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6058 Commits
Author | SHA1 | Message | Date | |
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Andrii Nakryiko
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1a80dbcb2d |
bpf: support deferring bpf_link dealloc to after RCU grace period
BPF link for some program types is passed as a "context" which can be used by those BPF programs to look up additional information. E.g., for multi-kprobes and multi-uprobes, link is used to fetch BPF cookie values. Because of this runtime dependency, when bpf_link refcnt drops to zero there could still be active BPF programs running accessing link data. This patch adds generic support to defer bpf_link dealloc callback to after RCU GP, if requested. This is done by exposing two different deallocation callbacks, one synchronous and one deferred. If deferred one is provided, bpf_link_free() will schedule dealloc_deferred() callback to happen after RCU GP. BPF is using two flavors of RCU: "classic" non-sleepable one and RCU tasks trace one. The latter is used when sleepable BPF programs are used. bpf_link_free() accommodates that by checking underlying BPF program's sleepable flag, and goes either through normal RCU GP only for non-sleepable, or through RCU tasks trace GP *and* then normal RCU GP (taking into account rcu_trace_implies_rcu_gp() optimization), if BPF program is sleepable. We use this for multi-kprobe and multi-uprobe links, which dereference link during program run. We also preventively switch raw_tp link to use deferred dealloc callback, as upcoming changes in bpf-next tree expose raw_tp link data (specifically, cookie value) to BPF program at runtime as well. Fixes: |
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Andrii Nakryiko
|
e9c856cabe |
bpf: put uprobe link's path and task in release callback
There is no need to delay putting either path or task to deallocation step. It can be done right after bpf_uprobe_unregister. Between release and dealloc, there could be still some running BPF programs, but they don't access either task or path, only data in link->uprobes, so it is safe to do. On the other hand, doing path_put() in dealloc callback makes this dealloc sleepable because path_put() itself might sleep. Which is problematic due to the need to call uprobe's dealloc through call_rcu(), which is what is done in the next bug fix patch. So solve the problem by releasing these resources early. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240328052426.3042617-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Linus Torvalds
|
962490525c |
Probes fixes for v6.9-rc1:
- tracing/probes: initialize a 'val' local variable with zero. This variable is read by FETCH_OP_ST_EDATA in a loop, and is expected to be initialized by FETCH_OP_ARG in the same loop. Since this expectation is not obvious, thus smatch warns it. Initializing 'val' with zero fixes this warning. -----BEGIN PGP SIGNATURE----- iQFPBAABCgA5FiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmYEKw4bHG1hc2FtaS5o aXJhbWF0c3VAZ21haWwuY29tAAoJENv7B78FKz8bZmkH/2TNnrQivrNEyihXaZNC i4kyOGiNpIKi1BvE2nBFItqMlKbry+bR74tgk9+9BZiwjnTSz+pVDsWuOrSvrLNy j9yOjqZMdEnx7YdSZX+HUxpXzklSyAd1PQ0kEOYHRgqcXgcUEYSaHPpZZJqBtIah X/4rmLyMTFE2CdbdJ+dfPn9GLn0C9TP+jGz0DC/efEXdXJ3bVY2d3DJXHNiVpW58 4Yy0UWwUu/QAk2JGUf1r3GEwoklKNNjvGLaCMm4mAoY3haDzfbGecstAB4cc/gD/ FzN2q+7Z7RgJloICJo1Bh91AWi06+EeFFk6MZ5oHzjsp7EH/aGCy5umEsIPGjHr4 Y0Q= =b4J5 -----END PGP SIGNATURE----- Merge tag 'probes-fixes-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull probes fixlet from Masami Hiramatsu: - tracing/probes: initialize a 'val' local variable with zero. This variable is read by FETCH_OP_ST_EDATA in a loop, and is initialized by FETCH_OP_ARG in the same loop. Since this initialization is not obvious, smatch warns about it. Explicitly initializing 'val' with zero fixes this warning. * tag 'probes-fixes-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: probes: Fix to zero initialize a local variable |
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Masami Hiramatsu (Google)
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0add699ad0 |
tracing: probes: Fix to zero initialize a local variable
Fix to initialize 'val' local variable with zero.
Dan reported that Smatch static code checker reports an error that a local
'val' variable needs to be initialized. Actually, the 'val' is expected to
be initialized by FETCH_OP_ARG in the same loop, but it is not obvious. So
initialize it with zero.
Link: https://lore.kernel.org/all/171092223833.237219.17304490075697026697.stgit@devnote2/
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/b010488e-68aa-407c-add0-3e059254aaa0@moroto.mountain/
Fixes:
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Thorsten Blum
|
d6cb38e108 |
tracing: Use div64_u64() instead of do_div()
Fixes Coccinelle/coccicheck warnings reported by do_div.cocci. Compared to do_div(), div64_u64() does not implicitly cast the divisor and does not unnecessarily calculate the remainder. Link: https://lore.kernel.org/linux-trace-kernel/20240225164507.232942-2-thorsten.blum@toblux.com Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Huang Yiwei
|
19f0423fd5 |
tracing: Support to dump instance traces by ftrace_dump_on_oops
Currently ftrace only dumps the global trace buffer on an OOPs. For debugging a production usecase, instance trace will be helpful to check specific problems since global trace buffer may be used for other purposes. This patch extend the ftrace_dump_on_oops parameter to dump a specific or multiple trace instances: - ftrace_dump_on_oops=0: as before -- don't dump - ftrace_dump_on_oops[=1]: as before -- dump the global trace buffer on all CPUs - ftrace_dump_on_oops=2 or =orig_cpu: as before -- dump the global trace buffer on CPU that triggered the oops - ftrace_dump_on_oops=<instance_name>: new behavior -- dump the tracing instance matching <instance_name> - ftrace_dump_on_oops[=2/orig_cpu],<instance1_name>[=2/orig_cpu], <instrance2_name>[=2/orig_cpu]: new behavior -- dump the global trace buffer and multiple instance buffer on all CPUs, or only dump on CPU that triggered the oops if =2 or =orig_cpu is given Also, the sysctl node can handle the input accordingly. Link: https://lore.kernel.org/linux-trace-kernel/20240223083126.1817731-1-quic_hyiwei@quicinc.com Cc: Ross Zwisler <zwisler@google.com> Cc: <mhiramat@kernel.org> Cc: <mark.rutland@arm.com> Cc: <mcgrof@kernel.org> Cc: <keescook@chromium.org> Cc: <j.granados@samsung.com> Cc: <mathieu.desnoyers@efficios.com> Cc: <corbet@lwn.net> Signed-off-by: Huang Yiwei <quic_hyiwei@quicinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Randy Dunlap
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d15304135c |
ftrace: Fix most kernel-doc warnings
Reduce the number of kernel-doc warnings from 52 down to 10, i.e., fix 42 kernel-doc warnings by (a) using the Returns: format for function return values or (b) using "@var:" instead of "@var -" for function parameter descriptions. Fix one return values list so that it is formatted correctly when rendered for output. Spell "non-zero" with a hyphen in several places. Link: https://lore.kernel.org/linux-trace-kernel/20240223054833.15471-1-rdunlap@infradead.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/oe-kbuild-all/202312180518.X6fRyDSN-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt (Google)
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2048fdc275 |
tracing: Decrement the snapshot if the snapshot trigger fails to register
Running the ftrace selftests caused the ring buffer mapping test to fail. Investigating, I found that the snapshot counter would be incremented every time a snapshot trigger was added, even if that snapshot trigger failed. # cd /sys/kernel/tracing # echo "snapshot" > events/sched/sched_process_fork/trigger # echo "snapshot" > events/sched/sched_process_fork/trigger -bash: echo: write error: File exists That second one that fails increments the snapshot counter but doesn't decrement it. It needs to be decremented when the snapshot fails. Link: https://lore.kernel.org/linux-trace-kernel/20240223013344.729055907@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vincent Donnefort <vdonnefort@google.com> Fixes: 16f7e48ffc53a ("tracing: Add snapshot refcount") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt (Google)
|
cca990c7b5 |
tracing: Fix snapshot counter going between two tracers that use it
Running the ftrace selftests caused the ring buffer mapping test to fail. Investigating, I found that the snapshot counter would be incremented every time a tracer that uses the snapshot is enabled even if the snapshot was used by the previous tracer. That is: # cd /sys/kernel/tracing # echo wakeup_rt > current_tracer # echo wakeup_dl > current_tracer # echo nop > current_tracer would leave the snapshot counter at 1 and not zero. That's because the enabling of wakeup_dl would increment the counter again but the setting the tracer to nop would only decrement it once. Do not arm the snapshot for a tracer if the previous tracer already had it armed. Link: https://lore.kernel.org/linux-trace-kernel/20240223013344.570525723@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vincent Donnefort <vdonnefort@google.com> Fixes: 16f7e48ffc53a ("tracing: Add snapshot refcount") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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John Garry
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ed89683763 |
tracing: Use init_utsname()->release
Instead of using UTS_RELEASE, use init_utsname()->release, which means that we don't need to rebuild the code just for the git head commit changing. Link: https://lore.kernel.org/linux-trace-kernel/20240222124639.65629-1-john.g.garry@oracle.com Signed-off-by: John Garry <john.g.garry@oracle.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Beau Belgrave
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64805e4039 |
tracing/user_events: Introduce multi-format events
Currently user_events supports 1 event with the same name and must have the exact same format when referenced by multiple programs. This opens an opportunity for malicious or poorly thought through programs to create events that others use with different formats. Another scenario is user programs wishing to use the same event name but add more fields later when the software updates. Various versions of a program may be running side-by-side, which is prevented by the current single format requirement. Add a new register flag (USER_EVENT_REG_MULTI_FORMAT) which indicates the user program wishes to use the same user_event name, but may have several different formats of the event. When this flag is used, create the underlying tracepoint backing the user_event with a unique name per-version of the format. It's important that existing ABI users do not get this logic automatically, even if one of the multi format events matches the format. This ensures existing programs that create events and assume the tracepoint name will match exactly continue to work as expected. Add logic to only check multi-format events with other multi-format events and single-format events to only check single-format events during find. Change system name of the multi-format event tracepoint to ensure that multi-format events are isolated completely from single-format events. This prevents single-format names from conflicting with multi-format events if they end with the same suffix as the multi-format events. Add a register_name (reg_name) to the user_event struct which allows for split naming of events. We now have the name that was used to register within user_events as well as the unique name for the tracepoint. Upon registering events ensure matches based on first the reg_name, followed by the fields and format of the event. This allows for multiple events with the same registered name to have different formats. The underlying tracepoint will have a unique name in the format of {reg_name}.{unique_id}. For example, if both "test u32 value" and "test u64 value" are used with the USER_EVENT_REG_MULTI_FORMAT the system would have 2 unique tracepoints. The dynamic_events file would then show the following: u:test u64 count u:test u32 count The actual tracepoint names look like this: test.0 test.1 Both would be under the new user_events_multi system name to prevent the older ABI from being used to squat on multi-formatted events and block their use. Deleting events via "!u:test u64 count" would only delete the first tracepoint that matched that format. When the delete ABI is used all events with the same name will be attempted to be deleted. If per-version deletion is required, user programs should either not use persistent events or delete them via dynamic_events. Link: https://lore.kernel.org/linux-trace-kernel/20240222001807.1463-3-beaub@linux.microsoft.com Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Beau Belgrave
|
1e953de9e9 |
tracing/user_events: Prepare find/delete for same name events
The current code for finding and deleting events assumes that there will never be cases when user_events are registered with the same name, but different formats. Scenarios exist where programs want to use the same name but have different formats. An example is multiple versions of a program running side-by-side using the same event name, but with updated formats in each version. This change does not yet allow for multi-format events. If user_events are registered with the same name but different arguments the programs see the same return values as before. This change simply makes it possible to easily accommodate for this. Update find_user_event() to take in argument parameters and register flags to accommodate future multi-format event scenarios. Have find validate argument matching and return error pointers to cover when an existing event has the same name but different format. Update callers to handle error pointer logic. Move delete_user_event() to use hash walking directly now that find_user_event() has changed. Delete all events found that match the register name, stop if an error occurs and report back to the user. Update user_fields_match() to cover list_empty() scenarios now that find_user_event() uses it directly. This makes the logic consistent across several callsites. Link: https://lore.kernel.org/linux-trace-kernel/20240222001807.1463-2-beaub@linux.microsoft.com Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Vincent Donnefort
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180e4e3909 |
tracing: Add snapshot refcount
When a ring-buffer is memory mapped by user-space, no trace or ring-buffer swap is possible. This means the snapshot feature is mutually exclusive with the memory mapping. Having a refcount on snapshot users will help to know if a mapping is possible or not. Instead of relying on the global trace_types_lock, a new spinlock is introduced to serialize accesses to trace_array->snapshot. This intends to allow access to that variable in a context where the mmap lock is already held. Link: https://lore.kernel.org/linux-trace-kernel/20240220202310.2489614-4-vdonnefort@google.com Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt (Google)
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b70f293824 |
ring-buffer: Make wake once of ring_buffer_wait() more robust
The default behavior of ring_buffer_wait() when passed a NULL "cond"
parameter is to exit the function the first time it is woken up. The
current implementation uses a counter that starts at zero and when it is
greater than one it exits the wait_event_interruptible().
But this relies on the internal working of wait_event_interruptible() as
that code basically has:
if (cond)
return;
prepare_to_wait();
if (!cond)
schedule();
finish_wait();
That is, cond is called twice before it sleeps. The default cond of
ring_buffer_wait() needs to account for that and wait for its counter to
increment twice before exiting.
Instead, use the seq/atomic_inc logic that is used by the tracing code
that calls this function. Add an atomic_t seq to rb_irq_work and when cond
is NULL, have the default callback take a descriptor as its data that
holds the rbwork and the value of the seq when it started.
The wakeups will now increment the rbwork->seq and the cond callback will
simply check if that number is different, and no longer have to rely on
the implementation of wait_event_interruptible().
Link: https://lore.kernel.org/linux-trace-kernel/20240315063115.6cb5d205@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes:
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linke li
|
f1e30cb636 |
ring-buffer: use READ_ONCE() to read cpu_buffer->commit_page in concurrent environment
In function ring_buffer_iter_empty(), cpu_buffer->commit_page is read while other threads may change it. It may cause the time_stamp that read in the next line come from a different page. Use READ_ONCE() to avoid having to reason about compiler optimizations now and in future. Link: https://lore.kernel.org/linux-trace-kernel/tencent_DFF7D3561A0686B5E8FC079150A02505180A@qq.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: linke li <lilinke99@qq.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Vincent Donnefort
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6b76323e5a |
ring-buffer: Zero ring-buffer sub-buffers
In preparation for the ring-buffer memory mapping where each subbuf will be accessible to user-space, zero all the page allocations. Link: https://lore.kernel.org/linux-trace-kernel/20240220202310.2489614-2-vdonnefort@google.com Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt (Google)
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2cc621fd2e |
tracing: Move saved_cmdline code into trace_sched_switch.c
The code that handles saved_cmdlines is split between the trace.c file and the trace_sched_switch.c. There's some history to this. The trace_sched_switch.c was originally created to handle the sched_switch tracer that was deprecated due to sched_switch trace event making it obsolete. But that file did not get deleted as it had some code to help with saved_cmdlines. But trace.c has grown tremendously since then. Just move all the saved_cmdlines code into trace_sched_switch.c as that's the only reason that file still exists, and trace.c has gotten too big. No functional changes. Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.497966629@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt (Google)
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e85d471c2b |
tracing: Move open coded processing of tgid_map into helper function
In preparation of moving the saved_cmdlines logic out of trace.c and into trace_sched_switch.c, replace the open coded manipulation of tgid_map in set_tracer_flag() into a helper function trace_alloc_tgid_map() so that it can be easily moved into trace_sched_switch.c without changing existing functions in trace.c. No functional changes. Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.338116216@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt (Google)
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0b18c852cc |
tracing: Have saved_cmdlines arrays all in one allocation
The saved_cmdlines have three arrays for mapping PIDs to COMMs:
- map_pid_to_cmdline[]
- map_cmdline_to_pid[]
- saved_cmdlines
The map_pid_to_cmdline[] is PID_MAX_DEFAULT in size and holds the index
into the other arrays. The map_cmdline_to_pid[] is a mapping back to the
full pid as it can be larger than PID_MAX_DEFAULT. And the
saved_cmdlines[] just holds the COMMs associated to the pids.
Currently the map_pid_to_cmdline[] and saved_cmdlines[] are allocated
together (in reality the saved_cmdlines is just in the memory of the
rounding of the allocation of the structure as it is always allocated in
powers of two). The map_cmdline_to_pid[] array is allocated separately.
Since the rounding to a power of two is rather large (it allows for 8000
elements in saved_cmdlines), also include the map_cmdline_to_pid[] array.
(This drops it to 6000 by default, which is still plenty for most use
cases). This saves even more memory as the map_cmdline_to_pid[] array
doesn't need to be allocated.
Link: https://lore.kernel.org/linux-trace-kernel/20240212174011.068211d9@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.182330529@goodmis.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Fixes:
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Linus Torvalds
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63bd30f249 |
Tracing/ring-buffer fixes for 6.8 (to be applied in 6.9-rc):
- Do not update shortest_full in rb_watermark_hit() if the watermark is hit. The shortest_full field was being updated regardless if the task was going to wait or not. If the watermark is hit, then the task is not going to wait, so do not update the shortest_full field (used by the waker). - Update shortest_full field before setting the full_waiters_pending flag In the poll logic, the full_waiters_pending flag was being set before the shortest_full field was set. If the full_waiters_pending flag is set, writers will check the shortest_full field which has the least percentage of data that the ring buffer needs to be filled before waking up. The writer will check shortest_full if full_waiters_pending is set, and if the ring buffer percentage filled is greater than shortest full, then it will call the irq_work to wake up the waiters. The problem was that the poll logic set the full_waiters_pending flag before updating shortest_full, which when zero will always trigger the writer to call the irq_work to wake up the waiters. The irq_work will reset the shortest_full field back to zero as the woken waiters is suppose to reset it. - There's some optimized logic in the rb_watermark_hit() that is used in ring_buffer_wait(). Use that helper function in the poll logic as well. - Restructure ring_buffer_wait() to use wait_event_interruptible() The logic to wake up pending readers when the file descriptor is closed is racy. Restructure ring_buffer_wait() to allow callers to pass in conditions besides the ring buffer having enough data in it by using wait_event_interruptible(). - Update the tracing_wait_on_pipe() to call ring_buffer_wait() with its own conditions to exit the wait loop. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZfH6MRQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qtlwAP9ZoSIkvw2MVu7FclgAguaX2CaylGEw sv0wZaCy1kgAPgD8CFhezZcHrt/RwJibpMxVnUs+DDqYnGdJsHYLihlbWgg= =99FG -----END PGP SIGNATURE----- Merge tag 'trace-ring-buffer-v6.8-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Do not update shortest_full in rb_watermark_hit() if the watermark is hit. The shortest_full field was being updated regardless if the task was going to wait or not. If the watermark is hit, then the task is not going to wait, so do not update the shortest_full field (used by the waker). - Update shortest_full field before setting the full_waiters_pending flag In the poll logic, the full_waiters_pending flag was being set before the shortest_full field was set. If the full_waiters_pending flag is set, writers will check the shortest_full field which has the least percentage of data that the ring buffer needs to be filled before waking up. The writer will check shortest_full if full_waiters_pending is set, and if the ring buffer percentage filled is greater than shortest full, then it will call the irq_work to wake up the waiters. The problem was that the poll logic set the full_waiters_pending flag before updating shortest_full, which when zero will always trigger the writer to call the irq_work to wake up the waiters. The irq_work will reset the shortest_full field back to zero as the woken waiters is suppose to reset it. - There's some optimized logic in the rb_watermark_hit() that is used in ring_buffer_wait(). Use that helper function in the poll logic as well. - Restructure ring_buffer_wait() to use wait_event_interruptible() The logic to wake up pending readers when the file descriptor is closed is racy. Restructure ring_buffer_wait() to allow callers to pass in conditions besides the ring buffer having enough data in it by using wait_event_interruptible(). - Update the tracing_wait_on_pipe() to call ring_buffer_wait() with its own conditions to exit the wait loop. * tag 'trace-ring-buffer-v6.8-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/ring-buffer: Fix wait_on_pipe() race ring-buffer: Use wait_event_interruptible() in ring_buffer_wait() ring-buffer: Reuse rb_watermark_hit() for the poll logic ring-buffer: Fix full_waiters_pending in poll ring-buffer: Do not set shortest_full when full target is hit |
||
Linus Torvalds
|
01732755ee |
Probes updates for v6.9:
- x96/kprobes: Use boolean for some function return instead of 0 and 1. - x86/kprobes: Prohibit probing on INT/UD. This prevents user to put kprobe on INTn/INT1/INT3/INTO and UD0/UD1/UD2 because these are used for a special purpose in the kernel. - x86/kprobes: Boost Grp instructions. Because a few percent of kernel instructions are Grp 2/3/4/5 and those are safe to be executed without ip register fixup, allow those to be boosted (direct execution on the trampoline buffer with a JMP). - tracing/probes: Add function argument access from return events (kretprobe and fprobe). This allows user to compare how a data structure field is changed after executing a function. With BTF, return event also accepts function argument access by name. This also includes below patches; . Fix a wrong comment (using "Kretprobe" in fprobe) . Cleanup a big probe argument parser function into three parts, type parser, post-processing function, and main parser. . Cleanup to set nr_args field when initializing trace_probe instead of counting up it while parsing. . Cleanup a redundant #else block from tracefs/README source code. . Update selftests to check entry argument access from return probes. . Documentation update about entry argument access from return probes. -----BEGIN PGP SIGNATURE----- iQFPBAABCgA5FiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmXwW4kbHG1hc2FtaS5o aXJhbWF0c3VAZ21haWwuY29tAAoJENv7B78FKz8bH80H/3H6JENlDAjaSLi4vYrP Qyw/cOGIuGu8cDEzkkOaFMol3TY23M7tQZH1lFefvV92gebZ0ttXnrQhSsKeO5XT PCZ6Eoift5rwJCY967W4V6O0DrAkOGHlPtlKs47APJnTXwn8RcFTqWlQmhWg1AfD g/FCWV7cs3eewZgV9iQcLydOoLLgRMr3G3rtPYQbCXhPzze0WTu4dSOXxCTjFe04 riHQy7R+ut6Cur8njpoqZl6bCMkQqAylByXf6wK96HjcS0+ZI7Ivi8Ey3l2aAFen EeIViMU2Bl02XzBszj7Xq2cT/ebYAgDonFW3/5ZKD1YMO6F7wPoVH5OHrQ518Xuw hQ8= =O6l5 -----END PGP SIGNATURE----- Merge tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull probes updates from Masami Hiramatsu: "x86 kprobes: - Use boolean for some function return instead of 0 and 1 - Prohibit probing on INT/UD. This prevents user to put kprobe on INTn/INT1/INT3/INTO and UD0/UD1/UD2 because these are used for a special purpose in the kernel - Boost Grp instructions. Because a few percent of kernel instructions are Grp 2/3/4/5 and those are safe to be executed without ip register fixup, allow those to be boosted (direct execution on the trampoline buffer with a JMP) tracing: - Add function argument access from return events (kretprobe and fprobe). This allows user to compare how a data structure field is changed after executing a function. With BTF, return event also accepts function argument access by name. - Fix a wrong comment (using "Kretprobe" in fprobe) - Cleanup a big probe argument parser function into three parts, type parser, post-processing function, and main parser - Cleanup to set nr_args field when initializing trace_probe instead of counting up it while parsing - Cleanup a redundant #else block from tracefs/README source code - Update selftests to check entry argument access from return probes - Documentation update about entry argument access from return probes" * tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: Documentation: tracing: Add entry argument access at function exit selftests/ftrace: Add test cases for entry args at function exit tracing/probes: Support $argN in return probe (kprobe and fprobe) tracing: Remove redundant #else block for BTF args from README tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init tracing/probes: Cleanup probe argument parser tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event x86/kprobes: Boost more instructions from grp2/3/4/5 x86/kprobes: Prohibit kprobing on INT and UD x86/kprobes: Refactor can_{probe,boost} return type to bool |
||
Linus Torvalds
|
9187210eee |
Networking changes for 6.9.
Core & protocols ---------------- - Large effort by Eric to lower rtnl_lock pressure and remove locks: - Make commonly used parts of rtnetlink (address, route dumps etc.) lockless, protected by RCU instead of rtnl_lock. - Add a netns exit callback which already holds rtnl_lock, allowing netns exit to take rtnl_lock once in the core instead of once for each driver / callback. - Remove locks / serialization in the socket diag interface. - Remove 6 calls to synchronize_rcu() while holding rtnl_lock. - Remove the dev_base_lock, depend on RCU where necessary. - Support busy polling on a per-epoll context basis. Poll length and budget parameters can be set independently of system defaults. - Introduce struct net_hotdata, to make sure read-mostly global config variables fit in as few cache lines as possible. - Add optional per-nexthop statistics to ease monitoring / debug of ECMP imbalance problems. - Support TCP_NOTSENT_LOWAT in MPTCP. - Ensure that IPv6 temporary addresses' preferred lifetimes are long enough, compared to other configured lifetimes, and at least 2 sec. - Support forwarding of ICMP Error messages in IPSec, per RFC 4301. - Add support for the independent control state machine for bonding per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled control state machine. - Add "network ID" to MCTP socket APIs to support hosts with multiple disjoint MCTP networks. - Re-use the mono_delivery_time skbuff bit for packets which user space wants to be sent at a specified time. Maintain the timing information while traversing veth links, bridge etc. - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets. - Simplify many places iterating over netdevs by using an xarray instead of a hash table walk (hash table remains in place, for use on fastpaths). - Speed up scanning for expired routes by keeping a dedicated list. - Speed up "generic" XDP by trying harder to avoid large allocations. - Support attaching arbitrary metadata to netconsole messages. Things we sprinkled into general kernel code -------------------------------------------- - Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce VM_SPARSE kind and vm_area_[un]map_pages (used by bpf_arena). - Rework selftest harness to enable the use of the full range of ksft exit code (pass, fail, skip, xfail, xpass). Netfilter --------- - Allow userspace to define a table that is exclusively owned by a daemon (via netlink socket aliveness) without auto-removing this table when the userspace program exits. Such table gets marked as orphaned and a restarting management daemon can re-attach/regain ownership. - Speed up element insertions to nftables' concatenated-ranges set type. Compact a few related data structures. BPF --- - Add BPF token support for delegating 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. - Introduce bpf_arena which is sparse shared memory region between BPF program and user space where structures inside the arena can have pointers to other areas of the arena, and pointers work seamlessly for both user-space programs and BPF programs. - Introduce may_goto instruction that is a contract between the verifier and the program. The verifier allows the program to loop assuming it's behaving well, but reserves the right to terminate it. - Extend the BPF verifier to enable static subprog calls in spin lock critical sections. - Support registration of struct_ops types from modules which helps projects like fuse-bpf that seeks to implement a new struct_ops type. - Add support for retrieval of cookies for perf/kprobe multi links. - Support arbitrary TCP SYN cookie generation / validation in the TC layer with BPF to allow creating SYN flood handling in BPF firewalls. - Add code generation to inline the bpf_kptr_xchg() helper which improves performance when stashing/popping the allocated BPF objects. Wireless -------- - Add SPP (signaling and payload protected) AMSDU support. - Support wider bandwidth OFDMA, as required for EHT operation. Driver API ---------- - Major overhaul of the Energy Efficient Ethernet internals to support new link modes (2.5GE, 5GE), share more code between drivers (especially those using phylib), and encourage more uniform behavior. Convert and clean up drivers. - Define an API for querying per netdev queue statistics from drivers. - IPSec: account in global stats for fully offloaded sessions. - Create a concept of Ethernet PHY Packages at the Device Tree level, to allow parameterizing the existing PHY package code. - Enable Rx hashing (RSS) on GTP protocol fields. Misc ---- - Improvements and refactoring all over networking selftests. - Create uniform module aliases for TC classifiers, actions, and packet schedulers to simplify creating modprobe policies. - Address all missing MODULE_DESCRIPTION() warnings in networking. - Extend the Netlink descriptions in YAML to cover message encapsulation or "Netlink polymorphism", where interpretation of nested attributes depends on link type, classifier type or some other "class type". Drivers ------- - Ethernet high-speed NICs: - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF. - Intel (100G, ice, idpf): - support E825-C devices - nVidia/Mellanox: - support devices with one port and multiple PCIe links - Broadcom (bnxt): - support n-tuple filters - support configuring the RSS key - Wangxun (ngbe/txgbe): - implement irq_domain for TXGBE's sub-interrupts - Pensando/AMD: - support XDP - optimize queue submission and wakeup handling (+17% bps) - optimize struct layout, saving 28% of memory on queues - Ethernet NICs embedded and virtual: - Google cloud vNIC: - refactor driver to perform memory allocations for new queue config before stopping and freeing the old queue memory - Synopsys (stmmac): - obey queueMaxSDU and implement counters required by 802.1Qbv - Renesas (ravb): - support packet checksum offload - suspend to RAM and runtime PM support - Ethernet switches: - nVidia/Mellanox: - support for nexthop group statistics - Microchip: - ksz8: implement PHY loopback - add support for KSZ8567, a 7-port 10/100Mbps switch - PTP: - New driver for RENESAS FemtoClock3 Wireless clock generator. - Support OCP PTP cards designed and built by Adva. - CAN: - Support recvmsg() flags for own, local and remote traffic on CAN BCM sockets. - Support for esd GmbH PCIe/402 CAN device family. - m_can: - Rx/Tx submission coalescing - wake on frame Rx - WiFi: - Intel (iwlwifi): - enable signaling and payload protected A-MSDUs - support wider-bandwidth OFDMA - support for new devices - bump FW API to 89 for AX devices; 90 for BZ/SC devices - MediaTek (mt76): - mt7915: newer ADIE version support - mt7925: radio temperature sensor support - Qualcomm (ath11k): - support 6 GHz station power modes: Low Power Indoor (LPI), Standard Power) SP and Very Low Power (VLP) - QCA6390 & WCN6855: support 2 concurrent station interfaces - QCA2066 support - Qualcomm (ath12k): - refactoring in preparation for Multi-Link Operation (MLO) support - 1024 Block Ack window size support - firmware-2.bin support - support having multiple identical PCI devices (firmware needs to have ATH12K_FW_FEATURE_MULTI_QRTR_ID) - QCN9274: support split-PHY devices - WCN7850: enable Power Save Mode in station mode - WCN7850: P2P support - RealTek: - rtw88: support for more rtw8811cu and rtw8821cu devices - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL - rtlwifi: speed up USB firmware initialization - rtwl8xxxu: - RTL8188F: concurrent interface support - Channel Switch Announcement (CSA) support in AP mode - Broadcom (brcmfmac): - per-vendor feature support - per-vendor SAE password setup - DMI nvram filename quirk for ACEPC W5 Pro Signed-off-by: Jakub Kicinski <kuba@kernel.org> -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAmXv0mgACgkQMUZtbf5S IrtgMxAAuRd+WJW++SENr4KxIWhYO1q6Xcxnai43wrNkan9swD24icG8TYALt4f3 yoT6idQvWReAb5JNlh9rUQz8R7E0nJXlvEFn5MtJwcthx2C6wFo/XkJlddlRrT+j c2xGILwLjRhW65LaC0MZ2ECbEERkFz8xcGfK2SWzUgh6KYvPjcRfKFxugpM7xOQK P/Wnqhs4fVRS/Mj/bCcXcO+yhwC121Q3qVeQVjGS0AzEC65hAW87a/kc2BfgcegD EyI9R7mf6criQwX+0awubjfoIdr4oW/8oDVNvUDczkJkbaEVaLMQk9P5x/0XnnVS UHUchWXyI80Q8Rj12uN1/I0h3WtwNQnCRBuLSmtm6GLfCAwbLvp2nGWDnaXiqryW DVKUIHGvqPKjkOOMOVfSvfB3LvkS3xsFVVYiQBQCn0YSs/gtu4CoF2Nty9CiLPbK tTuxUnLdPDZDxU//l0VArZmP8p2JM7XQGJ+JH8GFH4SBTyBR23e0iyPSoyaxjnYn RReDnHMVsrS1i7GPhbqDJWn+uqMSs7N149i0XmmyeqwQHUVSJN3J2BApP2nCaDfy H2lTuYly5FfEezt61NvCE4qr/VsWeEjm1fYlFQ9dFn4pGn+HghyCpw+xD1ZN56DN lujemau5B3kk1UTtAT4ypPqvuqjkRFqpNV2LzsJSk/Js+hApw8Y= =oY52 -----END PGP SIGNATURE----- Merge tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core & protocols: - Large effort by Eric to lower rtnl_lock pressure and remove locks: - Make commonly used parts of rtnetlink (address, route dumps etc) lockless, protected by RCU instead of rtnl_lock. - Add a netns exit callback which already holds rtnl_lock, allowing netns exit to take rtnl_lock once in the core instead of once for each driver / callback. - Remove locks / serialization in the socket diag interface. - Remove 6 calls to synchronize_rcu() while holding rtnl_lock. - Remove the dev_base_lock, depend on RCU where necessary. - Support busy polling on a per-epoll context basis. Poll length and budget parameters can be set independently of system defaults. - Introduce struct net_hotdata, to make sure read-mostly global config variables fit in as few cache lines as possible. - Add optional per-nexthop statistics to ease monitoring / debug of ECMP imbalance problems. - Support TCP_NOTSENT_LOWAT in MPTCP. - Ensure that IPv6 temporary addresses' preferred lifetimes are long enough, compared to other configured lifetimes, and at least 2 sec. - Support forwarding of ICMP Error messages in IPSec, per RFC 4301. - Add support for the independent control state machine for bonding per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled control state machine. - Add "network ID" to MCTP socket APIs to support hosts with multiple disjoint MCTP networks. - Re-use the mono_delivery_time skbuff bit for packets which user space wants to be sent at a specified time. Maintain the timing information while traversing veth links, bridge etc. - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets. - Simplify many places iterating over netdevs by using an xarray instead of a hash table walk (hash table remains in place, for use on fastpaths). - Speed up scanning for expired routes by keeping a dedicated list. - Speed up "generic" XDP by trying harder to avoid large allocations. - Support attaching arbitrary metadata to netconsole messages. Things we sprinkled into general kernel code: - Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce VM_SPARSE kind and vm_area_[un]map_pages (used by bpf_arena). - Rework selftest harness to enable the use of the full range of ksft exit code (pass, fail, skip, xfail, xpass). Netfilter: - Allow userspace to define a table that is exclusively owned by a daemon (via netlink socket aliveness) without auto-removing this table when the userspace program exits. Such table gets marked as orphaned and a restarting management daemon can re-attach/regain ownership. - Speed up element insertions to nftables' concatenated-ranges set type. Compact a few related data structures. BPF: - Add BPF token support for delegating 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. - Introduce bpf_arena which is sparse shared memory region between BPF program and user space where structures inside the arena can have pointers to other areas of the arena, and pointers work seamlessly for both user-space programs and BPF programs. - Introduce may_goto instruction that is a contract between the verifier and the program. The verifier allows the program to loop assuming it's behaving well, but reserves the right to terminate it. - Extend the BPF verifier to enable static subprog calls in spin lock critical sections. - Support registration of struct_ops types from modules which helps projects like fuse-bpf that seeks to implement a new struct_ops type. - Add support for retrieval of cookies for perf/kprobe multi links. - Support arbitrary TCP SYN cookie generation / validation in the TC layer with BPF to allow creating SYN flood handling in BPF firewalls. - Add code generation to inline the bpf_kptr_xchg() helper which improves performance when stashing/popping the allocated BPF objects. Wireless: - Add SPP (signaling and payload protected) AMSDU support. - Support wider bandwidth OFDMA, as required for EHT operation. Driver API: - Major overhaul of the Energy Efficient Ethernet internals to support new link modes (2.5GE, 5GE), share more code between drivers (especially those using phylib), and encourage more uniform behavior. Convert and clean up drivers. - Define an API for querying per netdev queue statistics from drivers. - IPSec: account in global stats for fully offloaded sessions. - Create a concept of Ethernet PHY Packages at the Device Tree level, to allow parameterizing the existing PHY package code. - Enable Rx hashing (RSS) on GTP protocol fields. Misc: - Improvements and refactoring all over networking selftests. - Create uniform module aliases for TC classifiers, actions, and packet schedulers to simplify creating modprobe policies. - Address all missing MODULE_DESCRIPTION() warnings in networking. - Extend the Netlink descriptions in YAML to cover message encapsulation or "Netlink polymorphism", where interpretation of nested attributes depends on link type, classifier type or some other "class type". Drivers: - Ethernet high-speed NICs: - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF. - Intel (100G, ice, idpf): - support E825-C devices - nVidia/Mellanox: - support devices with one port and multiple PCIe links - Broadcom (bnxt): - support n-tuple filters - support configuring the RSS key - Wangxun (ngbe/txgbe): - implement irq_domain for TXGBE's sub-interrupts - Pensando/AMD: - support XDP - optimize queue submission and wakeup handling (+17% bps) - optimize struct layout, saving 28% of memory on queues - Ethernet NICs embedded and virtual: - Google cloud vNIC: - refactor driver to perform memory allocations for new queue config before stopping and freeing the old queue memory - Synopsys (stmmac): - obey queueMaxSDU and implement counters required by 802.1Qbv - Renesas (ravb): - support packet checksum offload - suspend to RAM and runtime PM support - Ethernet switches: - nVidia/Mellanox: - support for nexthop group statistics - Microchip: - ksz8: implement PHY loopback - add support for KSZ8567, a 7-port 10/100Mbps switch - PTP: - New driver for RENESAS FemtoClock3 Wireless clock generator. - Support OCP PTP cards designed and built by Adva. - CAN: - Support recvmsg() flags for own, local and remote traffic on CAN BCM sockets. - Support for esd GmbH PCIe/402 CAN device family. - m_can: - Rx/Tx submission coalescing - wake on frame Rx - WiFi: - Intel (iwlwifi): - enable signaling and payload protected A-MSDUs - support wider-bandwidth OFDMA - support for new devices - bump FW API to 89 for AX devices; 90 for BZ/SC devices - MediaTek (mt76): - mt7915: newer ADIE version support - mt7925: radio temperature sensor support - Qualcomm (ath11k): - support 6 GHz station power modes: Low Power Indoor (LPI), Standard Power) SP and Very Low Power (VLP) - QCA6390 & WCN6855: support 2 concurrent station interfaces - QCA2066 support - Qualcomm (ath12k): - refactoring in preparation for Multi-Link Operation (MLO) support - 1024 Block Ack window size support - firmware-2.bin support - support having multiple identical PCI devices (firmware needs to have ATH12K_FW_FEATURE_MULTI_QRTR_ID) - QCN9274: support split-PHY devices - WCN7850: enable Power Save Mode in station mode - WCN7850: P2P support - RealTek: - rtw88: support for more rtw8811cu and rtw8821cu devices - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL - rtlwifi: speed up USB firmware initialization - rtwl8xxxu: - RTL8188F: concurrent interface support - Channel Switch Announcement (CSA) support in AP mode - Broadcom (brcmfmac): - per-vendor feature support - per-vendor SAE password setup - DMI nvram filename quirk for ACEPC W5 Pro" * tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2255 commits) nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y nexthop: Fix out-of-bounds access during attribute validation nexthop: Only parse NHA_OP_FLAGS for dump messages that require it nexthop: Only parse NHA_OP_FLAGS for get messages that require it bpf: move sleepable flag from bpf_prog_aux to bpf_prog bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes() selftests/bpf: Add kprobe multi triggering benchmarks ptp: Move from simple ida to xarray vxlan: Remove generic .ndo_get_stats64 vxlan: Do not alloc tstats manually devlink: Add comments to use netlink gen tool nfp: flower: handle acti_netdevs allocation failure net/packet: Add getsockopt support for PACKET_COPY_THRESH net/netlink: Add getsockopt support for NETLINK_LISTEN_ALL_NSID selftests/bpf: Add bpf_arena_htab test. selftests/bpf: Add bpf_arena_list test. selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages bpf: Add helper macro bpf_addr_space_cast() libbpf: Recognize __arena global variables. bpftool: Recognize arena map type ... |
||
Steven Rostedt (Google)
|
2aa043a55b |
tracing/ring-buffer: Fix wait_on_pipe() race
When the trace_pipe_raw file is closed, there should be no new readers on
the file descriptor. This is mostly handled with the waking and wait_index
fields of the iterator. But there's still a slight race.
CPU 0 CPU 1
----- -----
wait_index++;
index = wait_index;
ring_buffer_wake_waiters();
wait_on_pipe()
ring_buffer_wait();
The ring_buffer_wait() will miss the wakeup from CPU 1. The problem is
that the ring_buffer_wait() needs the logic of:
prepare_to_wait();
if (!condition)
schedule();
Where the missing condition check is the iter->wait_index update.
Have the ring_buffer_wait() take a conditional callback function and a
data parameter that can be used within the wait_event_interruptible() of
the ring_buffer_wait() function.
In wait_on_pipe(), pass a condition function that will check if the
wait_index has been updated, if it has, it will return true to break out
of the wait_event_interruptible() loop.
Create a new field "closed" in the trace_iterator and set it in the
.flush() callback before calling ring_buffer_wake_waiters().
This will keep any new readers from waiting on a closed file descriptor.
Have the wait_on_pipe() condition callback also check the closed field.
Change the wait_index field of the trace_iterator to atomic_t. There's no
reason it needs to be 'long' and making it atomic and using
atomic_read_acquire() and atomic_fetch_inc_release() will provide the
necessary memory barriers.
Add a "woken" flag to tracing_buffers_splice_read() to exit the loop after
one more try to fetch data. That is, if it waited for data and something
woke it up, it should try to collect any new data and then exit back to
user space.
Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wgsNgewHFxZAJiAQznwPMqEtQmi1waeS2O1v6L4c_Um5A@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240312121703.557950713@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes:
|
||
Steven Rostedt (Google)
|
7af9ded0c2 |
ring-buffer: Use wait_event_interruptible() in ring_buffer_wait()
Convert ring_buffer_wait() over to wait_event_interruptible(). The default
condition is to execute the wait loop inside __wait_event() just once.
This does not change the ring_buffer_wait() prototype yet, but
restructures the code so that it can take a "cond" and "data" parameter
and will call wait_event_interruptible() with a helper function as the
condition.
The helper function (rb_wait_cond) takes the cond function and data
parameters. It will first check if the buffer hit the watermark defined by
the "full" parameter and then call the passed in condition parameter. If
either are true, it returns true.
If rb_wait_cond() does not return true, it will set the appropriate
"waiters_pending" flag and returns false.
Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wgsNgewHFxZAJiAQznwPMqEtQmi1waeS2O1v6L4c_Um5A@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240312121703.399598519@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes:
|
||
Steven Rostedt (Google)
|
e36f19a645 |
ring-buffer: Reuse rb_watermark_hit() for the poll logic
The check for knowing if the poll should wait or not is basically the exact same logic as rb_watermark_hit(). The only difference is that rb_watermark_hit() also handles the !full case. But for the full case, the logic is the same. Just call that instead of duplicating the code in ring_buffer_poll_wait(). Link: https://lore.kernel.org/linux-trace-kernel/20240312131952.802267543@goodmis.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
Steven Rostedt (Google)
|
8145f1c35f |
ring-buffer: Fix full_waiters_pending in poll
If a reader of the ring buffer is doing a poll, and waiting for the ring
buffer to hit a specific watermark, there could be a case where it gets
into an infinite ping-pong loop.
The poll code has:
rbwork->full_waiters_pending = true;
if (!cpu_buffer->shortest_full ||
cpu_buffer->shortest_full > full)
cpu_buffer->shortest_full = full;
The writer will see full_waiters_pending and check if the ring buffer is
filled over the percentage of the shortest_full value. If it is, it calls
an irq_work to wake up all the waiters.
But the code could get into a circular loop:
CPU 0 CPU 1
----- -----
[ Poll ]
[ shortest_full = 0 ]
rbwork->full_waiters_pending = true;
if (rbwork->full_waiters_pending &&
[ buffer percent ] > shortest_full) {
rbwork->wakeup_full = true;
[ queue_irqwork ]
cpu_buffer->shortest_full = full;
[ IRQ work ]
if (rbwork->wakeup_full) {
cpu_buffer->shortest_full = 0;
wakeup poll waiters;
[woken]
if ([ buffer percent ] > full)
break;
rbwork->full_waiters_pending = true;
if (rbwork->full_waiters_pending &&
[ buffer percent ] > shortest_full) {
rbwork->wakeup_full = true;
[ queue_irqwork ]
cpu_buffer->shortest_full = full;
[ IRQ work ]
if (rbwork->wakeup_full) {
cpu_buffer->shortest_full = 0;
wakeup poll waiters;
[woken]
[ Wash, rinse, repeat! ]
In the poll, the shortest_full needs to be set before the
full_pending_waiters, as once that is set, the writer will compare the
current shortest_full (which is incorrect) to decide to call the irq_work,
which will reset the shortest_full (expecting the readers to update it).
Also move the setting of full_waiters_pending after the check if the ring
buffer has the required percentage filled. There's no reason to tell the
writer to wake up waiters if there are no waiters.
Link: https://lore.kernel.org/linux-trace-kernel/20240312131952.630922155@goodmis.org
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes:
|
||
Steven Rostedt (Google)
|
761d9473e2 |
ring-buffer: Do not set shortest_full when full target is hit
The rb_watermark_hit() checks if the amount of data in the ring buffer is
above the percentage level passed in by the "full" variable. If it is, it
returns true.
But it also sets the "shortest_full" field of the cpu_buffer that informs
writers that it needs to call the irq_work if the amount of data on the
ring buffer is above the requested amount.
The rb_watermark_hit() always sets the shortest_full even if the amount in
the ring buffer is what it wants. As it is not going to wait, because it
has what it wants, there's no reason to set shortest_full.
Link: https://lore.kernel.org/linux-trace-kernel/20240312115641.6aa8ba08@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes:
|
||
Linus Torvalds
|
685d982112 |
Core x86 changes for v6.9:
- The biggest change is the rework of the percpu code, to support the 'Named Address Spaces' GCC feature, by Uros Bizjak: - This allows C code to access GS and FS segment relative memory via variables declared with such attributes, which allows the compiler to better optimize those accesses than the previous inline assembly code. - The series also includes a number of micro-optimizations for various percpu access methods, plus a number of cleanups of %gs accesses in assembly code. - These changes have been exposed to linux-next testing for the last ~5 months, with no known regressions in this area. - Fix/clean up __switch_to()'s broken but accidentally working handling of FPU switching - which also generates better code. - Propagate more RIP-relative addressing in assembly code, to generate slightly better code. - Rework the CPU mitigations Kconfig space to be less idiosyncratic, to make it easier for distros to follow & maintain these options. - Rework the x86 idle code to cure RCU violations and to clean up the logic. - Clean up the vDSO Makefile logic. - Misc cleanups and fixes. [ Please note that there's a higher number of merge commits in this branch (three) than is usual in x86 topic trees. This happened due to the long testing lifecycle of the percpu changes that involved 3 merge windows, which generated a longer history and various interactions with other core x86 changes that we felt better about to carry in a single branch. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmXvB0gRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1jUqRAAqnEQPiabF5acQlHrwviX+cjSobDlqtH5 9q2AQy9qaEHapzD0XMOxvFye6XIvehGOGxSPvk6CoviSxBND8rb56lvnsEZuLeBV Bo5QSIL2x42Zrvo11iPHwgXZfTIusU90sBuKDRFkYBAxY3HK2naMDZe8MAsYCUE9 nwgHF8DDc/NYiSOXV8kosWoWpNIkoK/STyH5bvTQZMqZcwyZ49AIeP1jGZb/prbC e/rbnlrq5Eu6brpM7xo9kELO0Vhd34urV14KrrIpdkmUKytW2KIsyvW8D6fqgDBj NSaQLLcz0pCXbhF+8Nqvdh/1coR4L7Ymt08P1rfEjCsQgb/2WnSAGUQuC5JoGzaj ngkbFcZllIbD9gNzMQ1n4Aw5TiO+l9zxCqPC/r58Uuvstr+K9QKlwnp2+B3Q73Ft rojIJ04NJL6lCHdDgwAjTTks+TD2PT/eBWsDfJ/1pnUWttmv9IjMpnXD5sbHxoiU 2RGGKnYbxXczYdq/ALYDWM6JXpfnJZcXL3jJi0IDcCSsb92xRvTANYFHnTfyzGfw EHkhbF4e4Vy9f6QOkSP3CvW5H26BmZS9DKG0J9Il5R3u2lKdfbb5vmtUmVTqHmAD Ulo5cWZjEznlWCAYSI/aIidmBsp9OAEvYd+X7Z5SBIgTfSqV7VWHGt0BfA1heiVv F/mednG0gGc= =3v4F -----END PGP SIGNATURE----- Merge tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core x86 updates from Ingo Molnar: - The biggest change is the rework of the percpu code, to support the 'Named Address Spaces' GCC feature, by Uros Bizjak: - This allows C code to access GS and FS segment relative memory via variables declared with such attributes, which allows the compiler to better optimize those accesses than the previous inline assembly code. - The series also includes a number of micro-optimizations for various percpu access methods, plus a number of cleanups of %gs accesses in assembly code. - These changes have been exposed to linux-next testing for the last ~5 months, with no known regressions in this area. - Fix/clean up __switch_to()'s broken but accidentally working handling of FPU switching - which also generates better code - Propagate more RIP-relative addressing in assembly code, to generate slightly better code - Rework the CPU mitigations Kconfig space to be less idiosyncratic, to make it easier for distros to follow & maintain these options - Rework the x86 idle code to cure RCU violations and to clean up the logic - Clean up the vDSO Makefile logic - Misc cleanups and fixes * tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/idle: Select idle routine only once x86/idle: Let prefer_mwait_c1_over_halt() return bool x86/idle: Cleanup idle_setup() x86/idle: Clean up idle selection x86/idle: Sanitize X86_BUG_AMD_E400 handling sched/idle: Conditionally handle tick broadcast in default_idle_call() x86: Increase brk randomness entropy for 64-bit systems x86/vdso: Move vDSO to mmap region x86/vdso/kbuild: Group non-standard build attributes and primary object file rules together x86/vdso: Fix rethunk patching for vdso-image-{32,64}.o x86/retpoline: Ensure default return thunk isn't used at runtime x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32 x86/vdso: Use $(addprefix ) instead of $(foreach ) x86/vdso: Simplify obj-y addition x86/vdso: Consolidate targets and clean-files x86/bugs: Rename CONFIG_RETHUNK => CONFIG_MITIGATION_RETHUNK x86/bugs: Rename CONFIG_CPU_SRSO => CONFIG_MITIGATION_SRSO x86/bugs: Rename CONFIG_CPU_IBRS_ENTRY => CONFIG_MITIGATION_IBRS_ENTRY x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY => CONFIG_MITIGATION_UNRET_ENTRY x86/bugs: Rename CONFIG_SLS => CONFIG_MITIGATION_SLS ... |
||
Jakub Kicinski
|
5f20e6ab1f |
for-netdev
-----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE+soXsSLHKoYyzcli6rmadz2vbToFAmXvm7IACgkQ6rmadz2v bTqdMA//VMHNHVLb4oROoXyQD9fw2mCmIUEKzP88RXfqcxsfEX7HF+k8B5ZTk0ro CHXTAnc79+Qqg0j24bkQKxup/fKBQVw9D+Ia4b3ytlm1I2MtyU/16xNEzVhAPU2D iKk6mVBsEdCbt/GjpWORy/VVnZlZpC7BOpZLxsbbxgXOndnCegyjXzSnLGJGxdvi zkrQTn2SrFzLi6aNpVLqrv6Nks6HJusfCKsIrtlbkQ85dulasHOtwK9s6GF60nte aaho+MPx3L+lWEgapsm8rR779pHaYIB/GbZUgEPxE/xUJ/V8BzDgFNLMzEiIBRMN a0zZam11BkBzCfcO9gkvDRByaei/dZz2jdqfU4GlHklFj1WFfz8Q7fRLEPINksvj WXLgJADGY5mtGbjG21FScThxzj+Ruqwx0a13ddlyI/W+P3y5yzSWsLwJG5F9p0oU 6nlkJ4U8yg+9E1ie5ae0TibqvRJzXPjfOERZGwYDSVvfQGzv1z+DGSOPMmgNcWYM dIaO+A/+NS3zdbk8+1PP2SBbhHPk6kWyCUByWc7wMzCPTiwriFGY/DD2sN+Fsufo zorzfikUQOlTfzzD5jbmT49U8hUQUf6QIWsu7BijSiHaaC7am4S8QB2O6ibJMqdv yNiwvuX+ThgVIY3QKrLLqL0KPGeKMR5mtfq6rrwSpfp/b4g27FE= =eFgA -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Alexei Starovoitov says: ==================== pull-request: bpf-next 2024-03-11 We've added 59 non-merge commits during the last 9 day(s) which contain a total of 88 files changed, 4181 insertions(+), 590 deletions(-). The main changes are: 1) Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce VM_SPARSE kind and vm_area_[un]map_pages to be used in bpf_arena, from Alexei. 2) Introduce bpf_arena which is sparse shared memory region between bpf program and user space where structures inside the arena can have pointers to other areas of the arena, and pointers work seamlessly for both user-space programs and bpf programs, from Alexei and Andrii. 3) Introduce may_goto instruction that is a contract between the verifier and the program. The verifier allows the program to loop assuming it's behaving well, but reserves the right to terminate it, from Alexei. 4) Use IETF format for field definitions in the BPF standard document, from Dave. 5) Extend struct_ops libbpf APIs to allow specify version suffixes for stuct_ops map types, share the same BPF program between several map definitions, and other improvements, from Eduard. 6) Enable struct_ops support for more than one page in trampolines, from Kui-Feng. 7) Support kCFI + BPF on riscv64, from Puranjay. 8) Use bpf_prog_pack for arm64 bpf trampoline, from Puranjay. 9) Fix roundup_pow_of_two undefined behavior on 32-bit archs, from Toke. ==================== Link: https://lore.kernel.org/r/20240312003646.8692-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
||
Andrii Nakryiko
|
66c8473135 |
bpf: move sleepable flag from bpf_prog_aux to bpf_prog
prog->aux->sleepable is checked very frequently as part of (some) BPF program run hot paths. So this extra aux indirection seems wasteful and on busy systems might cause unnecessary memory cache misses. Let's move sleepable flag into prog itself to eliminate unnecessary pointer dereference. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Message-ID: <20240309004739.2961431-1-andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
Linus Torvalds
|
fa4b851b4a |
Tracing fixes for v6.8-rc7:
- Do not allow large strings (> 4096) as single write to trace_marker The size of a string written into trace_marker was determined by the size of the sub-buffer in the ring buffer. That size is dependent on the PAGE_SIZE of the architecture as it can be mapped into user space. But on PowerPC, where PAGE_SIZE is 64K, that made the limit of the string of writing into trace_marker 64K. One of the selftests looks at the size of the ring buffer sub-buffers and writes that plus more into the trace_marker. The write will take what it can and report back what it consumed so that the user space application (like echo) will write the rest of the string. The string is stored in the ring buffer and can be read via the "trace" or "trace_pipe" files. The reading of the ring buffer uses vsnprintf(), which uses a precision "%.*s" to make sure it only reads what is stored in the buffer, as a bug could cause the string to be non terminated. With the combination of the precision change and the PAGE_SIZE of 64K allowing huge strings to be added into the ring buffer, plus the test that would actually stress that limit, a bug was reported that the precision used was too big for "%.*s" as the string was close to 64K in size and the max precision of vsnprintf is 32K. Linus suggested not to have that precision as it could hide a bug if the string was again stored without a nul byte. Another issue that was brought up is that the trace_seq buffer is also based on PAGE_SIZE even though it is not tied to the architecture limit like the ring buffer sub-buffer is. Having it be 64K * 2 is simply just too big and wasting memory on systems with 64K page sizes. It is now hardcoded to 8K which is what all other architectures with 4K PAGE_SIZE has. Finally, the write to trace_marker is now limited to 4K as there is no reason to write larger strings into trace_marker. - ring_buffer_wait() should not loop. The ring_buffer_wait() does not have the full context (yet) on if it should loop or not. Just exit the loop as soon as its woken up and let the callers decide to loop or not (they already do, so it's a bit redundant). - Fix shortest_full field to be the smallest amount in the ring buffer that a waiter is waiting for. The "shortest_full" field is updated when a new waiter comes in and wants to wait for a smaller amount of data in the ring buffer than other waiters. But after all waiters are woken up, it's not reset, so if another waiter comes in wanting to wait for more data, it will be woken up when the ring buffer has a smaller amount from what the previous waiters were waiting for. - The wake up all waiters on close is incorrectly called frome .release() and not from .flush() so it will never wake up any waiters as the .release() will not get called until all .read() calls are finished. And the wakeup is for the waiters in those .read() calls. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZe3j6xQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qmYOAQD6rPZ+ILqHmRQMZjsxaasBeVYidspY wj3fRGzwfiB6fgEAkIeA7FOrkOK0CuG8R+2AtQNF5ZjXdmfZdiYQD1/EjQU= =Hqlf -----END PGP SIGNATURE----- Merge tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Do not allow large strings (> 4096) as single write to trace_marker The size of a string written into trace_marker was determined by the size of the sub-buffer in the ring buffer. That size is dependent on the PAGE_SIZE of the architecture as it can be mapped into user space. But on PowerPC, where PAGE_SIZE is 64K, that made the limit of the string of writing into trace_marker 64K. One of the selftests looks at the size of the ring buffer sub-buffers and writes that plus more into the trace_marker. The write will take what it can and report back what it consumed so that the user space application (like echo) will write the rest of the string. The string is stored in the ring buffer and can be read via the "trace" or "trace_pipe" files. The reading of the ring buffer uses vsnprintf(), which uses a precision "%.*s" to make sure it only reads what is stored in the buffer, as a bug could cause the string to be non terminated. With the combination of the precision change and the PAGE_SIZE of 64K allowing huge strings to be added into the ring buffer, plus the test that would actually stress that limit, a bug was reported that the precision used was too big for "%.*s" as the string was close to 64K in size and the max precision of vsnprintf is 32K. Linus suggested not to have that precision as it could hide a bug if the string was again stored without a nul byte. Another issue that was brought up is that the trace_seq buffer is also based on PAGE_SIZE even though it is not tied to the architecture limit like the ring buffer sub-buffer is. Having it be 64K * 2 is simply just too big and wasting memory on systems with 64K page sizes. It is now hardcoded to 8K which is what all other architectures with 4K PAGE_SIZE has. Finally, the write to trace_marker is now limited to 4K as there is no reason to write larger strings into trace_marker. - ring_buffer_wait() should not loop. The ring_buffer_wait() does not have the full context (yet) on if it should loop or not. Just exit the loop as soon as its woken up and let the callers decide to loop or not (they already do, so it's a bit redundant). - Fix shortest_full field to be the smallest amount in the ring buffer that a waiter is waiting for. The "shortest_full" field is updated when a new waiter comes in and wants to wait for a smaller amount of data in the ring buffer than other waiters. But after all waiters are woken up, it's not reset, so if another waiter comes in wanting to wait for more data, it will be woken up when the ring buffer has a smaller amount from what the previous waiters were waiting for. - The wake up all waiters on close is incorrectly called frome .release() and not from .flush() so it will never wake up any waiters as the .release() will not get called until all .read() calls are finished. And the wakeup is for the waiters in those .read() calls. * tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Use .flush() call to wake up readers ring-buffer: Fix resetting of shortest_full ring-buffer: Fix waking up ring buffer readers tracing: Limit trace_marker writes to just 4K tracing: Limit trace_seq size to just 8K and not depend on architecture PAGE_SIZE tracing: Remove precision vsnprintf() check from print event |
||
Steven Rostedt (Google)
|
e5d7c19165 |
tracing: Use .flush() call to wake up readers
The .release() function does not get called until all readers of a file
descriptor are finished.
If a thread is blocked on reading a file descriptor in ring_buffer_wait(),
and another thread closes the file descriptor, it will not wake up the
other thread as ring_buffer_wake_waiters() is called by .release(), and
that will not get called until the .read() is finished.
The issue originally showed up in trace-cmd, but the readers are actually
other processes with their own file descriptors. So calling close() would wake
up the other tasks because they are blocked on another descriptor then the
one that was closed(). But there's other wake ups that solve that issue.
When a thread is blocked on a read, it can still hang even when another
thread closed its descriptor.
This is what the .flush() callback is for. Have the .flush() wake up the
readers.
Link: https://lore.kernel.org/linux-trace-kernel/20240308202432.107909457@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes:
|
||
Steven Rostedt (Google)
|
68282dd930 |
ring-buffer: Fix resetting of shortest_full
The "shortest_full" variable is used to keep track of the waiter that is
waiting for the smallest amount on the ring buffer before being woken up.
When a tasks waits on the ring buffer, it passes in a "full" value that is
a percentage. 0 means wake up on any data. 1-100 means wake up from 1% to
100% full buffer.
As all waiters are on the same wait queue, the wake up happens for the
waiter with the smallest percentage.
The problem is that the smallest_full on the cpu_buffer that stores the
smallest amount doesn't get reset when all the waiters are woken up. It
does get reset when the ring buffer is reset (echo > /sys/kernel/tracing/trace).
This means that tasks may be woken up more often then when they want to
be. Instead, have the shortest_full field get reset just before waking up
all the tasks. If the tasks wait again, they will update the shortest_full
before sleeping.
Also add locking around setting of shortest_full in the poll logic, and
change "work" to "rbwork" to match the variable name for rb_irq_work
structures that are used in other places.
Link: https://lore.kernel.org/linux-trace-kernel/20240308202431.948914369@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes:
|
||
Steven Rostedt (Google)
|
b359457368 |
ring-buffer: Fix waking up ring buffer readers
A task can wait on a ring buffer for when it fills up to a specific
watermark. The writer will check the minimum watermark that waiters are
waiting for and if the ring buffer is past that, it will wake up all the
waiters.
The waiters are in a wait loop, and will first check if a signal is
pending and then check if the ring buffer is at the desired level where it
should break out of the loop.
If a file that uses a ring buffer closes, and there's threads waiting on
the ring buffer, it needs to wake up those threads. To do this, a
"wait_index" was used.
Before entering the wait loop, the waiter will read the wait_index. On
wakeup, it will check if the wait_index is different than when it entered
the loop, and will exit the loop if it is. The waker will only need to
update the wait_index before waking up the waiters.
This had a couple of bugs. One trivial one and one broken by design.
The trivial bug was that the waiter checked the wait_index after the
schedule() call. It had to be checked between the prepare_to_wait() and
the schedule() which it was not.
The main bug is that the first check to set the default wait_index will
always be outside the prepare_to_wait() and the schedule(). That's because
the ring_buffer_wait() doesn't have enough context to know if it should
break out of the loop.
The loop itself is not needed, because all the callers to the
ring_buffer_wait() also has their own loop, as the callers have a better
sense of what the context is to decide whether to break out of the loop
or not.
Just have the ring_buffer_wait() block once, and if it gets woken up, exit
the function and let the callers decide what to do next.
Link: https://lore.kernel.org/all/CAHk-=whs5MdtNjzFkTyaUy=vHi=qwWgPi0JgTe6OYUYMNSRZfg@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240308202431.792933613@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes:
|
||
Jakub Kicinski
|
e3afe5dd3a |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: net/core/page_pool_user.c |
||
Steven Rostedt (Google)
|
095fe48912 |
tracing: Limit trace_marker writes to just 4K
Limit the max print event of trace_marker to just 4K string size. This must also be less than the amount that can be held by a trace_seq along with the text that is before the output (like the task name, PID, CPU, state, etc). As trace_seq is made to handle large events (some greater than 4K). Make the max size of a trace_marker write event be 4K which is guaranteed to fit in the trace_seq buffer. Link: https://lore.kernel.org/linux-trace-kernel/20240304223433.4ba47dff@gandalf.local.home Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
Steven Rostedt (Google)
|
5efd3e2aef |
tracing: Remove precision vsnprintf() check from print event
This reverts |
||
Masami Hiramatsu (Google)
|
25f00e40ce |
tracing/probes: Support $argN in return probe (kprobe and fprobe)
Support accessing $argN in the return probe events. This will help users to record entry data in function return (exit) event for simplfing the function entry/exit information in one event, and record the result values (e.g. allocated object/initialized object) at function exit. For example, if we have a function `int init_foo(struct foo *obj, int param)` sometimes we want to check how `obj` is initialized. In such case, we can define a new return event like below; # echo 'r init_foo retval=$retval param=$arg2 field1=+0($arg1)' >> kprobe_events Thus it records the function parameter `param` and its result `obj->field1` (the dereference will be done in the function exit timing) value at once. This also support fprobe, BTF args and'$arg*'. So if CONFIG_DEBUG_INFO_BTF is enabled, we can trace both function parameters and the return value by following command. # echo 'f target_function%return $arg* $retval' >> dynamic_events Link: https://lore.kernel.org/all/170952365552.229804.224112990211602895.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> |
||
Masami Hiramatsu (Google)
|
c18f9eabee |
tracing: Remove redundant #else block for BTF args from README
Remove redundant #else block for BTF args from README message. This is a cleanup, so no change on the message. Link: https://lore.kernel.org/all/170952364558.229804.17285528811097152410.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
Masami Hiramatsu (Google)
|
035ba76014 |
tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init
Instead of incrementing the trace_probe::nr_args, init it at trace_probe_init(). Without this change, there is no way to get the number of trace_probe arguments while parsing it. This is a cleanup, so the behavior is not changed. Link: https://lore.kernel.org/all/170952363585.229804.13060759900346411951.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> |
||
Masami Hiramatsu (Google)
|
032330abd0 |
tracing/probes: Cleanup probe argument parser
Cleanup traceprobe_parse_probe_arg_body() to split out the type parser and post-processing part of fetch_insn. This makes no functional change. Link: https://lore.kernel.org/all/170952362603.229804.9942703761682605372.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
Masami Hiramatsu (Google)
|
7e37b6bc3c |
tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event
Despite the fprobe event, "Kretprobe" was commented. So fix it. Link: https://lore.kernel.org/all/170952361630.229804.10832200172327797860.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
Jakub Kicinski
|
4b2765ae41 |
bpf-next-for-netdev
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZeEKVAAKCRDbK58LschI g7oYAQD5Jlv4fIVTvxvfZrTTZ2tU+OsPa75mc8SDKwpash3YygEA8kvESy8+t6pg D6QmSf1DIZdFoSp/bV+pfkNWMeR8gwg= =mTAj -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2024-02-29 We've added 119 non-merge commits during the last 32 day(s) which contain a total of 150 files changed, 3589 insertions(+), 995 deletions(-). The main changes are: 1) Extend the BPF verifier to enable static subprog calls in spin lock critical sections, from Kumar Kartikeya Dwivedi. 2) Fix confusing and incorrect inference of PTR_TO_CTX argument type in BPF global subprogs, from Andrii Nakryiko. 3) Larger batch of riscv BPF JIT improvements and enabling inlining of the bpf_kptr_xchg() for RV64, from Pu Lehui. 4) Allow skeleton users to change the values of the fields in struct_ops maps at runtime, from Kui-Feng Lee. 5) Extend the verifier's capabilities of tracking scalars when they are spilled to stack, especially when the spill or fill is narrowing, from Maxim Mikityanskiy & Eduard Zingerman. 6) Various BPF selftest improvements to fix errors under gcc BPF backend, from Jose E. Marchesi. 7) Avoid module loading failure when the module trying to register a struct_ops has its BTF section stripped, from Geliang Tang. 8) Annotate all kfuncs in .BTF_ids section which eventually allows for automatic kfunc prototype generation from bpftool, from Daniel Xu. 9) Several updates to the instruction-set.rst IETF standardization document, from Dave Thaler. 10) Shrink the size of struct bpf_map resp. bpf_array, from Alexei Starovoitov. 11) Initial small subset of BPF verifier prepwork for sleepable bpf_timer, from Benjamin Tissoires. 12) Fix bpftool to be more portable to musl libc by using POSIX's basename(), from Arnaldo Carvalho de Melo. 13) Add libbpf support to gcc in CORE macro definitions, from Cupertino Miranda. 14) Remove a duplicate type check in perf_event_bpf_event, from Florian Lehner. 15) Fix bpf_spin_{un,}lock BPF helpers to actually annotate them with notrace correctly, from Yonghong Song. 16) Replace the deprecated bpf_lpm_trie_key 0-length array with flexible array to fix build warnings, from Kees Cook. 17) Fix resolve_btfids cross-compilation to non host-native endianness, from Viktor Malik. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits) selftests/bpf: Test if shadow types work correctly. bpftool: Add an example for struct_ops map and shadow type. bpftool: Generated shadow variables for struct_ops maps. libbpf: Convert st_ops->data to shadow type. libbpf: Set btf_value_type_id of struct bpf_map for struct_ops. bpf: Replace bpf_lpm_trie_key 0-length array with flexible array bpf, arm64: use bpf_prog_pack for memory management arm64: patching: implement text_poke API bpf, arm64: support exceptions arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT bpf: add is_async_callback_calling_insn() helper bpf: introduce in_sleepable() helper bpf: allow more maps in sleepable bpf programs selftests/bpf: Test case for lacking CFI stub functions. bpf: Check cfi_stubs before registering a struct_ops type. bpf: Clarify batch lookup/lookup_and_delete semantics bpf, docs: specify which BPF_ABS and BPF_IND fields were zero bpf, docs: Fix typos in instruction-set.rst selftests/bpf: update tcp_custom_syncookie to use scalar packet offset bpf: Shrink size of struct bpf_map/bpf_array. ... ==================== Link: https://lore.kernel.org/r/20240301001625.8800-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Linus Torvalds
|
161671a6eb |
Probes fixes for v6.8-rc5:
- fprobe: Fix to allocate entry_data_size buffer for each rethook instance. This fixes a buffer overrun bug (which leads a kernel crash) when fprobe user uses its entry_data in the entry_handler. -----BEGIN PGP SIGNATURE----- iQFPBAABCgA5FiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmXhIPgbHG1hc2FtaS5o aXJhbWF0c3VAZ21haWwuY29tAAoJENv7B78FKz8bhwIH/1h5q2ZqNwNplDGVQpWU G1uuRHLlt47jwbGR3gfeYqVELtX0gFigBsmVouCKK3u3qerB1pDscYhULzKeHjS4 1HAsonj+vKY2pbdCaRnxRT7ejlEioN8CwPb1eqY6Bf6XQ2tJqS5gUqdej8JDJuY5 tpNAhHWqAnRvf1V5muclGAIU+9zavrAjbetpgrPEDIjE5idFvN+6D+4PXiM1cRIW KXW1oA7VlShdfY7xprSZ33Lx7C/dLWojM2P/z/BvqyXOf4f1ovqtGFJegW4n7V5b ZgamgOcSBwFLTVOTpOzn0peucduLFTfEWyC7fFGkHjBxTl2JypsQLEupdoaWLvBB el4= =bUgZ -----END PGP SIGNATURE----- Merge tag 'probes-fixes-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull fprobe fix from Masami Hiramatsu: - allocate entry_data_size buffer for each rethook instance. This fixes a buffer overrun bug (which leads a kernel crash) when fprobe user uses its entry_data in the entry_handler. * tag 'probes-fixes-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: fprobe: Fix to allocate entry_data_size buffer with rethook instances |
||
Masami Hiramatsu (Google)
|
6572786006 |
fprobe: Fix to allocate entry_data_size buffer with rethook instances
Fix to allocate fprobe::entry_data_size buffer with rethook instances.
If fprobe doesn't allocate entry_data_size buffer for each rethook instance,
fprobe entry handler can cause a buffer overrun when storing entry data in
entry handler.
Link: https://lore.kernel.org/all/170920576727.107552.638161246679734051.stgit@devnote2/
Reported-by: Jiri Olsa <olsajiri@gmail.com>
Closes: https://lore.kernel.org/all/Zd9eBn2FTQzYyg7L@krava/
Fixes:
|
||
Jakub Kicinski
|
fecc51559a |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR. Conflicts: net/ipv4/udp.c |
||
Steven Rostedt (Google)
|
e78fb4eac8 |
ring-buffer: Do not let subbuf be bigger than write mask
The data on the subbuffer is measured by a write variable that also
contains status flags. The counter is just 20 bits in length. If the
subbuffer is bigger than then counter, it will fail.
Make sure that the subbuffer can not be set to greater than the counter
that keeps track of the data on the subbuffer.
Link: https://lore.kernel.org/linux-trace-kernel/20240220095112.77e9cb81@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes:
|
||
Linus Torvalds
|
ad645dea35 |
Probes fixes for v6.8-rc4:
- tracing/probes: Fix BTF structure member finder to find the members which are placed after any anonymous union member correctly. -----BEGIN PGP SIGNATURE----- iQFPBAABCgA5FiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmXQqH8bHG1hc2FtaS5o aXJhbWF0c3VAZ21haWwuY29tAAoJENv7B78FKz8bKCsH/3EWGLBbwNMFFje+t2Bp L6LgeyG7ZUzeDb4ioO2bae++e3m7xtR7YAWbZoX193/BfPbBpr9rkUCfYqAaImBk dzdI+E8/gOkliLP0Vvj5GIecKDUdlB053NRgoOcq0n1NYOO3/4kyPZ+53tX5gsBI YNcdIKDdEVWX0+vinK6cCjWOLdVJc/8pH/6G2KNgG6Qs2T1dV0YzW5QRv1hhUOr3 1Obog64AFt7tVtIkGOK19gRJKa6VpysdD8wpekJnKfquTtFffrsgf4yTg84zf7Fe ueaOtJ7pV4R0SbQ/n5SnXe5cxXjX7MD24FZaeHCB7mp8sOsdeTukFmSTsIgOFeD/ cBQ= =KY+B -----END PGP SIGNATURE----- Merge tag 'probes-fixes-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull probes fix from Masami Hiramatsu: - tracing/probes: Fix BTF structure member finder to find the members which are placed after any anonymous union member correctly. * tag 'probes-fixes-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/probes: Fix to search structure fields correctly |
||
Masami Hiramatsu (Google)
|
9704669c38 |
tracing/probes: Fix to search structure fields correctly
Fix to search a field from the structure which has anonymous union
correctly.
Since the reference `type` pointer was updated in the loop, the search
loop suddenly aborted where it hits an anonymous union. Thus it can not
find the field after the anonymous union. This avoids updating the
cursor `type` pointer in the loop.
Link: https://lore.kernel.org/all/170791694361.389532.10047514554799419688.stgit@devnote2/
Fixes:
|
||
Linus Torvalds
|
4b6f7c624e |
Tracing fixes for v6.8:
- Fix the #ifndef that didn't have CONFIG_ on HAVE_DYNAMIC_FTRACE_WITH_REGS The fix to have dynamic trampolines work with x86 broke arm64 as the config used in the #ifdef was HAVE_DYNAMIC_FTRACE_WITH_REGS and not CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS which removed the fix that the previous fix was to fix. - Fix tracing_on state The code to test if "tracing_on" is set used ring_buffer_record_is_on() which returns false if the ring buffer isn't able to be written to. But the ring buffer disable has several bits that disable it. One is internal disabling which is used for resizing and other modifications of the ring buffer. But the "tracing_on" user space visible flag should only report if tracing is actually on and not internally disabled, as this can cause confusion as writing "1" when it is disabled will not enable it. Instead use ring_buffer_record_is_set_on() which shows the user space visible settings. - Fix a false positive kmemleak on saved cmdlines Now that the saved_cmdlines structure is allocated via alloc_page() and not via kmalloc() it has become invisible to kmemleak. The allocation done to one of its pointers was flagged as a dangling allocation leak. Make kmemleak aware of this allocation and free. - Fix synthetic event dynamic strings. A update that cleaned up the synthetic event code removed the return value of trace_string(), and had it return zero instead of the length, causing dynamic strings in the synthetic event to always have zero size. - Clean up documentation and header files for seq_buf -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZc92CxQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qiD6AQCCtF9hBWq7slLlBQ+k07hWXOi1h4nR Ae6UmoGlu3u4ugEA6/g8mO2vjABagnK7RSk/R+s1SvSGqWkmAsWeEKirEAY= =Eqjs -----END PGP SIGNATURE----- Merge tag 'trace-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix the #ifndef that didn't have the 'CONFIG_' prefix on HAVE_DYNAMIC_FTRACE_WITH_REGS The fix to have dynamic trampolines work with x86 broke arm64 as the config used in the #ifdef was HAVE_DYNAMIC_FTRACE_WITH_REGS and not CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS which removed the fix that the previous fix was to fix. - Fix tracing_on state The code to test if "tracing_on" is set incorrectly used ring_buffer_record_is_on() which returns false if the ring buffer isn't able to be written to. But the ring buffer disable has several bits that disable it. One is internal disabling which is used for resizing and other modifications of the ring buffer. But the "tracing_on" user space visible flag should only report if tracing is actually on and not internally disabled, as this can cause confusion as writing "1" when it is disabled will not enable it. Instead use ring_buffer_record_is_set_on() which shows the user space visible settings. - Fix a false positive kmemleak on saved cmdlines Now that the saved_cmdlines structure is allocated via alloc_page() and not via kmalloc() it has become invisible to kmemleak. The allocation done to one of its pointers was flagged as a dangling allocation leak. Make kmemleak aware of this allocation and free. - Fix synthetic event dynamic strings An update that cleaned up the synthetic event code removed the return value of trace_string(), and had it return zero instead of the length, causing dynamic strings in the synthetic event to always have zero size. - Clean up documentation and header files for seq_buf * tag 'trace-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: seq_buf: Fix kernel documentation seq_buf: Don't use "proxy" headers tracing/synthetic: Fix trace_string() return value tracing: Inform kmemleak of saved_cmdlines allocation tracing: Use ring_buffer_record_is_set_on() in tracer_tracing_is_on() tracing: Fix HAVE_DYNAMIC_FTRACE_WITH_REGS ifdef |