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the small set of driver core and kernfs changes for 6.10-rc1.
Nothing major here at all, just a small set of changes for some driver
core apis, and minor fixups. Included in here are:
- sysfs_bin_attr_simple_read() helper added and used
- device_show_string() helper added and used
All usages of these were acked by the various maintainers. Also in
here are:
- kernfs minor cleanup
- removed unused functions
- typo fix in documentation
- pay attention to sysfs_create_link() failures in module.c finally
All of these have been in linux-next for a very long time with no
reported problems"
* tag 'driver-core-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
device property: Fix a typo in the description of device_get_child_node_count()
kernfs: mount: Remove unnecessary ‘NULL’ values from knparent
scsi: Use device_show_string() helper for sysfs attributes
platform/x86: Use device_show_string() helper for sysfs attributes
perf: Use device_show_string() helper for sysfs attributes
IB/qib: Use device_show_string() helper for sysfs attributes
hwmon: Use device_show_string() helper for sysfs attributes
driver core: Add device_show_string() helper for sysfs attributes
treewide: Use sysfs_bin_attr_simple_read() helper
sysfs: Add sysfs_bin_attr_simple_read() helper
module: don't ignore sysfs_create_link() failures
driver core: Remove unused platform_notify, platform_notify_remove
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial updates from Greg KH:
"Here is the big set of tty/serial driver changes for 6.10-rc1.
Included in here are:
- Usual good set of api cleanups and evolution by Jiri Slaby to make
the serial interfaces move out of the 1990's by using kfifos
instead of hand-rolling their own logic.
- 8250_exar driver updates
- max3100 driver updates
- sc16is7xx driver updates
- exar driver updates
- sh-sci driver updates
- tty ldisc api addition to help refuse bindings
- other smaller serial driver updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (113 commits)
serial: Clear UPF_DEAD before calling tty_port_register_device_attr_serdev()
serial: imx: Raise TX trigger level to 8
serial: 8250_pnp: Simplify "line" related code
serial: sh-sci: simplify locking when re-issuing RXDMA fails
serial: sh-sci: let timeout timer only run when DMA is scheduled
serial: sh-sci: describe locking requirements for invalidating RXDMA
serial: sh-sci: protect invalidating RXDMA on shutdown
tty: add the option to have a tty reject a new ldisc
serial: core: Call device_set_awake_path() for console port
dt-bindings: serial: brcm,bcm2835-aux-uart: convert to dtschema
tty: serial: uartps: Add support for uartps controller reset
arm64: zynqmp: Add resets property for UART nodes
dt-bindings: serial: cdns,uart: Add optional reset property
serial: 8250_pnp: Switch to DEFINE_SIMPLE_DEV_PM_OPS()
serial: 8250_exar: Keep the includes sorted
serial: 8250_exar: Make type of bit the same in exar_ee_*_bit()
serial: 8250_exar: Use BIT() in exar_ee_read()
serial: 8250_exar: Switch to use dev_err_probe()
serial: 8250_exar: Return directly from switch-cases
serial: 8250_exar: Decrease indentation level
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/lee/leds
Pull LED updates from Lee Jones:
"Core Frameworks:
- Ensure seldom updated triggers have a brightness value before first
update
New Device Support:
- Add support for Simatic IPC Device BX_59A to IPC LEDs Core
- Add support for Qualcomm PMI8950 PWM to LPG Core
New Functionality:
- Add a bunch of new LED function identifiers
- Add support for High Resolution Timers in LED Trigger Patten
Fix-ups:
- Shift out Audio Trigger to the Sound subsystem
- Convert suitable calls to devm_* managed resources
- Device Tree binding adaptions/conversions/creation
- Remove superfluous code/variables/attributes and simplify overall
- Use/convert to new/better APIs/helpers/MACROs instead of
hand-rolling implementations
Bug Fixes:
- Repair enabling Torch Mode from V4L2 on the second LED
- Ensure PWM is disabled when suspending"
* tag 'leds-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/leds: (28 commits)
leds: mt6370: Remove unused field 'reg_cfgs' from 'struct mt6370_priv'
leds: lp50xx: Remove unused field 'num_of_banked_leds' from 'struct lp50xx'
leds: lp50xx: Remove unused field 'bank_modules' from 'struct lp50xx_led'
leds: aat1290: Remove unused field 'torch_brightness' from 'struct aat1290_led'
leds: sun50i-a100: Use match_string() helper to simplify the code
leds: pwm: Disable PWM when going to suspend
leds: trigger: pattern: Add support for hrtimer
leds: mt6360: Fix the second LED can not enable torch mode by V4L2
dt-bindings: leds: leds-qcom-lpg: Add support for PMI8950 PWM
leds: qcom-lpg: Add support for PMI8950 PWM
leds: apu: Remove duplicate DMI lookup data
leds: trigger: netdev: Remove not needed call to led_set_brightness in deactivate
dt-bindings: leds: Add LED_FUNCTION_SPEED_* for link speed on LAN/WAN
dt-bindings: leds: Add LED_FUNCTION_MOBILE for mobile network
leds: simatic-ipc-leds-gpio: Add support for module BX-59A
dt-bindings: leds: qcom-lpg: Document PM6150L compatible
dt-bindings: leds: pca963x: Convert text bindings to YAML
leds: an30259a: Use devm_mutex_init() for mutex initialization
leds: mlxreg: Use devm_mutex_init() for mutex initialization
leds: nic78bx: Use devm API to cleanup module's resources
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:
- Add byte/half-word compare-and-exchange, emulated via LR/SC loops
- Support for Rust
- Support for Zihintpause in hwprobe
- Add PR_RISCV_SET_ICACHE_FLUSH_CTX prctl()
- Support lockless lockrefs
* tag 'riscv-for-linus-6.10-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits)
riscv: defconfig: Enable CONFIG_CLK_SOPHGO_CV1800
riscv: select ARCH_HAS_FAST_MULTIPLIER
riscv: mm: still create swiotlb buffer for kmalloc() bouncing if required
riscv: Annotate pgtable_l{4,5}_enabled with __ro_after_init
riscv: Remove redundant CONFIG_64BIT from pgtable_l{4,5}_enabled
riscv: mm: Always use an ASID to flush mm contexts
riscv: mm: Preserve global TLB entries when switching contexts
riscv: mm: Make asid_bits a local variable
riscv: mm: Use a fixed layout for the MM context ID
riscv: mm: Introduce cntx2asid/cntx2version helper macros
riscv: Avoid TLB flush loops when affected by SiFive CIP-1200
riscv: Apply SiFive CIP-1200 workaround to single-ASID sfence.vma
riscv: mm: Combine the SMP and UP TLB flush code
riscv: Only send remote fences when some other CPU is online
riscv: mm: Broadcast kernel TLB flushes only when needed
riscv: Use IPIs for remote cache/TLB flushes by default
riscv: Factor out page table TLB synchronization
riscv: Flush the instruction cache during SMP bringup
riscv: hwprobe: export Zihintpause ISA extension
riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code
...
|
|
This removes the signal/coredump hacks added for vhost_tasks in:
Commit f9010dbdce91 ("fork, vhost: Use CLONE_THREAD to fix freezer/ps regression")
When that patch was added vhost_tasks did not handle SIGKILL and would
try to ignore/clear the signal and continue on until the device's close
function was called. In the previous patches vhost_tasks and the vhost
drivers were converted to support SIGKILL by cleaning themselves up and
exiting. The hacks are no longer needed so this removes them.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20240316004707.45557-10-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
|
|
Instead of lingering until the device is closed, this has us handle
SIGKILL by:
1. marking the worker as killed so we no longer try to use it with
new virtqueues and new flush operations.
2. setting the virtqueue to worker mapping so no new works are queued.
3. running all the exiting works.
Suggested-by: Edward Adam Davis <eadavis@qq.com>
Reported-and-tested-by: syzbot+98edc2df894917b3431f@syzkaller.appspotmail.com
Message-Id: <tencent_546DA49414E876EEBECF2C78D26D242EE50A@qq.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20240316004707.45557-9-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
|
|
The patch updates the function documentation comment for
rv_en(dis)able_monitor to adhere to the kernel-doc specification.
Link: https://lore.kernel.org/linux-trace-kernel/20240520054239.61784-1-yang.lee@linux.alibaba.com
Fixes: 102227b970a15 ("rv: Add Runtime Verification (RV) interface")
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Fix the 'make W=1' warning:
WARNING: modpost: missing MODULE_DESCRIPTION() in kernel/trace/preemptirq_delay_test.o
Link: https://lore.kernel.org/linux-trace-kernel/20240518-md-preemptirq_delay_test-v1-1-387d11b30d85@quicinc.com
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: f96e8577da10 ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The reader code in rb_get_reader_page() swaps a new reader page into the
ring buffer by doing cmpxchg on old->list.prev->next to point it to the
new page. Following that, if the operation is successful,
old->list.next->prev gets updated too. This means the underlying
doubly-linked list is temporarily inconsistent, page->prev->next or
page->next->prev might not be equal back to page for some page in the
ring buffer.
The resize operation in ring_buffer_resize() can be invoked in parallel.
It calls rb_check_pages() which can detect the described inconsistency
and stop further tracing:
[ 190.271762] ------------[ cut here ]------------
[ 190.271771] WARNING: CPU: 1 PID: 6186 at kernel/trace/ring_buffer.c:1467 rb_check_pages.isra.0+0x6a/0xa0
[ 190.271789] Modules linked in: [...]
[ 190.271991] Unloaded tainted modules: intel_uncore_frequency(E):1 skx_edac(E):1
[ 190.272002] CPU: 1 PID: 6186 Comm: cmd.sh Kdump: loaded Tainted: G E 6.9.0-rc6-default #5 158d3e1e6d0b091c34c3b96bfd99a1c58306d79f
[ 190.272011] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552c-rebuilt.opensuse.org 04/01/2014
[ 190.272015] RIP: 0010:rb_check_pages.isra.0+0x6a/0xa0
[ 190.272023] Code: [...]
[ 190.272028] RSP: 0018:ffff9c37463abb70 EFLAGS: 00010206
[ 190.272034] RAX: ffff8eba04b6cb80 RBX: 0000000000000007 RCX: ffff8eba01f13d80
[ 190.272038] RDX: ffff8eba01f130c0 RSI: ffff8eba04b6cd00 RDI: ffff8eba0004c700
[ 190.272042] RBP: ffff8eba0004c700 R08: 0000000000010002 R09: 0000000000000000
[ 190.272045] R10: 00000000ffff7f52 R11: ffff8eba7f600000 R12: ffff8eba0004c720
[ 190.272049] R13: ffff8eba00223a00 R14: 0000000000000008 R15: ffff8eba067a8000
[ 190.272053] FS: 00007f1bd64752c0(0000) GS:ffff8eba7f680000(0000) knlGS:0000000000000000
[ 190.272057] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 190.272061] CR2: 00007f1bd6662590 CR3: 000000010291e001 CR4: 0000000000370ef0
[ 190.272070] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 190.272073] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 190.272077] Call Trace:
[ 190.272098] <TASK>
[ 190.272189] ring_buffer_resize+0x2ab/0x460
[ 190.272199] __tracing_resize_ring_buffer.part.0+0x23/0xa0
[ 190.272206] tracing_resize_ring_buffer+0x65/0x90
[ 190.272216] tracing_entries_write+0x74/0xc0
[ 190.272225] vfs_write+0xf5/0x420
[ 190.272248] ksys_write+0x67/0xe0
[ 190.272256] do_syscall_64+0x82/0x170
[ 190.272363] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 190.272373] RIP: 0033:0x7f1bd657d263
[ 190.272381] Code: [...]
[ 190.272385] RSP: 002b:00007ffe72b643f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 190.272391] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1bd657d263
[ 190.272395] RDX: 0000000000000002 RSI: 0000555a6eb538e0 RDI: 0000000000000001
[ 190.272398] RBP: 0000555a6eb538e0 R08: 000000000000000a R09: 0000000000000000
[ 190.272401] R10: 0000555a6eb55190 R11: 0000000000000246 R12: 00007f1bd6662500
[ 190.272404] R13: 0000000000000002 R14: 00007f1bd6667c00 R15: 0000000000000002
[ 190.272412] </TASK>
[ 190.272414] ---[ end trace 0000000000000000 ]---
Note that ring_buffer_resize() calls rb_check_pages() only if the parent
trace_buffer has recording disabled. Recent commit d78ab792705c
("tracing: Stop current tracer when resizing buffer") causes that it is
now always the case which makes it more likely to experience this issue.
The window to hit this race is nonetheless very small. To help
reproducing it, one can add a delay loop in rb_get_reader_page():
ret = rb_head_page_replace(reader, cpu_buffer->reader_page);
if (!ret)
goto spin;
for (unsigned i = 0; i < 1U << 26; i++) /* inserted delay loop */
__asm__ __volatile__ ("" : : : "memory");
rb_list_head(reader->list.next)->prev = &cpu_buffer->reader_page->list;
.. and then run the following commands on the target system:
echo 1 > /sys/kernel/tracing/events/sched/sched_switch/enable
while true; do
echo 16 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
echo 8 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
done &
while true; do
for i in /sys/kernel/tracing/per_cpu/*; do
timeout 0.1 cat $i/trace_pipe; sleep 0.2
done
done
To fix the problem, make sure ring_buffer_resize() doesn't invoke
rb_check_pages() concurrently with a reader operating on the same
ring_buffer_per_cpu by taking its cpu_buffer->reader_lock.
Link: https://lore.kernel.org/linux-trace-kernel/20240517134008.24529-3-petr.pavlu@suse.com
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 659f451ff213 ("ring-buffer: Add integrity check at end of iter read")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
[ Fixed whitespace ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Adjust the following code documentation:
* Kernel-doc comments for ring_buffer_read_prepare() and
ring_buffer_read_finish() mention that recording to the ring buffer is
disabled when the read is active. Remove mention of this restriction
because it was already lifted in commit 1039221cc278 ("ring-buffer: Do
not disable recording when there is an iterator").
* Function ring_buffer_read_finish() performs a self-check of the
ring-buffer by locking cpu_buffer->reader_lock and then calling
rb_check_pages(). The preceding comment explains that the lock is
needed because rb_check_pages() clears the HEAD flag required by
readers which might be running in parallel. Remove this explanation
because commit 8843e06f67b1 ("ring-buffer: Handle race between
rb_move_tail and rb_check_pages") simplified the function so it no
longer resets the mentioned flag. Nonetheless, the lock is still
needed because a reader swapping a page into the ring buffer can make
the underlying doubly-linked list temporarily inconsistent.
This is a non-functional change.
Link: https://lore.kernel.org/linux-trace-kernel/20240517134008.24529-2-petr.pavlu@suse.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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