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trace_btf
Move generic function-proto find API and getting function parameter API
to BTF library code from trace_probe.c. This will avoid redundant efforts
on different feature.
Link: https://lore.kernel.org/all/169272155255.160970.719426926348706349.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Since the btf returned from bpf_get_btf_vmlinux() only covers functions in
the vmlinux, BTF argument is not available on the functions in the modules.
Use bpf_find_btf_id() instead of bpf_get_btf_vmlinux()+btf_find_name_kind()
so that BTF argument can find the correct struct btf and btf_type in it.
With this fix, fprobe events can use `$arg*` on module functions as below
# grep nf_log_ip_packet /proc/kallsyms
ffffffffa0005c00 t nf_log_ip_packet [nf_log_syslog]
ffffffffa0005bf0 t __pfx_nf_log_ip_packet [nf_log_syslog]
# echo 'f nf_log_ip_packet $arg*' > dynamic_events
# cat dynamic_events
f:fprobes/nf_log_ip_packet__entry nf_log_ip_packet net=net pf=pf hooknum=hooknum skb=skb in=in out=out loginfo=loginfo prefix=prefix
To support the module's btf which is removable, the struct btf needs to be
ref-counted. So this also records the btf in the traceprobe_parse_context
and returns the refcount when the parse has done.
Link: https://lore.kernel.org/all/169272154223.160970.3507930084247934031.stgit@devnote2/
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Refer to the description in [1], we can skip "container_of()" following
"list_for_each_entry()" by using "list_for_each_entry()" with
"struct trace_eprobe" and "tp.list".
Also, this patch defines "for_each_trace_eprobe_tp" to simplify the code
of the same logic.
[1] https://lore.kernel.org/all/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com/
Link: https://lore.kernel.org/all/20230822022433.262478-1-nashuiliang@gmail.com/
Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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Several of the list traversals in the user_events facility use safe list
traversals where they could be using the unsafe versions instead.
Replace these safe traversals with their unsafe counterparts in the
interest of optimization.
Link: https://lore.kernel.org/linux-trace-kernel/20230810194337.695983-1-ervaughn@linux.microsoft.com
Suggested-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Eric Vaughn <ervaughn@linux.microsoft.com>
Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Commit 9457158bbc0e ("tracing: Fix reset of time stamps during trace_clock changes")
left behind tracing_reset_current() declaration.
Also commit 6954e415264e ("tracing: Place trace_pid_list logic into abstract functions")
removed trace_free_pid_list() implementation but leave declaration.
Link: https://lore.kernel.org/linux-trace-kernel/20230803144028.25492-1-yuehaibing@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Per the previous commits, we now only enter do_filter_scalar_cpumask() with
a mask of weight greater than one. Optimise the equality checks.
Link: https://lkml.kernel.org/r/20230707172155.70873-9-vschneid@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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single CPU
Steven noted that when the user-provided cpumask contains a single CPU,
then the filtering function can use a scalar as input instead of a
full-fledged cpumask.
In this case we can directly re-use filter_pred_cpu(), we just need to
transform '&' into '==' before executing it.
Link: https://lkml.kernel.org/r/20230707172155.70873-8-vschneid@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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a single CPU
Steven noted that when the user-provided cpumask contains a single CPU,
then the filtering function can use a scalar as input instead of a
full-fledged cpumask.
When the mask contains a single CPU, directly re-use the unsigned field
predicate functions. Transform '&' into '==' beforehand.
Link: https://lkml.kernel.org/r/20230707172155.70873-7-vschneid@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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single CPU
Steven noted that when the user-provided cpumask contains a single CPU,
then the filtering function can use a scalar as input instead of a
full-fledged cpumask.
Reuse do_filter_scalar_cpumask() when the input mask has a weight of one.
Link: https://lkml.kernel.org/r/20230707172155.70873-6-vschneid@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The tracing_cpumask lets us specify which CPUs are traced in a buffer
instance, but doesn't let us do this on a per-event basis (unless one
creates an instance per event).
A previous commit added filtering scalar fields by a user-given cpumask,
make this work with the CPU common field as well.
This enables doing things like
$ trace-cmd record -e 'sched_switch' -f 'CPU & CPUS{12-52}' \
-e 'sched_wakeup' -f 'target_cpu & CPUS{12-52}'
Link: https://lkml.kernel.org/r/20230707172155.70873-5-vschneid@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Several events use a scalar field to denote a CPU:
o sched_wakeup.target_cpu
o sched_migrate_task.orig_cpu,dest_cpu
o sched_move_numa.src_cpu,dst_cpu
o ipi_send_cpu.cpu
o ...
Filtering these currently requires using arithmetic comparison functions,
which can be tedious when dealing with interleaved SMT or NUMA CPU ids.
Allow these to be filtered by a user-provided cpumask, which enables e.g.:
$ trace-cmd record -e 'sched_wakeup' -f 'target_cpu & CPUS{2,4,6,8-32}'
Link: https://lkml.kernel.org/r/20230707172155.70873-4-vschneid@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The recently introduced ipi_send_cpumask trace event contains a cpumask
field, but it currently cannot be used in filter expressions.
Make event filtering aware of cpumask fields, and allow these to be
filtered by a user-provided cpumask.
The user-provided cpumask is to be given in cpulist format and wrapped as:
"CPUS{$cpulist}". The use of curly braces instead of parentheses is to
prevent predicate_parse() from parsing the contents of CPUS{...} as a
full-fledged predicate subexpression.
This enables e.g.:
$ trace-cmd record -e 'ipi_send_cpumask' -f 'cpumask & CPUS{2,4,6,8-32}'
Link: https://lkml.kernel.org/r/20230707172155.70873-3-vschneid@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Every predicate allocation includes a MAX_FILTER_STR_VAL (256) char array
in the regex field, even if the predicate function does not use the field.
A later commit will introduce a dynamically allocated cpumask to struct
filter_pred, which will require a dedicated freeing function. Bite the
bullet and make filter_pred.regex dynamically allocated.
While at it, reorder the fields of filter_pred to fill in the byte
holes. The struct now fits on a single cacheline.
No change in behaviour intended.
The kfree()'s were patched via Coccinelle:
@@
struct filter_pred *pred;
@@
-kfree(pred);
+free_predicate(pred);
Link: https://lkml.kernel.org/r/20230707172155.70873-2-vschneid@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Adding support for bpf_get_func_ip helper being called from
ebpf program attached by uprobe_multi link.
It returns the ip of the uprobe.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230809083440.3209381-7-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Adding support to specify pid for uprobe_multi link and the uprobes
are created only for task with given pid value.
Using the consumer.filter filter callback for that, so the task gets
filtered during the uprobe installation.
We still need to check the task during runtime in the uprobe handler,
because the handler could get executed if there's another system
wide consumer on the same uprobe (thanks Oleg for the insight).
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230809083440.3209381-6-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Adding support to specify cookies array for uprobe_multi link.
The cookies array share indexes and length with other uprobe_multi
arrays (offsets/ref_ctr_offsets).
The cookies[i] value defines cookie for i-the uprobe and will be
returned by bpf_get_attach_cookie helper when called from ebpf
program hooked to that specific uprobe.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230809083440.3209381-5-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Adding new multi uprobe link that allows to attach bpf program
to multiple uprobes.
Uprobes to attach are specified via new link_create uprobe_multi
union:
struct {
__aligned_u64 path;
__aligned_u64 offsets;
__aligned_u64 ref_ctr_offsets;
__u32 cnt;
__u32 flags;
} uprobe_multi;
Uprobes are defined for single binary specified in path and multiple
calling sites specified in offsets array with optional reference
counters specified in ref_ctr_offsets array. All specified arrays
have length of 'cnt'.
The 'flags' supports single bit for now that marks the uprobe as
return probe.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230809083440.3209381-4-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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There is race issue when concurrently splice_read main trace_pipe and
per_cpu trace_pipes which will result in data read out being different
from what actually writen.
As suggested by Steven:
> I believe we should add a ref count to trace_pipe and the per_cpu
> trace_pipes, where if they are opened, nothing else can read it.
>
> Opening trace_pipe locks all per_cpu ref counts, if any of them are
> open, then the trace_pipe open will fail (and releases any ref counts
> it had taken).
>
> Opening a per_cpu trace_pipe will up the ref count for just that
> CPU buffer. This will allow multiple tasks to read different per_cpu
> trace_pipe files, but will prevent the main trace_pipe file from
> being opened.
But because we only need to know whether per_cpu trace_pipe is open or
not, using a cpumask instead of using ref count may be easier.
After this patch, users will find that:
- Main trace_pipe can be opened by only one user, and if it is
opened, all per_cpu trace_pipes cannot be opened;
- Per_cpu trace_pipes can be opened by multiple users, but each per_cpu
trace_pipe can only be opened by one user. And if one of them is
opened, main trace_pipe cannot be opened.
Link: https://lore.kernel.org/linux-trace-kernel/20230818022645.1948314-1-zhengyejian1@huawei.com
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Kmemleak report a leak in graph_trace_open():
unreferenced object 0xffff0040b95f4a00 (size 128):
comm "cat", pid 204981, jiffies 4301155872 (age 99771.964s)
hex dump (first 32 bytes):
e0 05 e7 b4 ab 7d 00 00 0b 00 01 00 00 00 00 00 .....}..........
f4 00 01 10 00 a0 ff ff 00 00 00 00 65 00 10 00 ............e...
backtrace:
[<000000005db27c8b>] kmem_cache_alloc_trace+0x348/0x5f0
[<000000007df90faa>] graph_trace_open+0xb0/0x344
[<00000000737524cd>] __tracing_open+0x450/0xb10
[<0000000098043327>] tracing_open+0x1a0/0x2a0
[<00000000291c3876>] do_dentry_open+0x3c0/0xdc0
[<000000004015bcd6>] vfs_open+0x98/0xd0
[<000000002b5f60c9>] do_open+0x520/0x8d0
[<00000000376c7820>] path_openat+0x1c0/0x3e0
[<00000000336a54b5>] do_filp_open+0x14c/0x324
[<000000002802df13>] do_sys_openat2+0x2c4/0x530
[<0000000094eea458>] __arm64_sys_openat+0x130/0x1c4
[<00000000a71d7881>] el0_svc_common.constprop.0+0xfc/0x394
[<00000000313647bf>] do_el0_svc+0xac/0xec
[<000000002ef1c651>] el0_svc+0x20/0x30
[<000000002fd4692a>] el0_sync_handler+0xb0/0xb4
[<000000000c309c35>] el0_sync+0x160/0x180
The root cause is descripted as follows:
__tracing_open() { // 1. File 'trace' is being opened;
...
*iter->trace = *tr->current_trace; // 2. Tracer 'function_graph' is
// currently set;
...
iter->trace->open(iter); // 3. Call graph_trace_open() here,
// and memory are allocated in it;
...
}
s_start() { // 4. The opened file is being read;
...
*iter->trace = *tr->current_trace; // 5. If tracer is switched to
// 'nop' or others, then memory
// in step 3 are leaked!!!
...
}
To fix it, in s_start(), close tracer before switching then reopen the
new tracer after switching. And some tracers like 'wakeup' may not update
'iter->private' in some cases when reopen, then it should be cleared
to avoid being mistakenly closed again.
Link: https://lore.kernel.org/linux-trace-kernel/20230817125539.1646321-1-zhengyejian1@huawei.com
Fixes: d7350c3f4569 ("tracing/core: make the read callbacks reentrants")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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While debugging another issue I noticed that the stack trace contains one
invalid entry at the end:
<idle>-0 [008] d..4. 26.484201: wake_lat: pid=0 delta=2629976084 000000009cc24024 stack=STACK:
=> __schedule+0xac6/0x1a98
=> schedule+0x126/0x2c0
=> schedule_timeout+0x150/0x2c0
=> kcompactd+0x9ca/0xc20
=> kthread+0x2f6/0x3d8
=> __ret_from_fork+0x8a/0xe8
=> 0x6b6b6b6b6b6b6b6b
This is because the code failed to add the one element containing the
number of entries to field_size.
Link: https://lkml.kernel.org/r/20230816154928.4171614-4-svens@linux.ibm.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 00cf3d672a9d ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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While debugging another issue I noticed that the stack trace output
contains the number of entries on top:
<idle>-0 [000] d..4. 203.322502: wake_lat: pid=0 delta=2268270616 stack=STACK:
=> 0x10
=> __schedule+0xac6/0x1a98
=> schedule+0x126/0x2c0
=> schedule_timeout+0x242/0x2c0
=> __wait_for_common+0x434/0x680
=> __wait_rcu_gp+0x198/0x3e0
=> synchronize_rcu+0x112/0x138
=> ring_buffer_reset_online_cpus+0x140/0x2e0
=> tracing_reset_online_cpus+0x15c/0x1d0
=> tracing_set_clock+0x180/0x1d8
=> hist_register_trigger+0x486/0x670
=> event_hist_trigger_parse+0x494/0x1318
=> trigger_process_regex+0x1d4/0x258
=> event_trigger_write+0xb4/0x170
=> vfs_write+0x210/0xad0
=> ksys_write+0x122/0x208
Fix this by skipping the first element. Also replace the pointer
logic with an index variable which is easier to read.
Link: https://lkml.kernel.org/r/20230816154928.4171614-3-svens@linux.ibm.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 00cf3d672a9d ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The current code uses a lot of casts to access the fields member in struct
synth_trace_events with different sizes. This makes the code hard to
read, and had already introduced an endianness bug. Use a union and struct
instead.
Link: https://lkml.kernel.org/r/20230816154928.4171614-2-svens@linux.ibm.com
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 00cf3d672a9dd ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Trace ring buffer can no longer record anything after executing
following commands at the shell prompt:
# cd /sys/kernel/tracing
# cat tracing_cpumask
fff
# echo 0 > tracing_cpumask
# echo 1 > snapshot
# echo fff > tracing_cpumask
# echo 1 > tracing_on
# echo "hello world" > trace_marker
-bash: echo: write error: Bad file descriptor
The root cause is that:
1. After `echo 0 > tracing_cpumask`, 'record_disabled' of cpu buffers
in 'tr->array_buffer.buffer' became 1 (see tracing_set_cpumask());
2. After `echo 1 > snapshot`, 'tr->array_buffer.buffer' is swapped
with 'tr->max_buffer.buffer', then the 'record_disabled' became 0
(see update_max_tr());
3. After `echo fff > tracing_cpumask`, the 'record_disabled' become -1;
Then array_buffer and max_buffer are both unavailable due to value of
'record_disabled' is not 0.
To fix it, enable or disable both array_buffer and max_buffer at the same
time in tracing_set_cpumask().
Link: https://lkml.kernel.org/r/20230805033816.3284594-2-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <vnagarnaik@google.com>
Cc: <shuah@kernel.org>
Fixes: 71babb2705e2 ("tracing: change CPU ring buffer state from tracing_cpumask")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Adding support for bpf_get_func_ip helper for uprobe program to return
probed address for both uprobe and return uprobe.
We discussed this in [1] and agreed that uprobe can have special use
of bpf_get_func_ip helper that differs from kprobe.
The kprobe bpf_get_func_ip returns:
- address of the function if probe is attach on function entry
for both kprobe and return kprobe
- 0 if the probe is not attach on function entry
The uprobe bpf_get_func_ip returns:
- address of the probe for both uprobe and return uprobe
The reason for this semantic change is that kernel can't really tell
if the probe user space address is function entry.
The uprobe program is actually kprobe type program attached as uprobe.
One of the consequences of this design is that uprobes do not have its
own set of helpers, but share them with kprobes.
As we need different functionality for bpf_get_func_ip helper for uprobe,
I'm adding the bool value to the bpf_trace_run_ctx, so the helper can
detect that it's executed in uprobe context and call specific code.
The is_uprobe bool is set as true in bpf_prog_run_array_sleepable, which
is currently used only for executing bpf programs in uprobe.
Renaming bpf_prog_run_array_sleepable to bpf_prog_run_array_uprobe
to address that it's only used for uprobes and that it sets the
run_ctx.is_uprobe as suggested by Yafang Shao.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
[1] https://lore.kernel.org/bpf/CAEf4BzZ=xLVkG5eurEuvLU79wAMtwho7ReR+XJAgwhFF4M-7Cg@mail.gmail.com/
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Viktor Malik <vmalik@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230807085956.2344866-2-jolsa@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Martin KaFai Lau says:
====================
pull-request: bpf-next 2023-08-03
We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 84 files changed, 4026 insertions(+), 562 deletions(-).
The main changes are:
1) Add SO_REUSEPORT support for TC bpf_sk_assign from Lorenz Bauer,
Daniel Borkmann
2) Support new insns from cpu v4 from Yonghong Song
3) Non-atomically allocate freelist during prefill from YiFei Zhu
4) Support defragmenting IPv(4|6) packets in BPF from Daniel Xu
5) Add tracepoint to xdp attaching failure from Leon Hwang
6) struct netdev_rx_queue and xdp.h reshuffling to reduce
rebuild time from Jakub Kicinski
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
net: invert the netdevice.h vs xdp.h dependency
net: move struct netdev_rx_queue out of netdevice.h
eth: add missing xdp.h includes in drivers
selftests/bpf: Add testcase for xdp attaching failure tracepoint
bpf, xdp: Add tracepoint to xdp attaching failure
selftests/bpf: fix static assert compilation issue for test_cls_*.c
bpf: fix bpf_probe_read_kernel prototype mismatch
riscv, bpf: Adapt bpf trampoline to optimized riscv ftrace framework
libbpf: fix typos in Makefile
tracing: bpf: use struct trace_entry in struct syscall_tp_t
bpf, devmap: Remove unused dtab field from bpf_dtab_netdev
bpf, cpumap: Remove unused cmap field from bpf_cpu_map_entry
netfilter: bpf: Only define get_proto_defrag_hook() if necessary
bpf: Fix an array-index-out-of-bounds issue in disasm.c
net: remove duplicate INDIRECT_CALLABLE_DECLARE of udp[6]_ehashfn
docs/bpf: Fix malformed documentation
bpf: selftests: Add defrag selftests
bpf: selftests: Support custom type and proto for client sockets
bpf: selftests: Support not connecting client socket
netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link
...
====================
Link: https://lore.kernel.org/r/20230803174845.825419-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Cross-merge networking fixes after downstream PR.
Conflicts:
net/dsa/port.c
9945c1fb03a3 ("net: dsa: fix older DSA drivers using phylink")
a88dd7538461 ("net: dsa: remove legacy_pre_march2020 detection")
https://lore.kernel.org/all/20230731102254.2c9868ca@canb.auug.org.au/
net/xdp/xsk.c
3c5b4d69c358 ("net: annotate data-races around sk->sk_mark")
b7f72a30e9ac ("xsk: introduce wrappers and helpers for supporting multi-buffer in Tx path")
https://lore.kernel.org/all/20230731102631.39988412@canb.auug.org.au/
drivers/net/ethernet/broadcom/bnxt/bnxt.c
37b61cda9c16 ("bnxt: don't handle XDP in netpoll")
2b56b3d99241 ("eth: bnxt: handle invalid Tx completions more gracefully")
https://lore.kernel.org/all/20230801101708.1dc7faac@canb.auug.org.au/
Adjacent changes:
drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c
62da08331f1a ("net/mlx5e: Set proper IPsec source port in L4 selector")
fbd517549c32 ("net/mlx5e: Add function to get IPsec offload namespace")
drivers/net/ethernet/sfc/selftest.c
55c1528f9b97 ("sfc: fix field-spanning memcpy in selftest")
ae9d445cd41f ("sfc: Miscellaneous comment removals")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from bpf and wireless.
Nothing scary here. Feels like the first wave of regressions from v6.5
is addressed - one outstanding fix still to come in TLS for the
sendpage rework.
Current release - regressions:
- udp: fix __ip_append_data()'s handling of MSG_SPLICE_PAGES
- dsa: fix older DSA drivers using phylink
Previous releases - regressions:
- gro: fix misuse of CB in udp socket lookup
- mlx5: unregister devlink params in case interface is down
- Revert "wifi: ath11k: Enable threaded NAPI"
Previous releases - always broken:
- sched: cls_u32: fix match key mis-addressing
- sched: bind logic fixes for cls_fw, cls_u32 and cls_route
- add bound checks to a number of places which hand-parse netlink
- bpf: disable preemption in perf_event_output helpers code
- qed: fix scheduling in a tasklet while getting stats
- avoid using APIs which are not hardirq-safe in couple of drivers,
when we may be in a hard IRQ (netconsole)
- wifi: cfg80211: fix return value in scan logic, avoid page
allocator warning
- wifi: mt76: mt7615: do not advertise 5 GHz on first PHY of MT7615D
(DBDC)
Misc:
- drop handful of inactive maintainers, put some new in place"
* tag 'net-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (98 commits)
MAINTAINERS: update TUN/TAP maintainers
test/vsock: remove vsock_perf executable on `make clean`
tcp_metrics: fix data-race in tcpm_suck_dst() vs fastopen
tcp_metrics: annotate data-races around tm->tcpm_net
tcp_metrics: annotate data-races around tm->tcpm_vals[]
tcp_metrics: annotate data-races around tm->tcpm_lock
tcp_metrics: annotate data-races around tm->tcpm_stamp
tcp_metrics: fix addr_same() helper
prestera: fix fallback to previous version on same major version
udp: Fix __ip_append_data()'s handling of MSG_SPLICE_PAGES
net/mlx5e: Set proper IPsec source port in L4 selector
net/mlx5: fs_core: Skip the FTs in the same FS_TYPE_PRIO_CHAINS fs_prio
net/mlx5: fs_core: Make find_closest_ft more generic
wifi: brcmfmac: Fix field-spanning write in brcmf_scan_params_v2_to_v1()
vxlan: Fix nexthop hash size
ip6mr: Fix skb_under_panic in ip6mr_cache_report()
s390/qeth: Don't call dev_close/dev_open (DOWN/UP)
net: tap_open(): set sk_uid from current_fsuid()
net: tun_chr_open(): set sk_uid from current_fsuid()
net: dcb: choose correct policy to parse DCB_ATTR_BCN
...
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Martin KaFai Lau says:
====================
pull-request: bpf 2023-08-03
We've added 5 non-merge commits during the last 7 day(s) which contain
a total of 3 files changed, 37 insertions(+), 20 deletions(-).
The main changes are:
1) Disable preemption in perf_event_output helpers code,
from Jiri Olsa
2) Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing,
from Lin Ma
3) Multiple warning splat fixes in cpumap from Hou Tao
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf, cpumap: Handle skb as well when clean up ptr_ring
bpf, cpumap: Make sure kthread is running before map update returns
bpf: Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing
bpf: Disable preemption in bpf_event_output
bpf: Disable preemption in bpf_perf_event_output
====================
Link: https://lore.kernel.org/r/20230803181429.994607-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
bpf_probe_read_kernel() has a __weak definition in core.c and another
definition with an incompatible prototype in kernel/trace/bpf_trace.c,
when CONFIG_BPF_EVENTS is enabled.
Since the two are incompatible, there cannot be a shared declaration in
a header file, but the lack of a prototype causes a W=1 warning:
kernel/bpf/core.c:1638:12: error: no previous prototype for 'bpf_probe_read_kernel' [-Werror=missing-prototypes]
On 32-bit architectures, the local prototype
u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
passes arguments in other registers as the one in bpf_trace.c
BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
const void *, unsafe_ptr)
which uses 64-bit arguments in pairs of registers.
As both versions of the function are fairly simple and only really
differ in one line, just move them into a header file as an inline
function that does not add any overhead for the bpf_trace.c callers
and actually avoids a function call for the other one.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/ac25cb0f-b804-1649-3afb-1dc6138c2716@iogearbox.net/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230801111449.185301-1-arnd@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
bpf tracepoint program uses struct trace_event_raw_sys_enter as
argument where trace_entry is the first field. Use the same instead
of unsigned long long since if it's amended (for example by RT
patch) it accesses data with wrong offset.
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230801075222.7717-1-ykaliuta@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Up until now, /sys/kernel/tracing/events was no different than any other
part of tracefs. The files and directories within the events directory was
created when the tracefs was mounted, and also created for the instances in
/sys/kernel/tracing/instances/<instance>/events. Most of these files and
directories will never be referenced. Since there are thousands of these
files and directories they spend their time wasting precious memory
resources.
Move the "events" directory to the new eventfs. The eventfs will take the
meta data of the events that they represent and store that. When the files
in the events directory are referenced, the dentry and inodes to represent
them are then created. When the files are no longer referenced, they are
freed. This saves the precious memory resources that were wasted on these
seldom referenced dentries and inodes.
Running the following:
~# cat /proc/meminfo /proc/slabinfo > before.out
~# mkdir /sys/kernel/tracing/instances/foo
~# cat /proc/meminfo /proc/slabinfo > after.out
to test the changes produces the following deltas:
Before this change:
Before after deltas for meminfo:
MemFree: -32260
MemAvailable: -21496
KReclaimable: 21528
Slab: 22440
SReclaimable: 21528
SUnreclaim: 912
VmallocUsed: 16
Before after deltas for slabinfo:
<slab>: <objects> [ * <size> = <total>]
tracefs_inode_cache: 14472 [* 1184 = 17134848]
buffer_head: 24 [* 168 = 4032]
hmem_inode_cache: 28 [* 1480 = 41440]
dentry: 14450 [* 312 = 4508400]
lsm_inode_cache: 14453 [* 32 = 462496]
vma_lock: 11 [* 152 = 1672]
vm_area_struct: 2 [* 184 = 368]
trace_event_file: 1748 [* 88 = 153824]
kmalloc-256: 1072 [* 256 = 274432]
kmalloc-64: 2842 [* 64 = 181888]
Total slab additions in size: 22,763,400 bytes
With this change:
Before after deltas for meminfo:
MemFree: -12600
MemAvailable: -12580
Cached: 24
Active: 12
Inactive: 68
Inactive(anon): 48
Active(file): 12
Inactive(file): 20
Dirty: -4
AnonPages: 68
KReclaimable: 12
Slab: 1856
SReclaimable: 12
SUnreclaim: 1844
KernelStack: 16
PageTables: 36
VmallocUsed: 16
Before after deltas for slabinfo:
<slab>: <objects> [ * <size> = <total>]
tracefs_inode_cache: 108 [* 1184 = 127872]
buffer_head: 24 [* 168 = 4032]
hmem_inode_cache: 18 [* 1480 = 26640]
dentry: 127 [* 312 = 39624]
lsm_inode_cache: 152 [* 32 = 4864]
vma_lock: 67 [* 152 = 10184]
vm_area_struct: -12 [* 184 = -2208]
trace_event_file: 1764 [* 96 = 169344]
kmalloc-96: 14322 [* 96 = 1374912]
kmalloc-64: 2814 [* 64 = 180096]
kmalloc-32: 1103 [* 32 = 35296]
kmalloc-16: 2308 [* 16 = 36928]
kmalloc-8: 12800 [* 8 = 102400]
Total slab additions in size: 2,109,984 bytes
Which is a savings of 20,653,416 bytes (20 MB) per tracing instance.
Link: https://lkml.kernel.org/r/1690568452-46553-10-git-send-email-akaher@vmware.com
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Tested-by: Ching-lin Yu <chinglinyu@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The creation of the trace event directory requires that a TRACE_SYSTEM is
defined that the trace event directory is added within the system it was
defined in.
The code handled the case where a TRACE_SYSTEM was not added, and would
then add the event at the events directory. But nothing should be doing
this. This code also prevents the implementation of creating dynamic
dentrys for the eventfs system.
As this path has never been hit on correct code, remove it. If it does get
hit, issues a WARN_ON_ONCE() and return ENODEV.
Link: https://lkml.kernel.org/r/1690568452-46553-2-git-send-email-akaher@vmware.com
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Currently we can resize trace ringbuffer by writing a value into file
'buffer_size_kb', then by reading the file, we get the value that is
usually what we wrote. However, this value may be not actual size of
trace ring buffer because of the round up when doing resize in kernel,
and the actual size would be more useful.
Link: https://lore.kernel.org/linux-trace-kernel/20230705002705.576633-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
As the trace iterator is created and used by various interfaces, the clean
up of it needs to be consistent. Create a free_trace_iter_content() helper
function that frees the content of the iterator and use that to clean it
up in all places that it is used.
Link: https://lkml.kernel.org/r/20230715141348.341887497@goodmis.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The iterator allocated a descriptor to copy the current_trace. This was done
with the assumption that the function pointers might change. But this was a
false assuption, as it does not change. There's no reason to make a copy of the
current_trace and just use the pointer it points to. This removes needing to
manage freeing the descriptor. Worse yet, there's locations that the iterator
is used but does make a copy and just uses the pointer. This could cause the
actual pointer to the trace descriptor to be freed and not the allocated copy.
This is more of a clean up than a fix.
Link: https://lkml.kernel.org/r/20230715141348.135792275@goodmis.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: d7350c3f45694 ("tracing/core: make the read callbacks reentrants")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in
ring_buffer.c. x86 CMPXCHG instruction returns success in ZF flag,
so this change saves a compare after cmpxchg (and related move
instruction in front of cmpxchg).
No functional change intended.
Link: https://lore.kernel.org/linux-trace-kernel/20230714154418.8884-1-ubizjak@gmail.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
For backward compatibility, older tooling expects to see the kernel_stack
event with a "caller" field that is a fixed size array of 8 addresses. The
code now supports more than 8 with an added "size" field that states the
real number of entries. But the "caller" field still just looks like a
fixed size to user space.
Since the tracing macros that create the user space format files also
creates the structures that those files represent, the kernel_stack event
structure had its "caller" field a fixed size of 8, but in reality, when
it is allocated on the ring buffer, it can hold more if the stack trace is
bigger that 8 functions. The copying of these entries was simply done with
a memcpy():
size = nr_entries * sizeof(unsigned long);
memcpy(entry->caller, fstack->calls, size);
The FORTIFY_SOURCE logic noticed at runtime that when the nr_entries was
larger than 8, that the memcpy() was writing more than what the structure
stated it can hold and it complained about it. This is because the
FORTIFY_SOURCE code is unaware that the amount allocated is actually
enough to hold the size. It does not expect that a fixed size field will
hold more than the fixed size.
This was originally solved by hiding the caller assignment with some
pointer arithmetic.
ptr = ring_buffer_data();
entry = ptr;
ptr += offsetof(typeof(*entry), caller);
memcpy(ptr, fstack->calls, size);
But it is considered bad form to hide from kernel hardening. Instead, make
it work nicely with FORTIFY_SOURCE by adding a new __stack_array() macro
that is specific for this one special use case. The macro will take 4
arguments: type, item, len, field (whereas the __array() macro takes just
the first three). This macro will act just like the __array() macro when
creating the code to deal with the format file that is exposed to user
space. But for the kernel, it will turn the caller field into:
type item[] __counted_by(field);
or for this instance:
unsigned long caller[] __counted_by(size);
Now the kernel code can expose the assignment of the caller to the
FORTIFY_SOURCE and everyone is happy!
Link: https://lore.kernel.org/linux-trace-kernel/20230712105235.5fc441aa@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20230713092605.2ddb9788@rorschach.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probe fixes from Masami Hiramatsu:
- probe-events: add NULL check for some BTF API calls which can return
error code and NULL.
- ftrace selftests: check fprobe and kprobe event correctly. This fixes
a miss condition of the test command.
- kprobes: do not allow probing functions that start with "__cfi_" or
"__pfx_" since those are auto generated for kernel CFI and not
executed.
* tag 'probes-fixes-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
kprobes: Prohibit probing on CFI preamble symbol
selftests/ftrace: Fix to check fprobe event eneblement
tracing/probes: Fix to add NULL check for BTF APIs
|
|
Warning happened in trace_buffered_event_disable() at
WARN_ON_ONCE(!trace_buffered_event_ref)
Call Trace:
? __warn+0xa5/0x1b0
? trace_buffered_event_disable+0x189/0x1b0
__ftrace_event_enable_disable+0x19e/0x3e0
free_probe_data+0x3b/0xa0
unregister_ftrace_function_probe_func+0x6b8/0x800
event_enable_func+0x2f0/0x3d0
ftrace_process_regex.isra.0+0x12d/0x1b0
ftrace_filter_write+0xe6/0x140
vfs_write+0x1c9/0x6f0
[...]
The cause of the warning is in __ftrace_event_enable_disable(),
trace_buffered_event_enable() was called once while
trace_buffered_event_disable() was called twice.
Reproduction script show as below, for analysis, see the comments:
```
#!/bin/bash
cd /sys/kernel/tracing/
# 1. Register a 'disable_event' command, then:
# 1) SOFT_DISABLED_BIT was set;
# 2) trace_buffered_event_enable() was called first time;
echo 'cmdline_proc_show:disable_event:initcall:initcall_finish' > \
set_ftrace_filter
# 2. Enable the event registered, then:
# 1) SOFT_DISABLED_BIT was cleared;
# 2) trace_buffered_event_disable() was called first time;
echo 1 > events/initcall/initcall_finish/enable
# 3. Try to call into cmdline_proc_show(), then SOFT_DISABLED_BIT was
# set again!!!
cat /proc/cmdline
# 4. Unregister the 'disable_event' command, then:
# 1) SOFT_DISABLED_BIT was cleared again;
# 2) trace_buffered_event_disable() was called second time!!!
echo '!cmdline_proc_show:disable_event:initcall:initcall_finish' > \
set_ftrace_filter
```
To fix it, IIUC, we can change to call trace_buffered_event_enable() at
fist time soft-mode enabled, and call trace_buffered_event_disable() at
last time soft-mode disabled.
Link: https://lore.kernel.org/linux-trace-kernel/20230726095804.920457-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Fixes: 0fc1b09ff1ff ("tracing: Use temp buffer when filtering events")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Fix kernel-doc warning:
kernel/trace/trace_seq.c:142: warning: Function parameter or member
'args' not described in 'trace_seq_vprintf'
Link: https://lkml.kernel.org/r/20230724140827.1023266-5-cuigaosheng1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Fix kernel-doc warnings:
kernel/trace/trace_events_trigger.c:59: warning: Function parameter
or member 'buffer' not described in 'event_triggers_call'
kernel/trace/trace_events_trigger.c:59: warning: Function parameter
or member 'event' not described in 'event_triggers_call'
Link: https://lkml.kernel.org/r/20230724140827.1023266-4-cuigaosheng1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Fix kernel-doc warning:
kernel/trace/trace_events_synth.c:1257: warning: Function parameter
or member 'mod' not described in 'synth_event_gen_cmd_array_start'
Link: https://lkml.kernel.org/r/20230724140827.1023266-3-cuigaosheng1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Fix kernel-doc warnings:
kernel/trace/ring_buffer.c:954: warning: Function parameter or
member 'cpu' not described in 'ring_buffer_wake_waiters'
kernel/trace/ring_buffer.c:3383: warning: Excess function parameter
'event' description in 'ring_buffer_unlock_commit'
kernel/trace/ring_buffer.c:5359: warning: Excess function parameter
'cpu' description in 'ring_buffer_reset_online_cpus'
Link: https://lkml.kernel.org/r/20230724140827.1023266-2-cuigaosheng1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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When pages are removed in rb_remove_pages(), 'cpu_buffer->read' is set
to 0 in order to make sure any read iterators reset themselves. However,
this will mess 'entries' stating, see following steps:
# cd /sys/kernel/tracing/
# 1. Enlarge ring buffer prepare for later reducing:
# echo 20 > per_cpu/cpu0/buffer_size_kb
# 2. Write a log into ring buffer of cpu0:
# taskset -c 0 echo "hello1" > trace_marker
# 3. Read the log:
# cat per_cpu/cpu0/trace_pipe
<...>-332 [000] ..... 62.406844: tracing_mark_write: hello1
# 4. Stop reading and see the stats, now 0 entries, and 1 event readed:
# cat per_cpu/cpu0/stats
entries: 0
[...]
read events: 1
# 5. Reduce the ring buffer
# echo 7 > per_cpu/cpu0/buffer_size_kb
# 6. Now entries became unexpected 1 because actually no entries!!!
# cat per_cpu/cpu0/stats
entries: 1
[...]
read events: 0
To fix it, introduce 'page_removed' field to count total removed pages
since last reset, then use it to let read iterators reset themselves
instead of changing the 'read' pointer.
Link: https://lore.kernel.org/linux-trace-kernel/20230724054040.3489499-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <vnagarnaik@google.com>
Fixes: 83f40318dab0 ("ring-buffer: Make removal of ring buffer pages atomic")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Cross-merge networking fixes after downstream PR.
No conflicts or adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Since find_btf_func_param() abd btf_type_by_id() can return NULL,
the caller must check the return value correctly.
Link: https://lore.kernel.org/all/169024903951.395371.11361556840733470934.stgit@devnote2/
Fixes: b576e09701c7 ("tracing/probes: Support function parameters if BTF is available")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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We received report [1] of kernel crash, which is caused by
using nesting protection without disabled preemption.
The bpf_event_output can be called by programs executed by
bpf_prog_run_array_cg function that disabled migration but
keeps preemption enabled.
This can cause task to be preempted by another one inside the
nesting protection and lead eventually to two tasks using same
perf_sample_data buffer and cause crashes like:
BUG: kernel NULL pointer dereference, address: 0000000000000001
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
...
? perf_output_sample+0x12a/0x9a0
? finish_task_switch.isra.0+0x81/0x280
? perf_event_output+0x66/0xa0
? bpf_event_output+0x13a/0x190
? bpf_event_output_data+0x22/0x40
? bpf_prog_dfc84bbde731b257_cil_sock4_connect+0x40a/0xacb
? xa_load+0x87/0xe0
? __cgroup_bpf_run_filter_sock_addr+0xc1/0x1a0
? release_sock+0x3e/0x90
? sk_setsockopt+0x1a1/0x12f0
? udp_pre_connect+0x36/0x50
? inet_dgram_connect+0x93/0xa0
? __sys_connect+0xb4/0xe0
? udp_setsockopt+0x27/0x40
? __pfx_udp_push_pending_frames+0x10/0x10
? __sys_setsockopt+0xdf/0x1a0
? __x64_sys_connect+0xf/0x20
? do_syscall_64+0x3a/0x90
? entry_SYSCALL_64_after_hwframe+0x72/0xdc
Fixing this by disabling preemption in bpf_event_output.
[1] https://github.com/cilium/cilium/issues/26756
Cc: stable@vger.kernel.org
Reported-by: Oleg "livelace" Popov <o.popov@livelace.ru>
Closes: https://github.com/cilium/cilium/issues/26756
Fixes: 2a916f2f546c ("bpf: Use migrate_disable/enable in array macros and cgroup/lirc code.")
Acked-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230725084206.580930-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The nesting protection in bpf_perf_event_output relies on disabled
preemption, which is guaranteed for kprobes and tracepoints.
However bpf_perf_event_output can be also called from uprobes context
through bpf_prog_run_array_sleepable function which disables migration,
but keeps preemption enabled.
This can cause task to be preempted by another one inside the nesting
protection and lead eventually to two tasks using same perf_sample_data
buffer and cause crashes like:
kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle page fault for address: ffffffff82be3eea
...
Call Trace:
? __die+0x1f/0x70
? page_fault_oops+0x176/0x4d0
? exc_page_fault+0x132/0x230
? asm_exc_page_fault+0x22/0x30
? perf_output_sample+0x12b/0x910
? perf_event_output+0xd0/0x1d0
? bpf_perf_event_output+0x162/0x1d0
? bpf_prog_c6271286d9a4c938_krava1+0x76/0x87
? __uprobe_perf_func+0x12b/0x540
? uprobe_dispatcher+0x2c4/0x430
? uprobe_notify_resume+0x2da/0xce0
? atomic_notifier_call_chain+0x7b/0x110
? exit_to_user_mode_prepare+0x13e/0x290
? irqentry_exit_to_user_mode+0x5/0x30
? asm_exc_int3+0x35/0x40
Fixing this by disabling preemption in bpf_perf_event_output.
Cc: stable@vger.kernel.org
Fixes: 8c7dcb84e3b7 ("bpf: implement sleepable uprobes by chaining gps")
Acked-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230725084206.580930-2-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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list
Commit 6018b585e8c6 ("tracing/histograms: Add histograms to hist_vars if
they have referenced variables") added a check to fail histogram creation
if save_hist_vars() failed to add histogram to hist_vars list. But the
commit failed to set ret to failed return code before jumping to
unregister histogram, fix it.
Link: https://lore.kernel.org/linux-trace-kernel/20230714203341.51396-1-mkhalfella@purestorage.com
Cc: stable@vger.kernel.org
Fixes: 6018b585e8c6 ("tracing/histograms: Add histograms to hist_vars if they have referenced variables")
Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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When ring_buffer_swap_cpu was called during resize process,
the cpu buffer was swapped in the middle, resulting in incorrect state.
Continuing to run in the wrong state will result in oops.
This issue can be easily reproduced using the following two scripts:
/tmp # cat test1.sh
//#! /bin/sh
for i in `seq 0 100000`
do
echo 2000 > /sys/kernel/debug/tracing/buffer_size_kb
sleep 0.5
echo 5000 > /sys/kernel/debug/tracing/buffer_size_kb
sleep 0.5
done
/tmp # cat test2.sh
//#! /bin/sh
for i in `seq 0 100000`
do
echo irqsoff > /sys/kernel/debug/tracing/current_tracer
sleep 1
echo nop > /sys/kernel/debug/tracing/current_tracer
sleep 1
done
/tmp # ./test1.sh &
/tmp # ./test2.sh &
A typical oops log is as follows, sometimes with other different oops logs.
[ 231.711293] WARNING: CPU: 0 PID: 9 at kernel/trace/ring_buffer.c:2026 rb_update_pages+0x378/0x3f8
[ 231.713375] Modules linked in:
[ 231.714735] CPU: 0 PID: 9 Comm: kworker/0:1 Tainted: G W 6.5.0-rc1-00276-g20edcec23f92 #15
[ 231.716750] Hardware name: linux,dummy-virt (DT)
[ 231.718152] Workqueue: events update_pages_handler
[ 231.719714] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 231.721171] pc : rb_update_pages+0x378/0x3f8
[ 231.722212] lr : rb_update_pages+0x25c/0x3f8
[ 231.723248] sp : ffff800082b9bd50
[ 231.724169] x29: ffff800082b9bd50 x28: ffff8000825f7000 x27: 0000000000000000
[ 231.726102] x26: 0000000000000001 x25: fffffffffffff010 x24: 0000000000000ff0
[ 231.728122] x23: ffff0000c3a0b600 x22: ffff0000c3a0b5c0 x21: fffffffffffffe0a
[ 231.730203] x20: ffff0000c3a0b600 x19: ffff0000c0102400 x18: 0000000000000000
[ 231.732329] x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffffe7aa8510
[ 231.734212] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000002
[ 231.736291] x11: ffff8000826998a8 x10: ffff800082b9baf0 x9 : ffff800081137558
[ 231.738195] x8 : fffffc00030e82c8 x7 : 0000000000000000 x6 : 0000000000000001
[ 231.740192] x5 : ffff0000ffbafe00 x4 : 0000000000000000 x3 : 0000000000000000
[ 231.742118] x2 : 00000000000006aa x1 : 0000000000000001 x0 : ffff0000c0007208
[ 231.744196] Call trace:
[ 231.744892] rb_update_pages+0x378/0x3f8
[ 231.745893] update_pages_handler+0x1c/0x38
[ 231.746893] process_one_work+0x1f0/0x468
[ 231.747852] worker_thread+0x54/0x410
[ 231.748737] kthread+0x124/0x138
[ 231.749549] ret_from_fork+0x10/0x20
[ 231.750434] ---[ end trace 0000000000000000 ]---
[ 233.720486] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 233.721696] Mem abort info:
[ 233.721935] ESR = 0x0000000096000004
[ 233.722283] EC = 0x25: DABT (current EL), IL = 32 bits
[ 233.722596] SET = 0, FnV = 0
[ 233.722805] EA = 0, S1PTW = 0
[ 233.723026] FSC = 0x04: level 0 translation fault
[ 233.723458] Data abort info:
[ 233.723734] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[ 233.724176] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 233.724589] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 233.725075] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000104943000
[ 233.725592] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[ 233.726231] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[ 233.726720] Modules linked in:
[ 233.727007] CPU: 0 PID: 9 Comm: kworker/0:1 Tainted: G W 6.5.0-rc1-00276-g20edcec23f92 #15
[ 233.727777] Hardware name: linux,dummy-virt (DT)
[ 233.728225] Workqueue: events update_pages_handler
[ 233.728655] pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 233.729054] pc : rb_update_pages+0x1a8/0x3f8
[ 233.729334] lr : rb_update_pages+0x154/0x3f8
[ 233.729592] sp : ffff800082b9bd50
[ 233.729792] x29: ffff800082b9bd50 x28: ffff8000825f7000 x27: 0000000000000000
[ 233.730220] x26: 0000000000000000 x25: ffff800082a8b840 x24: ffff0000c0102418
[ 233.730653] x23: 0000000000000000 x22: fffffc000304c880 x21: 0000000000000003
[ 233.731105] x20: 00000000000001f4 x19: ffff0000c0102400 x18: ffff800082fcbc58
[ 233.731727] x17: 0000000000000000 x16: 0000000000000001 x15: 0000000000000001
[ 233.732282] x14: ffff8000825fe0c8 x13: 0000000000000001 x12: 0000000000000000
[ 233.732709] x11: ffff8000826998a8 x10: 0000000000000ae0 x9 : ffff8000801b760c
[ 233.733148] x8 : fefefefefefefeff x7 : 0000000000000018 x6 : ffff0000c03298c0
[ 233.733553] x5 : 0000000000000002 x4 : 0000000000000000 x3 : 0000000000000000
[ 233.733972] x2 : ffff0000c3a0b600 x1 : 0000000000000000 x0 : 0000000000000000
[ 233.734418] Call trace:
[ 233.734593] rb_update_pages+0x1a8/0x3f8
[ 233.734853] update_pages_handler+0x1c/0x38
[ 233.735148] process_one_work+0x1f0/0x468
[ 233.735525] worker_thread+0x54/0x410
[ 233.735852] kthread+0x124/0x138
[ 233.736064] ret_from_fork+0x10/0x20
[ 233.736387] Code: 92400000 910006b5 aa000021 aa0303f7 (f9400060)
[ 233.736959] ---[ end trace 0000000000000000 ]---
After analysis, the seq of the error is as follows [1-5]:
int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
int cpu_id)
{
for_each_buffer_cpu(buffer, cpu) {
cpu_buffer = buffer->buffers[cpu];
//1. get cpu_buffer, aka cpu_buffer(A)
...
...
schedule_work_on(cpu,
&cpu_buffer->update_pages_work);
//2. 'update_pages_work' is queue on 'cpu', cpu_buffer(A) is passed to
// update_pages_handler, do the update process, set 'update_done' in
// complete(&cpu_buffer->update_done) and to wakeup resize process.
//---->
//3. Just at this moment, ring_buffer_swap_cpu is triggered,
//cpu_buffer(A) be swaped to cpu_buffer(B), the max_buffer.
//ring_buffer_swap_cpu is called as the 'Call trace' below.
Call trace:
dump_backtrace+0x0/0x2f8
show_stack+0x18/0x28
dump_stack+0x12c/0x188
ring_buffer_swap_cpu+0x2f8/0x328
update_max_tr_single+0x180/0x210
check_critical_timing+0x2b4/0x2c8
tracer_hardirqs_on+0x1c0/0x200
trace_hardirqs_on+0xec/0x378
el0_svc_common+0x64/0x260
do_el0_svc+0x90/0xf8
el0_svc+0x20/0x30
el0_sync_handler+0xb0/0xb8
el0_sync+0x180/0x1c0
//<----
/* wait for all the updates to complete */
for_each_buffer_cpu(buffer, cpu) {
cpu_buffer = buffer->buffers[cpu];
//4. get cpu_buffer, cpu_buffer(B) is used in the following process,
//the state of cpu_buffer(A) and cpu_buffer(B) is totally wrong.
//for example, cpu_buffer(A)->update_done will leave be set 1, and will
//not 'wait_for_completion' at the next resize round.
if (!cpu_buffer->nr_pages_to_update)
continue;
if (cpu_online(cpu))
wait_for_completion(&cpu_buffer->update_done);
cpu_buffer->nr_pages_to_update = 0;
}
...
}
//5. the state of cpu_buffer(A) and cpu_buffer(B) is totally wrong,
//Continuing to run in the wrong state, then oops occurs.
Link: https://lore.kernel.org/linux-trace-kernel/202307191558478409990@zte.com.cn
Signed-off-by: Chen Lin <chen.lin5@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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