linux-toradex.git/kernel/trace, branch v6.15-rc2 Linux kernel for Apalis and Colibri modules Merge tag 'trace-v6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 2025-04-12T22:37:40+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-04-12T22:37:40+00:00 7cdabafc001202de9984f22c973305f424e0a8b7 Pull tracing fixes from Steven Rostedt: - Hide get_vm_area() from MMUless builds The function get_vm_area() is not defined when CONFIG_MMU is not defined. Hide that function within #ifdef CONFIG_MMU. - Fix output of synthetic events when they have dynamic strings The print fmt of the synthetic event's format file use to have "%.*s" for dynamic size strings even though the user space exported arguments had only __get_str() macro that provided just a nul terminated string. This was fixed so that user space could parse this properly. But the reason that it had "%.*s" was because internally it provided the maximum size of the string as one of the arguments. The fix that replaced "%.*s" with "%s" caused the trace output (when the kernel reads the event) to write "(efault)" as it would now read the length of the string as "%s". As the string provided is always nul terminated, there's no reason for the internal code to use "%.*s" anyway. Just remove the length argument to match the "%s" that is now in the format. - Fix the ftrace subops hash logic of the manager ops hash The function_graph uses the ftrace subops code. The subops code is a way to have a single ftrace_ops registered with ftrace to determine what functions will call the ftrace_ops callback. More than one user of function graph can register a ftrace_ops with it. The function graph infrastructure will then add this ftrace_ops as a subops with the main ftrace_ops it registers with ftrace. This is because the functions will always call the function graph callback which in turn calls the subops ftrace_ops callbacks. The main ftrace_ops must add a callback to all the functions that the subops want a callback from. When a subops is registered, it will update the main ftrace_ops hash to include the functions it wants. This is the logic that was broken. The ftrace_ops hash has a "filter_hash" and a "notrace_hash" where all the functions in the filter_hash but not in the notrace_hash are attached by ftrace. The original logic would have the main ftrace_ops filter_hash be a union of all the subops filter_hashes and the main notrace_hash would be a intersect of all the subops filter hashes. But this was incorrect because the notrace hash depends on the filter_hash it is associated to and not the union of all filter_hashes. Instead, when a subops is added, just include all the functions of the subops hash that are in its filter_hash but not in its notrace_hash. The main subops hash should not use its notrace hash, unless all of its subops hashes have an empty filter_hash (which means to attach to all functions), and then, and only then, the main ftrace_ops notrace hash can be the intersect of all the subops hashes. This not only fixes the bug, but also simplifies the code. - Add a selftest to better test the subops filtering Add a selftest that would catch the bug fixed by the above change. - Fix extra newline printed in function tracing with retval The function parameter code changed the output logic slightly and called print_graph_retval() and also printed a newline. The print_graph_retval() also prints a newline which caused blank lines to be printed in the function graph tracer when retval was added. This caused one of the selftests to fail if retvals were enabled. Instead remove the new line output from print_graph_retval() and have the callers always print the new line so that it doesn't have to do special logic if it calls print_graph_retval() or not. - Fix out-of-bound memory access in the runtime verifier When rv_is_container_monitor() is called on the last entry on the link list it references the next entry, which is the list head and causes an out-of-bound memory access. * tag 'trace-v6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: rv: Fix out-of-bound memory access in rv_is_container_monitor() ftrace: Do not have print_graph_retval() add a newline tracing/selftest: Add test to better test subops filtering of function graph ftrace: Fix accounting of subop hashes ftrace: Properly merge notrace hashes tracing: Do not add length to print format in synthetic events tracing: Hide get_vm_area() from MMUless builds 
Pull tracing fixes from Steven Rostedt:

 - Hide get_vm_area() from MMUless builds

   The function get_vm_area() is not defined when CONFIG_MMU is not
   defined. Hide that function within #ifdef CONFIG_MMU.

 - Fix output of synthetic events when they have dynamic strings

   The print fmt of the synthetic event's format file use to have "%.*s"
   for dynamic size strings even though the user space exported
   arguments had only __get_str() macro that provided just a nul
   terminated string. This was fixed so that user space could parse this
   properly.

   But the reason that it had "%.*s" was because internally it provided
   the maximum size of the string as one of the arguments. The fix that
   replaced "%.*s" with "%s" caused the trace output (when the kernel
   reads the event) to write "(efault)" as it would now read the length
   of the string as "%s".

   As the string provided is always nul terminated, there's no reason
   for the internal code to use "%.*s" anyway. Just remove the length
   argument to match the "%s" that is now in the format.

 - Fix the ftrace subops hash logic of the manager ops hash

   The function_graph uses the ftrace subops code. The subops code is a
   way to have a single ftrace_ops registered with ftrace to determine
   what functions will call the ftrace_ops callback. More than one user
   of function graph can register a ftrace_ops with it. The function
   graph infrastructure will then add this ftrace_ops as a subops with
   the main ftrace_ops it registers with ftrace. This is because the
   functions will always call the function graph callback which in turn
   calls the subops ftrace_ops callbacks.

   The main ftrace_ops must add a callback to all the functions that the
   subops want a callback from. When a subops is registered, it will
   update the main ftrace_ops hash to include the functions it wants.
   This is the logic that was broken.

   The ftrace_ops hash has a "filter_hash" and a "notrace_hash" where
   all the functions in the filter_hash but not in the notrace_hash are
   attached by ftrace. The original logic would have the main ftrace_ops
   filter_hash be a union of all the subops filter_hashes and the main
   notrace_hash would be a intersect of all the subops filter hashes.
   But this was incorrect because the notrace hash depends on the
   filter_hash it is associated to and not the union of all
   filter_hashes.

   Instead, when a subops is added, just include all the functions of
   the subops hash that are in its filter_hash but not in its
   notrace_hash. The main subops hash should not use its notrace hash,
   unless all of its subops hashes have an empty filter_hash (which
   means to attach to all functions), and then, and only then, the main
   ftrace_ops notrace hash can be the intersect of all the subops
   hashes.

   This not only fixes the bug, but also simplifies the code.

 - Add a selftest to better test the subops filtering

   Add a selftest that would catch the bug fixed by the above change.

 - Fix extra newline printed in function tracing with retval

   The function parameter code changed the output logic slightly and
   called print_graph_retval() and also printed a newline. The
   print_graph_retval() also prints a newline which caused blank lines
   to be printed in the function graph tracer when retval was added.
   This caused one of the selftests to fail if retvals were enabled.
   Instead remove the new line output from print_graph_retval() and have
   the callers always print the new line so that it doesn't have to do
   special logic if it calls print_graph_retval() or not.

 - Fix out-of-bound memory access in the runtime verifier

   When rv_is_container_monitor() is called on the last entry on the
   link list it references the next entry, which is the list head and
   causes an out-of-bound memory access.

* tag 'trace-v6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  rv: Fix out-of-bound memory access in rv_is_container_monitor()
  ftrace: Do not have print_graph_retval() add a newline
  tracing/selftest: Add test to better test subops filtering of function graph
  ftrace: Fix accounting of subop hashes
  ftrace: Properly merge notrace hashes
  tracing: Do not add length to print format in synthetic events
  tracing: Hide get_vm_area() from MMUless builds
rv: Fix out-of-bound memory access in rv_is_container_monitor() 2025-04-12T16:13:30+00:00 Nam Cao namcao@linutronix.de 2025-04-11T07:37:17+00:00 8d7861ac507d23024c7d74b6cb59a9cca248bcb7 When rv_is_container_monitor() is called on the last monitor in rv_monitors_list, KASAN yells: BUG: KASAN: global-out-of-bounds in rv_is_container_monitor+0x101/0x110 Read of size 8 at addr ffffffff97c7c798 by task setup/221 The buggy address belongs to the variable: rv_monitors_list+0x18/0x40 This is due to list_next_entry() is called on the last entry in the list. It wraps around to the first list_head, and the first list_head is not embedded in struct rv_monitor_def. Fix it by checking if the monitor is last in the list. Cc: stable@vger.kernel.org Cc: Gabriele Monaco <gmonaco@redhat.com> Fixes: cb85c660fcd4 ("rv: Add option for nested monitors and include sched") Link: https://lore.kernel.org/e85b5eeb7228bfc23b8d7d4ab5411472c54ae91b.1744355018.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> 
When rv_is_container_monitor() is called on the last monitor in
rv_monitors_list, KASAN yells:

  BUG: KASAN: global-out-of-bounds in rv_is_container_monitor+0x101/0x110
  Read of size 8 at addr ffffffff97c7c798 by task setup/221

  The buggy address belongs to the variable:
   rv_monitors_list+0x18/0x40

This is due to list_next_entry() is called on the last entry in the list.
It wraps around to the first list_head, and the first list_head is not
embedded in struct rv_monitor_def.

Fix it by checking if the monitor is last in the list.

Cc: stable@vger.kernel.org
Cc: Gabriele Monaco <gmonaco@redhat.com>
Fixes: cb85c660fcd4 ("rv: Add option for nested monitors and include sched")
Link: https://lore.kernel.org/e85b5eeb7228bfc23b8d7d4ab5411472c54ae91b.1744355018.git.namcao@linutronix.de
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
ftrace: Do not have print_graph_retval() add a newline 2025-04-12T16:13:30+00:00 Steven Rostedt rostedt@goodmis.org 2025-04-11T17:30:15+00:00 485acd207d7daf8cf941a5f0fd0c09bc6d049402 The retval and retaddr options for function_graph tracer will add a comment at the end of a function for both leaf and non leaf functions that looks like: __wake_up_common(); /* ret=0x1 */ } /* pick_next_task_fair ret=0x0 */ The function print_graph_retval() adds a newline after the "*/". But if that's not called, the caller function needs to make sure there's a newline added. This is confusing and when the function parameters code was added, it added a newline even when calling print_graph_retval() as the fact that the print_graph_retval() function prints a newline isn't obvious. This caused an extra newline to be printed and that made it fail the selftests when the retval option was set, as the selftests were not expecting blank lines being injected into the trace. Instead of having print_graph_retval() print a newline, just have the caller always print the newline regardless if it calls print_graph_retval() or not. This not only fixes this bug, but it also simplifies the code. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250411133015.015ca393@gandalf.local.home Reported-by: Mark Brown <broonie@kernel.org> Tested-by: Mark Brown <broonie@kernel.org> Closes: https://lore.kernel.org/all/ccc40f2b-4b9e-4abd-8daf-d22fce2a86f0@sirena.org.uk/ Fixes: ff5c9c576e754 ("ftrace: Add support for function argument to graph tracer") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> 
The retval and retaddr options for function_graph tracer will add a
comment at the end of a function for both leaf and non leaf functions that
looks like:

               __wake_up_common(); /* ret=0x1 */

               } /* pick_next_task_fair ret=0x0 */

The function print_graph_retval() adds a newline after the "*/". But if
that's not called, the caller function needs to make sure there's a
newline added.

This is confusing and when the function parameters code was added, it
added a newline even when calling print_graph_retval() as the fact that
the print_graph_retval() function prints a newline isn't obvious.

This caused an extra newline to be printed and that made it fail the
selftests when the retval option was set, as the selftests were not
expecting blank lines being injected into the trace.

Instead of having print_graph_retval() print a newline, just have the
caller always print the newline regardless if it calls print_graph_retval()
or not. This not only fixes this bug, but it also simplifies the code.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250411133015.015ca393@gandalf.local.home
Reported-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/all/ccc40f2b-4b9e-4abd-8daf-d22fce2a86f0@sirena.org.uk/
Fixes: ff5c9c576e754 ("ftrace: Add support for function argument to graph tracer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
ftrace: Fix accounting of subop hashes 2025-04-11T20:02:08+00:00 Steven Rostedt rostedt@goodmis.org 2025-04-09T15:15:50+00:00 0ae6b8ce200da00a78f33c055fdc4fe3225d22ec The function graph infrastructure uses ftrace to hook to functions. It has a single ftrace_ops to manage all the users of function graph. Each individual user (tracing, bpf, fprobes, etc) has its own ftrace_ops to track the functions it will have its callback called from. These ftrace_ops are "subops" to the main ftrace_ops of the function graph infrastructure. Each ftrace_ops has a filter_hash and a notrace_hash that is defined as: Only trace functions that are in the filter_hash but not in the notrace_hash. If the filter_hash is empty, it means to trace all functions. If the notrace_hash is empty, it means do not disable any function. The function graph main ftrace_ops needs to be a superset containing all the functions to be traced by all the subops it has. The algorithm to perform this merge was incorrect. When the first subops was added to the main ops, it simply made the main ops a copy of the subops (same filter_hash and notrace_hash). When a second ops was added, it joined the new subops filter_hash with the main ops filter_hash as a union of the two sets. The intersect between the new subops notrace_hash and the main ops notrace_hash was created as the new notrace_hash of the main ops. The issue here is that it would then start tracing functions than no subops were tracing. For example if you had two subops that had: subops 1: filter_hash = '*sched*' # trace all functions with "sched" in it notrace_hash = '*time*' # except do not trace functions with "time" subops 2: filter_hash = '*lock*' # trace all functions with "lock" in it notrace_hash = '*clock*' # except do not trace functions with "clock" The intersect of '*time*' functions with '*clock*' functions could be the empty set. That means the main ops will be tracing all functions with '*time*' and all "*clock*" in it! Instead, modify the algorithm to be a bit simpler and correct. First, when adding a new subops, even if it's the first one, do not add the notrace_hash if the filter_hash is not empty. Instead, just add the functions that are in the filter_hash of the subops but not in the notrace_hash of the subops into the main ops filter_hash. There's no reason to add anything to the main ops notrace_hash. The notrace_hash of the main ops should only be non empty iff all subops filter_hashes are empty (meaning to trace all functions) and all subops notrace_hashes include the same functions. That is, the main ops notrace_hash is empty if any subops filter_hash is non empty. The main ops notrace_hash only has content in it if all subops filter_hashes are empty, and the content are only functions that intersect all the subops notrace_hashes. If any subops notrace_hash is empty, then so is the main ops notrace_hash. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/20250409152720.216356767@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> 
The function graph infrastructure uses ftrace to hook to functions. It has
a single ftrace_ops to manage all the users of function graph. Each
individual user (tracing, bpf, fprobes, etc) has its own ftrace_ops to
track the functions it will have its callback called from. These
ftrace_ops are "subops" to the main ftrace_ops of the function graph
infrastructure.

Each ftrace_ops has a filter_hash and a notrace_hash that is defined as:

  Only trace functions that are in the filter_hash but not in the
  notrace_hash.

If the filter_hash is empty, it means to trace all functions.
If the notrace_hash is empty, it means do not disable any function.

The function graph main ftrace_ops needs to be a superset containing all
the functions to be traced by all the subops it has. The algorithm to
perform this merge was incorrect.

When the first subops was added to the main ops, it simply made the main
ops a copy of the subops (same filter_hash and notrace_hash).

When a second ops was added, it joined the new subops filter_hash with the
main ops filter_hash as a union of the two sets. The intersect between the
new subops notrace_hash and the main ops notrace_hash was created as the
new notrace_hash of the main ops.

The issue here is that it would then start tracing functions than no
subops were tracing. For example if you had two subops that had:

subops 1:

  filter_hash = '*sched*' # trace all functions with "sched" in it
  notrace_hash = '*time*' # except do not trace functions with "time"

subops 2:

  filter_hash = '*lock*' # trace all functions with "lock" in it
  notrace_hash = '*clock*' # except do not trace functions with "clock"

The intersect of '*time*' functions with '*clock*' functions could be the
empty set. That means the main ops will be tracing all functions with
'*time*' and all "*clock*" in it!

Instead, modify the algorithm to be a bit simpler and correct.

First, when adding a new subops, even if it's the first one, do not add
the notrace_hash if the filter_hash is not empty. Instead, just add the
functions that are in the filter_hash of the subops but not in the
notrace_hash of the subops into the main ops filter_hash. There's no
reason to add anything to the main ops notrace_hash.

The notrace_hash of the main ops should only be non empty iff all subops
filter_hashes are empty (meaning to trace all functions) and all subops
notrace_hashes include the same functions.

That is, the main ops notrace_hash is empty if any subops filter_hash is
non empty.

The main ops notrace_hash only has content in it if all subops
filter_hashes are empty, and the content are only functions that intersect
all the subops notrace_hashes. If any subops notrace_hash is empty, then
so is the main ops notrace_hash.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Andy Chiu <andybnac@gmail.com>
Link: https://lore.kernel.org/20250409152720.216356767@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
ftrace: Properly merge notrace hashes 2025-04-11T19:14:54+00:00 Andy Chiu andybnac@gmail.com 2025-04-08T16:02:57+00:00 04a80a34c22f4db245f553d8696d1318d1c00ece The global notrace hash should be jointly decided by the intersection of each subops's notrace hash, but not the filter hash. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20250408160258.48563-1-andybnac@gmail.com Fixes: 5fccc7552ccb ("ftrace: Add subops logic to allow one ops to manage many") Signed-off-by: Andy Chiu <andybnac@gmail.com> [ fixed removing of freeing of filter_hash ] Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> 
The global notrace hash should be jointly decided by the intersection of
each subops's notrace hash, but not the filter hash.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250408160258.48563-1-andybnac@gmail.com
Fixes: 5fccc7552ccb ("ftrace: Add subops logic to allow one ops to manage many")
Signed-off-by: Andy Chiu <andybnac@gmail.com>
[ fixed removing of freeing of filter_hash ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
tracing: Do not add length to print format in synthetic events 2025-04-09T15:34:21+00:00 Steven Rostedt rostedt@goodmis.org 2025-04-07T19:41:39+00:00 e1a453a57bc76be678bd746f84e3d73f378a9511 The following causes a vsnprintf fault: # echo 's:wake_lat char[] wakee; u64 delta;' >> /sys/kernel/tracing/dynamic_events # echo 'hist:keys=pid:ts=common_timestamp.usecs if !(common_flags & 0x18)' > /sys/kernel/tracing/events/sched/sched_waking/trigger # echo 'hist:keys=next_pid:delta=common_timestamp.usecs-$ts:onmatch(sched.sched_waking).trace(wake_lat,next_comm,$delta)' > /sys/kernel/tracing/events/sched/sched_switch/trigger Because the synthetic event's "wakee" field is created as a dynamic string (even though the string copied is not). The print format to print the dynamic string changed from "%*s" to "%s" because another location (__set_synth_event_print_fmt()) exported this to user space, and user space did not need that. But it is still used in print_synth_event(), and the output looks like: <idle>-0 [001] d..5. 193.428167: wake_lat: wakee=(efault)sshd-sessiondelta=155 sshd-session-879 [001] d..5. 193.811080: wake_lat: wakee=(efault)kworker/u34:5delta=58 <idle>-0 [002] d..5. 193.811198: wake_lat: wakee=(efault)bashdelta=91 bash-880 [002] d..5. 193.811371: wake_lat: wakee=(efault)kworker/u35:2delta=21 <idle>-0 [001] d..5. 193.811516: wake_lat: wakee=(efault)sshd-sessiondelta=129 sshd-session-879 [001] d..5. 193.967576: wake_lat: wakee=(efault)kworker/u34:5delta=50 The length isn't needed as the string is always nul terminated. Just print the string and not add the length (which was hard coded to the max string length anyway). Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Douglas Raillard <douglas.raillard@arm.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://lore.kernel.org/20250407154139.69955768@gandalf.local.home Fixes: 4d38328eb442d ("tracing: Fix synth event printk format for str fields"); Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> 
The following causes a vsnprintf fault:

  # echo 's:wake_lat char[] wakee; u64 delta;' >> /sys/kernel/tracing/dynamic_events
  # echo 'hist:keys=pid:ts=common_timestamp.usecs if !(common_flags & 0x18)' > /sys/kernel/tracing/events/sched/sched_waking/trigger
  # echo 'hist:keys=next_pid:delta=common_timestamp.usecs-$ts:onmatch(sched.sched_waking).trace(wake_lat,next_comm,$delta)' > /sys/kernel/tracing/events/sched/sched_switch/trigger

Because the synthetic event's "wakee" field is created as a dynamic string
(even though the string copied is not). The print format to print the
dynamic string changed from "%*s" to "%s" because another location
(__set_synth_event_print_fmt()) exported this to user space, and user
space did not need that. But it is still used in print_synth_event(), and
the output looks like:

          <idle>-0       [001] d..5.   193.428167: wake_lat: wakee=(efault)sshd-sessiondelta=155
    sshd-session-879     [001] d..5.   193.811080: wake_lat: wakee=(efault)kworker/u34:5delta=58
          <idle>-0       [002] d..5.   193.811198: wake_lat: wakee=(efault)bashdelta=91
            bash-880     [002] d..5.   193.811371: wake_lat: wakee=(efault)kworker/u35:2delta=21
          <idle>-0       [001] d..5.   193.811516: wake_lat: wakee=(efault)sshd-sessiondelta=129
    sshd-session-879     [001] d..5.   193.967576: wake_lat: wakee=(efault)kworker/u34:5delta=50

The length isn't needed as the string is always nul terminated. Just print
the string and not add the length (which was hard coded to the max string
length anyway).

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/20250407154139.69955768@gandalf.local.home
Fixes: 4d38328eb442d ("tracing: Fix synth event printk format for str fields");
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Merge tag 'probes-fixes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 2025-04-08T19:51:34+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-04-08T19:51:34+00:00 bec7dcbc242c6c087cede1a6fdfaeb5d6eaf25bf Pull probes fixes from Masami Hiramatsu: - fprobe: remove fprobe_hlist_node when module unloading When a fprobe target module is removed, the fprobe_hlist_node should be removed from the fprobe's hash table to prevent reusing accidentally if another module is loaded at the same address. - fprobe: lock module while registering fprobe The module containing the function to be probeed is locked using a reference counter until the fprobe registration is complete, which prevents use after free. - fprobe-events: fix possible UAF on modules Basically as same as above, but in the fprobe-events layer we also need to get module reference counter when we find the tracepoint in the module. * tag 'probes-fixes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: fprobe: Cleanup fprobe hash when module unloading tracing: fprobe events: Fix possible UAF on modules tracing: fprobe: Fix to lock module while registering fprobe 
Pull probes fixes from Masami Hiramatsu:

 - fprobe: remove fprobe_hlist_node when module unloading

   When a fprobe target module is removed, the fprobe_hlist_node should
   be removed from the fprobe's hash table to prevent reusing
   accidentally if another module is loaded at the same address.

 - fprobe: lock module while registering fprobe

   The module containing the function to be probeed is locked using a
   reference counter until the fprobe registration is complete, which
   prevents use after free.

 - fprobe-events: fix possible UAF on modules

   Basically as same as above, but in the fprobe-events layer we also
   need to get module reference counter when we find the tracepoint in
   the module.

* tag 'probes-fixes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: fprobe: Cleanup fprobe hash when module unloading
  tracing: fprobe events: Fix possible UAF on modules
  tracing: fprobe: Fix to lock module while registering fprobe
tracing: fprobe: Cleanup fprobe hash when module unloading 2025-04-07T23:46:25+00:00 Masami Hiramatsu (Google) mhiramat@kernel.org 2025-03-31T15:35:44+00:00 a3dc2983ca7b90fd35f978502de6d4664d965cfb Cleanup fprobe address hash table on module unloading because the target symbols will be disappeared when unloading module and not sure the same symbol is mapped on the same address. Note that this is at least disables the fprobes if a part of target symbols on the unloaded modules. Unlike kprobes, fprobe does not re-enable the probe point by itself. To do that, the caller should take care register/unregister fprobe when loading/unloading modules. This simplifies the fprobe state managememt related to the module loading/unloading. Link: https://lore.kernel.org/all/174343534473.843280.13988101014957210732.stgit@devnote2/ Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> 
Cleanup fprobe address hash table on module unloading because the
target symbols will be disappeared when unloading module and not
sure the same symbol is mapped on the same address.

Note that this is at least disables the fprobes if a part of target
symbols on the unloaded modules. Unlike kprobes, fprobe does not
re-enable the probe point by itself. To do that, the caller should
take care register/unregister fprobe when loading/unloading modules.
This simplifies the fprobe state managememt related to the module
loading/unloading.

Link: https://lore.kernel.org/all/174343534473.843280.13988101014957210732.stgit@devnote2/

Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
tracing: Hide get_vm_area() from MMUless builds 2025-04-07T16:02:11+00:00 Steven Rostedt rostedt@goodmis.org 2025-04-07T16:01:11+00:00 4808595a9922e89726ec5611d7749b63966b7fa8 The function get_vm_area() is not defined for non-MMU builds and causes a build error if it is used. Hide the map_pages() function around a: #ifdef CONFIG_MMU to keep it from being compiled when CONFIG_MMU is not set. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250407120111.2ccc9319@gandalf.local.home Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Closes: https://lore.kernel.org/all/4f8ece8b-8862-4f7c-8ede-febd28f8a9fe@roeck-us.net/ Fixes: 394f3f02de531 ("tracing: Use vmap_page_range() to map memmap ring buffer") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> 
The function get_vm_area() is not defined for non-MMU builds and causes a
build error if it is used. Hide the map_pages() function around a:

 #ifdef CONFIG_MMU

to keep it from being compiled when CONFIG_MMU is not set.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250407120111.2ccc9319@gandalf.local.home
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/all/4f8ece8b-8862-4f7c-8ede-febd28f8a9fe@roeck-us.net/
Fixes: 394f3f02de531 ("tracing: Use vmap_page_range() to map memmap ring buffer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Merge tag 'trace-ringbuffer-v6.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 2025-04-03T23:09:29+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-04-03T23:09:29+00:00 6cb0bd94c08e37236f7ba2ff474c1e70c8318484 Pull ring-buffer updates from Steven Rostedt: "Persistent buffer cleanups and simplifications. It was mistaken that the physical memory returned from "reserve_mem" had to be vmap()'d to get to it from a virtual address. But reserve_mem already maps the memory to the virtual address of the kernel so a simple phys_to_virt() can be used to get to the virtual address from the physical memory returned by "reserve_mem". With this new found knowledge, the code can be cleaned up and simplified. - Enforce that the persistent memory is page aligned As the buffers using the persistent memory are all going to be mapped via pages, make sure that the memory given to the tracing infrastructure is page aligned. If it is not, it will print a warning and fail to map the buffer. - Use phys_to_virt() to get the virtual address from reserve_mem Instead of calling vmap() on the physical memory returned from "reserve_mem", use phys_to_virt() instead. As the memory returned by "memmap" or any other means where a physical address is given to the tracing infrastructure, it still needs to be vmap(). Since this memory can never be returned back to the buddy allocator nor should it ever be memmory mapped to user space, flag this buffer and up the ref count. The ref count will keep it from ever being freed, and the flag will prevent it from ever being memory mapped to user space. - Use vmap_page_range() for memmap virtual address mapping For the memmap buffer, instead of allocating an array of struct pages, assigning them to the contiguous phsycial memory and then passing that to vmap(), use vmap_page_range() instead - Replace flush_dcache_folio() with flush_kernel_vmap_range() Instead of calling virt_to_folio() and passing that to flush_dcache_folio(), just call flush_kernel_vmap_range() directly. This also fixes a bug where if a subbuffer was bigger than PAGE_SIZE only the PAGE_SIZE portion would be flushed" * tag 'trace-ringbuffer-v6.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Use flush_kernel_vmap_range() over flush_dcache_folio() tracing: Use vmap_page_range() to map memmap ring buffer tracing: Have reserve_mem use phys_to_virt() and separate from memmap buffer tracing: Enforce the persistent ring buffer to be page aligned 
Pull ring-buffer updates from Steven Rostedt:
 "Persistent buffer cleanups and simplifications.

  It was mistaken that the physical memory returned from "reserve_mem"
  had to be vmap()'d to get to it from a virtual address. But
  reserve_mem already maps the memory to the virtual address of the
  kernel so a simple phys_to_virt() can be used to get to the virtual
  address from the physical memory returned by "reserve_mem". With this
  new found knowledge, the code can be cleaned up and simplified.

   - Enforce that the persistent memory is page aligned

     As the buffers using the persistent memory are all going to be
     mapped via pages, make sure that the memory given to the tracing
     infrastructure is page aligned. If it is not, it will print a
     warning and fail to map the buffer.

   - Use phys_to_virt() to get the virtual address from reserve_mem

     Instead of calling vmap() on the physical memory returned from
     "reserve_mem", use phys_to_virt() instead.

     As the memory returned by "memmap" or any other means where a
     physical address is given to the tracing infrastructure, it still
     needs to be vmap(). Since this memory can never be returned back to
     the buddy allocator nor should it ever be memmory mapped to user
     space, flag this buffer and up the ref count. The ref count will
     keep it from ever being freed, and the flag will prevent it from
     ever being memory mapped to user space.

   - Use vmap_page_range() for memmap virtual address mapping

     For the memmap buffer, instead of allocating an array of struct
     pages, assigning them to the contiguous phsycial memory and then
     passing that to vmap(), use vmap_page_range() instead

   - Replace flush_dcache_folio() with flush_kernel_vmap_range()

     Instead of calling virt_to_folio() and passing that to
     flush_dcache_folio(), just call flush_kernel_vmap_range() directly.
     This also fixes a bug where if a subbuffer was bigger than
     PAGE_SIZE only the PAGE_SIZE portion would be flushed"

* tag 'trace-ringbuffer-v6.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Use flush_kernel_vmap_range() over flush_dcache_folio()
  tracing: Use vmap_page_range() to map memmap ring buffer
  tracing: Have reserve_mem use phys_to_virt() and separate from memmap buffer
  tracing: Enforce the persistent ring buffer to be page aligned