linux-toradex.git/kernel/trace/trace.c, branch v7.0-rc1

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

2026-02-22T04:03:00+00:00

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

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using

    git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

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

tracing: Fix indentation of return statement in print_trace_fmt()

2026-02-12T02:58:21+00:00

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 
Link: https://patch.msgid.link/20260210153903.8041-1-tttturtleruss@gmail.com
Signed-off-by: Haoyang LIU 
Acked-by: Masami Hiramatsu (Google) 
Signed-off-by: Steven Rostedt (Google)

tracing: Reset last_boot_info if ring buffer is reset

2026-02-11T15:49:48+00:00

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 
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) 
Signed-off-by: Steven Rostedt (Google)

tracing: Fix to set write permission to per-cpu buffer_size_kb

2026-02-11T15:48:44+00:00

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 
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) 
Signed-off-by: Steven Rostedt (Google)

tracing: Better separate SNAPSHOT and MAX_TRACE options

2026-02-09T02:01:13+00:00

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 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20260208183856.767870992@kernel.org
Signed-off-by: Steven Rostedt (Google)

tracing: Add tracer_uses_snapshot() helper to remove #ifdefs

2026-02-09T02:01:13+00:00

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 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20260208183856.599390238@kernel.org
Signed-off-by: Steven Rostedt (Google)

tracing: Rename trace_array field max_buffer to snapshot_buffer

2026-02-09T02:01:13+00:00

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 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20260208183856.428446729@kernel.org
Signed-off-by: Steven Rostedt (Google)

tracing: Move pid filtering into trace_pid.c

2026-02-09T02:01:13+00:00

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 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20260208032450.998330662@kernel.org
Signed-off-by: Steven Rostedt (Google)