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2026-04-17Merge tag 'trace-v7.1' of ↵Linus Torvalds1-1178/+52
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Fix printf format warning for bprintf sunrpc uses a trace_printk() that triggers a printf warning during the compile. Move the __printf() attribute around for when debugging is not enabled the warning will go away - Remove redundant check for EVENT_FILE_FL_FREED in event_filter_write() The FREED flag is checked in the call to event_file_file() and then checked again right afterward, which is unneeded - Clean up event_file_file() and event_file_data() helpers These helper functions played a different role in the past, but now with eventfs, the READ_ONCE() isn't needed. Simplify the code a bit and also add a warning to event_file_data() if the file or its data is not present - Remove updating file->private_data in tracing open All access to the file private data is handled by the helper functions, which do not use file->private_data. Stop updating it on open - Show ENUM names in function arguments via BTF in function tracing When showing the function arguments when func-args option is set for function tracing, if one of the arguments is found to be an enum, show the name of the enum instead of its number - Add new trace_call__##name() API for tracepoints Tracepoints are enabled via static_branch() blocks, where when not enabled, there's only a nop that is in the code where the execution will just skip over it. When tracing is enabled, the nop is converted to a direct jump to the tracepoint code. Sometimes more calculations are required to be performed to update the parameters of the tracepoint. In this case, trace_##name##_enabled() is called which is a static_branch() that gets enabled only when the tracepoint is enabled. This allows the extra calculations to also be skipped by the nop: if (trace_foo_enabled()) { x = bar(); trace_foo(x); } Where the x=bar() is only performed when foo is enabled. The problem with this approach is that there's now two static_branch() calls. One for checking if the tracepoint is enabled, and then again to know if the tracepoint should be called. The second one is redundant Introduce trace_call__foo() that will call the foo() tracepoint directly without doing a static_branch(): if (trace_foo_enabled()) { x = bar(); trace_call__foo(); } - Update various locations to use the new trace_call__##name() API - Move snapshot code out of trace.c Cleaning up trace.c to not be a "dump all", move the snapshot code out of it and into a new trace_snapshot.c file - Clean up some "%*.s" to "%*s" - Allow boot kernel command line options to be called multiple times Have options like: ftrace_filter=foo ftrace_filter=bar ftrace_filter=zoo Equal to: ftrace_filter=foo,bar,zoo - Fix ipi_raise event CPU field to be a CPU field The ipi_raise target_cpus field is defined as a __bitmask(). There is now a __cpumask() field definition. Update the field to use that - Have hist_field_name() use a snprintf() and not a series of strcat() It's safer to use snprintf() that a series of strcat() - Fix tracepoint regfunc balancing A tracepoint can define a "reg" and "unreg" function that gets called before the tracepoint is enabled, and after it is disabled respectively. But on error, after the "reg" func is called and the tracepoint is not enabled, the "unreg" function is not called to tear down what the "reg" function performed - Fix output that shows what histograms are enabled Event variables are displayed incorrectly in the histogram output Instead of "sched.sched_wakeup.$var", it is showing "$sched.sched_wakeup.var" where the '$' is in the incorrect location - Some other simple cleanups * tag 'trace-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (24 commits) selftests/ftrace: Add test case for fully-qualified variable references tracing: Fix fully-qualified variable reference printing in histograms tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func() tracing: Rebuild full_name on each hist_field_name() call tracing: Report ipi_raise target CPUs as cpumask tracing: Remove duplicate latency_fsnotify() stub tracing: Preserve repeated trace_trigger boot parameters tracing: Append repeated boot-time tracing parameters tracing: Remove spurious default precision from show_event_trigger/filter formats cpufreq: Use trace_call__##name() at guarded tracepoint call sites tracing: Remove tracing_alloc_snapshot() when snapshot isn't defined tracing: Move snapshot code out of trace.c and into trace_snapshot.c mm: damon: Use trace_call__##name() at guarded tracepoint call sites btrfs: Use trace_call__##name() at guarded tracepoint call sites spi: Use trace_call__##name() at guarded tracepoint call sites i2c: Use trace_call__##name() at guarded tracepoint call sites kernel: Use trace_call__##name() at guarded tracepoint call sites tracepoint: Add trace_call__##name() API tracing: trace_mmap.h: fix a kernel-doc warning tracing: Pretty-print enum parameters in function arguments ...
2026-04-02tracing: Allow backup to save persistent ring buffer before it startsSteven Rostedt1-0/+22
When the persistent ring buffer was first introduced, it did not make sense to start tracing for it on the kernel command line. That's because if there was a crash, the start of events would invalidate the events from the previous boot that had the crash. But now that there's a "backup" instance that can take a snapshot of the persistent ring buffer when boot starts, it is possible to have the persistent ring buffer start events at boot up and not lose the old events. Update the code where the boot events start after all boot time instances are created. This will allow the backup instance to copy the persistent ring buffer from the previous boot, and allow the persistent ring buffer to start tracing new events for the current boot. reserve_mem=100M:12M:trace trace_instance=boot_mapped^@trace,sched trace_instance=backup=boot_mapped The above will create a boot_mapped persistent ring buffer and enabled the scheduler events. If there's a crash, a "backup" instance will be created holding the events of the persistent ring buffer from the previous boot, while the persistent ring buffer will once again start tracing scheduler events of the current boot. Now the user doesn't have to remember to start the persistent ring buffer. It will always have the events started at each boot. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: John Stultz <jstultz@google.com> Link: https://patch.msgid.link/20260331163924.6ccb3896@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-04-02tracing: Remove the backup instance automatically after readMasami Hiramatsu (Google)1-6/+73
Since the backup instance is readonly, after reading all data via pipe, no data is left on the instance. Thus it can be removed safely after closing all files. This also removes it if user resets the ring buffer manually via 'trace' file. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/177502547711.1311542.12572973358010839400.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-04-02tracing: Make the backup instance non-reusableMasami Hiramatsu (Google)1-31/+50
Since there is no reason to reuse the backup instance, make it readonly (but erasable). Note that only backup instances are readonly, because other trace instances will be empty unless it is writable. Only backup instances have copy entries from the original. With this change, most of the trace control files are removed from the backup instance, including eventfs enable/filter etc. # find /sys/kernel/tracing/instances/backup/events/ | wc -l 4093 # find /sys/kernel/tracing/instances/boot_map/events/ | wc -l 9573 Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/177502546939.1311542.1826814401724828930.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-31tracing: Append repeated boot-time tracing parametersWesley Atwell1-1/+30
Some tracing boot parameters already accept delimited value lists, but their __setup() handlers keep only the last instance seen at boot. Make repeated instances append to the same boot-time buffer in the format each parser already consumes. Use a shared trace_append_boot_param() helper for the ftrace filters, trace_options, and kprobe_event boot parameters. This also lets Bootconfig array values work naturally when they expand to repeated param=value entries. Before this change, only the last instance from each repeated parameter survived boot. Link: https://patch.msgid.link/20260330181103.1851230-1-atwellwea@gmail.com Signed-off-by: Wesley Atwell <atwellwea@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-28tracing: Remove tracing_alloc_snapshot() when snapshot isn't definedSteven Rostedt1-7/+0
The function tracing_alloc_snapshot() is only used between trace.c and trace_snapshot.c. When snapshot isn't configured, it's not used at all. The stub function was defined as a global with no users and no prototype causing build issues. Remove the function when snapshot isn't configured as nothing is calling it. Also remove the EXPORT_SYMBOL_GPL() that was associated with it as it's not used outside of the tracing subsystem which also includes any modules. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20260328101946.2c4ef4a5@robin Reported-by: Mark Brown <broonie@kernel.org> Closes: https://lore.kernel.org/all/acb-IuZ4vDkwwQLW@sirena.co.uk/ Fixes: bade44fe546212 (tracing: Move snapshot code out of trace.c and into trace_snapshot.c) Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-26tracing: Move snapshot code out of trace.c and into trace_snapshot.cSteven Rostedt1-1169/+23
The trace.c file was a dumping ground for most tracing code. Start organizing it better by moving various functions out into their own files. Move all the snapshot code, including the max trace code into its own trace_snapshot.c file. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20260324140145.36352d6a@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-24Merge commit 'f35dbac6942171dc4ce9398d1d216a59224590a9' into ↵Steven Rostedt1-9/+27
trace/ring-buffer/core The commit f35dbac69421 ("ring-buffer: Fix to update per-subbuf entries of persistent ring buffer") was a fix and merged upstream. It is needed for some other work in the ring buffer. The current branch has the remote buffer code that is shared with the Arm64 subsystem and can't be rebased. Merge in the upstream commit to allow continuing of the ring buffer work. Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-23tracing: Free up file->private_data for use by individual eventsPetr Pavlu1-2/+0
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>
2026-03-21tracing: Fix trace_marker copy link list updatesSteven Rostedt1-9/+10
When the "copy_trace_marker" option is enabled for an instance, anything written into /sys/kernel/tracing/trace_marker is also copied into that instances buffer. When the option is set, that instance's trace_array descriptor is added to the marker_copies link list. This list is protected by RCU, as all iterations uses an RCU protected list traversal. When the instance is deleted, all the flags that were enabled are cleared. This also clears the copy_trace_marker flag and removes the trace_array descriptor from the list. The issue is after the flags are called, a direct call to update_marker_trace() is performed to clear the flag. This function returns true if the state of the flag changed and false otherwise. If it returns true here, synchronize_rcu() is called to make sure all readers see that its removed from the list. But since the flag was already cleared, the state does not change and the synchronization is never called, leaving a possible UAF bug. Move the clearing of all flags below the updating of the copy_trace_marker option which then makes sure the synchronization is performed. Also use the flag for checking the state in update_marker_trace() instead of looking at if the list is empty. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20260318185512.1b6c7db4@gandalf.local.home Fixes: 7b382efd5e8a ("tracing: Allow the top level trace_marker to write into another instances") Reported-by: Sasha Levin <sashal@kernel.org> Closes: https://lore.kernel.org/all/20260225133122.237275-1-sashal@kernel.org/ Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-21tracing: Fix failure to read user space from system call trace eventsSteven Rostedt1-0/+17
The system call trace events call trace_user_fault_read() to read the user space part of some system calls. This is done by grabbing a per-cpu buffer, disabling migration, enabling preemption, calling copy_from_user(), disabling preemption, enabling migration and checking if the task was preempted while preemption was enabled. If it was, the buffer is considered corrupted and it tries again. There's a safety mechanism that will fail out of this loop if it fails 100 times (with a warning). That warning message was triggered in some pi_futex stress tests. Enabling the sched_switch trace event and traceoff_on_warning, showed the problem: pi_mutex_hammer-1375 [006] d..21 138.981648: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981651: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981656: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981659: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981664: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981667: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981671: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981675: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981679: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981682: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981687: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981690: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981695: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981698: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981703: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981706: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981711: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981714: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981719: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981722: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981727: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981730: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 pi_mutex_hammer-1375 [006] d..21 138.981735: sched_switch: prev_comm=pi_mutex_hammer prev_pid=1375 prev_prio=95 prev_state=R+ ==> next_comm=migration/6 next_pid=47 next_prio=0 migration/6-47 [006] d..2. 138.981738: sched_switch: prev_comm=migration/6 prev_pid=47 prev_prio=0 prev_state=S ==> next_comm=pi_mutex_hammer next_pid=1375 next_prio=95 What happened was the task 1375 was flagged to be migrated. When preemption was enabled, the migration thread woke up to migrate that task, but failed because migration for that task was disabled. This caused the loop to fail to exit because the task scheduled out while trying to read user space. Every time the task enabled preemption the migration thread would schedule in, try to migrate the task, fail and let the task continue. But because the loop would only enable preemption with migration disabled, it would always fail because each time it enabled preemption to read user space, the migration thread would try to migrate it. To solve this, when the loop fails to read user space without being scheduled out, enabled and disable preemption with migration enabled. This will allow the migration task to successfully migrate the task and the next loop should succeed to read user space without being scheduled out. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20260316130734.1858a998@gandalf.local.home Fixes: 64cf7d058a005 ("tracing: Have trace_marker use per-cpu data to read user space") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-09tracing: Add non-consuming read to trace remotesVincent Donnefort1-1/+1
Allow reading the trace file for trace remotes. This performs a non-consuming read of the trace buffer. Link: https://patch.msgid.link/20260309162516.2623589-8-vdonnefort@google.com Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-09tracing: Introduce trace remotesVincent Donnefort1-1/+1
A trace remote relies on ring-buffer remotes to read and control compatible tracing buffers, written by entity such as firmware or hypervisor. Add a Tracefs directory remotes/ that contains all instances of trace remotes. Each instance follows the same hierarchy as any other to ease the support by existing user-space tools. This currently does not provide any event support, which will come later. Link: https://patch.msgid.link/20260309162516.2623589-6-vdonnefort@google.com Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-06tracing: Fix trace_buf_size= cmdline parameter with sizes >= 2GCalvin Owens1-3/+3
Some of the sizing logic through tracer_alloc_buffers() uses int internally, causing unexpected behavior if the user passes a value that does not fit in an int (on my x86 machine, the result is uselessly tiny buffers). Fix by plumbing the parameter's real type (unsigned long) through to the ring buffer allocation functions, which already use unsigned long. It has always been possible to create larger ring buffers via the sysfs interface: this only affects the cmdline parameter. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/bff42a4288aada08bdf74da3f5b67a2c28b761f8.1772852067.git.calvin@wbinvd.org Fixes: 73c5162aa362 ("tracing: keep ring buffer to minimum size till used") Signed-off-by: Calvin Owens <calvin@wbinvd.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-03tracing: Fix WARN_ON in tracing_buffers_mmap_closeQing Wang1-0/+13
When a process forks, the child process copies the parent's VMAs but the user_mapped reference count is not incremented. As a result, when both the parent and child processes exit, tracing_buffers_mmap_close() is called twice. On the second call, user_mapped is already 0, causing the function to return -ENODEV and triggering a WARN_ON. Normally, this isn't an issue as the memory is mapped with VM_DONTCOPY set. But this is only a hint, and the application can call madvise(MADVISE_DOFORK) which resets the VM_DONTCOPY flag. When the application does that, it can trigger this issue on fork. Fix it by incrementing the user_mapped reference count without re-mapping the pages in the VMA's open callback. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Link: https://patch.msgid.link/20260227025842.1085206-1-wangqing7171@gmail.com Fixes: cf9f0f7c4c5bb ("tracing: Allow user-space mapping of the ring-buffer") Reported-by: syzbot+3b5dd2030fe08afdf65d@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3b5dd2030fe08afdf65d Tested-by: syzbot+3b5dd2030fe08afdf65d@syzkaller.appspotmail.com Signed-off-by: Qing Wang <wangqing7171@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-21Convert more 'alloc_obj' cases to default GFP_KERNEL argumentsLinus Torvalds1-6/+3
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>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds1-14/+14
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>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook1-19/+20
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>
2026-02-11tracing: Fix indentation of return statement in print_trace_fmt()Haoyang LIU1-1/+1
The return statement inside the nested if block in print_trace_fmt() is not properly indented, making the code structure unclear. This was flagged by smatch as a warning. Add proper indentation to the return statement to match the kernel coding style and improve readability. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20260210153903.8041-1-tttturtleruss@gmail.com Signed-off-by: Haoyang LIU <tttturtleruss@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-11tracing: Reset last_boot_info if ring buffer is resetMasami Hiramatsu (Google)1-0/+6
Commit 32dc0042528d ("tracing: Reset last-boot buffers when reading out all cpu buffers") resets the last_boot_info when user read out all data via trace_pipe* files. But it is not reset when user resets the buffer from other files. (e.g. write `trace` file) Reset it when the corresponding ring buffer is reset too. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/177071302364.2293046.17895165659153977720.stgit@mhiramat.tok.corp.google.com Fixes: 32dc0042528d ("tracing: Reset last-boot buffers when reading out all cpu buffers") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-11tracing: Fix to set write permission to per-cpu buffer_size_kbMasami Hiramatsu (Google)1-1/+1
Since the per-cpu buffer_size_kb file is writable for changing per-cpu ring buffer size, the file should have the write access permission. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/177071301597.2293046.11683339475076917920.stgit@mhiramat.tok.corp.google.com Fixes: 21ccc9cd7211 ("tracing: Disable "other" permission bits in the tracefs files") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Better separate SNAPSHOT and MAX_TRACE optionsSteven Rostedt1-35/+38
The latency tracers (scheduler, irqsoff, etc) were created when tracing was first added. These tracers required a "snapshot" buffer that was the same size as the ring buffer being written to. When a new max latency was hit, the main ring buffer would swap with the snapshot buffer so that the trace leading up to the latency would be saved in the snapshot buffer (The snapshot buffer is never written to directly and the data within it can be viewed without fear of being overwritten). Later, a new feature was added to allow snapshots to be taken by user space or even event triggers. This created a "snapshot" file that allowed users to trigger a snapshot from user space to save the current trace. The config for this new feature (CONFIG_TRACER_SNAPSHOT) would select the latency tracer config (CONFIG_TRACER_MAX_LATENCY) as it would need all the functionality from it as it already existed. But this was incorrect. As the snapshot feature is really what the latency tracers need and not the other way around. Have CONFIG_TRACER_MAX_TRACE select CONFIG_TRACER_SNAPSHOT where the tracers that needs the max latency buffer selects the TRACE_MAX_TRACE which will then select TRACER_SNAPSHOT. Also, go through trace.c and trace.h and make the code that only needs the TRACER_MAX_TRACE protected by that and the code that always requires the snapshot to be protected by TRACER_SNAPSHOT. 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/20260208183856.767870992@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Add tracer_uses_snapshot() helper to remove #ifdefsSteven Rostedt1-35/+16
Instead of having #ifdef CONFIG_TRACER_MAX_TRACE around every access to the struct tracer's use_max_tr field, add a helper function for that access and if CONFIG_TRACER_MAX_TRACE is not configured it just returns false. 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/20260208183856.599390238@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Rename trace_array field max_buffer to snapshot_bufferSteven Rostedt1-36/+36
When tracing was first added, there were latency tracers that would take a snapshot of the current trace when a new max latency was hit. This snapshot buffer was called "max_buffer". Since then, a snapshot feature was added that allowed user space or event triggers to trigger a snapshot of the current buffer using the same max_buffer of the trace_array. As this snapshot buffer now has a more generic use case, calling it "max_buffer" is confusing. Rename it to snapshot_buffer. 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/20260208183856.428446729@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Move pid filtering into trace_pid.cSteven Rostedt1-242/+0
The trace.c file was a dumping ground for most tracing code. Start organizing it better by moving various functions out into their own files. Move the PID filtering functions from trace.c into its own trace_pid.c file. 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/20260208032450.998330662@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Move trace_printk functions out of trace.c and into trace_printk.cSteven Rostedt1-431/+0
The file trace.c has become a catchall for most things tracing. Start making it smaller by breaking out various aspects into their own files. Move the functions associated to the trace_printk operations out of trace.c and into trace_printk.c. 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/20260208032450.828744197@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Use system_state in trace_printk_init_buffers()Steven Rostedt1-3/+2
The function trace_printk_init_buffers() is used to expand tha trace_printk buffers when trace_printk() is used within the kernel or in modules. On kernel boot up, it holds off from starting the sched switch cmdline recorder, but will start it immediately when it is added by a module. Currently it uses a trick to see if the global_trace buffer has been allocated or not to know if it was called by module load or not. But this is more of a hack, and can not be used when this code is moved out of trace.c. Instead simply look at the system_state and if it is running then it is know that it could only be called by module load. 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/20260208032450.660237094@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Have trace_printk functions use flags instead of using global_traceSteven Rostedt1-4/+5
The trace.c file has become a dumping ground for all tracing code and has become quite large. In order to move the trace_printk functions out of it these functions can not access global_trace directly, as that is something that needs to stay static in trace.c. Instead of testing the trace_array tr pointer to &global_trace, test the tr->flags to see if TRACE_ARRAY_FL_GLOBAL set. 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/20260208032450.491116245@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Make tracing_update_buffers() take NULL for global_traceSteven Rostedt1-1/+4
The trace.c file has become a dumping ground for all tracing code and has become quite large. In order to move the trace_printk functions out of it these functions can not access global_trace directly, as that is something that needs to stay static in trace.c. Have tracing_update_buffers() take NULL for its trace_array to denote it should work on the global_trace top level trace_array allows that function to be used outside of trace.c and still update the global_trace trace_array. 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/20260208032450.318864210@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Make printk_trace global for tracing systemSteven Rostedt1-1/+1
The printk_trace is used to determine which trace_array trace_printk() writes to. By making it a global variable among the tracing subsystem it will allow the trace_printk functions to be moved out of trace.c and still have direct access to that variable. 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/20260208032450.144525891@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Move ftrace_trace_stack() out of trace.c and into trace.hSteven Rostedt1-41/+4
The file trace.c has become a catchall for most things tracing. Start making it smaller by breaking out various aspects into their own files. Make ftrace_trace_stack() into a static inline that tests if stack tracing is enabled and if so to call __ftrace_trace_stack() to do the stack trace. This keeps the test inlined in the fast paths and only does the function call if stack tracing is enabled. 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/20260208032449.974218132@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Move __trace_buffer_{un}lock_*() functions to trace.hSteven Rostedt1-42/+0
The file trace.c has become a catchall for most things tracing. Start making it smaller by breaking out various aspects into their own files. Move the __always_inline functions __trace_buffer_lock_reserve(), __trace_buffer_unlock_commit() and trace_event_setup() into trace.h. The trace.c file will be split up and these functions will be used in more than one of these files. As they are already __always_inline they can easily be moved into the trace.h header file. 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/20260208032449.813550600@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Make tracing_selftest_running global to the tracing subsystemSteven Rostedt1-2/+1
The file trace.c has become a catchall for most things tracing. Start making it smaller by breaking out various aspects into their own files. Make the variable tracing_selftest_running global so that it can be used by other files in the tracing subsystem and trace.c can be split up. 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/20260208032449.648932796@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Make tracing_disabled global for tracing systemSteven Rostedt1-9/+4
The tracing_disabled variable is set to one on boot up to prevent some parts of tracing to access the tracing infrastructure before it is set up. It also can be set after boot if an anomaly is discovered. It is currently a static variable in trace.c and can be accessed via a function call trace_is_disabled(). There's really no reason to use a function call as the tracing subsystem should be able to access it directly. By making the variable accessed directly, code can be moved out of trace.c without adding overhead of a function call to see if tracing is disabled or not. Make tracing_disabled global and remove the tracing_is_disabled() helper function. Also add some "unlikely()"s around tracing_disabled where it's checked in hot paths. 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/20260208032449.483690153@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Clean up use of trace_create_maxlat_file()Steven Rostedt1-22/+16
In trace.c, the function trace_create_maxlat_file() is defined behind the #ifdef CONFIG_TRACER_MAX_TRACE block. The #else part defines it as: #define trace_create_maxlat_file(tr, d_tracer) \ trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, \ d_tracer, tr, &tracing_max_lat_fops) But the one place that it it used has: #ifdef CONFIG_TRACER_MAX_TRACE trace_create_maxlat_file(tr, d_tracer); #endif Which is pointless and also wrong! It only gets created when both CONFIG_TRACE_MAX_TRACE and CONFIG_FS_NOTIFY is defined, but the file itself should not be dependent on CONFIG_FS_NOTIFY. Always create that file when TRACE_MAX_TRACE is defined regardless if FS_NOTIFY is or is not. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://patch.msgid.link/20260207191101.0e014abd@robin Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-08tracing: Move tracing_set_filter_buffering() into trace_events_hist.cSteven Rostedt1-20/+0
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>
2026-02-06tracing: Rename `eval_map_wq` and allow other parts of tracing use itYaxiong Tian1-9/+9
The eval_map_work_func() function, though queued in eval_map_wq, holds the trace_event_sem read-write lock for a long time during kernel boot. This causes blocking issues for other functions. Rename eval_map_wq to trace_init_wq and make it global, thereby allowing other parts of tracing to schedule work on this queue asynchronously and avoiding blockage of the main boot thread. Link: https://patch.msgid.link/20260204015344.162818-1-tianyaxiong@kylinos.cn Suggested-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Yaxiong Tian <tianyaxiong@kylinos.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-01-26tracing: Disable trace_printk buffer on warning tooSteven Rostedt1-0/+9
When /proc/sys/kernel/traceoff_on_warning is set to 1, the top level tracing buffer is disabled when a warning happens. This is very useful when debugging and want the tracing buffer to stop taking new data when a warning triggers keeping the events that lead up to the warning from being overwritten. Now that there is also a persistent ring buffer and an option to have trace_printk go to that buffer, the same holds true for that buffer. A warning could happen just before a crash but still write enough events to lose the events that lead up to the first warning that was the reason for the crash. When /proc/sys/kernel/traceoff_on_warning is set to 1 and a warning is triggered, not only disable the top level tracing buffer, but also disable the buffer that trace_printk()s are written to. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://patch.msgid.link/20260121093858.5c5d7e7b@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-01-26tracing: Check the return value of tracing_update_buffers()Steven Rostedt1-3/+4
In the very unlikely event that tracing_update_buffers() fails in trace_printk_init_buffers(), report the failure so that it is known. Link: https://lore.kernel.org/all/20220917020353.3836285-1-floridsleeves@gmail.com/ Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20260107161510.4dc98b15@gandalf.local.home Suggested-by: Li Zhong <floridsleeves@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-01-23tracing: Avoid possible signed 64-bit truncationIan Rogers1-4/+4