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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Borislav Petkov:
- Make sure a warning is issued when a hrtimer gets queued after the
timers have been migrated on the CPU down path and thus said timer
will get ignored
* tag 'timers_urgent_for_v6.8_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hrtimer: Report offline hrtimer enqueue
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"21 hotfixes. 12 are cc:stable and the remainder pertain to post-6.7
issues or aren't considered to be needed in earlier kernel versions"
* tag 'mm-hotfixes-stable-2024-02-10-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits)
nilfs2: fix potential bug in end_buffer_async_write
mm/damon/sysfs-schemes: fix wrong DAMOS tried regions update timeout setup
nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()
MAINTAINERS: Leo Yan has moved
mm/zswap: don't return LRU_SKIP if we have dropped lru lock
fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super
mailmap: switch email address for John Moon
mm: zswap: fix objcg use-after-free in entry destruction
mm/madvise: don't forget to leave lazy MMU mode in madvise_cold_or_pageout_pte_range()
arch/arm/mm: fix major fault accounting when retrying under per-VMA lock
selftests: core: include linux/close_range.h for CLOSE_RANGE_* macros
mm/memory-failure: fix crash in split_huge_page_to_list from soft_offline_page
mm: memcg: optimize parent iteration in memcg_rstat_updated()
nilfs2: fix data corruption in dsync block recovery for small block sizes
mm/userfaultfd: UFFDIO_MOVE implementation should use ptep_get()
exit: wait_task_zombie: kill the no longer necessary spin_lock_irq(siglock)
fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children stats
fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand()
getrusage: use sig->stats_lock rather than lock_task_sighand()
getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix broken direct trampolines being called when another callback is
attached the same function.
ARM 64 does not support FTRACE_WITH_REGS, and when it added direct
trampoline calls from ftrace, it removed the "WITH_REGS" flag from
the ftrace_ops for direct trampolines. This broke x86 as x86 requires
direct trampolines to have WITH_REGS.
This wasn't noticed because direct trampolines work as long as the
function it is attached to is not shared with other callbacks (like
the function tracer). When there are other callbacks, a helper
trampoline is called, to call all the non direct callbacks and when
it returns, the direct trampoline is called.
For x86, the direct trampoline sets a flag in the regs field to tell
the x86 specific code to call the direct trampoline. But this only
works if the ftrace_ops had WITH_REGS set. ARM does things
differently that does not require this. For now, set WITH_REGS if the
arch supports WITH_REGS (which ARM does not), and this makes it work
for both ARM64 and x86.
- Fix wasted memory in the saved_cmdlines logic.
The saved_cmdlines is a cache that maps PIDs to COMMs that tracing
can use. Most trace events only save the PID in the event. The
saved_cmdlines file lists PIDs to COMMs so that the tracing tools can
show an actual name and not just a PID for each event. There's an
array of PIDs that map to a small set of saved COMM strings. The
array is set to PID_MAX_DEFAULT which is usually set to 32768. When a
PID comes in, it will add itself to this array along with the index
into the COMM array (note if the system allows more than
PID_MAX_DEFAULT, this cache is similar to cache lines as an update of
a PID that has the same PID_MAX_DEFAULT bits set will flush out
another task with the same matching bits set).
A while ago, the size of this cache was changed to be dynamic and the
array was moved into a structure and created with kmalloc(). But this
new structure had the size of 131104 bytes, or 0x20020 in hex. As
kmalloc allocates in powers of two, it was actually allocating
0x40000 bytes (262144) leaving 131040 bytes of wasted memory. The
last element of this structure was a pointer to the COMM string array
which defaulted to just saving 128 COMMs.
By changing the last field of this structure to a variable length
string, and just having it round up to fill the allocated memory, the
default size of the saved COMM cache is now 8190. This not only uses
the wasted space, but actually saves space by removing the extra
allocation for the COMM names.
* tag 'trace-v6.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Fix wasted memory in saved_cmdlines logic
ftrace: Fix DIRECT_CALLS to use SAVE_REGS by default
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While looking at improving the saved_cmdlines cache I found a huge amount
of wasted memory that should be used for the cmdlines.
The tracing data saves pids during the trace. At sched switch, if a trace
occurred, it will save the comm of the task that did the trace. This is
saved in a "cache" that maps pids to comms and exposed to user space via
the /sys/kernel/tracing/saved_cmdlines file. Currently it only caches by
default 128 comms.
The structure that uses this creates an array to store the pids using
PID_MAX_DEFAULT (which is usually set to 32768). This causes the structure
to be of the size of 131104 bytes on 64 bit machines.
In hex: 131104 = 0x20020, and since the kernel allocates generic memory in
powers of two, the kernel would allocate 0x40000 or 262144 bytes to store
this structure. That leaves 131040 bytes of wasted space.
Worse, the structure points to an allocated array to store the comm names,
which is 16 bytes times the amount of names to save (currently 128), which
is 2048 bytes. Instead of allocating a separate array, make the structure
end with a variable length string and use the extra space for that.
This is similar to a recommendation that Linus had made about eventfs_inode names:
https://lore.kernel.org/all/[email protected]/
Instead of allocating a separate string array to hold the saved comms,
have the structure end with: char saved_cmdlines[]; and round up to the
next power of two over sizeof(struct saved_cmdline_buffers) + num_cmdlines * TASK_COMM_LEN
It will use this extra space for the saved_cmdline portion.
Now, instead of saving only 128 comms by default, by using this wasted
space at the end of the structure it can save over 8000 comms and even
saves space by removing the need for allocating the other array.
Link: https://lore.kernel.org/linux-trace-kernel/[email protected]
Cc: [email protected]
Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Vincent Donnefort <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Mete Durlu <[email protected]>
Fixes: 939c7a4f04fcd ("tracing: Introduce saved_cmdlines_size file")
Signed-off-by: Steven Rostedt (Google) <[email protected]>
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The commit 60c8971899f3 ("ftrace: Make DIRECT_CALLS work WITH_ARGS
and !WITH_REGS") changed DIRECT_CALLS to use SAVE_ARGS when there
are multiple ftrace_ops at the same function, but since the x86 only
support to jump to direct_call from ftrace_regs_caller, when we set
the function tracer on the same target function on x86, ftrace-direct
does not work as below (this actually works on arm64.)
At first, insmod ftrace-direct.ko to put a direct_call on
'wake_up_process()'.
# insmod kernel/samples/ftrace/ftrace-direct.ko
# less trace
...
<idle>-0 [006] ..s1. 564.686958: my_direct_func: waking up rcu_preempt-17
<idle>-0 [007] ..s1. 564.687836: my_direct_func: waking up kcompactd0-63
<idle>-0 [006] ..s1. 564.690926: my_direct_func: waking up rcu_preempt-17
<idle>-0 [006] ..s1. 564.696872: my_direct_func: waking up rcu_preempt-17
<idle>-0 [007] ..s1. 565.191982: my_direct_func: waking up kcompactd0-63
Setup a function filter to the 'wake_up_process' too, and enable it.
# cd /sys/kernel/tracing/
# echo wake_up_process > set_ftrace_filter
# echo function > current_tracer
# less trace
...
<idle>-0 [006] ..s3. 686.180972: wake_up_process <-call_timer_fn
<idle>-0 [006] ..s3. 686.186919: wake_up_process <-call_timer_fn
<idle>-0 [002] ..s3. 686.264049: wake_up_process <-call_timer_fn
<idle>-0 [002] d.h6. 686.515216: wake_up_process <-kick_pool
<idle>-0 [002] d.h6. 686.691386: wake_up_process <-kick_pool
Then, only function tracer is shown on x86.
But if you enable 'kprobe on ftrace' event (which uses SAVE_REGS flag)
on the same function, it is shown again.
# echo 'p wake_up_process' >> dynamic_events
# echo 1 > events/kprobes/p_wake_up_process_0/enable
# echo > trace
# less trace
...
<idle>-0 [006] ..s2. 2710.345919: p_wake_up_process_0: (wake_up_process+0x4/0x20)
<idle>-0 [006] ..s3. 2710.345923: wake_up_process <-call_timer_fn
<idle>-0 [006] ..s1. 2710.345928: my_direct_func: waking up rcu_preempt-17
<idle>-0 [006] ..s2. 2710.349931: p_wake_up_process_0: (wake_up_process+0x4/0x20)
<idle>-0 [006] ..s3. 2710.349934: wake_up_process <-call_timer_fn
<idle>-0 [006] ..s1. 2710.349937: my_direct_func: waking up rcu_preempt-17
To fix this issue, use SAVE_REGS flag for multiple ftrace_ops flag of
direct_call by default.
Link: https://lore.kernel.org/linux-trace-kernel/170484558617.178953.1590516949390270842.stgit@devnote2
Fixes: 60c8971899f3 ("ftrace: Make DIRECT_CALLS work WITH_ARGS and !WITH_REGS")
Cc: [email protected]
Cc: Florent Revest <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Reviewed-by: Mark Rutland <[email protected]>
Tested-by: Mark Rutland <[email protected]> [arm64]
Acked-by: Jiri Olsa <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
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Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
drivers/net/ethernet/stmicro/stmmac/common.h
38cc3c6dcc09 ("net: stmmac: protect updates of 64-bit statistics counters")
fd5a6a71313e ("net: stmmac: est: Per Tx-queue error count for HLBF")
c5c3e1bfc9e0 ("net: stmmac: Offload queueMaxSDU from tc-taprio")
drivers/net/wireless/microchip/wilc1000/netdev.c
c9013880284d ("wifi: fill in MODULE_DESCRIPTION()s for wilc1000")
328efda22af8 ("wifi: wilc1000: do not realloc workqueue everytime an interface is added")
net/unix/garbage.c
11498715f266 ("af_unix: Remove io_uring code for GC.")
1279f9d9dec2 ("af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.")
Signed-off-by: Jakub Kicinski <[email protected]>
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Similar to the handling in the functions __register_btf_kfunc_id_set()
and register_btf_id_dtor_kfuncs(), this patch uses the newly added
helper check_btf_kconfigs() to handle module with its btf section
stripped.
While at it, the patch also adds the missed IS_ERR() check to fix the
commit f6be98d19985 ("bpf, net: switch to dynamic registration")
Fixes: f6be98d19985 ("bpf, net: switch to dynamic registration")
Signed-off-by: Geliang Tang <[email protected]>
Link: https://lore.kernel.org/r/69082b9835463fe36f9e354bddf2d0a97df39c2b.1707373307.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <[email protected]>
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This patch extracts duplicate code on error path when btf_get_module_btf()
returns NULL from the functions __register_btf_kfunc_id_set() and
register_btf_id_dtor_kfuncs() into a new helper named check_btf_kconfigs()
to check CONFIG_DEBUG_INFO_BTF and CONFIG_DEBUG_INFO_BTF_MODULES in it.
Signed-off-by: Geliang Tang <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Link: https://lore.kernel.org/r/fa5537fc55f1e4d0bfd686598c81b7ab9dbd82b7.1707373307.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <[email protected]>
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The same as __register_btf_kfunc_id_set(), to let the modules with
stripped btf section loaded, this patch changes the return value of
register_btf_id_dtor_kfuncs() too from -ENOENT to 0 when btf is NULL.
Signed-off-by: Geliang Tang <[email protected]>
Link: https://lore.kernel.org/r/eab65586d7fb0e72f2707d3747c7d4a5d60c823f.1707373307.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <[email protected]>
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ri and sym is assigned first, so it does not need to initialize the
assignment.
Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Li zeming <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
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Since the BTF type setting updates probe_arg::type, the type size
calculation and setting print-fmt should be done after that.
Without this fix, the argument size and print-fmt can be wrong.
Link: https://lore.kernel.org/all/170602218196.215583.6417859469540955777.stgit@devnote2/
Fixes: b576e09701c7 ("tracing/probes: Support function parameters if BTF is available")
Cc: [email protected]
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
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Fix to show a parse error for bad type (non-string) for $comm/$COMM and
immediate-string. With this fix, error_log file shows appropriate error
message as below.
/sys/kernel/tracing # echo 'p vfs_read $comm:u32' >> kprobe_events
sh: write error: Invalid argument
/sys/kernel/tracing # echo 'p vfs_read \"hoge":u32' >> kprobe_events
sh: write error: Invalid argument
/sys/kernel/tracing # cat error_log
[ 30.144183] trace_kprobe: error: $comm and immediate-string only accepts string type
Command: p vfs_read $comm:u32
^
[ 62.618500] trace_kprobe: error: $comm and immediate-string only accepts string type
Command: p vfs_read \"hoge":u32
^
Link: https://lore.kernel.org/all/170602215411.215583.2238016352271091852.stgit@devnote2/
Fixes: 3dd1f7f24f8c ("tracing: probeevent: Fix to make the type of $comm string")
Cc: [email protected]
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
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After the recent changes nobody use siglock to read the values protected
by stats_lock, we can kill spin_lock_irq(¤t->sighand->siglock) and
update the comment.
With this patch only __exit_signal() and thread_group_start_cputime() take
stats_lock under siglock.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Oleg Nesterov <[email protected]>
Signed-off-by: Dylan Hatch <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call
getrusage() at the same time and the process has NR_THREADS, spin_lock_irq
will spin with irqs disabled O(NR_CPUS * NR_THREADS) time.
Change getrusage() to use sig->stats_lock, it was specifically designed
for this type of use. This way it runs lockless in the likely case.
TODO:
- Change do_task_stat() to use sig->stats_lock too, then we can
remove spin_lock_irq(siglock) in wait_task_zombie().
- Turn sig->stats_lock into seqcount_rwlock_t, this way the
readers in the slow mode won't exclude each other. See
https://lore.kernel.org/all/[email protected]/
- stats_lock has to disable irqs because ->siglock can be taken
in irq context, it would be very nice to change __exit_signal()
to avoid the siglock->stats_lock dependency.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Oleg Nesterov <[email protected]>
Reported-by: Dylan Hatch <[email protected]>
Tested-by: Dylan Hatch <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Patch series "getrusage: use sig->stats_lock", v2.
This patch (of 2):
thread_group_cputime() does its own locking, we can safely shift
thread_group_cputime_adjusted() which does another for_each_thread loop
outside of ->siglock protected section.
This is also preparation for the next patch which changes getrusage() to
use stats_lock instead of siglock, thread_group_cputime() takes the same
lock. With the current implementation recursive read_seqbegin_or_lock()
is fine, thread_group_cputime() can't enter the slow mode if the caller
holds stats_lock, yet this looks more safe and better performance-wise.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Oleg Nesterov <[email protected]>
Reported-by: Dylan Hatch <[email protected]>
Tested-by: Dylan Hatch <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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'config BPF' exists in both init/Kconfig and kernel/bpf/Kconfig.
Commit b24abcff918a ("bpf, kconfig: Add consolidated menu entry for bpf
with core options") added the second one to kernel/bpf/Kconfig instead
of moving the existing one.
Merge them together.
Signed-off-by: Masahiro Yamada <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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The hrtimers migration on CPU-down hotplug process has been moved
earlier, before the CPU actually goes to die. This leaves a small window
of opportunity to queue an hrtimer in a blind spot, leaving it ignored.
For example a practical case has been reported with RCU waking up a
SCHED_FIFO task right before the CPUHP_AP_IDLE_DEAD stage, queuing that
way a sched/rt timer to the local offline CPU.
Make sure such situations never go unnoticed and warn when that happens.
Fixes: 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier")
Reported-by: Paul E. McKenney <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
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Allow transferring an imbalanced RCU lock state between subprog calls
during verification. This allows patterns where a subprog call returns
with an RCU lock held, or a subprog call releases an RCU lock held by
the caller. Currently, the verifier would end up complaining if the RCU
lock is not released when processing an exit from a subprog, which is
non-ideal if its execution is supposed to be enclosed in an RCU read
section of the caller.
Instead, simply only check whether we are processing exit for frame#0
and do not complain on an active RCU lock otherwise. We only need to
update the check when processing BPF_EXIT insn, as copy_verifier_state
is already set up to do the right thing.
Suggested-by: David Vernet <[email protected]>
Tested-by: Yafang Shao <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]>
Acked-by: David Vernet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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Currently, calling any helpers, kfuncs, or subprogs except the graph
data structure (lists, rbtrees) API kfuncs while holding a bpf_spin_lock
is not allowed. One of the original motivations of this decision was to
force the BPF programmer's hand into keeping the bpf_spin_lock critical
section small, and to ensure the execution time of the program does not
increase due to lock waiting times. In addition to this, some of the
helpers and kfuncs may be unsafe to call while holding a bpf_spin_lock.
However, when it comes to subprog calls, atleast for static subprogs,
the verifier is able to explore their instructions during verification.
Therefore, it is similar in effect to having the same code inlined into
the critical section. Hence, not allowing static subprog calls in the
bpf_spin_lock critical section is mostly an annoyance that needs to be
worked around, without providing any tangible benefit.
Unlike static subprog calls, global subprog calls are not safe to permit
within the critical section, as the verifier does not explore them
during verification, therefore whether the same lock will be taken
again, or unlocked, cannot be ascertained.
Therefore, allow calling static subprogs within a bpf_spin_lock critical
section, and only reject it in case the subprog linkage is global.
Acked-by: Yonghong Song <[email protected]>
Acked-by: David Vernet <[email protected]>
Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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workqueue_apply_unbound_cpumask()"
This reverts commit ca10d851b9ad0338c19e8e3089e24d565ebfffd7.
The commit allowed workqueue_apply_unbound_cpumask() to clear __WQ_ORDERED
on now removed implicitly ordered workqueues. This was incorrect in that
system-wide config change shouldn't break ordering properties of all
workqueues. The reason why apply_workqueue_attrs() path was allowed to do so
was because it was targeting the specific workqueue - either the workqueue
had WQ_SYSFS set or the workqueue user specifically tried to change
max_active, both of which indicate that the workqueue doesn't need to be
ordered.
The implicitly ordered workqueue promotion was removed by the previous
commit 3bc1e711c26b ("workqueue: Don't implicitly make UNBOUND workqueues w/
@max_active==1 ordered"). However, it didn't update this path and broke
build. Let's revert the commit which was incorrect in the first place which
also fixes build.
Signed-off-by: Tejun Heo <[email protected]>
Fixes: 3bc1e711c26b ("workqueue: Don't implicitly make UNBOUND workqueues w/ @max_active==1 ordered")
Fixes: ca10d851b9ad ("workqueue: Override implicit ordered attribute in workqueue_apply_unbound_cpumask()")
Cc: [email protected] # v6.6+
Signed-off-by: Tejun Heo <[email protected]>
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The "i" here is always equal to "btf_type_vlen(t)" since
the "for_each_member()" loop never breaks.
Signed-off-by: Kui-Feng Lee <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Martin KaFai Lau <[email protected]>
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When btf_prepare_func_args() was generalized to handle both static and
global subprogs, a few warnings/errors that are meant only for global
subprog cases started to be emitted for static subprogs, where they are
sort of expected and irrelavant.
Stop polutting verifier logs with irrelevant scary-looking messages.
Fixes: e26080d0da87 ("bpf: prepare btf_prepare_func_args() for handling static subprogs")
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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Add PTR_TRUSTED | PTR_MAYBE_NULL modifiers for PTR_TO_BTF_ID to
check_reg_type() to support passing trusted nullable PTR_TO_BTF_ID
registers into global functions accepting `__arg_trusted __arg_nullable`
arguments. This hasn't been caught earlier because tests were either
passing known non-NULL PTR_TO_BTF_ID registers or known NULL (SCALAR)
registers.
When utilizing this functionality in complicated real-world BPF
application that passes around PTR_TO_BTF_ID_OR_NULL, it became apparent
that verifier rejects valid case because check_reg_type() doesn't handle
this case explicitly. Existing check_reg_type() logic is already
anticipating this combination, so we just need to explicitly list this
combo in the switch statement.
Fixes: e2b3c4ff5d18 ("bpf: add __arg_trusted global func arg tag")
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing and eventfs fixes from Steven Rostedt:
- Fix the return code for ring_buffer_poll_wait()
It was returing a -EINVAL instead of EPOLLERR.
- Zero out the tracefs_inode so that all fields are initialized.
The ti->private could have had stale data, but instead of just
initializing it to NULL, clear out the entire structure when it is
allocated.
- Fix a crash in timerlat
The hrtimer was initialized at read and not open, but is canceled at
close. If the file was opened and never read the close will pass a
NULL pointer to hrtime_cancel().
- Rewrite of eventfs.
Linus wrote a patch series to remove the dentry references in the
eventfs_inode and to use ref counting and more of proper VFS
interfaces to make it work.
- Add warning to put_ei() if ei is not set to free. That means
something is about to free it when it shouldn't.
- Restructure the eventfs_inode to make it more compact, and remove the
unused llist field.
- Remove the fsnotify*() funtions for when the inodes were being
created in the lookup code. It doesn't make sense to notify about
creation just because something is being looked up.
- The inode hard link count was not accurate.
It was being updated when a file was looked up. The inodes of
directories were updating their parent inode hard link count every
time the inode was created. That means if memory reclaim cleaned a
stale directory inode and the inode was lookup up again, it would
increment the parent inode again as well. Al Viro said to just have
all eventfs directories have a hard link count of 1. That tells user
space not to trust it.
* tag 'trace-v6.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
eventfs: Keep all directory links at 1
eventfs: Remove fsnotify*() functions from lookup()
eventfs: Restructure eventfs_inode structure to be more condensed
eventfs: Warn if an eventfs_inode is freed without is_freed being set
tracing/timerlat: Move hrtimer_init to timerlat_fd open()
eventfs: Get rid of dentry pointers without refcounts
eventfs: Clean up dentry ops and add revalidate function
eventfs: Remove unused d_parent pointer field
tracefs: dentry lookup crapectomy
tracefs: Avoid using the ei->dentry pointer unnecessarily
eventfs: Initialize the tracefs inode properly
tracefs: Zero out the tracefs_inode when allocating it
ring-buffer: Clean ring_buffer_poll_wait() error return
|
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When check_stack_read_fixed_off() reads value from an spi
all stack slots of which are set to STACK_{MISC,INVALID},
the destination register is set to unbound SCALAR_VALUE.
Exploit this fact by allowing stacksafe() to use a fake
unbound scalar register to compare 'mmmm mmmm' stack value
in old state vs spilled 64-bit scalar in current state
and vice versa.
Veristat results after this patch show some gains:
./veristat -C -e file,prog,states -f 'states_pct>10' not-opt after
File Program States (DIFF)
----------------------- --------------------- ---------------
bpf_overlay.o tail_rev_nodeport_lb4 -45 (-15.85%)
bpf_xdp.o tail_lb_ipv4 -541 (-19.57%)
pyperf100.bpf.o on_event -680 (-10.42%)
pyperf180.bpf.o on_event -2164 (-19.62%)
pyperf600.bpf.o on_event -9799 (-24.84%)
strobemeta.bpf.o on_event -9157 (-65.28%)
xdp_synproxy_kern.bpf.o syncookie_tc -54 (-19.29%)
xdp_synproxy_kern.bpf.o syncookie_xdp -74 (-24.50%)
Signed-off-by: Eduard Zingerman <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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When the width of a fill is smaller than the width of the preceding
spill, the information about scalar boundaries can still be preserved,
as long as it's coerced to the right width (done by coerce_reg_to_size).
Even further, if the actual value fits into the fill width, the ID can
be preserved as well for further tracking of equal scalars.
Implement the above improvements, which makes narrowing fills behave the
same as narrowing spills and MOVs between registers.
Two tests are adjusted to accommodate for endianness differences and to
take into account that it's now allowed to do a narrowing fill from the
least significant bits.
reg_bounds_sync is added to coerce_reg_to_size to correctly adjust
umin/umax boundaries after the var_off truncation, for example, a 64-bit
value 0xXXXXXXXX00000000, when read as a 32-bit, gets umin = 0, umax =
0xFFFFFFFF, var_off = (0x0; 0xffffffff00000000), which needs to be
synced down to umax = 0, otherwise reg_bounds_sanity_check doesn't pass.
Signed-off-by: Maxim Mikityanskiy <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
|
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Support the pattern where an unbounded scalar is spilled to the stack,
then boundary checks are performed on the src register, after which the
stack frame slot is refilled into a register.
Before this commit, the verifier didn't treat the src register and the
stack slot as related if the src register was an unbounded scalar. The
register state wasn't copied, the id wasn't preserved, and the stack
slot was marked as STACK_MISC. Subsequent boundary checks on the src
register wouldn't result in updating the boundaries of the spilled
variable on the stack.
After this commit, the verifier will preserve the bond between src and
dst even if src is unbounded, which permits to do boundary checks on src
and refill dst later, still remembering its boundaries. Such a pattern
is sometimes generated by clang when compiling complex long functions.
One test is adjusted to reflect that now unbounded scalars are tracked.
Signed-off-by: Maxim Mikityanskiy <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Eduard Zingerman <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
|
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Cross-merge networking fixes after downstream PR.
No conflicts or adjacent changes.
Signed-off-by: Jakub Kicinski <[email protected]>
|
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There's already one main CONFIG_SECURITY_NETWORK ifdef block within
the sleepable_lsm_hooks BTF set. Consolidate this duplicated ifdef
block as there's no need for it and all things guarded by it should
remain in one place in this specific context.
Signed-off-by: Matt Bobrowski <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
|
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Currently, the timerlat's hrtimer is initialized at the first read of
timerlat_fd, and destroyed at close(). It works, but it causes an error
if the user program open() and close() the file without reading.
Here's an example:
# echo NO_OSNOISE_WORKLOAD > /sys/kernel/debug/tracing/osnoise/options
# echo timerlat > /sys/kernel/debug/tracing/current_tracer
# cat <<EOF > ./timerlat_load.py
# !/usr/bin/env python3
timerlat_fd = open("/sys/kernel/tracing/osnoise/per_cpu/cpu0/timerlat_fd", 'r')
timerlat_fd.close();
EOF
# ./taskset -c 0 ./timerlat_load.py
<BOOM>
BUG: kernel NULL pointer dereference, address: 0000000000000010
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 1 PID: 2673 Comm: python3 Not tainted 6.6.13-200.fc39.x86_64 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014
RIP: 0010:hrtimer_active+0xd/0x50
Code: 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 57 30 <8b> 42 10 a8 01 74 09 f3 90 8b 42 10 a8 01 75 f7 80 7f 38 00 75 1d
RSP: 0018:ffffb031009b7e10 EFLAGS: 00010286
RAX: 000000000002db00 RBX: ffff9118f786db08 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff9117a0e64400 RDI: ffff9118f786db08
RBP: ffff9118f786db80 R08: ffff9117a0ddd420 R09: ffff9117804d4f70
R10: 0000000000000000 R11: 0000000000000000 R12: ffff9118f786db08
R13: ffff91178fdd5e20 R14: ffff9117840978c0 R15: 0000000000000000
FS: 00007f2ffbab1740(0000) GS:ffff9118f7840000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 00000001b402e000 CR4: 0000000000750ee0
PKRU: 55555554
Call Trace:
<TASK>
? __die+0x23/0x70
? page_fault_oops+0x171/0x4e0
? srso_alias_return_thunk+0x5/0x7f
? avc_has_extended_perms+0x237/0x520
? exc_page_fault+0x7f/0x180
? asm_exc_page_fault+0x26/0x30
? hrtimer_active+0xd/0x50
hrtimer_cancel+0x15/0x40
timerlat_fd_release+0x48/0xe0
__fput+0xf5/0x290
__x64_sys_close+0x3d/0x80
do_syscall_64+0x60/0x90
? srso_alias_return_thunk+0x5/0x7f
? __x64_sys_ioctl+0x72/0xd0
? srso_alias_return_thunk+0x5/0x7f
? syscall_exit_to_user_mode+0x2b/0x40
? srso_alias_return_thunk+0x5/0x7f
? do_syscall_64+0x6c/0x90
? srso_alias_return_thunk+0x5/0x7f
? exit_to_user_mode_prepare+0x142/0x1f0
? srso_alias_return_thunk+0x5/0x7f
? syscall_exit_to_user_mode+0x2b/0x40
? srso_alias_return_thunk+0x5/0x7f
? do_syscall_64+0x6c/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7f2ffb321594
Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d d5 cd 0d 00 00 74 13 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3c c3 0f 1f 00 55 48 89 e5 48 83 ec 10 89 7d
RSP: 002b:00007ffe8d8eef18 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f2ffba4e668 RCX: 00007f2ffb321594
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007ffe8d8eef40 R08: 0000000000000000 R09: 0000000000000000
R10: 55c926e3167eae79 R11: 0000000000000202 R12: 0000000000000003
R13: 00007ffe8d8ef030 R14: 0000000000000000 R15: 00007f2ffba4e668
</TASK>
CR2: 0000000000000010
---[ end trace 0000000000000000 ]---
Move hrtimer_init to timerlat_fd open() to avoid this problem.
Link: https://lore.kernel.org/linux-trace-kernel/7324dd3fc0035658c99b825204a66049389c56e3.1706798888.git.bristot@kernel.org
Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: [email protected]
Fixes: e88ed227f639 ("tracing/timerlat: Add user-space interface")
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
|
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This commit marks kfuncs as such inside the .BTF_ids section. The upshot
of these annotations is that we'll be able to automatically generate
kfunc prototypes for downstream users. The process is as follows:
1. In source, use BTF_KFUNCS_START/END macro pair to mark kfuncs
2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for
each function inside BTF_KFUNCS sets
3. At runtime, vmlinux or module BTF is made available in sysfs
4. At runtime, bpftool (or similar) can look at provided BTF and
generate appropriate prototypes for functions with "bpf_kfunc" tag
To ensure future kfunc are similarly tagged, we now also return error
inside kfunc registration for untagged kfuncs. For vmlinux kfuncs,
we also WARN(), as initcall machinery does not handle errors.
Signed-off-by: Daniel Xu <[email protected]>
Acked-by: Benjamin Tissoires <[email protected]>
Link: https://lore.kernel.org/r/e55150ceecbf0a5d961e608941165c0bee7bc943.1706491398.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <[email protected]>
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The return type for ring_buffer_poll_wait() is __poll_t. This is behind
the scenes an unsigned where we can set event bits. In case of a
non-allocated CPU, we do return instead -EINVAL (0xffffffea). Lucky us,
this ends up setting few error bits (EPOLLERR | EPOLLHUP | EPOLLNVAL), so
user-space at least is aware something went wrong.
Nonetheless, this is an incorrect code. Replace that -EINVAL with a
proper EPOLLERR to clean that output. As this doesn't change the
behaviour, there's no need to treat this change as a bug fix.
Link: https://lore.kernel.org/linux-trace-kernel/[email protected]
Cc: [email protected]
Fixes: 6721cb6002262 ("ring-buffer: Do not poll non allocated cpu buffers")
Signed-off-by: Vincent Donnefort <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
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Add ability to mark arg:trusted arguments with optional arg:nullable
tag to mark it as PTR_TO_BTF_ID_OR_NULL variant, which will allow
callers to pass NULL, and subsequently will force global subprog's code
to do NULL check. This allows to have "optional" PTR_TO_BTF_ID values
passed into global subprogs.
For now arg:nullable cannot be combined with anything else.
Acked-by: Eduard Zingerman <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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Add support for passing PTR_TO_BTF_ID registers to global subprogs.
Currently only PTR_TRUSTED flavor of PTR_TO_BTF_ID is supported.
Non-NULL semantics is assumed, so caller will be forced to prove
PTR_TO_BTF_ID can't be NULL.
Note, we disallow global subprogs to destroy passed in PTR_TO_BTF_ID
arguments, even the trusted one. We achieve that by not setting
ref_obj_id when validating subprog code. This basically enforces (in
Rust terms) borrowing semantics vs move semantics. Borrowing semantics
seems to be a better fit for isolated global subprog validation
approach.
Implementation-wise, we utilize existing logic for matching
user-provided BTF type to kernel-side BTF type, used by BPF CO-RE logic
and following same matching rules. We enforce a unique match for types.
Acked-by: Eduard Zingerman <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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Replace the '(1ULL << *)' with the macro BIT_ULL(nr).
Signed-off-by: Haiyue Wang <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
"Two small fixes for tracefs and eventfs:
- Fix register_snapshot_trigger() on allocation error
If the snapshot fails to allocate, the register_snapshot_trigger()
can still return success. If the call to
tracing_alloc_snapshot_instance() returned anything but 0, it
returned 0, but it should have been returning the error code from
that allocation function.
- Remove leftover code from tracefs doing a dentry walk on remount.
The update_gid() function was called by the tracefs code on remount
to update the gid of eventfs, but that is no longer the case, but
that code wasn't deleted. Nothing calls it. Remove it"
* tag 'trace-v6.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracefs: remove stale 'update_gid' code
tracing/trigger: Fix to return error if failed to alloc snapshot
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"22 hotfixes. 11 are cc:stable and the remainder address post-6.7
issues or aren't considered appropriate for backporting"
* tag 'mm-hotfixes-stable-2024-01-28-23-21' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
mm: thp_get_unmapped_area must honour topdown preference
mm: huge_memory: don't force huge page alignment on 32 bit
userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb
selftests/mm: ksm_tests should only MADV_HUGEPAGE valid memory
scs: add CONFIG_MMU dependency for vfree_atomic()
mm/memory: fix folio_set_dirty() vs. folio_mark_dirty() in zap_pte_range()
mm/huge_memory: fix folio_set_dirty() vs. folio_mark_dirty()
selftests/mm: Update va_high_addr_switch.sh to check CPU for la57 flag
selftests: mm: fix map_hugetlb failure on 64K page size systems
MAINTAINERS: supplement of zswap maintainers update
stackdepot: make fast paths lock-less again
stackdepot: add stats counters exported via debugfs
mm, kmsan: fix infinite recursion due to RCU critical section
mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again
selftests/mm: switch to bash from sh
MAINTAINERS: add man-pages git trees
mm: memcontrol: don't throttle dying tasks on memory.high
mm: mmap: map MAP_STACK to VM_NOHUGEPAGE
uprobes: use pagesize-aligned virtual address when replacing pages
selftests/mm: mremap_test: fix build warning
...
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Remove the duplicate check on type and unify result.
Signed-off-by: Florian Lehner <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Acked-by: Song Liu <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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Now that bpf and bpf-next trees converged and we don't run the risk of
merge conflicts, move btf_validate_prog_ctx_type() into its most logical
place inside the main logic loop.
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Borislav Petkov:
- Prevent an inconsistent futex operation leading to stale state
exposure
* tag 'locking_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Prevent the reuse of stale pi_state
|
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Borislav Petkov:
- Initialize the resend node of each IRQ descriptor, not only the first
one
* tag 'irq_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Initialize resend_node hlist for all interrupt descriptors
|
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Borislav Petkov:
- Preserve the number of idle calls and sleep entries across CPU
hotplug events in order to be able to compute correct averages
- Limit the duration of the clocksource watchdog checking interval as
too long intervals lead to wrongly marking the TSC as unstable
* tag 'timers_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/sched: Preserve number of idle sleeps across CPU hotplug events
clocksource: Skip watchdog check for large watchdog intervals
|
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-01-26
We've added 107 non-merge commits during the last 4 day(s) which contain
a total of 101 files changed, 6009 insertions(+), 1260 deletions(-).
The main changes are:
1) Add BPF token support to delegate a subset of BPF subsystem
functionality from privileged system-wide daemons such as systemd
through special mount options for userns-bound BPF fs to a trusted
& unprivileged application. With addressed changes from Christian
and Linus' reviews, from Andrii Nakryiko.
2) Support registration of struct_ops types from modules which helps
projects like fuse-bpf that seeks to implement a new struct_ops type,
from Kui-Feng Lee.
3) Add support for retrieval of cookies for perf/kprobe multi links,
from Jiri Olsa.
4) Bigger batch of prep-work for the BPF verifier to eventually support
preserving boundaries and tracking scalars on narrowing fills,
from Maxim Mikityanskiy.
5) Extend the tc BPF flavor to support arbitrary TCP SYN cookies to help
with the scenario of SYN floods, from Kuniyuki Iwashima.
6) Add code generation to inline the bpf_kptr_xchg() helper which
improves performance when stashing/popping the allocated BPF objects,
from Hou Tao.
7) Extend BPF verifier to track aligned ST stores as imprecise spilled
registers, from Yonghong Song.
8) Several fixes to BPF selftests around inline asm constraints and
unsupported VLA code generation, from Jose E. Marchesi.
9) Various updates to the BPF IETF instruction set draft document such
as the introduction of conformance groups for instructions,
from Dave Thaler.
10) Fix BPF verifier to make infinite loop detection in is_state_visited()
exact to catch some too lax spill/fill corner cases,
from Eduard Zingerman.
11) Refactor the BPF verifier pointer ALU check to allow ALU explicitly
instead of implicitly for various register types, from Hao Sun.
12) Fix the flaky tc_redirect_dtime BPF selftest due to slowness
in neighbor advertisement at setup time, from Martin KaFai Lau.
13) Change BPF selftests to skip callback tests for the case when the
JIT is disabled, from Tiezhu Yang.
14) Add a small extension to libbpf which allows to auto create
a map-in-map's inner map, from Andrey Grafin.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (107 commits)
selftests/bpf: Add missing line break in test_verifier
bpf, docs: Clarify definitions of various instructions
bpf: Fix error checks against bpf_get_btf_vmlinux().
bpf: One more maintainer for libbpf and BPF selftests
selftests/bpf: Incorporate LSM policy to token-based tests
selftests/bpf: Add tests for LIBBPF_BPF_TOKEN_PATH envvar
libbpf: Support BPF token path setting through LIBBPF_BPF_TOKEN_PATH envvar
selftests/bpf: Add tests for BPF object load with implicit token
selftests/bpf: Add BPF object loading tests with explicit token passing
libbpf: Wire up BPF token support at BPF object level
libbpf: Wire up token_fd into feature probing logic
libbpf: Move feature detection code into its own file
libbpf: Further decouple feature checking logic from bpf_object
libbpf: Split feature detectors definitions from cached results
selftests/bpf: Utilize string values for delegate_xxx mount options
bpf: Support symbolic BPF FS delegation mount options
bpf: Fail BPF_TOKEN_CREATE if no delegation option was set on BPF FS
bpf,selinux: Allocate bpf_security_struct per BPF token
selftests/bpf: Add BPF token-enabled tests
libbpf: Add BPF token support to bpf_prog_load() API
...
====================
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
|
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Fix register_snapshot_trigger() to return error code if it failed to
allocate a snapshot instead of 0 (success). Unless that, it will register
snapshot trigger without an error.
Link: https://lore.kernel.org/linux-trace-kernel/170622977792.270660.2789298642759362200.stgit@devnote2
Fixes: 0bbe7f719985 ("tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation")
Cc: [email protected]
Cc: Vincent Donnefort <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
|
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uprobes passes an unaligned page mapping address to
folio_add_new_anon_rmap(), which ends up triggering a VM_BUG_ON() we
recently extended in commit 372cbd4d5a066 ("mm: non-pmd-mappable, large
folios for folio_add_new_anon_rmap()").
Arguably, this is uprobes code doing something wrong; however, for the
time being it would have likely worked in rmap code because
__folio_set_anon() would set folio->index to the same value.
Looking at __replace_page(), we'd also pass slightly wrong values to
mmu_notifier_range_init(), page_vma_mapped_walk(), flush_cache_page(),
ptep_clear_flush() and set_pte_at_notify(). I suspect most of them are
fine, but let's just mark the introducing commit as the one needed fixing.
I don't think CC stable is warranted.
We'll add more sanity checks in rmap code separately, to make sure that we
always get properly aligned addresses.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: c517ee744b96 ("uprobes: __replace_page() should not use page_address_in_vma()")
Signed-off-by: David Hildenbrand <[email protected]>
Reported-by: Jiri Olsa <[email protected]>
Closes: https://lkml.kernel.org/r/ZaMR2EWN-HvlCfUl@krava
Tested-by: Jiri Olsa <[email protected]>
Reviewed-by: Ryan Roberts <[email protected]>
Acked-by: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Alexander Shishkin
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
In bpf_struct_ops_map_alloc, it needs to check for NULL in the returned
pointer of bpf_get_btf_vmlinux() when CONFIG_DEBUG_INFO_BTF is not set.
ENOTSUPP is used to preserve the same behavior before the
struct_ops kmod support.
In the function check_struct_ops_btf_id(), instead of redoing the
bpf_get_btf_vmlinux() that has already been done in syscall.c, the fix
here is to check for prog->aux->attach_btf_id.
BPF_PROG_TYPE_STRUCT_OPS must require attach_btf_id and syscall.c
guarantees a valid attach_btf as long as attach_btf_id is set.
When attach_btf_id is not set, this patch returns -ENOTSUPP
because it is what the selftest in test_libbpf_probe_prog_types()
and libbpf_probes.c are expecting for feature probing purpose.
Changes from v1:
- Remove an unnecessary NULL check in check_struct_ops_btf_id()
Reported-by: [email protected]
Closes: https://lore.kernel.org/bpf/[email protected]/
Reported-by: [email protected]
Closes: https://lore.kernel.org/bpf/[email protected]/
Fixes: fcc2c1fb0651 ("bpf: pass attached BTF to the bpf_struct_ops subsystem")
Signed-off-by: Kui-Feng Lee <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Martin KaFai Lau <[email protected]>
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Pull RCU fix from Neeraj Upadhyay:
"This fixes RCU grace period stalls, which are observed when an
outgoing CPU's quiescent state reporting results in wakeup of one of
the grace period kthreads, to complete the grace period.
If those kthreads have SCHED_FIFO policy, the wake up can indirectly
arm the RT bandwith timer to the local offline CPU.
Earlier migration of the hrtimers from the CPU introduced in commit
5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU
earlier") results in this timer getting ignored.
If the RCU grace period kthreads are waiting for RT bandwidth to be
available, they may never be actually scheduled, resulting in RCU
stall warnings"
* tag 'urgent-rcu.2024.01.24a' of https://github.com/neeraju/linux:
rcu: Defer RCU kthreads wakeup when CPU is dying
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Commit 71fee48f ("tick-sched: Fix idle and iowait sleeptime accounting vs
CPU hotplug") preserved total idle sleep time and iowait sleeptime across
CPU hotplug events.
Similar reasoning applies to the number of idle calls and idle sleeps to
get the proper average of sleep time per idle invocation.
Preserve those fields too.
Fixes: 71fee48f ("tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug")
Signed-off-by: Tim Chen <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
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There have been reports of the watchdog marking clocksources unstable on
machines with 8 NUMA nodes:
clocksource: timekeeping watchdog on CPU373:
Marking clocksource 'tsc' as unstable because the skew is too large:
clocksource: 'hpet' wd_nsec: 14523447520
clocksource: 'tsc' cs_nsec: 14524115132
The measured clocksource skew - the absolute difference between cs_nsec
and wd_nsec - was 668 microseconds:
cs_nsec - wd_nsec = 14524115132 - 14523447520 = 667612
The kernel used 200 microseconds for the uncertainty_margin of both the
clocksource and watchdog, resulting in a threshold of 400 microseconds (the
md variable). Both the cs_nsec and the wd_nsec value indicate that the
readout interval was circa 14.5 seconds. The observed behaviour is that
watchdog checks failed for large readout intervals on 8 NUMA node
machines. This indicates that the size of the skew was directly proportinal
to the length of the readout interval on those machines. The measured
clocksource skew, 668 microseconds, was evaluated against a threshold (the
md variable) that is suited for readout intervals of roughly
WATCHDOG_INTERVAL, i.e. HZ >> 1, which is 0.5 second.
The intention of 2e27e793e280 ("clocksource: Reduce clocksource-skew
threshold") was to tighten the threshold for evaluating skew and set the
lower bound for the uncertainty_margin of clocksources to twice
WATCHDOG_MAX_SKEW. Later in c37e85c135ce ("clocksource: Loosen clocksource
watchdog constraints"), the WATCHDOG_MAX_SKEW constant was increased to
125 microseconds to fit the limit of NTP, which is able to use a
clocksource that suffers from up to 500 microseconds of skew per second.
Both the TSC and the HPET use default uncertainty_margin. When the
readout interval gets stretched the default uncertainty_margin is no
longer a suitable lower bound for evaluating skew - it imposes a limit
that is far stricter than the skew with which NTP can deal.
The root causes of the skew being directly proportinal to the length of
the readout interval are:
* the inaccuracy of the shift/mult pairs of clocksources and the watchdog
* the conversion to nanoseconds is imprecise for large readout intervals
Prevent this by skipping the current watchdog check if the readout
interval exceeds 2 * WATCHDOG_INTERVAL. Considering the maximum readout
interval of 2 * WATCHDOG_INTERVAL, the current default uncertainty margin
(of the TSC and HPET) corresponds to a limit on clocksource skew of 250
ppm (microseconds of skew per second). To keep the limit imposed by NTP
(500 microseconds of skew per second) for all possible readout intervals,
the margins would have to be scaled so that the threshold value is
proportional to the length of the actual readout interval.
As for why the readout interval may get stretched: Since the watchdog is
executed in softirq context the expiration of the watchdog timer can get
severely delayed on account of a ksoftirqd thread not getting to run in a
timely manner. Surely, a system with such belated softirq execution is not
working well and the scheduling issue should be looked into but the
clocksource watchdog should be able to deal with it accordingly.
Fixes: 2e27e793e280 ("clocksource: Reduce clocksource-skew threshold")
Suggested-by: Feng Tang <[email protected]>
Signed-off-by: Jiri Wiesner <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Paul E. McKenney <[email protected]>
Reviewed-by: Feng Tang <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/20240122172350.GA740@incl
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Besides already supported special "any" value and hex bit mask, support
string-based parsing of delegation masks based on exact enumerator
names. Utilize BTF information of `enum bpf_cmd`, `enum bpf_map_type`,
`enum bpf_prog_type`, and `enum bpf_attach_type` types to find supported
symbolic names (ignoring __MAX_xxx guard values and stripping repetitive
prefixes like BPF_ for cmd and attach types, BPF_MAP_TYPE_ for maps, and
BPF_PROG_TYPE_ for prog types). The case doesn't matter, but it is
normalized to lower case in mount option output. So "PROG_LOAD",
"prog_load", and "MAP_create" are all valid values to specify for
delegate_cmds options, "array" is among supported for map types, etc.
Besides supporting string values, we also support multiple values
specified at the same time, using colon (':') separator.
There are corresponding changes on bpf_show_options side to use known
values to print them in human-readable format, falling back to hex mask
printing, if there are any unrecognized bits. This shouldn't be
necessary when enum BTF information is present, but in general we should
always be able to fall back to this even if kernel was built without BTF.
As mentioned, emitted symbolic names are normalized to be all lower case.
Example below shows various ways to specify delegate_cmds options
through mount command and how mount options are printed back:
12/14 14:39:07.604
vmuser@archvm:~/local/linux/tools/testing/selftests/bpf
$ mount | rg token
$ sudo mkdir -p /sys/fs/bpf/token
$ sudo mount -t bpf bpffs /sys/fs/bpf/token \
-o delegate_cmds=prog_load:MAP_CREATE \
-o delegate_progs=kprobe \
-o delegate_attachs=xdp
$ mount | grep token
bpffs on /sys/fs/bpf/token type bpf (rw,relatime,delegate_cmds=map_create:prog_load,delegate_progs=kprobe,delegate_attachs=xdp)
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: John Fastabend <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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