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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix several tracefs files that did not take the trace_array reference
A trace instance can be created and destroyed in the tracefs
"instances" directory via mkdir and rmdir respectively. The instance
is represented by a trace_array descriptor.
Most tracefs files pass the trace_array as the private data of the
inode to the open/read/write functions. Since there is no locking
between the time a task opens a file and the deletion of the instance
(and the freeing of the trace_array), each open needs to get a
reference to the trace_array and each close must remove it.
An instance can't be removed if there's any reference taken on its
trace_array. The open function uses trace_array_get() that takes a
lock (preventing removal of instances) and iterates the list of all
existing trace_arrays and if it finds a match, it takes the reference
and releases the lock. If it doesn't find a match, it causes the open
to return -ENODEV.
There were some added files that did not take the trace_array
reference on open that needed to be fixed. Sashiko also correctly
pointed out that there were some files that took an address of an
field or element of the trace_array which had a pointer back to the
trace_array to take its reference on open. But this leaves a slight
race between referencing this element to get the trace_array as the
element itself could be freed. To solve this, some helper functions
were created to look for trace_arrays with this field or element in
the search so that the element did not have to be dereferenced before
the trace_array's reference was taken.
- Add a lock around ftrace_ops initialization
When a ftrace_ops is first used by ftrace, some internal
initialization is performed on the ops. But if multiple tasks were
calling functions that did this initialization, it could race and
perform doing the initialization more than once, corrupting the
internal data. Add a lock in the initialization code to prevent this
from happening.
- Fix splice reads on mmapped buffers
The logic in the ring buffer splice code for mmapped buffers is
supposed to do a copy of the memory as the mapped buffers can't be
given to splice. But there was an if statement within the copy code
that would return a -1 if a request for a full page was done and it
wasn't a partial read. This is because this logic was written before
mmapped buffers existed and this case didn't make sense at the time.
For mmapped buffers it makes perfect sense and by returning early can
drop a lot of pages unnecessarily.
- Have the persistent ring buffer validation check nr_subbufs
Sashiko reported that the validation code was relying on the saved
nr_subbufs to match the calculated nr_pages + 1 and if they were off,
that the code could cause corruption. Sashiko is correct, and the
saved nr_subbufs should be validated before assuming it is correct.
- Do not allow more than one instance with the same name on cmdline
If an admin were to add more than one trace instances with the same
name they all would be created, but only the first one would be
accessible via tracefs. This used to not be allowed but some
restructuring of code has since made it possible.
- Fix the race between subbuf resize and trace_pipe_raw readers
If a task was reading trace_pipe_raw while another task was changing
the ring buffer subbuf size, it could crash the reader. The
trace_pipe_raw readers do get their own copy of the page from the
buffer, but the code needs some restructuring to not have the resize
of the subbuffers cause issues.
- Cap the size of the mapped (static) ring buffer nr_pages
The meta data used for ring buffer mapped buffers is 32 bit in size.
A normal ring buffer could (in theory) have more than 4 billion
pages. But this is not allowed by mapped buffers, so enforce it.
* tag 'trace-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Use a macro for static buffer bits
tracing: Fix comment in tracing_buffers_splice_read()
ring-buffer: Prevent truncation of nr_pages / nr_subbufs
ring-buffer: Cap static ring buffer nr_pages
tracing: Fix subbuf resize races with trace_pipe_raw readers
tracing: Fix to avoid creating trace instances with duplicate names
ring-buffer: Add checking nr_subbufs to persistent ring buffer validation
ring-buffer: Allow splice reads on static buffers
tracing: Take trace_array reference when opening options file
ftrace: Synchronize the initialization of ftrace_ops
ftrace: Take trace_array reference before accessing its ftrace_ops
tracing: Have show_event_filters/triggers files take trace array ref
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This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci
This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.
Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.
Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>
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Instead of hard coding 30 for the number of bits used for the static
buffer ids in two places, create a macro. This way if it changes in the
future, it will change in all the locations that use it.
Link: https://patch.msgid.link/20260904151641.17eae0aa@gandalf.local.home
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The comment about returning an error if the read fails on the first
iteration is slightly incorrect. It makes it sound like the only reason it
could fail on a later iteration is if the subbuf order changed. That is
incorrect, it could also fail if the length passed in was not a multiple
of the subbuf size. Fix the comment.
Link: https://lore.kernel.org/all/20260904143527.40e73d36@gandalf.local.home/
Link: https://patch.msgid.link/20260904144902.506862a1@gandalf.local.home
Fixes: dae8dda341d2 ("tracing: Fix subbuf resize races with trace_pipe_raw readers")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Although ring_buffer_per_cpu::nr_pages is defined as unsigned long, it
is capped to 32-bits in a few places, limiting the operations possible
on a very large buffer. Use `unsigned long` where appropriate and
prevent truncation of values using nr_pages (or nr_subbufs).
While at it, subbuf_size must be at least `unsigned int`.
Note that persistent, remote and user-mapped ring buffers are capping
the number of pages to 30 bits already, making "int" safe in many
places.
Link: https://patch.msgid.link/20260904164450.1345852-5-vdonnefort@google.com
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Static ring buffers (i.e. persistent, user-mapped and remote) rely on
the bpage::id field. The number of pages for those ring buffers must fit
into that variable. Enforce this limit on ring buffer creation or
user-mapping.
While at it, prevent nr_pages underflow when allocating a persistent
buffer.
Link: https://patch.msgid.link/20260904164450.1345852-4-vdonnefort@google.com
Fixes: be68d63a139b ("ring-buffer: Add ring_buffer_alloc_range()")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Concurrent subbuffer resizes may crash trace_pipe_raw readers or leak
uninitialized memory to userspace due to stale size values.
Modify ring_buffer_alloc_read_page() to handle the resizing of an
existing buffer_data_read_page if necessary and add a new
ring_buffer_read_page_size(). This new function enables ring-buffer
buffer_data_read_page users to not call the racy
ring_buffer_subbuf_size_get(). This makes the spare_size member of
ftrace_buffer_info redundant.
Finally, handle buffer_data_read_page/reader_page order discrepancy in
ring_buffer_read_page(). On a mismatch simply copy manually the data to
the buffer_data_read_page.
Link: https://lore.kernel.org/all/20260817140812.2C7D41F00A3A@smtp.kernel.org/
Link: https://patch.msgid.link/20260904164450.1345852-3-vdonnefort@google.com
Fixes: bce761d75745 ("ring-buffer: Read and write to ring buffers with custom sub buffer size")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Since commit e645535a954a ("tracing: Add option to use memmapped
memory for trace boot instance") changed trace_array_get_by_name() to
trace_array_create_systems(), enable_instances() does not reuse the
same name instance. Therefore, if an administrator mistakenly specifies
multiple `trace_instance=` options with duplicate names, all are
created but only the first is accessible via tracefs.
Check whether an instance with the same name already exists before
creating a new one, and reject duplicates with a warning.
Link: https://patch.msgid.link/178847790399.283263.5313150997200138426.stgit@devnote2
Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Sashiko reported that the code was using meta->nr_subbufs without making
sure that it matched the nr_pages + 1 on data that was assuming the two
were the same.
Add a check to the persistent ring buffer validation code to make sure
that the saved nr_subbufs matches what we expect.
Link: https://patch.msgid.link/20260903132728.7fb27d34@gandalf.local.home
Fixes: f5b95f1fa2ef3 ("ring-buffer: Validate the persistent meta data subbuf array")
Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/all/20260901164836.D962D1F000E9@smtp.kernel.org/
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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ring_buffer_read_page() rejects splice (full=1) reads on static buffers
(that is user-mapped, persistent or remote) because !read check assumes
unread pages must be swapped. However for those buffers we have no other
choice than memcpy the data.
For the memcpy case, only return an error when the writer is still on
the reader page for the splice interface to wait.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260901155445.1475405-2-vdonnefort@google.com
Fixes: 117c39200d9d ("ring-buffer: Introducing ring-buffer mapping functions")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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multiple probes
The fields of a probe-based dynamic event (kprobe, uprobe, eprobe and
fprobe events) are created in traceprobe_define_arg_fields() by handing
the probe_arg name/type strings to trace_define_field(), which only
stores the pointers without copying. Those strings are owned by the
trace_probe and are freed when that probe is removed.
An event can have several probes attached. The field list is defined
only once, by the first probe that registers the event, but it is kept
alive by any surviving sibling probe. Deleting just that first probe by
symbol -
# primary A: fields are defined from A's args
echo 'p:kprobes/ev vfs_read a1=$arg1' > kprobe_events
# append B: shares A's event call
echo 'p:kprobes/ev vfs_write a1=$arg1' >> kprobe_events
# delete only A (matched by symbol), B survives
echo '-:kprobes/ev vfs_read' >> kprobe_events
frees A's args (trace_probe_cleanup() -> traceprobe_free_probe_arg()),
but trace_probe_unlink() keeps the trace_probe_event because the probe
list is not empty. The event call stays registered via B while its
fields now reference freed memory. Any field lookup then reads it, e.g.
echo 'a1 == 1' > events/kprobes/ev/filter
BUG: KASAN: slab-use-after-free in strcmp+0xa7/0xb0
Call Trace:
strcmp
trace_find_event_field
parse_pred
process_preds
create_filter
apply_event_filter
event_filter_write
field->name references parg->name (kstrdup'd, freed with the probe) and,
for array arguments, field->type references parg->fmt (kmalloc'd, freed
with the probe) - the scalar type otherwise points at the static
fmttype rodata, which is safe.
Have traceprobe_define_arg_fields() duplicate the name and type strings
and anchor the copies on the trace_probe_event, which embeds the event
call and outlives every individual probe; trace_probe_event_free()
releases them.
The reproducer above triggers reliably; the field lookup and the delete
both run under event_mutex, so this is a dangling reference after
removal rather than a race.
The issue was found by the autokbug dynamic kernel fuzzer at Tencent
Yunding Lab.
Link: https://lore.kernel.org/all/20260826030009.1855331-1-bsdhenrymartin@gmail.com/
Fixes: ca89bc071d5e4 ("tracing/kprobe: Add multi-probe per event support")
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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Fix code block indentation introduced by commit f21834524025
("tracing/probes: Support field specifier option for typecast").
Link: https://lore.kernel.org/all/178827252027.123716.7095571176291547259.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
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btf_find_struct_member() traverses into nested anonymous structures and
unions to find a struct member. However, get_bitoffset_of_field() in
trace_probe.c checked btf_type_kflag(type) using the outer parent type
instead of the actual anonymous structure/union that directly contains
the found member.
If the parent structure and anonymous structure have mismatched kflags
(e.g., the parent has kflag=0 while the anonymous structure has kflag=1
because it contains bitfields), the bitfield size encoded in the upper
8 bits of member->offset is erroneously treated as part of the byte/bit
offset, corrupting the resolved offset and failing to set last_bitsize.
Similarly, btf_find_struct_member() pushed anonymous member offsets
onto anon_stack without masking BTF_MEMBER_BIT_OFFSET() when kflag is set.
To fix this problem, update btf_find_struct_member() to return actual
containing structure/union type via member_type, use appropriate
__btf_member_bit_offset() to get bit offset, and use member_type for
btf_type_kflag() in get_bitoffset_of_field().
Link: https://lore.kernel.org/all/178827250904.123716.17452648791331881284.stgit@devnote2/
Fixes: c440adfbe302 ("tracing/probes: Support BTF based data structure field access")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260822095110.0772E1F000E9@smtp.kernel.org/
Assisted-by: Antigravity:gemini-3.7-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
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btf_find_struct_member
btf_find_struct_member() traverses into nested anonymous structures
and unions by pushing members with !member->name_off onto anon_stack.
However, it does not consider the unnamed bitfields (e.g. `int : 5`
or `unsigned int : 0`) which also have member->name_off == 0.
If such an unnamed bitfield is pushed to anon_stack, the
btf_find_struct_member() return an error even if there are other
valid entries in anon_stack.
To fix this, only push unnamed struct/union members to anon_stack.
Also move the btf_type_is_struct() check to the entry of this function
because now it is sure only struct/union are pushed to anon_stack.
Link: https://lore.kernel.org/all/178827249775.123716.7813217688423513612.stgit@devnote2/
Fixes: 302db0f5b3d8 ("tracing/probes: Add a function to search a member of a struct/union")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260830143859.D56991F00A3D@smtp.kernel.org/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
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The options files do not take the trace_array reference for the options
they represent. This could cause a use-after-free kernel crash if one of
these files is opened by one task and another task removes the instance
that the option is for. Because it doesn't take a reference upon opening,
it will not stop the removal which will free the options descriptor that
is being used.
As the options are somewhat dynamic in their creation at boot up, each
file represents a flag in the trace_array. The trace_array has an array of
indexes to represent each of these flags that is stored in the
trace_flags_index array. The address of the index array element is used to
pass to the inode->i_private pointer. Then that element is read which
holds the index (which represents the flag) and then the index is used to
calculate the trace_array descriptor from its trace_flags_index array.
One issue is that the index element can not be referenced until the
trace_array's reference is taken. To handle this, create a new helper
function called: trace_array_options_get() that will iterate all the
existing trace_arrays in the ftrace_trace_arrays list (under the
trace_types_lock), and compare the passed in address of the index element
with the entire array of the trace_array's trace_flags_index array.
If it matches, then up the corresponding trace_array's reference and
return.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902121918.5a9e9d1b@gandalf.local.home
Fixes: 577b785f55168 ("tracing: add tracer dependent options to options directory")
Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/linux-trace-kernel/20260828135858.2AC501F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.
Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The trace instance files set_ftrace_filter and set_ftrace_notrace was
updated to work with specific trace instances (trace_arrays). The issue is
that when these files are opened, there is a small race window where it
will use the ftrace_ops from the inode->private pointer to get a reference
to the trace_array and then take its reference. The problem is that the
ftrace_ops itself could be freed. If the rmdir on the instance happens at
the same time the set_ftrace_filter file is opened, the rmdir could have
also freed the ftrace_ops and referencing it will cause a use-after-free
bug and crash the kernel.
Instead, pass in the trace_array as the file private data (NULL for the
top level instance), and then pass both the trace_array and the ftrace_ops
to the ftrace_regex_open() function. If the trace_array is NULL, then it
just uses the ftrace_ops without the need to take its reference (like
normal). If the ftrace_ops is NULL, that is only the case for the top
level instance and the global_ops can be used.
This allows the trace_array to have its reference incremented before
touching the ftrace_ops that could also be freed when the instance is.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260828223901.29e26edb@robin
Fixes: 591dffdade9f0 ("ftrace: Allow for function tracing instance to filter functions")
Reported-by: Breno Leitao <leitao@debian.org>
Tested-by: Breno Leitao <leitao@debian.org>
Closes: https://lore.kernel.org/all/apGORjltZgAiAYHT@gmail.com/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The newly added files show_event_filters and show_event_triggers that show
all filters or triggers that are set within the trace array do not take a
reference for the trace array it is showing. Without taking a reference,
the trace_array may be freed via "rmdir" while a task is reading one of
theses files. Those files iterate all the events within an instance
(trace_array) and nothing prevents that instance from being freed while
its data is being read. This causes a use-after-free crash.
Have the open of both those files take the trace_array reference via the
trace_array_get() that prevents the trace_array from being freed while the
files are opened.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260828094153.17b95037@gandalf.local.home
Fixes: 729757b96a662 ("tracing: Add show_event_filters to expose active event filters")
Fixes: 6a80838814eea ("tracing: Add show_event_triggers to expose active event triggers")
Reported-by: Farhad Alemi <farhad.alemi@berkeley.edu>
Closes: https://lore.kernel.org/all/CA+0ovCjerKZJLwXScM9bF2ga2rLi4_XOpUfK41NDbENpeu98jA@mail.gmail.com/
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Sashiko pointed out the some of the scope cleanups for free_uprobe
could get an error pointer. Handle this case in free_uprobe
to prevent a crash.
On the other hand the macro doesn't need the guard because
free_uprobe itself already does the check.
Link: https://lore.kernel.org/all/20260831150651.1134594-2-ak@kernel.org/
Assisted-by: omp:gpt-5.6-luna sashiko
Signed-off-by: Andi Kleen <ak@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix error output of boot instance creation failure
Currently if a boot instance creation fails, instead of printing out
the name of the instance that failed, it prints "(null)". That is
because it prints "cur_str" that had already been processed by
strsep(). Print the saved name instead.
While at it, print the error code of the failure.
- Fix use-after-free for same named historgrams
Histograms can be named so that they can be used in multiple events.
But if the named histogram has a variable attached, the second event
that uses the named histogram which duplicates it and needs to free
the original after duplication leaves the old variable in place and
still visible. If another histogram uses than variable, it will use
the stale one which will try to reference the freed duplicate
histogram and crash the kernel.
Free the duplicate variables along with the duplicated histogram
data.
- Check return value of kthread_run() in event self test
The events self tests uses a kthread for testing but does not check
if it succeeded in creating a kthread. If the kthread creation were
to fail, the code will still try to call kthread_stop() on the error
returned.
- Fix race between reading trace_pipe and updating subbuffer size
If a user is reading the trace_pipe file at the same time they update
the ring buffer sub-buffer size, can cause the trace_pipe read to
read stale data. Add trace_access_lock() around updating the ring
buffer sub-buffer size.
- Fix eventfs_inode on failure path in creation of the events directory
In the creation of the "events" directory, if after allocating the
eventfs_inode a failure is detected, it calls cleanup_ei() which
calls free_ei(). The free_ei() will test if eventfs_inode being freed
has no children. It is a bug if it does. But on the failure case of
the creation of the "events" directory, the children lists have not
yet been initialized and the free will trigger a warning because
list_empty() on an uninitialized list returns false.
Move the initialization into init_ei() where it makes more sense and
makes sure that a created eventfs_inode has its lists initialized
upon creation.
- Check return value of kthread_run() in ftrace direct sample code
The sample code that shows how to use the ftrace direct calls does
not test the return of kthread_run() to see if it succeeds. Return a
failure if the kthread_run() doesn't succeed.
- Clear user events state on fork in case of alloc failure
On fork, the child gets a pointer to the parent's user events state.
It makes a copy of it then updates the child's pointer to it. But if
the allocation fails, the duplication function leaves the child with
a pointer to its parent's descriptor. When the child cleans up its
data, it will free the parent's descriptor while the parent is still
using it.
In the duplication function, set the child's user_event_mm to NULL
before testing if the allocation succeeded, and when it exits it will
not free the parent's descriptor.
- Fix retry exhaustion in simple ring buffer reader swap
simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
post-decrements it only after a failed link replacement. On the final
attempt, a successful replacement leaves retry at zero, while a
failed replacement leaves it at -1.
But the check for success expects the retry value to be non-zero and
exits with an error on zero. This is the opposite result. Fix it.
- Fail nicely when the remote swap_reader_page() returns an error
Currently, if the swap_reader_page() of a remote buffer fails, it
triggers a WARN_ON_ONCE() and continues normally. Instead, have it
exit with an error and a pr_warn() print instead of a full WARNING.
* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Stop remote reader update when page swap fails
tracing: Fix retry exhaustion in simple ring buffer reader swap
tracing/user_events: Clear copied tracing state before fork duplication
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
eventfs: Initialize ei->children and ei->list in init_ei()
tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
tracing: Fix crash passing ERR_PTR to kthread_stop()
tracing: Fix use-after-free with same-name named triggers
tracing: Fix logged instance name on creation failure
|
|
The remote swap_reader_page callback can return -EBUSY when the writer
moves the head before the remote catches it, particularly during an event
storm on a small buffer. __rb_get_reader_page_from_remote() currently
warns about that failure but continues with the unchanged reader ID and
rearranges the local page list as though the swap succeeded.
Handle the callback failure as a recoverable error. Report it with
pr_warn_ratelimited() and return NULL. Callers already handle a NULL reader
page as a failed attempt. This avoids splicing the same page as both the
previous and new reader without flooding the log under contention.
Cc: stable@vger.kernel.org
Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes")
Link: https://patch.msgid.link/20260825-kernel-patch-1-v2-2-bb3461807a32@gmail.com
Assisted-by: LLM sparse
Signed-off-by: Ivan Immanuel Shaji <ivanimmanuel1234@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
|
|
simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
post-decrements it only after a failed link replacement. On the final
attempt, a successful replacement leaves retry at zero, while a failed
replacement leaves it at -1.
The current !retry test reverses both outcomes. It returns an error after
a successful final replacement, leaving the link update complete but the
reader bookkeeping unfinished. After a failed final replacement, it
falls through and updates the head and reader pointers as though the
replacement succeeded, which can corrupt the ring.
Treat only a negative counter as exhaustion and return the documented
-EBUSY error.
Cc: stable@vger.kernel.org
Fixes: 34e5b958bdad ("tracing: Introduce simple_ring_buffer")
Link: https://patch.msgid.link/20260825-kernel-patch-1-v2-1-bb3461807a32@gmail.com
Assisted-by: LLM sparse
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Ivan Immanuel Shaji <ivanimmanuel1234@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
|
|
dup_task_struct() copies user_event_mm from the parent into the child,
without grabbing a reference to it. user_event_mm_dup() should
replace it, but it leaves that copied pointer unmodified if
user_event_mm_alloc() fails.
When the child exits, user_event_mm_remove() decrements a reference
the child never owned, which ultimately frees user_event_mm, while
the parent still as a stale pointer to it. This creates a UAF, which
KASAN reports as:
BUG: KASAN: slab-use-after-free in
current_user_event_mm+0x51/0x1d0 Write of size 4 at addr
ffff888005010d30 by task init/44
Call Trace:
<TASK>
kasan_report+0xce/0x100
kasan_check_range+0x10f/0x1e0
current_user_event_mm+0x51/0x1d0
user_events_ioctl+0x82e/0x15c0
__x64_sys_ioctl+0x139/0x1c0
do_syscall_64+0xce/0x450
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Allocated by task 44:
__kasan_kmalloc+0x8f/0xa0
__kmalloc_cache_noprof+0x180/0x3a0
user_event_mm_alloc+0x3c/0x1f0
current_user_event_mm+0x88/0x1d0
Freed by task 42:
__kasan_slab_free+0x43/0x70
kfree+0x13a/0x390
process_one_work+0x696/0xf90
worker_thread+0x420/0xba0
The fix simply clears the copied pointer before any possible failure.
In case of failure, the child then has nothing to free.
Cc: stable@vger.kernel.org
Fixes: 7235759084a4 ("tracing/user_events: Use remote writes for event enablement")
Link: https://patch.msgid.link/20260827184321.2964601-2-Jeremy.Jean@oss.cyber.gouv.fr
Assisted-by: Codex:gpt-5
Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr>
Reviewed-by: Bradley Morgan <brads@mainlining.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
|
|
Writing to buffer_subbuf_size_kb calls ring_buffer_subbuf_order_set(),
which frees every sub-buffer of the ring buffer, including the reader
page, and replaces them with newly allocated ones.
Readers of trace_pipe hold pointers into those pages. ring_buffer_peek()
looks up an event under cpu_buffer->reader_lock but returns the event
pointer after dropping the lock, and peek_next_entry() then calls
ring_buffer_event_length() and ring_buffer_event_data() on it. If the
sub-buffer order is changed in that window, the reader dereferences
freed memory:
BUG: KASAN: use-after-free in ring_buffer_peek+0x3e0/0x430
Read of size 1 at addr ffff88802a4cf010 by task syz-executor989/6002
Freed by:
free_buffer_page kernel/trace/ring_buffer.c:398 [inline]
ring_buffer_subbuf_order_set+0x1325/0x18e0 kernel/trace/ring_buffer.c:7444
buffer_subbuf_size_write+0x182/0x280 kernel/trace/trace.c:8221
Take trace_access_lock(RING_BUFFER_ALL_CPUS) around the order change.
This is the lock trace_pipe readers already hold across their entire
peek-and-print loop, so the swap can no longer race with a reader that
is dereferencing a peeked event.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260817140655.5694-1-kartikey406@gmail.com
Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page")
Reported-by: syzbot+685955db58555575fdd2@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=685955db58555575fdd2
Tested-by: syzbot+685955db58555575fdd2@syzkaller.appspotmail.com
Reviewed-by: Bradley Morgan <include@grrlz.net>
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
|
|
event_test_stuff() calls kthread_run() and unconditionally passes the
returned task_struct pointer to kthread_stop(). kthread_run() returns an
error pointer such as ERR_PTR(-ENOMEM) when kthread creation fails, for
example under memory pressure during the boot-time event self-test.
kthread_stop() then dereferences the invalid pointer, crashing the kernel.
Check the result of kthread_run() before passing it to kthread_stop(). Use
WARN_ON() so that a failure to create the self-test thread does not go
unnoticed, matching the ring-buffer self-test fix in commit
91542863abad ("ring-buffer: Fix crash passing ERR_PTR to kthread_stop()").
Cc: stable@vger.kernel.org
Fixes: e6187007d6c3 ("tracing/events: add startup tests for events")
Link: https://patch.msgid.link/20260817120642.668375-3-sh_def@163.com
Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
|
|
When two hist triggers on different events are registered with the same
name=, the second one reuses the first as named_data. Both are added to
tr->hist_vars by save_hist_vars() during event_hist_trigger_parse(),
because save_hist_vars() is called before event_trigger_register() while
the named reuse is only detected later, in hist_register_trigger().
In the named-data branch hist_register_trigger() then frees the second
histogram's hist_data via destroy_hist_data(), but never removes its
tr->hist_vars list entry, leaving a dangling pointer and leaking the
trace_array reference it holds.
A later hist trigger that references a variable makes find_var_file()
walk tr->hist_vars and dereference the freed hist_data. The bug is
reproducible from userspace by writing three hist triggers to tracefs:
cd /sys/kernel/tracing
echo 'hist:keys=common_pid:x=common_pid:name=mh' > events/sched/sched_switch/trigger
echo 'hist:keys=common_pid:x=common_pid:name=mh' > events/sched/sched_process_fork/trigger
echo 'hist:keys=common_pid:vals=$x' > events/sched/sched_process_exit/trigger
The third write panics the kernel:
BUG: KASAN: slab-use-after-free in find_var_file.part.0+0x272/0x290
Read of size 8 at addr ffff888001f8a0e0 by task sh/1
CPU: 1 UID: 0 PID: 1 Comm: sh Tainted: G D N
Call Trace:
find_var_file.part.0
find_event_var
parse_atom
parse_expr
__create_val_field
event_hist_trigger_parse
trigger_process_regex
event_trigger_write
vfs_write
ksys_write
do_syscall_64
entry_SYSCALL_64_after_hwframe
Allocated by task 1:
event_hist_trigger_parse
Freed by task 1:
hist_register_trigger+0x618/0xa30
event_hist_trigger_parse
The buggy address belongs to freed 2048-byte region
Oops: general protection fault ... RIP: find_var_file.part.0
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
Fix by removing the hist_data from tr->hist_vars and releasing the
trace_array reference in the named-data branch of hist_register_trigger()
before freeing the hist_data.
Cc: stable@vger.kernel.org
Fixes: 6f86bdeab633 ("tracing: Fix bad hist from corrupting named_triggers list")
Link: https://patch.msgid.link/20260816100427.33642-3-sh_def@163.com
Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
|
|
When boot instance creation fails, the kernel incorrectly logs "(null)"
as the instance name because strsep() consumes curr_str entirely during
parsing.
Print the properly parsed name variable instead. And while at it log
the error code.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260807085423.4175161-1-vdonnefort@google.com
Fixes: cb1f98c5e574 ("tracing: Add creation of instances at boot command line")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "mm: drop "sub" prefix from various places" (Dev Jain)
page->folio conversion and a naming cleanup
- "mm/kasan: remove redundant initialization for kasan_flag_write_only"
(Igor Putko)
KASAN cleanup work
- "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)
Small speedup in the pagecaache read code
- "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)
Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
allocations when the caller asked for GFP_NOFS or GFP_NOIO
- "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
Leitao)
Avoid a soft lockup watchdog trigger from the kmemleak scanning code
in extreme situations
- "mm/page_owner: misc cleanups" (Ye Liu)
Cleanups to the page_owner code. For some reason lots of people have
been working on the page_owner code this cycle.
- "mm: convert to walk_page_range_vma() to eliminate find_vma()"
(Kefeng Wang)
Simplify and accelerate the page walking library function
- "mm/migrate: preparatory cleanups for batch copy and offload"
(Shivank Garg)
Cleanups in the migration code
- "mm/page_owner: add per-fd filter infrastructure for print_mode and
NUMA filtering" (Zhen Ni)
Per-fd filtering to page_owner in order to reduce the sometimes vast
amount of output it can produce
- "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)
Fixes and preparatory cleanups around bootmem HugeTLB handling,
sparse initialization ordering, and related vmemmap setup
- "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)
Reduce lock contention in zs_free(), which dominates the unmap path
under memory pressure on Android (LMK kills) and on x86 servers
running zswap-heavy workloads.
Up to 1.83x improvement in microbenchmarking.
- "move alloc_tag.c file under mm/" (Suren Baghdasaryan)
- "samples/damon: handle damon_{start,stop}() failures" (SJ Park)
Fix improper handling of damon_start(), damon_stop(), and
damon_call() failures across DAMON sample modules to prevent
potential memory leaks, operation disruptions and use-after-free
bugs
- "mm/damon/sysfs: kobject_del() directories that users can
create/remove" (SJ Park)
Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
causeing creation failures due to duplicate directory names by adding
missing kobject_del() calls before creating new directories
- "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)
Clean up the core pte handling code
- "selftests/damon: misc fixes for test bugs" (Kunwu Chan)
Fix several bugs in the DAMON selftests
- "selftests/damon: fix memcg_path staging handling" (Cheng Nie)
Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
add a test case for it in sysfs.py.
- "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)
Selftest coverage for DAMON's refresh_ms sysfs feature by updating
the test control module and verifying that scheme stats update
automatically without manual intervention
- "mm/damon: five misc fixups" (Akinobu Mita)
Miscellaneous DAMON fixups.
- "mm/damon/core: detect internal variation above max_nr_regions/2"
(Jiayuan Chen)
Fix DAMON's region splitting behavior when region counts exceed half
the maximum budget by dynamically scaling down the split fraction as
the limit approaches, preventing large regions from staying un-split,
and add corresponding KUnit test coverage
- "mm: preparatory patches for PMD level swap entries" (Usama Arif)
Refactor and clean up PMD softleaf helpers, call sites, and
architecture flags to lay the groundwork for a follow-up series that
introduces PMD page table swap entries
- "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
Park)
Update DAMON design and ABI documentation, expands unit and selftest
coverage, optimize damon_commit_target_regions(), and clean up
recently added sysfs interface code for better readability
- "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
(Usama Arif)
Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
userspace event notifications and refactor v1-only eventfd handling
into mm/memcontrol-v1.c to reduce memory overhead and code complexity
- "selftests/mm: refactor pkey helpers and fix mmap error handling"
(Hongfu Li)
Refactor pkeys shared tracing and assertion helpers into a common
file, unify protection key selftests to use consistent diagnostic
logging and assertions, and enforce standardized MAP_FAILED return
checks for mmap() calls across the tests
- "mm/damon: optimize out nr_accesses_bp" (SJ Park)
Replace the error-prone, continuously updated nr_accesses_bp field in
damon_region with an on-demand moving sum function, reducing
structure memory overhead and avoiding state corruption bugs
- "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)
Decouple HugeTLB folio allocation from VMA dependencies by
introducing hugetlb_alloc_folio(), enabling subsystems like
guest_memfd to allocate HugeTLB folios without standard VMA
reservations or pseudo-VMAs
- "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)
Integrate DAMON's probe_hits attribute counter into the pseudo moving
sum infrastructure, enabling real-time, online monitoring without
waiting for full aggregation intervals
- "mm: Some cleanups for page allocator APIs" (Brendan Jackman)
Simplify and refactor the page allocator entry points and flags by
unifying allocation paths, adding internal alloc_flags arguments, and
eliminating redundant __ prefixed alloc_pages variants.
- "Fix incorrect access of hugetlb pte entries" (Dev Jain)
Enforce the consistent use of huge_ptep_get() instead of ptep_get()
for HugeTLB entries and fixes an unaligned address issue in arm64's
huge_ptep_get() implementation
- "mm/damon: validate all parameters in the core" (SJ Park)
Consolidate parameter validation into the DAMON core specifically
within damon_start() and damon_commit_ctx() to centralize error
checking, eliminate caller-side redundant checks and to improve
maintenance efficiency
- "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
Chen)
Rename is_need() to filter_record() for clearer return semantics, fix
per-record allocation memory leaks and bound output copies in
search_pattern() to address an existing buffer issue
- "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)
Mitigate a system-wide stall which occurs when a cgroup is removed
while one of its memory control files is doing synchronous reclaim
- "mm/memory-failure: add panic option for unrecoverable pages" (Breno
Leitao)
Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
that immediately panics the kernel on unrecoverable memory errors in
kernel-owned pages to preserve error context and prevent delayed,
silent data corruption
- "mm/damon: refactor damon_{start,stop,commit}() for simple error
handling" (SJ Park)
Refactor the DAMON core API functions to guarantee that all contexts
are fully stopped when damon_start(), damon_stop(), or damon_commit()
fail, eliminating the need for complex and error-prone caller-side
cleanup code
- "Keep tail page private zero at free and folio split" (Zi Yan)
Add checks to ensure tail_page->private is zero when freeing compound
or high-order pages and when promoting tail pages during large folio
splits. By validating these fields at free and split time, it allows
the removal of redundant private field clearing inside
prep_compound_tail()
- "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
Song)
Eliminate redundant lru_add_drain() calls in
wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
contention and system overhead
By validating folio refcounts against the LRU cache before draining
and removing unnecessary drains in the swap path, it achieves up to a
30.5% reduction in drain calls during heavy swap workloads
- "mm: clean up folio LRU and swap declarations" (Jianyue Wu)
Reorganize folio LRU and swap code by relocating page-cluster state
to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
MM-internal reclaim declarations into mm/internal.h.
- "userfaultfd: working set tracking for VM guest memory" (Kiryl
Shutsemau)
Add userfaultfd support for tracking the working set of VM guest
memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage
- "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
Hildenbrand)
Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
performing some smaller cleanups around freeing of reserved vmemmap
pages on the way.
- "mm/damon: update probe hits for runtime parameter commits" (SJ Park)
Ensure that DAMON's probe_hits attribute counter is properly updated
when monitoring intervals are changed at runtime, matching the
behavior of nr_accesses. To achieve this, it refactors and renames
existing helper functions for shared use, applies the updates to
probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
maintain measurement accuracy.
- "KSM: performance optimizations for rmap_walk_ksm" (xu xin)
Resolve a severe KSM reverse-mapping performance bottleneck where
thousands of split VMAs sharing a single anon_vma cause extended lock
contention.
By adding an interval-filtering check during the rmap walk, it
reduces worst-case anon_vma lock hold times from over 500ms down to
under 2ms, preventing application freezes and latency spikes under
memory pressure.
- "mm: split a couple of headers from internal.h" (Mike Rapoport)
Split declarations related to mm_init, memblock, vmalloc and sparse
into new headers
- "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)
Apply the interval tree optimization from rmap_walk_ksm() to
collect_procs_ksm() to avoid iterating over non-matching VMAs during
KSM memory error handling.
It hoists loop-invariant address initialization and restricts the
anon_vma_interval_tree_foreach walk to a targeted page offset range,
reducing redundant checks and improving lookup efficiency.
- "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
Patil)
Fix issues in the hugetlb and KSM MM selftest categories that can
report failures when the prerequisites for the tests are not
satisfied
- "mm/damon: introduce data attributes only monitoring" (SJ Park)
Introduce attribute-weighted region management in DAMON, allowing
users to prioritize specific data attributes (such as page sizes or
cgroups) over or instead of access monitoring.
By assigning weights to attribute probes, DAMON can completely
disable access tracking and adjust monitoring regions based on
weighted probe-hit counters to optimize monitoring quality for
attribute-focused workloads.
- "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
(Stanislav Kinsburskii)
Extend hmm_range_fault() to support userfaultfd-backed regions by
allowing the mmap lock to be dropped during fault handling via a new
hmm_range_fault_locked() helper.
By accepting a locked pointer and signaling retry status when lock
release occurs, it enables page fault resolution in userfaultfd
regions while preserving backward compatibility for existing callers.
- "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)
Clean up and standardize how vma->vm_pgoff is accessed and
manipulated across file-backed and anonymous mappings in the kernel
It introduces dedicated helper functions such as vma_start_pgoff(),
vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
renaming rmap interval tree helpers to better reflect their
functionality.
These changes establish a cleaner foundation for future work that
will unify virtual page offset indexing for all anonymous and CoW'd
folios.
- "mm: handle device-private PMDs in walk callbacks" (Usama Arif)
Address kernel panics and state corruption caused by MM walk
callbacks reaching non-present device-private PMD swap entries
created during HMM migrations
It ensures that functions which acquire pmd_trans_huge_lock()
properly recognize device-private PMDs instead of assuming a present
THP or a standard migration entry.
- "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)
Refactor try_to_unmap_one by modularizing Hugetlb,
anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
functions, laying the structural groundwork for batched anonymous
large folio unmapping.
- "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)
Fix typos and fills in missing entries in the DAMON sysfs ABI
document
- "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)
Introduce an atomic sysfs state attribute and supporting DAX/MM
infrastructure to prevent userland races when offlining and removing
entire memory regions
By adding an unplugged state alongside standard online modes, it
enables whole-device atomic hotplug control while preserving backward
compatibility.
- "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)
Continue transitioning the kernel from the deprecated vm_flags_t type
to vma_flags_t across core memory management infrastructure.
It replaces legacy type usage in core functions such as do_mmap(),
unmapped area allocation, mm->def_vma_flags, and VMA operations like
mlock, mprotect, and mremap.
- "Two small patches to clean up mm/mm_slot.h" (xu xin)
Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
slot deletion sequences in khugepaged and KSM. It also adds code
documentation explaining why mm_slot_lookup and mm_slot_insert must
remain as preprocessor macros rather than static inline functions.
- "mm/damon/core: hide core-private struct fields" (SJ Park)
Clean up DAMON core structures by consistently marking internal-only
fields with private: comment tags to prevent improper direct access
from outer layers.
It enforces encapsulation across core structures including
damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
interact through approved access APIs instead of exposing raw struct
members.
- "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
(SJ Park)
Address potential infinite loops, NULL dereferences, and race
conditions identified in DAMON
It fixes an infinite loop triggered by extreme user configurations, a
NULL pointer dereference within unit tests and minor monitoring
accuracy degradation caused by subtle runtime races.
- "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
Jackman)
Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
via non-PCP or isolated migration paths.
It also resolves potential kernel crashes and privilege escalation
risks triggered when BPF tracing runs in NMI context alongside memory
hotplug or large allocation frees.
- "mm/page_alloc: couple of followups for recent cleanups" (Brendan
Jackman)
Clean up and update page allocator nomenclature, documentation, and
debug assertions.
It aligns internal FPI_ flags with the public "nolock" naming
convention, removes outdated internal implementation details from
high-level page allocator comments, and eliminates obsolete
VM_BUG_ON() assertions in allocation paths.
- "mm/mseal: further cleanups" (Lorenzo Stoakes)
Refactor and simplify the mseal implementation by clarifying API
boundaries and removing unnecessary code complexity.
It replaces generic do_mseal() usage outside the syscall with a
dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
eliminates mm_struct parameters to enforce that sealing applies only
to current->mm, and streamlines overall logic and comments with no
functional changes intended.
- "mm/vmscan: fix swappiness=max and clean up per-node proactive
reclaim" (Ridong Chen)
Resolve reclaim behavior bugs and clean up function parameters across
memory reclaim paths
It fixes swappiness=max in both standard reclaim and MGLRU so
unswappable anonymous memory no longer falls back to evicting page
cache, ensures reclaim_store() returns accurate error codes instead
of collapsing all failures into -EAGAIN, and removes the obsolete
gfp_mask parameter from __node_reclaim().
- "mm: mincore: misc cleanups" (Kefeng Wang)
Clean up and simplifies the mincore code. Most importantly, it
removes the historical special behavior that always reports VM_PFNMAP
pages as non-resident.
- "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)
Two trivial cleanups in the folio split API
- "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
bugs" (SJ Park)
Resolve minor operational and testing bugs in DAMON identified by
Sashiko. It initializes the damos->last_applied field to prevent
occasional efficiency degradation and fixes invalid memory accesses
in DAMON KUnit tests during test failure handling.
- "cleanup for stable_page_flags()" (Jinjiang Tu)
Clean up and refactor stable_page_flags() used by /proc/kpageflags
without altering functionality.
It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
bits, converts folio-specific flag checks to standard folio_test_*()
helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
- "Batch unmap of uffd-wp file folios" (Dev Jain)
Extend batched folio unmapping support to file folios within
userfaultfd write-protect (uffd-wp) VMAs by adding batching
capabilities to pte_install_uffd_wp_if_needed().
This removes special-case restrictions on uffd-wp VMAs in
try_to_unmap_one(), significantly simplifying the function's control
flow and complexity.
- "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
(Sang-Heon Jeon)
Clarify and clean up the architecture-specific usage of
__late_set_fixmap() and __late_clear_fixmap() after
early_ioremap_reset()
It adds explicit documentation regarding when early_ioremap_reset()
must be called and removes redundant macro definitions and reset
calls in the RISC-V and ARM64 architectures.
- "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)
Address severe performance regressions, swap storms, and spurious
OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
production
It updates the page allocator slowpath so non-movable allocation
requests actively trigger direct reclaim and direct compaction at
pageblock_order scale, allowing them to claim whole pageblocks rather
than spinning unproductively.
- "zram: lockmap tweaks" (Sebastian Siewior)
Optimize and fix lockdep tracking for zram devices by consolidating
per-entry lockmaps and isolate lock classes across multiple instances
This reduces memory overhead by replacing per-entry lockdep_map
instances with a single map per struct zram, and assigns a dynamic
lock_class_key to each instance to prevent false deadlock reports
when different zram devices are backed by distinct filesystems.
* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
selftests/mm: unpoison pages in memory-failure teardown
mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
mm/zsmalloc: fix release order of locks in zs_page_migrate()
Documentation: zram: remove sections numbering
ksm: stop iterating VMAs when ksm_test_exit returns true
mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
zram: use a custom key for each zram object
zram: move lockmap to be per-zram instead per table
selftests/mm: fix gup_longterm EINVAL error message
mm: page_alloc: fix non-movable reclaim storm in defrag_mode
mm: page_alloc: move capture_control to the page allocator
mm: compaction: support non-movable compaction for pageblock requests
mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
hugetlb: evaluate subpool free state while locked
mm/damon: remove trailing semicolons after function definitions
mm/damon/ops-common: prevent migration fallback to non-target nodes
mm/damon: update outdated comment about DAMOS filter handling
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes updates from Masami Hiramatsu:
"BTF typecasting and variable fetch enhancements:
- Typecast support across probe events: Extended BTF typecasting
syntax (e.g., (STRUCT)PARAM->MEMBER) to kprobes, uprobes, and
fprobes on function entry and return
- Nested typecasts: Added support for chaining and nesting typecasts
up to 3 levels, including casting registers and stack variables
- Field specifier option: Added (STRUCT,FIELD) syntax to emulate
container_of(), allowing retrieval of parent structures from member
pointers
- $current variable support: Introduced $current special variable to
access the running task_struct via BTF dereferencing
- Per-CPU variable access: Added this_cpu_read() and this_cpu_ptr()
fetcharg methods to trace CPU-local data safely
- Fetcharg bytecode dumper: Added CONFIG_PROBE_EVENTS_DUMP_FETCHARG
to dump the compiled fetcharg bytecode instructions as comments in
dynamic_events
- Extended symbol name handling: Removed the MAX_COMMON_HEAD_LEN
limit and extended MAX_ARGSTR_LEN to 256 bytes, enabling probing of
long symbols, mangled Rust symbols and complex BTF expressions
- eprobe variable syntax: Allowed eprobes to reference event fields
directly without requiring a '$' prefix
- Cleanup unused parameters, redundant codes, duplicate macros and
pointer arithmetic
- Use a ternary operator for simplifying fetch_type_from_btf_type()
Expanded boot time dynamic probe support:
- Add boot-time tracing configuration support for event probes
(eprobes), function probes (fprobes), and tracepoint probes
(tprobes)
- Allow comment lines ('#') in dynamic_events file
Optimization, robustness, and cleanups:
- Simplify fprobe_remove_ips() by reusing graph and ftrace helpers
- Remove __packed attribute from struct __fprobe_header to avoid
unaligned memory access penalties on RISC architectures
- Remove redundant memset() calls in perf event probe handlers
- Replace legacy __ASSEMBLY__ with __ASSEMBLER__ in header files
Selftests & refactoring:
- Refactor parse_probe_arg() and parse_probe_vars(), and eliminate
recursion in probe argument parsing to protect kernel stack depth
- Add selftests for BTF typecasts and module probing without module
prefixes
- Force LC_ALL=C in ftracetest to prevent test failures on localized
systems
- Refactor btf_type_skip_modifiers() to remove ignored id parameter
- Sort ERRORS list in trace_probe.h alphabetically
- Fix typo in fprobe docs, and trace_fprobe function name
- Rename FETCH_OP_DATA to FETCH_OP_IMMSTR
- Make file offset error message probe-agnostic"
* tag 'probes-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (37 commits)
fprobe: Simplify fprobe_remove_ips() by reusing existing helpers
tracing/boot: Add support for eprobe, fprobe, and tprobe events
selftests/ftrace: Force C locale in ftracetest
tracing/probes: Treating longer symbol name on event comparation
docs: trace: fprobe: fix 'thos' spelling
tracing/probes: Fix extra whitespace in trace_probe_kernel.h
tracing/kprobe: Remove redundant memset in kprobe_perf_func()
tracing/fprobe: Remove redundant memset in fentry_perf_func()
tracing/fprobe: Remove redundant snprintf in trace_fprobe_match_command_head()
tracing/probes: Simplify BTF_KIND_PTR case in fetch_type_from_btf_type()
tracing/probes: Cleanup pointer arithmetic in store_trace_entry_data()
tracing/probes: Remove unused parameter from parse_probe_var_retval()
tracing/probes: Remove redundant bounds check in trace_probe_compare_arg_type()
tracing/probes: Remove redundant boolean conversion in trace_probe_has_single_file()
tracing/probes: Remove duplicate MAX_ARRAY_LEN macro definition
selftests/ftrace: Add test case for a symbol in a module without module name
tracing/probes: Eliminate recursion in parse_probe_arg()
tracing/probes: Extend max length of argument string
tracing/probes: Sort ERRORS list in trace_probe.h alphabetically
tracing/probes: Refactor parse_probe_arg()
...
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|
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Daniel Borkmann:
"Major changes:
- Redesign the verifier error reporting: failures now carry source
and instruction annotations along with the causal event history
that led to them, making program rejections far easier to debug and
repair (Kumar Kartikeya Dwivedi)
- Add arena argument support to kfuncs and struct_ops through the new
__arena and __arena__nullable suffixes (Tejun Heo, Puranjay Mohan,
Kumar Kartikeya Dwivedi, Ihor Solodrai)
- Signed BPF program loader rework to accommodate both BPF and
security community needs where the kernel runs the signature
verification at BPF_PROG_LOAD time before the LSM admission hook
(Daniel Borkmann)
- Add a set of ksock kfuncs which let BPF LSM and syscall programs
create, connect and send on UDP sockets in order to emit telemetry
data (Mahe Tardy)
- Unify helper and kfunc call argument verification and classify
kfunc arguments purely from BTF into a generated bpf_func_proto
which is computed once at add-call time (Amery Hung)
Other features and fixes:
- Enable EXECMEM_ROX_CACHE for BPF allocations on x86 (Mike Rapoport)
- Add bidirectional VLAN support to bpf_fib_lookup() through the new
BPF_FIB_LOOKUP_VLAN and BPF_FIB_LOOKUP_VLAN_INPUT flags (Avinash
Duduskar)
- Infer zext_dst from static register liveness analysis to fix 32-bit
zero-extension semantics, and remove the artificial limitations on
pointer types eligible for spilling (Eduard Zingerman)
- Inline the numeric open-coded iterator kfuncs so that bpf_for()
loops no longer pay a kfunc call on every iteration (Puranjay
Mohan)
- Add an arena-based bitmap data structure to libarena along with
serial and parallel selftests (Emil Tsalapatis)
- Teach resolve_btfids to discover kfuncs from the kernel's BTF ID
sets and to emit kfunc BTF decl tags, reducing the kernel build's
dependency on pahole features (Ihor Solodrai)
- Add BPF_F_ADJ_ROOM_DECAP_* flags to bpf_skb_adjust_room() so that
tunnel decapsulation can update the GSO and encapsulation state of
the skb (Nick Hudson)
- Fix the ring buffer pending_pos walk and the available-data
accounting on 32-bit position wrap (Israel Téllez García)
- Add memory usage accounting for arena maps and fix an mmap_lock
deadlock on arena lock failure (Jiayuan Chen)
- Add tracing_multi link info support to the kernel UAPI and bpftool,
and refactor the stack map code to run with preemption disabled
(Jiri Olsa)
- Support BPF_F_EGRESS in bpf_redirect_peer() to emit the skb in the
egress direction of the target's peer device (Jordan Rife)
- Add a KF_SPINLOCK_SAFE kfunc flag so that providers, in particular
modules, can declare kfuncs safe to call under bpf_spin_lock
instead of relying on the verifier's hard-coded allowlist (Kaitao
Cheng)
- Introduce global percpu data for BPF programs with libbpf probing
and bpftool skeleton support, and stop exposing uninitialized
kernel heap memory when copying per-CPU map values (Leon Hwang)
- Add s390 JIT support for load-acquire and store-release
instructions (Maxim Khmelevskii)
- Fix a CFI mismatch in the task work callback and an arm64 KASAN
false positive after bpf_throw() (Mykyta Yatsenko)
- Reject writes through untrusted BTF pointers and bound the
rdonly/rdwr_buf_size kfunc arguments (Nicholas Dudar)
- Invalidate RCU pointers only after the final spin unlock and
account for preempt and IRQ disabled regions as overlapping RCU
protection (Ning Ding)
- Support mixing bpf2bpf calls and tail calls on RV64, add signed
operations and 32-bit atomics to the RV32 JIT, and add timed
may_goto support (Pu Lehui, Kuan-Wei Chiu, Feng Jiang)
- Fix a use-after-free on mm_struct in bpf_find_vma() for foreign
tasks and an mmap_lock leak in the irq_work path (Sanghyun Park)
- Populate mmap-able BPF array map memory lazily which makes mmap()
O(1) instead of proportional to the map size (Song Liu)
- Introduce a jit_required flag and reject programs with inlined
helpers when no JIT is available, where the interpreter would
otherwise jump into an invalid address (Tiezhu Yang)
- Fix the x86 JIT per-CPU address resolution into an extended
register where the REX prefix dropped the high destination register
bit (Vineet Gupta)
- Reject MEM_ALLOC BTF accesses past object bounds, arena frees below
the arena base, and mixed arena and ordinary atomic paths (Yiyang
Chen)
- Fix the trampoline handling of 128-bit arguments and of return
values larger than 8 bytes (Yonghong Song)
- Ensure that any fault prone load is rewritten with exception table
handling, and fix the arena load-acquire and atomic fetch handling
in the x86, arm64, riscv and s390 JITs (Daniel Borkmann)
- Many more fixes and cleanups across the verifier, arena,
trampolines, sockmap, cgroup, ring buffer, x86/arm64/riscv/s390
JITs, libbpf, bpftool, resolve_btfids and selftests"
* tag 'bpf-next-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (373 commits)
selftests/bpf: Add tests for a store on a fault prone qdisc pointer
selftests/bpf: Add tests for fault prone loads out of RCU pointers
selftests/bpf: Add tests for pointer type merge at a shared load
selftests/bpf: Remove duplicate copies of the arena spinlock qnodes
selftests/bpf: Retry stat generation in cgroup_iter_memcg
selftests/bpf: Test pseudo-function policy diagnostics
bpf: Distinguish function references in policy diagnostics
bpf: Preserve source attribution without source text
selftests/bpf: Test kfunc argument diagnostics
bpf: Correct kfunc argument diagnostics
bpf: Use canonical stack argument names in diagnostics
bpf: Preserve R0 lineage across helper calls
selftests/bpf: Exercise negative optlen in cgroup getsockopt hook
bpf: Reject negative optlen in cgroup getsockopt hook
selftests/bpf: tc_tunnel - validate decap GSO and encapsulation state
bpf: Clear decap state on skb_adjust_room shrink path
bpf: Allow new DECAP flags and add guard rails
bpf: Add BPF_F_ADJ_ROOM_DECAP_* flags for tunnel decapsulation
bpf: Refactor masks for ADJ_ROOM flags and encap validation
bpf: Name the enum for BPF_FUNC_skb_adjust_room flags
...
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|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer updates from Steven Rostedt:
- Remove unneeded semicolon
A macro ended with a semicolon that wasn't needed.
- Fix freeing cpu_buffer extra subbuffer with order greater than zero
When the cpu_buffer was being freed, its "free" page, was using
free_page() to free it when it could be more than one page.
- Hold the cpu_buffer lock when resizing the subbuffer
The freeing of the "free" page of the cpu_buffer was done without
locking. The order of the data was being saved and then the "free"
page was set to NULL. But there is a race that the "free" page could
have been updated between those two operations. Add locking around it
to prevent the race.
- Save the order of the data along with the data in the free page
The cpu_buffer would store just the data portion of the subbuffer
page in its descriptor. But it did not store the order of the data
pages. The order was being saved in the global buffer descriptor. But
this leads to races.
Have the cpu_buffer save the subbuf data along with its metadata
(which includes the order of the page) to make sure when it frees it,
it frees the correct order along with it.
- Remove the subbuf_size and use the order directly when needed
Having a size field for the size of the subbufer along with its order
allowed for races to have them get out of sync. Remove the
subbuf_size and use the order from the subbuf meta data directly
under locks.
Use the subbuf_order for other calculations in the ring buffer.
- Remove the useless "cpus" field of trace_buffer
The code has been restructured and the "cpus" field is no longer
used. Remove it.
- Remove the "mapped" field of the ring buffer and use a helper
function instead.
The "mapped" field has become a bit overused and made the code come
complex in using a counter for what is denoted as being mapped or
not. There are other fields that are set when the ring buffer is
considered mapped. Add a helper function to check those fields and
use that instead of keeping track of a counter.
* tag 'trace-ringbuffer-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Remove ring_buffer_per_cpu::mapped
ring-buffer: Remove trace_buffer::cpus
ring-buffer: Dynamically calculate max_data_size
ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()
ring-buffer: Fix subbuf resize race with ring buffer readers
ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page
ring-buffer: Hold cpu_buffer::lock when resizing a subbuf
ring-buffer: Free cpu_buffer::free_page with subbuf_order
ring-buffer: drop unneeded semicolon
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracefs updates from Steven Rostedt:
- Define event fields before directory creation
Move the event_define_fields() call in event_create_dir() before the
eventfs directory creation. Previously, a failure after directory
creation wouldn't clean up eventfs_inode because the error path
didn't call eventfs_remove_dir(). This eliminates the need to clean
up the eventfs directories if event_define_fields() fails.
- Add warning for out of bounds pos in __eventfs_iterate()
Sashiko complains about the ctx->pos causing issues if it is less
than 2 or greater than MAX_INT in __eventfs_iterate(). The thing is,
the logic prevents that from happening. But to make Sashiko happy,
add a WARN_ON() and exit safely if the function ever does get input
that is out of the range the function expects.
* tag 'tracefs-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
eventfs: Add warning for out of bounds pos in __eventfs_iterate()
eventfs: Define event fields before directory creation
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Expose btf_ids to trace events
In order to allow BPF programs to attach to system call trace events
(which are actually pseudo trace events built on top of raw_syscall
events), expose the BTF ID of the events. This will allow BPF
programs better precision in attaching to events.
- Use "u64" to assign to hist_field->type
Instead of using kstrdup("u64", GFP_KERNEL) to assign the
hist_field->type, just point it to "u64" instead. The
hist_field->type is freed via kfree_const().
- Replace kmalloc()/strcpy() with kstrdup() for trace_printk
Instead of having two calls to copy the module format string, just
use kstrdup().
- Use __free() in trace event histograms and triggres where possible
- Use seq_buf in trace event code instead of strcat()
Instead of calculating the size of the buffer to use and filling it
with strcat(), use the seq_buf infrastructure that takes care of
making sure not to overflow the string size.
- Reject invalid preemptirq_delay_test CPU affinity
The preempt_delay_test module can take an invalid CPU affinity mask
and create confusing output. Simply have the module reject invalid
affinity masks.
- Prevent division by zero in ftrace_ops sample module code
If the ftrace_ops sample module code receives the module parameter
nr_function_calls set to zero, it can cause a division by zero error.
- Warn when an event dereferences a parameter in TP_printk()
On boot up and module load, the trace event TP_printk() is scanned
for possible bugs. As the TP_printk() code is executed when the user
reads the "trace" file and processes the data written when the
trace_event executed, the data it reads can be literally days old.
The scan currently checks for dereferencing printk formats like
"%pI6". But it does not check if the parameters themselves have a
dereference like:
TP_printk("offset %08x: value %08x",
(u32)(__entry->addr - __entry->edma->membase), __entry->value)
__entry represents the pointer to the event on the ring buffer. The
__entry->edma->membase is dereferencing a pointer on the ring buffer
to find membase, but the __entry->edma may no longer be a valid
pointer.
Warn on this case too.
- Replace some strcpy() with strscpy()
- Clean up mmiotrace events to use assign_type() macro
The assign_type() macro makes sure the event type is indeed the type
that is being parsed. The mmiotrace trace was written before that
macro was created so it just simply typecasted the pointer.
Replace the typecasting with the macro.
- Have the ENUM processing to numbers only process what is added
The code that converts ENUMs to their numbers in the trace events
scanned all events to do the processing. This was true when a module
was loaded too. That is, instead of processing just the events for
the module, it processed *all* events. Even the builtin ones that
were processed at boot up.
Add a check for the event->module matching mod if it is a module
before processing it.
* tag 'trace-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (21 commits)
tracing: Have trace_event_update_all() only handle module that is loading
tracing: Cleanup event_enable_trigger_parse() by using __free()
tracing: Report every TP_printk double dereference
tracing/mmiotrace: Use trace_assign_type() in mmio_print_mark()
tracing: Make per-template BTF id lists file-local
tracing: Use seq_buf for string concatenation
tracing: Use strscpy() instead of strcpy() in trace_sched_switch
tracing: Warn when an event dereferences a pointer in TP_printk()
samples/ftrace: Prevent division by zero when nr_function_calls is zero
tracing: Reject invalid preemptirq_delay_test CPU affinity
fgraph: Use trace_seq_putc() in print_graph_return()
tracing/user_events: Replace a seq_printf() call by seq_puts() in user_seq_show()
tracing/user_events: Use seq_putc() in two functions
tracing: Bound histogram expression strings with seq_buf
tracing: Return ERR_PTR() from expr_str()
tracing: Use __free() for expr_str() buffer
kernel/trace/trace_printk: Use kstrdup() instead of kmalloc() and strcpy()
tracing: Point constant hist field type to string literal
selftests/bpf: Add test for tracepoint btf_ids tracefs file
tracing: Expose tracepoint BTF ids via tracefs
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace updates from Steven Rostedt:
- Deprecrate ftrace_enabled in disabling ftrace
The file /proc/sys/kernel/ftrace_enabled was created when ftrace was
first introduced back in 2008. It was to be a "kill switch" if
something was to go wrong. It was also used as a way to turn off
function tracing for the latency tracers that would have it on by
default. But in 2013 (Linux 3.10) the option "function-trace" was
introduced to disable function tracing for the latency tracers as the
"ftrace_enabled" file was considered too big of a hammer and caused
too many side effects.
When live kernel patching came along, disabling ftrace via the
ftrace_enabled file would put the system into an unstable state if a
live kernel patch was installed. This created the need to mark some
function hooks as "PERMANENT".
Now there's a need for BPF usage marked as PERMANENT for the same
reasons.
The file "ftrace_enabled" usage is no longer viable. It doesn't do
what it says it does and there is no reason to use it.
Make writing '0' to it a nop and print a message saying its usage is
deprecated. The return value of writing '0' is -EOPNOTSUPP so that
user space will error on that write (hopefully to inform any
developer that it no longer works).
Eventually the file should be removed completely, but for now just
making it not do anything is the path forward to that.
- Update the livepatch tests to handle ftrace_enabled being disabled
Because in the past, livepatch was broken by ftrace_enabled being
turned off, there's a test case that checks to make sure it still
doesn't break. But having the write of '0' return an error caused
that test to break. Updated the test to handle the new change.
* tag 'ftrace-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
selftests/livepatch: update test-ftrace.sh for deprecated ftrace_enabled
ftrace: deprecate disabling via ftrace_enabled sysctl
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull Real-time Verifier updates from Steven Rostedt:
- Switch LTL and DOT parsers to Lark in code generation tool
The rvgen code generation tool originally parsed DOT files and LTL
specifications using custom string parsing and Ply, which is no
longer maintained. The DOT parser was fragile and prone to failure on
minor format variations. Both LTL and DOT parsers have been rewritten
to use the Lark parsing library.
- Simplify Hybrid Automata clock variables
The clock variables in hybrid automata monitors now use a single
representation of the elapsed time since the clock was reset, rather
than converting between invariant and guard representations. This
allows simpler code generation for the newly refactored parser.
- Generate cleanup hook for per-obj monitor
The code generation scripts now adds a cleanup function to per-obj
monitors for the user to wire to the appropriate event (e.g.
sched_process_exit for tasks).
- Reduce read_lock scope during per-task cleanup
Take the tasklist_lock only when necessary, that is when iterating
over for_each_process_thread().
- Simplify task monitor slot management
Only rely on the slot array for per-task slot management to avoid
inconsistency with the unused counter.
- Improve rvgen code robustness and templates
Use pathlib in rvgen and improve kernel path discovery. Also improve
consistency across templates when generating code (e.g. author
placeholder and monitor struct name).
- Update rtapp sleep monitor
Simplify the sleep monitor by excluding kernel threads and updating
the nanosleep check to focus only on CLOCK_REALTIME. Also switch to
use the sched_exit tracepoint to run in the context of the offending
(wakee) task.
- Add wakeup monitor
Add the new rtapp/wakeup monitor to detect when lower-priority tasks
wake up higher-priority ones, complementing the existing sleep
monitor by running in the waker context and capturing its stack
trace.
- Fix tools/rv exit status on failure
Ensure the rv tool returns a failure exit code when a monitor fails
to start because it was already running.
- Add automated selftests for tools/rv and rvgen
Introduced automated bash selftests to validate rv monitor listing
and execution under different configurations. Added tests for the
rvgen code generator, validating generated files against expected
output (golden). Tests are reachable via make check.
- Add KUnit test coverage for verification monitors
Added comprehensive KUnit tests to validate the functionality of
deterministic, hybrid, and LTL monitors by emulating event sequences
and timing in a mock environment without affecting the running kernel
while expecting mock reactions to fire. Ensure real RV monitors
cannot run during KUnit tests to avoid state corruption.
- Mock current in rv monitors
Mock the call to current in rv monitors when the KUnit tests are
built to allow them to run the test on dummy tasks. No overhead is
expected when KUnit tests aren't running.
- Introduce rvgen kunit subcommand
Added a new 'kunit' subcommand to rvgen to automatically patch an
already generated monitor with KUnit integration templates by parsing
its event handlers and creating the required mock structures and
initializations.
- Refine kernel verification selftests
Added new selftests for the deadline and stall monitors and
rearranged the existing wwnr_printk test to resolve flakiness.
Additionally, fixed an issue in the selftests framework where
negative assertion failures were not correctly propagated due to
shell rules.
- Fix 32-bit build of nomiss KUnit test
A previous commit introduced a division between an u64 and a constant
value and that doesn't build on 32-bit systems. Use div_u64()
instead.
- Document changes in sleep monitor
The sleep monitor introduced some changes in the past like allowing
epoll_wait() as a valid sleep and a task going to runnable before
scheduling as a valid wakeup. Document both.
* tag 'trace-rv-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (40 commits)
Documentation/rv: Explain epoll and aborted sleeps
rv: Fix 32-bit build of nomiss KUnit test
selftests/verification: Add selftests for deadline and stall monitors
selftests/verification: Rearrange the wwnr_printk test
selftests/verification: Fix wrong errexit assumption
rv: Add KUnit tests for some LTL monitors
rv: Add KUnit mock for current
rv: Add KUnit tests for some DA/HA monitors
rv: Export task monitor slot and react symbols
verification/rvgen: Add selftests for rvgen kunit
verification/rvgen: Add the rvgen kunit subcommand
verification/rvgen: Add selftests
verification/rvgen: Add golden and spec folders for tests
tools/rv: Add selftests
verification/rvgen: Improve consistency in template files
verification/rvgen: Use pathlib instead of os.path
verification/rvgen: Improve rv_dir discovery in RVGenerator
tools/rv: Fix exit status when monitor execution fails
rv: Use generic rv_this for the rv_monitor variable in LTL
rv/rtapp: Add wakeup monitor
...
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ring_buffer_per_cpu::mapped tracks if a ring-buffer is either mapped by
user-space or if it is a persistent buffer. We already have user_mapped
for the former and ring_meta for the latter. Get rid of mapped and
instead create rb_is_static(). A static ring-buffer cannot be resized,
swapped or have its pages extracted.
Link: https://patch.msgid.link/20260813131152.3589632-10-vdonnefort@google.com
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The 'cpus' field in struct trace_buffer became useless in commit
8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their
allocation order"). Remove it
Link: https://patch.msgid.link/20260813131152.3589632-9-vdonnefort@google.com
Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The ring buffer order can be dynamically modified and temporarily
disables writing to do so. It is therefore safe to use the updated value
to calculate the maximum event size which can be written onto the ring
buffer.
However, notice it is hardly making any difference for trace_marker
because of the TRACE_MARKER_MAX_SIZE limit. For an 8KiB subbuf size,
trace_marker can take 4096 characters while it can 'only' take 4054
bytes for smaller subbufs.
Link: https://patch.msgid.link/20260813131152.3589632-8-vdonnefort@google.com
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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ring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set,
it can allocate a reader page with an outdated order. This isn't a big
issue, the user can still re-allocate a new reader page and try again.
However, what is more problematic is if the value of subbuf_order
changes in the middle of ring_buffer_alloc_read_page(). In that case,
bpage->order might not match the actual allocated memory.
Use bpage->order for the allocation to prevent this race.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260813131152.3589632-6-vdonnefort@google.com
Fixes: bce761d75745 ("ring-buffer: Read and write to ring buffers with custom sub buffer size")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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trace_buffer subbuf_size is read lockless in ring_buffer_read_page() and
ring_buffer_read_start(), while it can simultaneously be resized with
ring_buffer_subbuf_order_set().
Instead of trace_buffer::subbuf_size, use bpage::order in
ring_buffer_read_start() and ring_buffer_read_page().
In ring_buffer_read_start(), even with resize_disabled, there is still a
possibility of a race with a buffer modification. Hold the trace_buffer
mutex to synchronise with any pending ring buffer order modification.
trace_buffer::subbuf_size is now actually useless, remove it. Also,
create accessors rb_subbuf_capacity() and rb_page_capacity() which
return the actual size available for storing events, while
rb_subbuf_size() returns the actual subbuf page-size.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260813131152.3589632-5-vdonnefort@google.com
Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260805153225.2096152-1-vdonnefort%40google.com # patch 1
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Discarding a cached reader page after a concurrent ring buffer resize
uses the new global subbuf_order for the free_pages() call. This
mismatched order may crashes the kernel or leaks memory because the cached
page was allocated under the old size.
Save the actual free_page order alongside the page address to ensure we
always refer to the correct value and do not rely on the potentially
stalled cpu_buffer->subbuf_order value. The simplest is to make
free_page a buffer_data_read_page which already covers exactly what we
need: a page address and a page order.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260813131152.3589632-4-vdonnefort@google.com
Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Because, ring_buffer_subbuf_order_set() can clear cpu_buffer->free_page,
hold cpu_buffer->lock to prevent races with
ring_buffer_alloc_read_page() and ring_buffer_free_read_page().
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260813131152.3589632-3-vdonnefort@google.com
Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260810125633.3344684-1-vdonnefort%40google.com # patch 3
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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When sub-buffers use an order greater than 0, cpu_buffer->free_page is
allocated with subbuf_order. Use the correct order for
cpu_buffer->free_page.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260813131152.3589632-2-vdonnefort@google.com
Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260806211306.3704194-1-vdonnefort%40google.com # patch 3
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The function trace_event_update_all() does a scan of events looking to
replace enums with their values in the strings that get exported to the
event format files. It's run at boot up on all events and again when a
module loads.
The issue is that when a module loads, it still runs on *all* events.
There's no reason to process every event when a module loads as the
previous events have already been processed. Only execute on the events
that are loaded with the module.
Link: https://patch.msgid.link/20260813204226.29563591@gandalf.local.home
Fixes: 3673b8e4ce723 ("tracing: Allow for modules to convert their enums to values")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The following sequence may leads race between event_define_fields()
and update_event_fields():
CPU0 (loads module A) CPU1 (loads module B)
=============================== ===============================
load_module(A) load_module(B)
notifier_call_chain notifier_call_chain
trace_module_notify trace_module_notify
mutex_lock(&event_mutex) trace_event_update_all()
trace_module_add_events(A) down_write(&trace_event_sem)
__register_event(call_A)
__add_event_to_tracers(call_A)
event_define_fields(call_A)
for each f: list_for_each_entry(field,
list_add(&f->link, &class->fields, link)
&class->fields) field = class->fields->next;
Where access to the class->fields is not protected by the event_mutex in
trace_event_update_all().
This produces the following panic:
Unable to handle kernel access ... at virtual address 0000000000000018
pc : update_event_fields+0xf8/0x368
Call trace:
update_event_fields+0xf8/0x368
trace_event_update_all+0x7c/0x2b4
trace_module_notify+0x4c/0x1dc
notifier_call_chain+0x84/0x168
blocking_notifier_call_chain_robust+0x64/0xd4
load_module+0x10c8/0x123c
__arm64_sys_finit_module+0x230/0x31c
Fix by taking event_mutex in trace_event_update_all() before
trace_event_sem.
Cc: stable@vger.kernel.org
Fixes: b3bc8547d3be ("tracing: Have TRACE_DEFINE_ENUM affect trace event types as well")
Link: https://patch.msgid.link/2e5730d2-c631-da41-3a3a-ae35bb4895f3@allwinnertech.com
Signed-off-by: Michael Wu <michael@allwinnertech.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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A module-only event filter such as ":mod:foo" is cached with a NULL
event_mod->match when foo has not been loaded. If a later write tries to
remove a specific match from the same module, remove_cache_mod() passes
the NULL cached match to strcmp(), causing a NULL pointer dereference.
The issue can be reproduced from userspace:
echo ':mod:trace_events_kunit_missing' > /sys/kernel/tracing/set_event
echo '!foo_bar:mod:trace_events_kunit_missing' >> /sys/kernel/tracing/set_event
The second write must be a concatenation (">>") to not include O_TRUNC as
that would cause ftrace_clear_events() to clear the cached modules lines.
The crash was reproduced on x86_64 QEMU while KUnit workers contended on
the event tracing path:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
RIP: 0010:strcmp+0x10/0x30
Call Trace:
__ftrace_set_clr_event_nolock+0x373/0x4a0
ftrace_set_clr_event+0xf0/0x180
ftrace_event_write+0xdf/0x110
vfs_write+0xf6/0x440
ksys_write+0x68/0xe0
do_syscall_64+0xf9/0x540
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Check event_mod->match before comparing it, consistent with the existing
NULL checks for the cached system and event fields. The mismatched removal
continues to return -EINVAL; a broad cached module filter is removed with
"!:mod:<module>".
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260811173902.1927376-2-sh_def@163.com
Fixes: b355247df104 ("tracing: Cache \":mod:\" events for modules not loaded yet")
Reported-by: syzbot+4d3143c8e28f6266c636@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/6a7a6b7f.9c11d2ce.289b96.00f8.GAE@google.com/
Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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bpf_trampoline_multi_detach() always returns 0 and the sole caller
ignores the return value. Change it to return void and drop the
WARN_ON_ONCE at the call site.
Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
Acked-by: Leon Hwang <leon.hwang@linux.dev>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/12beba657f5c9e86a016a097750209287a2f262a.1786412280.git.zhuhui@kylinos.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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When a function-like macro expands to an expression, that expression
doesn't need a semicolon after it. All uses have been verified to
have their own semicolons.
This was found using the following Coccinelle semantic patch:
@r@
identifier i : script:ocaml() { String.lowercase_ascii i = i };
expression e;
@@
*#define i(...) e;
Link: https://patch.msgid.link/20260801191002.1383835-6-Julia.Lawall@inria.fr
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The enable_data variable gets freed on most error paths in
event_enable_trigger_parse(). Use free() to free it and just before
returning normally, call retain_and_null_ptr(enable_data) just before a
successful exit to keep it from being freed. On success, the enable_data
is assigned to the trigger_data->private_data field.
Also add a comment to why event_trigger_free(trigger_data) is being called
before a successful exit.
Link: https://patch.msgid.link/20260807113558.0ff14e96@gandalf.local.home
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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WARN_ONCE() splats once per call site, so only the first offending event
registered is ever reported. The tree currently has six:
ice_{rx,tx}_dim_template, two hfi1 txq events, mtu3_ep and edma_log_io.
Whichever registers first hides the rest, and each has to be found again
on the next boot.
Add a pr_warn() next to the WARN_ONCE() so every offender is listed, the
same way test_event_printk() already pairs WARN_ON_ONCE() with pr_warn()
for unsafe %p* dereferences. The WARN_ONCE() stays so the condition still
fails tests and panics under panic_on_warn.
Link: https://patch.msgid.link/20260806215256.1680267-1-devnexen@gmail.com
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: David Carlier <devnexen@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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