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274
Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
  David CarlierandSteven Rostedt
|
576ec047d2 |
tracing: Avoid NULL return from hist_field_name() on truncation
hist_field_name() returns "" everywhere except the fully-qualified
VAR_REF/EXPR case, where snprintf() truncation returns NULL early
and bypasses the bottom NULL->"" guard. Callers don't expect NULL:
strcat(expr, hist_field_name(field, 0)) at trace_events_hist.c:1758
and the strcmp() in the sort-key match loop at :4804 both deref it.
system and event_name are bounded by MAX_EVENT_NAME_LEN, but the
field name on a VAR_REF is kstrdup'd from a histogram variable
name parsed out of the trigger string and has no length cap, so
a long enough var name in a fully qualified reference can reach
the truncation path.
Keep the length check but leave field_name as "" on overflow.
Link: https://patch.msgid.link/20260508195747.25492-1-devnexen@gmail.com
Fixes:
|
||
 Tom ZanussiandSteven Rostedt (Google)
|
9236eebd13 |
tracing: Fix fully-qualified variable reference printing in histograms
The syntax for fully-qualified variable references in histograms is subsys.event.$var, which is parsed correctly, but not displayed correctly when printing a histogram spec. The current code puts the $ reference at the beginning of the fully-qualified variable name i.e. $subsys.event.var, which is incorrect. Before: trigger info: hist:keys=next_comm:vals=hitcount:wakeup_lat=common_timestamp.usecs-$sched.sched_wakeup.ts0: ... After: trigger info: hist:keys=next_comm:vals=hitcount:wakeup_lat=common_timestamp.usecs-sched.sched_wakeup.$ts0: ... Link: https://patch.msgid.link/5dee9a86d062a4dd68c2214f3d90ac93811e1951.1776112478.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
 Pengpeng HouandSteven Rostedt (Google)
|
5ec1d1e97d |
tracing: Rebuild full_name on each hist_field_name() call
hist_field_name() uses a static MAX_FILTER_STR_VAL buffer for fully
qualified variable-reference names, but it currently appends into that
buffer with strcat() without rebuilding it first. As a result, repeated
calls append a new "system.event.field" name onto the previous one,
which can eventually run past the end of full_name.
Build the name with snprintf() on each call and return NULL if the fully
qualified name does not fit in MAX_FILTER_STR_VAL.
Link: https://patch.msgid.link/20260401112224.85582-1-pengpeng@iscas.ac.cn
Fixes:
|
||
 Petr PavluandSteven Rostedt (Google)
|
f54f08b1b8 |
tracing: Free up file->private_data for use by individual events
The tracing_open_file_tr() function currently copies the trace_event_file pointer from inode->i_private to file->private_data when the file is successfully opened. This duplication is not particularly useful, as all event code should utilize event_file_file() or event_file_data() to retrieve a trace_event_file pointer from a file struct and these access functions read file->f_inode->i_private. Moreover, this setup requires the code for opening hist files to explicitly clear file->private_data before calling single_open(), since this function expects the private_data member to be set to NULL and uses it to store a pointer to a seq_file. Remove the unnecessary setting of file->private_data in tracing_open_file_tr() and simplify the hist code. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Tom Zanussi <zanussi@kernel.org> Link: https://patch.msgid.link/20260219162737.314231-6-petr.pavlu@suse.com Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
 Linus Torvalds
|
32a92f8c89 |
Convert more 'alloc_obj' cases to default GFP_KERNEL arguments
This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
bf4afc53b7 |
Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
 Kees Cook
|
69050f8d6d |
treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org> |
||
|
Petr PavluandSteven Rostedt (Google)
|
f0a0da1f90 |
tracing: Fix checking of freed trace_event_file for hist files
The event_hist_open() and event_hist_poll() functions currently retrieve
a trace_event_file pointer from a file struct by invoking
event_file_data(), which simply returns file->f_inode->i_private. The
functions then check if the pointer is NULL to determine whether the event
is still valid. This approach is flawed because i_private is assigned when
an eventfs inode is allocated and remains set throughout its lifetime.
Instead, the code should call event_file_file(), which checks for
EVENT_FILE_FL_FREED. Using the incorrect access function may result in the
code potentially opening a hist file for an event that is being removed or
becoming stuck while polling on this file.
Correct the access method to event_file_file() in both functions.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20260219162737.314231-2-petr.pavlu@suse.com
Fixes:
|
||
|
Steven Rostedt
|
326669faf3 |
tracing: Move tracing_set_filter_buffering() into trace_events_hist.c
The function tracing_set_filter_buffering() is only used in trace_events_hist.c. Move it to that file and make it static. 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> Link: https://patch.msgid.link/20260206195936.617080218@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
e62750b6ab |
tracing: Up the hist stacktrace size from 16 to 31
Recording stacktraces is very useful, but the size of 16 deep is very
restrictive. For example, in seeing where tasks schedule out in a non
running state, the following can be used:
~# cd /sys/kernel/tracing
~# echo 'hist:keys=common_stacktrace:vals=hitcount if prev_state & 3' > events/sched/sched_switch/trigger
~# cat events/sched/sched_switch/hist
[..]
{ common_stacktrace:
__schedule+0xdc0/0x1860
schedule+0x27/0xd0
schedule_timeout+0xb5/0x100
wait_for_completion+0x8a/0x140
xfs_buf_iowait+0x20/0xd0 [xfs]
xfs_buf_read_map+0x103/0x250 [xfs]
xfs_trans_read_buf_map+0x161/0x310 [xfs]
xfs_btree_read_buf_block+0xa0/0x120 [xfs]
xfs_btree_lookup_get_block+0xa3/0x1e0 [xfs]
xfs_btree_lookup+0xea/0x530 [xfs]
xfs_alloc_fixup_trees+0x72/0x570 [xfs]
xfs_alloc_ag_vextent_size+0x67f/0x800 [xfs]
xfs_alloc_vextent_iterate_ags.constprop.0+0x52/0x230 [xfs]
xfs_alloc_vextent_start_ag+0x9d/0x1b0 [xfs]
xfs_bmap_btalloc+0x2af/0x680 [xfs]
xfs_bmapi_allocate+0xdb/0x2c0 [xfs]
} hitcount: 1
[..]
The above stops at 16 functions where knowing more would be useful. As the
allocated storage for stacks is the same for strings, and that size is 256
bytes, there is a lot of space not being used for stacktraces.
16 * 8 = 128
Up the size to 31 (it requires the last slot to be zero, so it can't be 32).
Also change the BUILD_BUG_ON() to allow the size of the stacktrace storage
to be equal to the max size. One slot is used to hold the number of
elements in the stack.
BUILD_BUG_ON((HIST_STACKTRACE_DEPTH + 1) * sizeof(long) >= STR_VAR_LEN_MAX);
Change that from ">=" to just ">", as now they are equal.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20260123105415.2be26bf4@gandalf.local.home
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
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|
Steven Rostedt
|
45641096c9 |
tracing: Have hist_debug show what function a field uses
When CONFIG_HIST_TRIGGERS_DEBUG is enabled, each trace event has a
"hist_debug" file that explains the histogram internal data. This is very
useful for debugging histograms.
One bit of data that was missing from this file was what function a
histogram field uses to process its data. The hist_field structure now has
a fn_num that is used by a switch statement in hist_fn_call() to call a
function directly (to avoid spectre mitigations).
Instead of displaying that number, create a string array that maps to the
histogram function enums so that the function for a field may be
displayed:
~# cat /sys/kernel/tracing/events/sched/sched_switch/hist_debug
[..]
hist_data: 0000000043d62762
n_vals: 2
n_keys: 1
n_fields: 3
val fields:
hist_data->fields[0]:
flags:
VAL: HIST_FIELD_FL_HITCOUNT
type: u64
size: 8
is_signed: 0
function: hist_field_counter()
hist_data->fields[1]:
flags:
HIST_FIELD_FL_VAR
var.name: __arg_3921_2
var.idx (into tracing_map_elt.vars[]): 0
type: unsigned long[]
size: 128
is_signed: 0
function: hist_field_nop()
key fields:
hist_data->fields[2]:
flags:
HIST_FIELD_FL_KEY
ftrace_event_field name: prev_pid
type: pid_t
size: 8
is_signed: 1
function: hist_field_s32()
The "function:" field above is added.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20260122203822.58df4d80@gandalf.local.home
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
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|
Steven Rostedt
|
a4e0ea0e10 |
tracing: Remove redundant call to event_trigger_reset_filter() in event_hist_trigger_parse()
With the change to replace kfree() with trigger_data_free(), which starts out doing the exact same thing as event_trigger_reset_filter(), there's no reason to call event_trigger_reset_filter() before calling trigger_data_free(). Remove the call to it. Link: https://lore.kernel.org/linux-trace-kernel/20251211204520.0f3ba6d1@fedora/ Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Miaoqian Lin <linmq006@gmail.com> Link: https://patch.msgid.link/20260108174429.2d9ca51f@gandalf.local.home Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
 Miaoqian LinandSteven Rostedt (Google)
|
0550069cc2 |
tracing: Properly process error handling in event_hist_trigger_parse()
Memory allocated with trigger_data_alloc() requires trigger_data_free()
for proper cleanup.
Replace kfree() with trigger_data_free() to fix this.
Found via static analysis and code review.
This isn't a real bug due to the current code basically being an open
coded version of trigger_data_free() without the synchronization. The
synchronization isn't needed as this is the error path of creation and
there's nothing to synchronize against yet. Replace the kfree() to be
consistent with the allocation.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20251211100058.2381268-1-linmq006@gmail.com
Fixes:
|
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|
Steven Rostedt
|
90f9f5d64c |
tracing: Fix crash on synthetic stacktrace field usage
When creating a synthetic event based on an existing synthetic event that
had a stacktrace field and the new synthetic event used that field a
kernel crash occurred:
~# cd /sys/kernel/tracing
~# echo 's:stack unsigned long stack[];' > dynamic_events
~# echo 'hist:keys=prev_pid:s0=common_stacktrace if prev_state & 3' >> events/sched/sched_switch/trigger
~# echo 'hist:keys=next_pid:s1=$s0:onmatch(sched.sched_switch).trace(stack,$s1)' >> events/sched/sched_switch/trigger
The above creates a synthetic event that takes a stacktrace when a task
schedules out in a non-running state and passes that stacktrace to the
sched_switch event when that task schedules back in. It triggers the
"stack" synthetic event that has a stacktrace as its field (called "stack").
~# echo 's:syscall_stack s64 id; unsigned long stack[];' >> dynamic_events
~# echo 'hist:keys=common_pid:s2=stack' >> events/synthetic/stack/trigger
~# echo 'hist:keys=common_pid:s3=$s2,i0=id:onmatch(synthetic.stack).trace(syscall_stack,$i0,$s3)' >> events/raw_syscalls/sys_exit/trigger
The above makes another synthetic event called "syscall_stack" that
attaches the first synthetic event (stack) to the sys_exit trace event and
records the stacktrace from the stack event with the id of the system call
that is exiting.
When enabling this event (or using it in a historgram):
~# echo 1 > events/synthetic/syscall_stack/enable
Produces a kernel crash!
BUG: unable to handle page fault for address: 0000000000400010
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
CPU: 6 UID: 0 PID: 1257 Comm: bash Not tainted 6.16.3+deb14-amd64 #1 PREEMPT(lazy) Debian 6.16.3-1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
RIP: 0010:trace_event_raw_event_synth+0x90/0x380
Code: c5 00 00 00 00 85 d2 0f 84 e1 00 00 00 31 db eb 34 0f 1f 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 2e 0f 1f 84 00 00 00 00 00 <49> 8b 04 24 48 83 c3 01 8d 0c c5 08 00 00 00 01 cd 41 3b 5d 40 0f
RSP: 0018:ffffd2670388f958 EFLAGS: 00010202
RAX: ffff8ba1065cc100 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: fffff266ffda7b90 RDI: ffffd2670388f9b0
RBP: 0000000000000010 R08: ffff8ba104e76000 R09: ffffd2670388fa50
R10: ffff8ba102dd42e0 R11: ffffffff9a908970 R12: 0000000000400010
R13: ffff8ba10a246400 R14: ffff8ba10a710220 R15: fffff266ffda7b90
FS: 00007fa3bc63f740(0000) GS:ffff8ba2e0f48000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000400010 CR3: 0000000107f9e003 CR4: 0000000000172ef0
Call Trace:
<TASK>
? __tracing_map_insert+0x208/0x3a0
action_trace+0x67/0x70
event_hist_trigger+0x633/0x6d0
event_triggers_call+0x82/0x130
trace_event_buffer_commit+0x19d/0x250
trace_event_raw_event_sys_exit+0x62/0xb0
syscall_exit_work+0x9d/0x140
do_syscall_64+0x20a/0x2f0
? trace_event_raw_event_sched_switch+0x12b/0x170
? save_fpregs_to_fpstate+0x3e/0x90
? _raw_spin_unlock+0xe/0x30
? finish_task_switch.isra.0+0x97/0x2c0
? __rseq_handle_notify_resume+0xad/0x4c0
? __schedule+0x4b8/0xd00
? restore_fpregs_from_fpstate+0x3c/0x90
? switch_fpu_return+0x5b/0xe0
? do_syscall_64+0x1ef/0x2f0
? do_fault+0x2e9/0x540
? __handle_mm_fault+0x7d1/0xf70
? count_memcg_events+0x167/0x1d0
? handle_mm_fault+0x1d7/0x2e0
? do_user_addr_fault+0x2c3/0x7f0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The reason is that the stacktrace field is not labeled as such, and is
treated as a normal field and not as a dynamic event that it is.
In trace_event_raw_event_synth() the event is field is still treated as a
dynamic array, but the retrieval of the data is considered a normal field,
and the reference is just the meta data:
// Meta data is retrieved instead of a dynamic array
str_val = (char *)(long)var_ref_vals[val_idx];
// Then when it tries to process it:
len = *((unsigned long *)str_val) + 1;
It triggers a kernel page fault.
To fix this, first when defining the fields of the first synthetic event,
set the filter type to FILTER_STACKTRACE. This is used later by the second
synthetic event to know that this field is a stacktrace. When creating
the field of the new synthetic event, have it use this FILTER_STACKTRACE
to know to create a stacktrace field to copy the stacktrace into.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20260122194824.6905a38e@gandalf.local.home
Fixes:
|
||
 Maurice HieronymusandSteven Rostedt (Google)
|
c29e75532e |
tracing: Fix typo in trace_events_hist.c
Fix typo "tigger" to "trigger". Link: https://patch.msgid.link/20251121221835.28032-10-mhi@mailbox.org Signed-off-by: Maurice Hieronymus <mhi@mailbox.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Linus Torvalds
|
69c5079b49 |
Merge tag 'trace-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Extend tracing option mask to 64 bits
The trace options were defined by a 32 bit variable. This limits the
tracing instances to have a total of 32 different options. As that
limit has been hit, and more options are being added, increase the
option mask to a 64 bit number, doubling the number of options
available.
As this is required for the kprobe topic branches as well as the
tracing topic branch, a separate branch was created and merged into
both.
- Make trace_user_fault_read() available for the rest of tracing
The function trace_user_fault_read() is used by trace_marker file
read to allow reading user space to be done fast and without locking
or allocations. Make this available so that the system call trace
events can use it too.
- Have system call trace events read user space values
Now that the system call trace events callbacks are called in a
faultable context, take advantage of this and read the user space
buffers for various system calls. For example, show the path name of
the openat system call instead of just showing the pointer to that
path name in user space. Also show the contents of the buffer of the
write system call. Several system call trace events are updated to
make tracing into a light weight strace tool for all applications in
the system.
- Update perf system call tracing to do the same
- And a config and syscall_user_buf_size file to control the size of
the buffer
Limit the amount of data that can be read from user space. The
default size is 63 bytes but that can be expanded to 165 bytes.
- Allow the persistent ring buffer to print system calls normally
The persistent ring buffer prints trace events by their type and
ignores the print_fmt. This is because the print_fmt may change from
kernel to kernel. As the system call output is fixed by the system
call ABI itself, there's no reason to limit that. This makes reading
the system call events in the persistent ring buffer much nicer and
easier to understand.
- Add options to show text offset to function profiler
The function profiler that counts the number of times a function is
hit currently lists all functions by its name and offset. But this
becomes ambiguous when there are several functions with the same
name.
Add a tracing option that changes the output to be that of
'_text+offset' instead. Now a user space tool can use this
information to map the '_text+offset' to the unique function it is
counting.
- Report bad dynamic event command
If a bad command is passed to the dynamic_events file, report it
properly in the error log.
- Clean up tracer options
Clean up the tracer option code a bit, by removing some useless code
and also using switch statements instead of a series of if
statements.
- Have tracing options be instance specific
Tracers can have their own options (function tracer, irqsoff tracer,
function graph tracer, etc). But now that the same tracer can be
enabled in multiple trace instances, their options are still global.
The API is per instance, thus changing one affects other instances.
This isn't even consistent, as the option take affect differently
depending on when an tracer started in an instance. Make the options
for instances only affect the instance it is changed under.
- Optimize pid_list lock contention
Whenever the pid_list is read, it uses a spin lock. This happens at
every sched switch. Taking the lock at sched switch can be removed by
instead using a seqlock counter.
- Clean up the trace trigger structures
The trigger code uses two different structures to implement a single
tigger. This was due to trying to reuse code for the two different
types of triggers (always on trigger, and count limited trigger). But
by adding a single field to one structure, the other structure could
be absorbed into the first structure making he code easier to
understand.
- Create a bulk garbage collector for trace triggers
If user space has triggers for several hundreds of events and then
removes them, it can take several seconds to complete. This is
because each removal calls tracepoint_synchronize_unregister() that
can take hundreds of milliseconds to complete.
Instead, create a helper thread that will do the clean up. When a
trigger is removed, it will create the kthread if it isn't already
created, and then add the trigger to a llist. The kthread will take
the items off the llist, call tracepoint_synchronize_unregister(),
and then remove the items it took off. It will then check if there's
more items to free before sleeping.
This makes user space removing all these triggers to finish in less
than a second.
- Allow function tracing of some of the tracing infrastructure code
Because the tracing code can cause recursion issues if it is traced
by the function tracer the entire tracing directory disables function
tracing. But not all of tracing causes issues if it is traced.
Namely, the event tracing code. Add a config that enables some of the
tracing code to be traced to help in debugging it. Note, when this is
enabled, it does add noise to general function tracing, especially if
events are enabled as well (which is a common case).
- Add boot-time backup instance for persistent buffer
The persistent ring buffer is used mostly for kernel crash analysis
in the field. One issue is that if there's a crash, the data in the
persistent ring buffer must be read before tracing can begin using
it. This slows down the boot process. Once tracing starts in the
persistent ring buffer, the old data must be freed and the addresses
no longer match and old events can't be in the buffer with new
events.
Create a way to create a backup buffer that copies the persistent
ring buffer at boot up. Then after a crash, the always on tracer can
begin immediately as well as the normal boot process while the crash
analysis tooling uses the backup buffer. After the backup buffer is
finished being read, it can be removed.
- Enable function graph args and return address options at the same
time
Currently the when reading of arguments in the function graph tracer
is enabled, the option to record the parent function in the entry
event can not be enabled. Update the code so that it can.
- Add new struct_offset() helper macro
Add a new macro that takes a pointer to a structure and a name of one
of its members and it will return the offset of that member. This
allows the ring buffer code to simplify the following:
From: size = struct_size(entry, buf, cnt - sizeof(entry->id));
To: size = struct_offset(entry, id) + cnt;
There should be other simplifications that this macro can help out
with as well
* tag 'trace-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (42 commits)
overflow: Introduce struct_offset() to get offset of member
function_graph: Enable funcgraph-args and funcgraph-retaddr to work simultaneously
tracing: Add boot-time backup of persistent ring buffer
ftrace: Allow tracing of some of the tracing code
tracing: Use strim() in trigger_process_regex() instead of skip_spaces()
tracing: Add bulk garbage collection of freeing event_trigger_data
tracing: Remove unneeded event_mutex lock in event_trigger_regex_release()
tracing: Merge struct event_trigger_ops into struct event_command
tracing: Remove get_trigger_ops() and add count_func() from trigger ops
tracing: Show the tracer options in boot-time created instance
ftrace: Avoid redundant initialization in register_ftrace_direct
tracing: Remove unused variable in tracing_trace_options_show()
fgraph: Make fgraph_no_sleep_time signed
tracing: Convert function graph set_flags() to use a switch() statement
tracing: Have function graph tracer option sleep-time be per instance
tracing: Move graph-time out of function graph options
tracing: Have function graph tracer option funcgraph-irqs be per instance
trace/pid_list: optimize pid_list->lock contention
tracing: Have function graph tracer define options per instance
tracing: Have function tracer define options per instance
...
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Steven Rostedt
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b052d70f7c |
tracing: Merge struct event_trigger_ops into struct event_command
Now that there's pretty much a one to one mapping between the struct event_trigger_ops and struct event_command, there's no reason to have two different structures. Merge the function pointers of event_trigger_ops into event_command. There's one exception in trace_events_hist.c for the event_hist_trigger_named_ops. This has special logic for the init and free function pointers for "named histograms". In this case, allocate the cmd_ops of the event_trigger_data and set it to the proper init and free functions, which are used to initialize and free the event_trigger_data respectively. Have the free function and the init function (on failure) free the cmd_ops of the data element. 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> Link: https://patch.msgid.link/20251125200932.446322765@kernel.org Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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bdafb4d4cb |
tracing: Remove get_trigger_ops() and add count_func() from trigger ops
The struct event_command has a callback function called get_trigger_ops(). This callback returns the "trigger_ops" to use for the trigger. These ops define the trigger function, how to init the trigger, how to print the trigger and how to free it. The only reason there's a callback function to get these ops is because some triggers have two types of operations. One is an "always on" operation, and the other is a "count down" operation. If a user passes in a parameter to say how many times the trigger should execute. For example: echo stacktrace:5 > events/kmem/kmem_cache_alloc/trigger It will trigger the stacktrace for the first 5 times the kmem_cache_alloc event is hit. Instead of having two different trigger_ops since the only difference between them is the tigger itself (the print, init and free functions are all the same), just use a single ops that the event_command points to and add a function field to the trigger_ops to have a count_func. When a trigger is added to an event, if there's a count attached to it and the trigger ops has the count_func field, the data allocated to represent this trigger will have a new flag set called COUNT. Then when the trigger executes, it will check if the COUNT data flag is set, and if so, it will call the ops count_func(). If that returns false, it returns without executing the trigger. This removes the need for duplicate event_trigger_ops structures. 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> Link: https://patch.msgid.link/20251125200932.274566147@kernel.org Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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 Zilin GuanandSteven Rostedt (Google)
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80f0d631dc |
tracing: Fix memory leaks in create_field_var()
The function create_field_var() allocates memory for 'val' through
create_hist_field() inside parse_atom(), and for 'var' through
create_var(), which in turn allocates var->type and var->var.name
internally. Simply calling kfree() to release these structures will
result in memory leaks.
Use destroy_hist_field() to properly free 'val', and explicitly release
the memory of var->type and var->var.name before freeing 'var' itself.
Link: https://patch.msgid.link/20251106120132.3639920-1-zilin@seu.edu.cn
Fixes:
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Steven Rostedt
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f2947c4b7d |
tracing: Rename event_trigger_alloc() to trigger_data_alloc()
The function event_trigger_alloc() creates an event_trigger_data
descriptor and states that it needs to be freed via event_trigger_free().
This is incorrect, it needs to be freed by trigger_data_free() as
event_trigger_free() adds ref counting.
Rename event_trigger_alloc() to trigger_data_alloc() and state that it
needs to be freed via trigger_data_free(). This naming convention
was introducing bugs.
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: Tom Zanussi <zanussi@kernel.org>
Link: https://lore.kernel.org/20250507145455.776436410@goodmis.org
Fixes:
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Steven Rostedt
|
54c53dfdb6 |
tracing: Add common_comm to histograms
If one wants to trace the name of the task that wakes up a process and pass that to the synthetic events, there's nothing currently that lets the synthetic events do that. Add a "common_comm" to the histogram logic that allows histograms save the current->comm as a variable that can be passed through and added to a synthetic event: # cd /sys/kernel/tracing # echo 's:wake_lat char[] waker; char[] wakee; u64 delta;' >> dynamic_events # echo 'hist:keys=pid:comm=common_comm:ts=common_timestamp.usecs if !(common_flags & 0x18)' > events/sched/sched_waking/trigger # echo 'hist:keys=next_pid:wake_comm=$comm:delta=common_timestamp.usecs-$ts:onmatch(sched.sched_waking).trace(wake_lat,$wake_comm,next_comm,$delta)' > events/sched/sched_switch/trigger The above will create a synthetic trace event that will save both the name of the waker and the wakee but only if the wakeup did not happen in a hard or soft interrupt context. The "common_comm" is used to save the task->comm at the time of the initial event and is passed via the "comm" variable to the second event, and that is saved as the "waker" field in the "wake_lat" synthetic event. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250407154912.3c6c6246@gandalf.local.home Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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7ab0fc61ce |
tracing: Move histogram trigger variables from stack to per CPU structure
The histogram trigger has three somewhat large arrays on the kernel stack:
unsigned long entries[HIST_STACKTRACE_DEPTH];
u64 var_ref_vals[TRACING_MAP_VARS_MAX];
char compound_key[HIST_KEY_SIZE_MAX];
Checking the function event_hist_trigger() stack frame size, it currently
uses 816 bytes for its stack frame due to these variables!
Instead, allocate a per CPU structure that holds these arrays for each
context level (normal, softirq, irq and NMI). That is, each CPU will have
4 of these structures. This will be allocated when the first histogram
trigger is enabled and freed when the last is disabled. When the
histogram callback triggers, it will request this structure. The request
will disable preemption, get the per CPU structure at the index of the
per CPU variable, and increment that variable.
The callback will use the arrays in this structure to perform its work and
then release the structure. That in turn will simply decrement the per CPU
index and enable preemption.
Moving the variables from the kernel stack to the per CPU structure brings
the stack frame of event_hist_trigger() down to just 112 bytes.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://lore.kernel.org/20250407123851.74ea8d58@gandalf.local.home
Fixes:
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Steven Rostedt
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872a0d90c1 |
tracing: Always use memcpy() in histogram add_to_key()
The add_to_key() function tests if the key is a string or some data. If
it's a string it does some further calculations of the string size (still
truncating it to the max size it can be), and calls strncpy().
If the key isn't as string it calls memcpy(). The interesting point is
that both use the exact same parameters:
strncpy(compound_key + key_field->offset, (char *)key, size);
} else
memcpy(compound_key + key_field->offset, key, size);
As strncpy() is being used simply as a memcpy() for a string, and since
strncpy() is deprecated, just call memcpy() for both memory and string
keys.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/20250403210637.1c477d4a@gandalf.local.home
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Linus Torvalds
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744fab2d9f |
Merge tag 'trace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt: - Add option traceoff_after_boot In order to debug kernel boot, it sometimes is helpful to enable tracing via the kernel command line. Unfortunately, by the time the login prompt appears, the trace is overwritten by the init process and other user space start up applications. Adding a "traceoff_after_boot" will disable tracing when the kernel passes control to init which will allow developers to be able to see the traces that occurred during boot. - Clean up the mmflags macros that display the GFP flags in trace events The macros to print the GFP flags for trace events had a bit of duplication. The code was restructured to remove duplication and in the process it also adds some flags that were missed before. - Removed some dead code and scripts/draw_functrace.py draw_functrace.py hasn't worked in years and as nobody complained about it, remove it. - Constify struct event_trigger_ops The event_trigger_ops is just a structure that has function pointers that are assigned when the variables are created. These variables should all be constants. - Other minor clean ups and fixes * tag 'trace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Replace strncpy with memcpy for fixed-length substring copy tracing: Fix synth event printk format for str fields tracing: Do not use PERF enums when perf is not defined tracing: Ensure module defining synth event cannot be unloaded while tracing tracing: fix return value in __ftrace_event_enable_disable for TRACE_REG_UNREGISTER tracing/osnoise: Fix possible recursive locking for cpus_read_lock() tracing: Align synth event print fmt tracing: gfp: vsprintf: Do not print "none" when using %pGg printf format tracepoint: Print the function symbol when tracepoint_debug is set tracing: Constify struct event_trigger_ops scripts/tracing: Remove scripts/tracing/draw_functrace.py tracing: Update MAINTAINERS file to include tracepoint.c tracing/user_events: Slightly simplify user_seq_show() tracing/user_events: Don't use %pK through printk tracing: gfp: Remove duplication of recording GFP flags tracing: Remove orphaned event_trace_printk ring-buffer: Fix typo in comment about header page pointer tracing: Add traceoff_after_boot option |
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 Christophe JAILLETandSteven Rostedt (Google)
|
502d2e71a8 |
tracing: Constify struct event_trigger_ops
'event_trigger_ops mwifiex_if_ops' are not modified in these drivers. Constifying these structures moves some data to a read-only section, so increase overall security, especially when the structure holds some function pointers. On a x86_64, with allmodconfig, as an example: Before: ====== text data bss dec hex filename 31368 9024 6200 46592 b600 kernel/trace/trace_events_trigger.o After: ===== text data bss dec hex filename 31752 8608 6200 46560 b5e0 kernel/trace/trace_events_trigger.o Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/66e8f990e649678e4be37d4d1a19158ca0dea2f4.1741521295.git.christophe.jaillet@wanadoo.fr Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |