Commit Graph

6206 Commits

Author SHA1 Message Date
Andrii Nakryiko
10cdb82aa7 uprobes: turn trace_uprobe's nhit counter to be per-CPU one
trace_uprobe->nhit counter is not incremented atomically, so its value
is questionable in when uprobe is hit on multiple CPUs simultaneously.

Also, doing this shared counter increment across many CPUs causes heavy
cache line bouncing, limiting uprobe/uretprobe performance scaling with
number of CPUs.

Solve both problems by making this a per-CPU counter.

Link: https://lore.kernel.org/all/20240813203409.3985398-1-andrii@kernel.org/

Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-09-25 20:10:38 +09:00
Steven Rostedt
5bfbcd1ee5 tracing/timerlat: Add interface_lock around clearing of kthread in stop_kthread()
The timerlat interface will get and put the task that is part of the
"kthread" field of the osn_var to keep it around until all references are
released. But here's a race in the "stop_kthread()" code that will call
put_task_struct() on the kthread if it is not a kernel thread. This can
race with the releasing of the references to that task struct and the
put_task_struct() can be called twice when it should have been called just
once.

Take the interface_lock() in stop_kthread() to synchronize this change.
But to do so, the function stop_per_cpu_kthreads() needs to change the
loop from for_each_online_cpu() to for_each_possible_cpu() and remove the
cpu_read_lock(), as the interface_lock can not be taken while the cpu
locks are held. The only side effect of this change is that it may do some
extra work, as the per_cpu variables of the offline CPUs would not be set
anyway, and would simply be skipped in the loop.

Remove unneeded "return;" in stop_kthread().

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20240905113359.2b934242@gandalf.local.home
Fixes: e88ed227f6 ("tracing/timerlat: Add user-space interface")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-05 12:01:37 -04:00
Steven Rostedt
e6a53481da tracing/timerlat: Only clear timer if a kthread exists
The timerlat tracer can use user space threads to check for osnoise and
timer latency. If the program using this is killed via a SIGTERM, the
threads are shutdown one at a time and another tracing instance can start
up resetting the threads before they are fully closed. That causes the
hrtimer assigned to the kthread to be shutdown and freed twice when the
dying thread finally closes the file descriptors, causing a use-after-free
bug.

Only cancel the hrtimer if the associated thread is still around. Also add
the interface_lock around the resetting of the tlat_var->kthread.

Note, this is just a quick fix that can be backported to stable. A real
fix is to have a better synchronization between the shutdown of old
threads and the starting of new ones.

Link: https://lore.kernel.org/all/20240820130001.124768-1-tglozar@redhat.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20240905085330.45985730@gandalf.local.home
Fixes: e88ed227f6 ("tracing/timerlat: Add user-space interface")
Reported-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-05 11:30:23 -04:00
Steven Rostedt
177e1cc2f4 tracing/osnoise: Use a cpumask to know what threads are kthreads
The start_kthread() and stop_thread() code was not always called with the
interface_lock held. This means that the kthread variable could be
unexpectedly changed causing the kthread_stop() to be called on it when it
should not have been, leading to:

 while true; do
   rtla timerlat top -u -q & PID=$!;
   sleep 5;
   kill -INT $PID;
   sleep 0.001;
   kill -TERM $PID;
   wait $PID;
  done

Causing the following OOPS:

 Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI
 KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
 CPU: 5 UID: 0 PID: 885 Comm: timerlatu/5 Not tainted 6.11.0-rc4-test-00002-gbc754cc76d1b-dirty #125 a533010b71dab205ad2f507188ce8c82203b0254
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
 RIP: 0010:hrtimer_active+0x58/0x300
 Code: 48 c1 ee 03 41 54 48 01 d1 48 01 d6 55 53 48 83 ec 20 80 39 00 0f 85 30 02 00 00 49 8b 6f 30 4c 8d 75 10 4c 89 f0 48 c1 e8 03 <0f> b6 3c 10 4c 89 f0 83 e0 07 83 c0 03 40 38 f8 7c 09 40 84 ff 0f
 RSP: 0018:ffff88811d97f940 EFLAGS: 00010202
 RAX: 0000000000000002 RBX: ffff88823c6b5b28 RCX: ffffed10478d6b6b
 RDX: dffffc0000000000 RSI: ffffed10478d6b6c RDI: ffff88823c6b5b28
 RBP: 0000000000000000 R08: ffff88823c6b5b58 R09: ffff88823c6b5b60
 R10: ffff88811d97f957 R11: 0000000000000010 R12: 00000000000a801d
 R13: ffff88810d8b35d8 R14: 0000000000000010 R15: ffff88823c6b5b28
 FS:  0000000000000000(0000) GS:ffff88823c680000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000561858ad7258 CR3: 000000007729e001 CR4: 0000000000170ef0
 Call Trace:
  <TASK>
  ? die_addr+0x40/0xa0
  ? exc_general_protection+0x154/0x230
  ? asm_exc_general_protection+0x26/0x30
  ? hrtimer_active+0x58/0x300
  ? __pfx_mutex_lock+0x10/0x10
  ? __pfx_locks_remove_file+0x10/0x10
  hrtimer_cancel+0x15/0x40
  timerlat_fd_release+0x8e/0x1f0
  ? security_file_release+0x43/0x80
  __fput+0x372/0xb10
  task_work_run+0x11e/0x1f0
  ? _raw_spin_lock+0x85/0xe0
  ? __pfx_task_work_run+0x10/0x10
  ? poison_slab_object+0x109/0x170
  ? do_exit+0x7a0/0x24b0
  do_exit+0x7bd/0x24b0
  ? __pfx_migrate_enable+0x10/0x10
  ? __pfx_do_exit+0x10/0x10
  ? __pfx_read_tsc+0x10/0x10
  ? ktime_get+0x64/0x140
  ? _raw_spin_lock_irq+0x86/0xe0
  do_group_exit+0xb0/0x220
  get_signal+0x17ba/0x1b50
  ? vfs_read+0x179/0xa40
  ? timerlat_fd_read+0x30b/0x9d0
  ? __pfx_get_signal+0x10/0x10
  ? __pfx_timerlat_fd_read+0x10/0x10
  arch_do_signal_or_restart+0x8c/0x570
  ? __pfx_arch_do_signal_or_restart+0x10/0x10
  ? vfs_read+0x179/0xa40
  ? ksys_read+0xfe/0x1d0
  ? __pfx_ksys_read+0x10/0x10
  syscall_exit_to_user_mode+0xbc/0x130
  do_syscall_64+0x74/0x110
  ? __pfx___rseq_handle_notify_resume+0x10/0x10
  ? __pfx_ksys_read+0x10/0x10
  ? fpregs_restore_userregs+0xdb/0x1e0
  ? fpregs_restore_userregs+0xdb/0x1e0
  ? syscall_exit_to_user_mode+0x116/0x130
  ? do_syscall_64+0x74/0x110
  ? do_syscall_64+0x74/0x110
  ? do_syscall_64+0x74/0x110
  entry_SYSCALL_64_after_hwframe+0x71/0x79
 RIP: 0033:0x7ff0070eca9c
 Code: Unable to access opcode bytes at 0x7ff0070eca72.
 RSP: 002b:00007ff006dff8c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007ff0070eca9c
 RDX: 0000000000000400 RSI: 00007ff006dff9a0 RDI: 0000000000000003
 RBP: 00007ff006dffde0 R08: 0000000000000000 R09: 00007ff000000ba0
 R10: 00007ff007004b08 R11: 0000000000000246 R12: 0000000000000003
 R13: 00007ff006dff9a0 R14: 0000000000000007 R15: 0000000000000008
  </TASK>
 Modules linked in: snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hwdep snd_hda_core
 ---[ end trace 0000000000000000 ]---

This is because it would mistakenly call kthread_stop() on a user space
thread making it "exit" before it actually exits.

Since kthreads are created based on global behavior, use a cpumask to know
when kthreads are running and that they need to be shutdown before
proceeding to do new work.

Link: https://lore.kernel.org/all/20240820130001.124768-1-tglozar@redhat.com/

This was debugged by using the persistent ring buffer:

Link: https://lore.kernel.org/all/20240823013902.135036960@goodmis.org/

Note, locking was originally used to fix this, but that proved to cause too
many deadlocks to work around:

  https://lore.kernel.org/linux-trace-kernel/20240823102816.5e55753b@gandalf.local.home/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20240904103428.08efdf4c@gandalf.local.home
Fixes: e88ed227f6 ("tracing/timerlat: Add user-space interface")
Reported-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-05 11:30:22 -04:00
Zheng Yejian
49aa8a1f4d tracing: Avoid possible softlockup in tracing_iter_reset()
In __tracing_open(), when max latency tracers took place on the cpu,
the time start of its buffer would be updated, then event entries with
timestamps being earlier than start of the buffer would be skipped
(see tracing_iter_reset()).

Softlockup will occur if the kernel is non-preemptible and too many
entries were skipped in the loop that reset every cpu buffer, so add
cond_resched() to avoid it.

Cc: stable@vger.kernel.org
Fixes: 2f26ebd549 ("tracing: use timestamp to determine start of latency traces")
Link: https://lore.kernel.org/20240827124654.3817443-1-zhengyejian@huaweicloud.com
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian@huaweicloud.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-05 10:18:48 -04:00
Masami Hiramatsu (Google)
bc754cc76d tracing: Fix memory leak in fgraph storage selftest
With ftrace boot-time selftest, kmemleak reported some memory leaks in
the new test case for function graph storage for multiple tracers.

unreferenced object 0xffff888005060080 (size 32):
  comm "swapper/0", pid 1, jiffies 4294676440
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 20 10 06 05 80 88 ff ff  ........ .......
    54 0c 1e 81 ff ff ff ff 00 00 00 00 00 00 00 00  T...............
  backtrace (crc 7c93416c):
    [<000000000238ee6f>] __kmalloc_cache_noprof+0x11f/0x2a0
    [<0000000033d2b6c5>] enter_record+0xe8/0x150
    [<0000000054c38424>] match_records+0x1cd/0x230
    [<00000000c775b63d>] ftrace_set_hash+0xff/0x380
    [<000000007bf7208c>] ftrace_set_filter+0x70/0x90
    [<00000000a5c08dda>] test_graph_storage_multi+0x2e/0xf0
    [<000000006ba028ca>] trace_selftest_startup_function_graph+0x1e8/0x260
    [<00000000a715d3eb>] run_tracer_selftest+0x111/0x190
    [<00000000395cbf90>] register_tracer+0xdf/0x1f0
    [<0000000093e67f7b>] do_one_initcall+0x141/0x3b0
    [<00000000c591b682>] do_initcall_level+0x82/0xa0
    [<000000004e4c6600>] do_initcalls+0x43/0x70
    [<0000000034f3c4e4>] kernel_init_freeable+0x170/0x1f0
    [<00000000c7a5dab2>] kernel_init+0x1a/0x1a0
    [<00000000ea105947>] ret_from_fork+0x3a/0x50
    [<00000000a1932e84>] ret_from_fork_asm+0x1a/0x30
...

This means filter hash allocated for the fixtures are not correctly
released after the test.

Free those hash lists after tests are done and split the loop for
initialize fixture and register fixture for rollback.

Fixes: dd120af2d5 ("ftrace: Add multiple fgraph storage selftest")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/172411539857.28895.13119957560263401102.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-21 15:10:33 -04:00
Masami Hiramatsu (Google)
a069a22f39 tracing: fgraph: Fix to add new fgraph_ops to array after ftrace_startup_subops()
Since the register_ftrace_graph() assigns a new fgraph_ops to
fgraph_array before registring it by ftrace_startup_subops(), the new
fgraph_ops can be used in function_graph_enter().

In most cases, it is still OK because those fgraph_ops's hashtable is
already initialized by ftrace_set_filter*() etc.

But if a user registers a new fgraph_ops which does not initialize the
hash list, ftrace_ops_test() in function_graph_enter() causes a NULL
pointer dereference BUG because fgraph_ops->ops.func_hash is NULL.

This can be reproduced by the below commands because function profiler's
fgraph_ops does not initialize the hash list;

 # cd /sys/kernel/tracing
 # echo function_graph > current_tracer
 # echo 1 > function_profile_enabled

To fix this problem, add a new fgraph_ops to fgraph_array after
ftrace_startup_subops(). Thus, until the new fgraph_ops is initialized,
we will see fgraph_stub on the corresponding fgraph_array entry.

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/172398528350.293426.8347220120333730248.stgit@devnote2
Fixes: c132be2c4f ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-21 13:49:59 -04:00
Steven Rostedt
d0949cd44a tracing: Return from tracing_buffers_read() if the file has been closed
When running the following:

 # cd /sys/kernel/tracing/
 # echo 1 > events/sched/sched_waking/enable
 # echo 1 > events/sched/sched_switch/enable
 # echo 0 > tracing_on
 # dd if=per_cpu/cpu0/trace_pipe_raw of=/tmp/raw0.dat

The dd task would get stuck in an infinite loop in the kernel. What would
happen is the following:

When ring_buffer_read_page() returns -1 (no data) then a check is made to
see if the buffer is empty (as happens when the page is not full), it will
call wait_on_pipe() to wait until the ring buffer has data. When it is it
will try again to read data (unless O_NONBLOCK is set).

The issue happens when there's a reader and the file descriptor is closed.
The wait_on_pipe() will return when that is the case. But this loop will
continue to try again and wait_on_pipe() will again return immediately and
the loop will continue and never stop.

Simply check if the file was closed before looping and exit out if it is.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240808235730.78bf63e5@rorschach.local.home
Fixes: 2aa043a55b ("tracing/ring-buffer: Fix wait_on_pipe() race")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-09 12:59:35 -04:00
Jianhui Zhou
58f7e4d7ba ring-buffer: Remove unused function ring_buffer_nr_pages()
Because ring_buffer_nr_pages() is not an inline function and user accesses
buffer->buffers[cpu]->nr_pages directly, the function ring_buffer_nr_pages
is removed.

Signed-off-by: Jianhui Zhou <912460177@qq.com>
Link: https://lore.kernel.org/tencent_F4A7E9AB337F44E0F4B858D07D19EF460708@qq.com
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 20:26:44 -04:00
Tze-nan Wu
bcf86c01ca tracing: Fix overflow in get_free_elt()
"tracing_map->next_elt" in get_free_elt() is at risk of overflowing.

Once it overflows, new elements can still be inserted into the tracing_map
even though the maximum number of elements (`max_elts`) has been reached.
Continuing to insert elements after the overflow could result in the
tracing_map containing "tracing_map->max_size" elements, leaving no empty
entries.
If any attempt is made to insert an element into a full tracing_map using
`__tracing_map_insert()`, it will cause an infinite loop with preemption
disabled, leading to a CPU hang problem.

Fix this by preventing any further increments to "tracing_map->next_elt"
once it reaches "tracing_map->max_elt".

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 08d43a5fa0 ("tracing: Add lock-free tracing_map")
Co-developed-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Link: https://lore.kernel.org/20240805055922.6277-1-Tze-nan.Wu@mediatek.com
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 20:23:12 -04:00
Petr Pavlu
604b72b325 function_graph: Fix the ret_stack used by ftrace_graph_ret_addr()
When ftrace_graph_ret_addr() is invoked to convert a found stack return
address to its original value, the function can end up producing the
following crash:

[   95.442712] BUG: kernel NULL pointer dereference, address: 0000000000000028
[   95.442720] #PF: supervisor read access in kernel mode
[   95.442724] #PF: error_code(0x0000) - not-present page
[   95.442727] PGD 0 P4D 0-
[   95.442731] Oops: Oops: 0000 [#1] PREEMPT SMP PTI
[   95.442736] CPU: 1 UID: 0 PID: 2214 Comm: insmod Kdump: loaded Tainted: G           OE K    6.11.0-rc1-default #1 67c62a3b3720562f7e7db5f11c1fdb40b7a2857c
[   95.442747] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE, [K]=LIVEPATCH
[   95.442750] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
[   95.442754] RIP: 0010:ftrace_graph_ret_addr+0x42/0xc0
[   95.442766] Code: [...]
[   95.442773] RSP: 0018:ffff979b80ff7718 EFLAGS: 00010006
[   95.442776] RAX: ffffffff8ca99b10 RBX: ffff979b80ff7760 RCX: ffff979b80167dc0
[   95.442780] RDX: ffffffff8ca99b10 RSI: ffff979b80ff7790 RDI: 0000000000000005
[   95.442783] RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
[   95.442786] R10: 0000000000000005 R11: 0000000000000000 R12: ffffffff8e9491e0
[   95.442790] R13: ffffffff8d6f70f0 R14: ffff979b80167da8 R15: ffff979b80167dc8
[   95.442793] FS:  00007fbf83895740(0000) GS:ffff8a0afdd00000(0000) knlGS:0000000000000000
[   95.442797] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   95.442800] CR2: 0000000000000028 CR3: 0000000005070002 CR4: 0000000000370ef0
[   95.442806] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   95.442809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   95.442816] Call Trace:
[   95.442823]  <TASK>
[   95.442896]  unwind_next_frame+0x20d/0x830
[   95.442905]  arch_stack_walk_reliable+0x94/0xe0
[   95.442917]  stack_trace_save_tsk_reliable+0x7d/0xe0
[   95.442922]  klp_check_and_switch_task+0x55/0x1a0
[   95.442931]  task_call_func+0xd3/0xe0
[   95.442938]  klp_try_switch_task.part.5+0x37/0x150
[   95.442942]  klp_try_complete_transition+0x79/0x2d0
[   95.442947]  klp_enable_patch+0x4db/0x890
[   95.442960]  do_one_initcall+0x41/0x2e0
[   95.442968]  do_init_module+0x60/0x220
[   95.442975]  load_module+0x1ebf/0x1fb0
[   95.443004]  init_module_from_file+0x88/0xc0
[   95.443010]  idempotent_init_module+0x190/0x240
[   95.443015]  __x64_sys_finit_module+0x5b/0xc0
[   95.443019]  do_syscall_64+0x74/0x160
[   95.443232]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   95.443236] RIP: 0033:0x7fbf82f2c709
[   95.443241] Code: [...]
[   95.443247] RSP: 002b:00007fffd5ea3b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[   95.443253] RAX: ffffffffffffffda RBX: 000056359c48e750 RCX: 00007fbf82f2c709
[   95.443257] RDX: 0000000000000000 RSI: 000056356ed4efc5 RDI: 0000000000000003
[   95.443260] RBP: 000056356ed4efc5 R08: 0000000000000000 R09: 00007fffd5ea3c10
[   95.443263] R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
[   95.443267] R13: 000056359c48e6f0 R14: 0000000000000000 R15: 0000000000000000
[   95.443272]  </TASK>
[   95.443274] Modules linked in: [...]
[   95.443385] Unloaded tainted modules: intel_uncore_frequency(E):1 isst_if_common(E):1 skx_edac(E):1
[   95.443414] CR2: 0000000000000028

The bug can be reproduced with kselftests:

 cd linux/tools/testing/selftests
 make TARGETS='ftrace livepatch'
 (cd ftrace; ./ftracetest test.d/ftrace/fgraph-filter.tc)
 (cd livepatch; ./test-livepatch.sh)

The problem is that ftrace_graph_ret_addr() is supposed to operate on the
ret_stack of a selected task but wrongly accesses the ret_stack of the
current task. Specifically, the above NULL dereference occurs when
task->curr_ret_stack is non-zero, but current->ret_stack is NULL.

Correct ftrace_graph_ret_addr() to work with the right ret_stack.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/20240803131211.17255-1-petr.pavlu@suse.com
Fixes: 7aa1eaef9f ("function_graph: Allow multiple users to attach to function graph")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 20:20:30 -04:00
Steven Rostedt
6e2fdceffd tracing: Use refcount for trace_event_file reference counter
Instead of using an atomic counter for the trace_event_file reference
counter, use the refcount interface. It has various checks to make sure
the reference counting is correct, and will warn if it detects an error
(like refcount_inc() on '0').

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240726144208.687cce24@rorschach.local.home
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 18:12:46 -04:00
Steven Rostedt
b156040869 tracing: Have format file honor EVENT_FILE_FL_FREED
When eventfs was introduced, special care had to be done to coordinate the
freeing of the file meta data with the files that are exposed to user
space. The file meta data would have a ref count that is set when the file
is created and would be decremented and freed after the last user that
opened the file closed it. When the file meta data was to be freed, it
would set a flag (EVENT_FILE_FL_FREED) to denote that the file is freed,
and any new references made (like new opens or reads) would fail as it is
marked freed. This allowed other meta data to be freed after this flag was
set (under the event_mutex).

All the files that were dynamically created in the events directory had a
pointer to the file meta data and would call event_release() when the last
reference to the user space file was closed. This would be the time that it
is safe to free the file meta data.

A shortcut was made for the "format" file. It's i_private would point to
the "call" entry directly and not point to the file's meta data. This is
because all format files are the same for the same "call", so it was
thought there was no reason to differentiate them.  The other files
maintain state (like the "enable", "trigger", etc). But this meant if the
file were to disappear, the "format" file would be unaware of it.

This caused a race that could be trigger via the user_events test (that
would create dynamic events and free them), and running a loop that would
read the user_events format files:

In one console run:

 # cd tools/testing/selftests/user_events
 # while true; do ./ftrace_test; done

And in another console run:

 # cd /sys/kernel/tracing/
 # while true; do cat events/user_events/__test_event/format; done 2>/dev/null

With KASAN memory checking, it would trigger a use-after-free bug report
(which was a real bug). This was because the format file was not checking
the file's meta data flag "EVENT_FILE_FL_FREED", so it would access the
event that the file meta data pointed to after the event was freed.

After inspection, there are other locations that were found to not check
the EVENT_FILE_FL_FREED flag when accessing the trace_event_file. Add a
new helper function: event_file_file() that will make sure that the
event_mutex is held, and will return NULL if the trace_event_file has the
EVENT_FILE_FL_FREED flag set. Have the first reference of the struct file
pointer use event_file_file() and check for NULL. Later uses can still use
the event_file_data() helper function if the event_mutex is still held and
was not released since the event_file_file() call.

Link: https://lore.kernel.org/all/20240719204701.1605950-1-minipli@grsecurity.net/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers   <mathieu.desnoyers@efficios.com>
Cc: Ajay Kaher <ajay.kaher@broadcom.com>
Cc: Ilkka Naulapää    <digirigawa@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al   Viro <viro@zeniv.linux.org.uk>
Cc: Dan Carpenter   <dan.carpenter@linaro.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Florian Fainelli  <florian.fainelli@broadcom.com>
Cc: Alexey Makhalov    <alexey.makhalov@broadcom.com>
Cc: Vasavi Sirnapalli    <vasavi.sirnapalli@broadcom.com>
Link: https://lore.kernel.org/20240730110657.3b69d3c1@gandalf.local.home
Fixes: b63db58e2f ("eventfs/tracing: Add callback for release of an eventfs_inode")
Reported-by: Mathias Krause <minipli@grsecurity.net>
Tested-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 18:12:46 -04:00
Linus Torvalds
1a251f52cf minmax: make generic MIN() and MAX() macros available everywhere
This just standardizes the use of MIN() and MAX() macros, with the very
traditional semantics.  The goal is to use these for C constant
expressions and for top-level / static initializers, and so be able to
simplify the min()/max() macros.

These macro names were used by various kernel code - they are very
traditional, after all - and all such users have been fixed up, with a
few different approaches:

 - trivial duplicated macro definitions have been removed

   Note that 'trivial' here means that it's obviously kernel code that
   already included all the major kernel headers, and thus gets the new
   generic MIN/MAX macros automatically.

 - non-trivial duplicated macro definitions are guarded with #ifndef

   This is the "yes, they define their own versions, but no, the include
   situation is not entirely obvious, and maybe they don't get the
   generic version automatically" case.

 - strange use case #1

   A couple of drivers decided that the way they want to describe their
   versioning is with

	#define MAJ 1
	#define MIN 2
	#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)

   which adds zero value and I just did my Alexander the Great
   impersonation, and rewrote that pointless Gordian knot as

	#define DRV_VERSION "1.2"

   instead.

 - strange use case #2

   A couple of drivers thought that it's a good idea to have a random
   'MIN' or 'MAX' define for a value or index into a table, rather than
   the traditional macro that takes arguments.

   These values were re-written as C enum's instead. The new
   function-line macros only expand when followed by an open
   parenthesis, and thus don't clash with enum use.

Happily, there weren't really all that many of these cases, and a lot of
users already had the pattern of using '#ifndef' guarding (or in one
case just using '#undef MIN') before defining their own private version
that does the same thing. I left such cases alone.

Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-28 15:49:18 -07:00
Joel Granados
78eb4ea25c sysctl: treewide: constify the ctl_table argument of proc_handlers
const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
  virtual patch

  @r1@
  identifier ctl, write, buffer, lenp, ppos;
  identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

  @r2@
  identifier func, ctl, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos)
  { ... }

  @r3@
  identifier func;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int , void *, size_t *, loff_t *);

  @r4@
  identifier func, ctl;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int , void *, size_t *, loff_t *);

  @r5@
  identifier func, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
  conventions. The xfs_stats_clear_proc_handler,
  xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
  adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
  This is called from a proc_handler itself and is calling back into
  another proc_handler, making it necessary to change it as part of the
  proc_handler migration.

Co-developed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-07-24 20:59:29 +02:00
Linus Torvalds
fbc90c042c - 875fa64577 ("mm/hugetlb_vmemmap: fix race with speculative PFN
walkers") is known to cause a performance regression
   (https://lore.kernel.org/all/3acefad9-96e5-4681-8014-827d6be71c7a@linux.ibm.com/T/#mfa809800a7862fb5bdf834c6f71a3a5113eb83ff).
   Yu has a fix which I'll send along later via the hotfixes branch.
 
 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.
 
 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that.  This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches.  My bad.
 
 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"
 
 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability of
   cgroup writeback"
 
 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache index".
 
 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of the
   zeropage in MAP_SHARED mappings.  I don't see any runtime effects here -
   more a cleanup/understandability/maintainablity thing.
 
 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of
   higher addresses, for aarch64.  The (poorly named) series is
   "Restructure va_high_addr_switch".
 
 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".
 
 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the
   series "Enhance soft hwpoison handling and injection".
 
 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything.  Some landed in this pull.
 
 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has
   simplified migration's use of hardware-offload memory copying.
 
 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".
 
 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code.  This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.
 
 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.
 
 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP.  By default this
   is a no-op - users must opt in vis sysfs controls.  Dramatic
   improvements in pagefault latency are realized.
 
 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".
 
 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".
 
 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".
 
 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".
 
 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances.  A 10x speedup is seen in a microbenchmark.
 
   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.
 
 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".
 
 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.
 
 - Is anyone reading this stuff?  If so, email me!
 
 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.
 
 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".
 
 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.
 
 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".
 
 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE".  It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.
 
 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.
 
 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large folio
   userspace copying.
 
 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers.  From SeongJae Park.
 
 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.
 
 - David Hildenbrand sends along more cleanups, this time against the
   migration code.  The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".
 
 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code.  He addresses this in the series "mm: Fix various
   readahead quirks".
 
 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's self
   testing code.
 
 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code.  The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this.  The series is marked cc:stable.
 
 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.
 
 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion.  The series (which also makes the memcg-v1 code
   Kconfigurable) are
 
   "mm: memcg: separate legacy cgroup v1 code and put under config
   option" and
   "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1"
 
 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.
 
 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of excessive
   correctable memory errors.  In order to permit userspace to monitor and
   handle this situation.
 
 - Kefeng Wang's series "mm: migrate: support poison recover from migrate
   folio" teaches the kernel to appropriately handle migration from
   poisoned source folios rather than simply panicing.
 
 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.
 
 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory utilization.
 
 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare
   refcount increments.  So these paes can first be moved aside if they
   reside in the movable zone or a CMA block.
 
 - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps
   for much faster reading of vma information.  The series is "query VMAs
   from /proc/<pid>/maps".
 
 - In the series "mm: introduce per-order mTHP split counters" Lance Yang
   improves the kernel's presentation of developer information related to
   multisize THP splitting.
 
 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)".  This permits
   userspace to use all available huge page sizes.
 
 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and not
   very useful feature from slab fault injection.
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Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/<pid>/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
2024-07-21 17:15:46 -07:00
Linus Torvalds
70045bfc4c ftrace: Rewrite of function graph tracer
Up until now, the function graph tracer could only have a single user
 attached to it. If another user tried to attach to the function graph
 tracer while one was already attached, it would fail. Allowing function
 graph tracer to have more than one user has been asked for since 2009, but
 it required a rewrite to the logic to pull it off so it never happened.
 Until now!
 
 There's three systems that trace the return of a function. That is
 kretprobes, function graph tracer, and BPF. kretprobes and function graph
 tracing both do it similarly. The difference is that kretprobes uses a
 shadow stack per callback and function graph tracer creates a shadow stack
 for all tasks. The function graph tracer method makes it possible to trace
 the return of all functions. As kretprobes now needs that feature too,
 allowing it to use function graph tracer was needed. BPF also wants to
 trace the return of many probes and its method doesn't scale either.
 Having it use function graph tracer would improve that.
 
 By allowing function graph tracer to have multiple users allows both
 kretprobes and BPF to use function graph tracer in these cases. This will
 allow kretprobes code to be removed in the future as it's version will no
 longer be needed. Note, function graph tracer is only limited to 16
 simultaneous users, due to shadow stack size and allocated slots.
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Merge tag 'ftrace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace updates from Steven Rostedt:
 "Rewrite of function graph tracer to allow multiple users

  Up until now, the function graph tracer could only have a single user
  attached to it. If another user tried to attach to the function graph
  tracer while one was already attached, it would fail. Allowing
  function graph tracer to have more than one user has been asked for
  since 2009, but it required a rewrite to the logic to pull it off so
  it never happened. Until now!

  There's three systems that trace the return of a function. That is
  kretprobes, function graph tracer, and BPF. kretprobes and function
  graph tracing both do it similarly. The difference is that kretprobes
  uses a shadow stack per callback and function graph tracer creates a
  shadow stack for all tasks. The function graph tracer method makes it
  possible to trace the return of all functions. As kretprobes now needs
  that feature too, allowing it to use function graph tracer was needed.
  BPF also wants to trace the return of many probes and its method
  doesn't scale either. Having it use function graph tracer would
  improve that.

  By allowing function graph tracer to have multiple users allows both
  kretprobes and BPF to use function graph tracer in these cases. This
  will allow kretprobes code to be removed in the future as it's version
  will no longer be needed.

  Note, function graph tracer is only limited to 16 simultaneous users,
  due to shadow stack size and allocated slots"

* tag 'ftrace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (49 commits)
  fgraph: Use str_plural() in test_graph_storage_single()
  function_graph: Add READ_ONCE() when accessing fgraph_array[]
  ftrace: Add missing kerneldoc parameters to unregister_ftrace_direct()
  function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove it
  function_graph: Fix up ftrace_graph_ret_addr()
  function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACE
  function_graph: Rename BYTE_NUMBER to CHAR_NUMBER in selftests
  fgraph: Remove some unused functions
  ftrace: Hide one more entry in stack trace when ftrace_pid is enabled
  function_graph: Do not update pid func if CONFIG_DYNAMIC_FTRACE not enabled
  function_graph: Make fgraph_do_direct static key static
  ftrace: Fix prototypes for ftrace_startup/shutdown_subops()
  ftrace: Assign RCU list variable with rcu_assign_ptr()
  ftrace: Assign ftrace_list_end to ftrace_ops_list type cast to RCU
  ftrace: Declare function_trace_op in header to quiet sparse warning
  ftrace: Add comments to ftrace_hash_move() and friends
  ftrace: Convert "inc" parameter to bool in ftrace_hash_rec_update_modify()
  ftrace: Add comments to ftrace_hash_rec_disable/enable()
  ftrace: Remove "filter_hash" parameter from __ftrace_hash_rec_update()
  ftrace: Rename dup_hash() and comment it
  ...
2024-07-18 13:36:33 -07:00
Linus Torvalds
2fd4130e53 tracing: Trivial updates for 6.11
- Set rtla/osnoise default threshold to 1us from 5us
   The 5us default was missing noise that people cared about.
   Changing it to 1us makes it work as expected.
 
 - Restructure how sched_switch prev_comm and next_comm was being saved.
   The prev_comm was being saved along with the other next fields, and the
   next_comm was being saved along with the other prev fields. This is just
   a cosmetic change.
 
 - Have the allocation of pid_list use GFP_NOWAIT instead of GFP_KERNEL.
   The allocation can happen in irq_work context, but luckily, the size
   was by default so large, it was never triggered. But in case it ever is,
   use the NOWAIT allocation in the interrupt context.
 
 - Fix some kernel doc errors.
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Merge tag 'trace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:
 "Trivial updates for 6.11:

   - Set rtla/osnoise default threshold to 1us from 5us

     The 5us default was missing noise that people cared about. Changing
     it to 1us makes it work as expected.

   - Restructure how sched_switch prev_comm and next_comm was being saved

     The prev_comm was being saved along with the other next fields, and
     the next_comm was being saved along with the other prev fields.
     This is just a cosmetic change.

   - Have the allocation of pid_list use GFP_NOWAIT instead of GFP_KERNEL

     The allocation can happen in irq_work context, but luckily, the
     size was by default so large, it was never triggered. But in case
     it ever is, use the NOWAIT allocation in the interrupt context.

   - Fix some kernel doc errors"

* tag 'trace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  trace/pid_list: Change gfp flags in pid_list_fill_irq()
  tracing/sched: sched_switch: place prev_comm and next_comm in right order
  rtla/osnoise: set the default threshold to 1us
  tracing: Fix trace_pid_list_free() kernel-doc
2024-07-18 13:29:25 -07:00
Linus Torvalds
91bd008d4e Probes updates for v6.11:
Uprobes:
 - x86/shstk: Make return uprobe work with shadow stack.
 - Add uretprobe syscall which speeds up the uretprobe 10-30% faster. This
   syscall is automatically used from user-space trampolines which are
   generated by the uretprobe. If this syscall is used by normal
   user program, it will cause SIGILL. Note that this is currently only
   implemented on x86_64.
   (This also has 2 fixes for adjusting the syscall number to avoid conflict
    with new *attrat syscalls.)
 - uprobes/perf: fix user stack traces in the presence of pending uretprobe.
   This corrects the uretprobe's trampoline address in the stacktrace with
   correct return address.
 - selftests/x86: Add a return uprobe with shadow stack test.
 - selftests/bpf: Add uretprobe syscall related tests.
   . test case for register integrity check.
   . test case with register changing case.
   . test case for uretprobe syscall without uprobes (expected to be failed).
   . test case for uretprobe with shadow stack.
 - selftests/bpf: add test validating uprobe/uretprobe stack traces
 - MAINTAINERS: Add uprobes entry. This does not specify the tree but to
   clarify who maintains and reviews the uprobes.
 
 Kprobes:
 - tracing/kprobes: Test case cleanups. Replace redundant WARN_ON_ONCE() +
   pr_warn() with WARN_ONCE() and remove unnecessary code from selftest.
 - tracing/kprobes: Add symbol counting check when module loads. This
   checks the uniqueness of the probed symbol on modules. The same check
   has already done for kernel symbols.
   (This also has a fix for build error with CONFIG_MODULES=n)
 
 Cleanup:
 - Add MODULE_DESCRIPTION() macros for fprobe and kprobe examples.
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Merge tag 'probes-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:
 "Uprobes:

   - x86/shstk: Make return uprobe work with shadow stack

   - Add uretprobe syscall which speeds up the uretprobe 10-30% faster.
     This syscall is automatically used from user-space trampolines
     which are generated by the uretprobe. If this syscall is used by
     normal user program, it will cause SIGILL. Note that this is
     currently only implemented on x86_64.

     (This also has two fixes for adjusting the syscall number to avoid
     conflict with new *attrat syscalls.)

   - uprobes/perf: fix user stack traces in the presence of pending
     uretprobe. This corrects the uretprobe's trampoline address in the
     stacktrace with correct return address

   - selftests/x86: Add a return uprobe with shadow stack test

   - selftests/bpf: Add uretprobe syscall related tests.
      - test case for register integrity check
      - test case with register changing case
      - test case for uretprobe syscall without uprobes (expected to fail)
      - test case for uretprobe with shadow stack

   - selftests/bpf: add test validating uprobe/uretprobe stack traces

   - MAINTAINERS: Add uprobes entry. This does not specify the tree but
     to clarify who maintains and reviews the uprobes

  Kprobes:

   - tracing/kprobes: Test case cleanups.

     Replace redundant WARN_ON_ONCE() + pr_warn() with WARN_ONCE() and
     remove unnecessary code from selftest

   - tracing/kprobes: Add symbol counting check when module loads.

     This checks the uniqueness of the probed symbol on modules. The
     same check has already done for kernel symbols

     (This also has a fix for build error with CONFIG_MODULES=n)

  Cleanup:

   - Add MODULE_DESCRIPTION() macros for fprobe and kprobe examples"

* tag 'probes-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  MAINTAINERS: Add uprobes entry
  selftests/bpf: Change uretprobe syscall number in uprobe_syscall test
  uprobe: Change uretprobe syscall scope and number
  tracing/kprobes: Fix build error when find_module() is not available
  tracing/kprobes: Add symbol counting check when module loads
  selftests/bpf: add test validating uprobe/uretprobe stack traces
  perf,uprobes: fix user stack traces in the presence of pending uretprobes
  tracing/kprobe: Remove cleanup code unrelated to selftest
  tracing/kprobe: Integrate test warnings into WARN_ONCE
  selftests/bpf: Add uretprobe shadow stack test
  selftests/bpf: Add uretprobe syscall call from user space test
  selftests/bpf: Add uretprobe syscall test for regs changes
  selftests/bpf: Add uretprobe syscall test for regs integrity
  selftests/x86: Add return uprobe shadow stack test
  uprobe: Add uretprobe syscall to speed up return probe
  uprobe: Wire up uretprobe system call
  x86/shstk: Make return uprobe work with shadow stack
  samples: kprobes: add missing MODULE_DESCRIPTION() macros
  fprobe: add missing MODULE_DESCRIPTION() macro
2024-07-18 12:19:20 -07:00
levi.yun
7dc836187f trace/pid_list: Change gfp flags in pid_list_fill_irq()
pid_list_fill_irq() runs via irq_work.
When CONFIG_PREEMPT_RT is disabled, it would run in irq_context.
so it shouldn't sleep while memory allocation.

Change gfp flags from GFP_KERNEL to GFP_NOWAIT to prevent sleep in
irq_work.

This change wouldn't impact functionality in practice because the worst-size
is 2K.

Cc: stable@goodmis.org
Fixes: 8d6e90983a ("tracing: Create a sparse bitmask for pid filtering")
Link: https://lore.kernel.org/20240704150226.1359936-1-yeoreum.yun@arm.com
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: levi.yun <yeoreum.yun@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-15 15:07:14 -04:00
Masami Hiramatsu (Google)
b10545b6b8 tracing/kprobes: Fix build error when find_module() is not available
The kernel test robot reported that the find_module() is not available
if CONFIG_MODULES=n.
Fix this error by hiding find_modules() in #ifdef CONFIG_MODULES with
related rcu locks as try_module_get_by_name().

Link: https://lore.kernel.org/all/172056819167.201571.250053007194508038.stgit@devnote2/

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202407070744.RcLkn8sq-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202407070917.VVUCBlaS-lkp@intel.com/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-07-10 09:47:00 +09:00
Paolo Abeni
7b769adc26 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-07-08

The following pull-request contains BPF updates for your *net-next* tree.

We've added 102 non-merge commits during the last 28 day(s) which contain
a total of 127 files changed, 4606 insertions(+), 980 deletions(-).

The main changes are:

1) Support resilient split BTF which cuts down on duplication and makes BTF
   as compact as possible wrt BTF from modules, from Alan Maguire & Eduard Zingerman.

2) Add support for dumping kfunc prototypes from BTF which enables both detecting
   as well as dumping compilable prototypes for kfuncs, from Daniel Xu.

3) Batch of s390x BPF JIT improvements to add support for BPF arena and to implement
   support for BPF exceptions, from Ilya Leoshkevich.

4) Batch of riscv64 BPF JIT improvements in particular to add 12-argument support
   for BPF trampolines and to utilize bpf_prog_pack for the latter, from Pu Lehui.

5) Extend BPF test infrastructure to add a CHECKSUM_COMPLETE validation option
   for skbs and add coverage along with it, from Vadim Fedorenko.

6) Inline bpf_get_current_task/_btf() helpers in the arm64 BPF JIT which gives
   a small 1% performance improvement in micro-benchmarks, from Puranjay Mohan.

7) Extend the BPF verifier to track the delta between linked registers in order
   to better deal with recent LLVM code optimizations, from Alexei Starovoitov.

8) Fix bpf_wq_set_callback_impl() kfunc signature where the third argument should
   have been a pointer to the map value, from Benjamin Tissoires.

9) Extend BPF selftests to add regular expression support for test output matching
   and adjust some of the selftest when compiled under gcc, from Cupertino Miranda.

10) Simplify task_file_seq_get_next() and remove an unnecessary loop which always
    iterates exactly once anyway, from Dan Carpenter.

11) Add the capability to offload the netfilter flowtable in XDP layer through
    kfuncs, from Florian Westphal & Lorenzo Bianconi.

12) Various cleanups in networking helpers in BPF selftests to shave off a few
    lines of open-coded functions on client/server handling, from Geliang Tang.

13) Properly propagate prog->aux->tail_call_reachable out of BPF verifier, so
    that x86 JIT does not need to implement detection, from Leon Hwang.

14) Fix BPF verifier to add a missing check_func_arg_reg_off() to prevent an
    out-of-bounds memory access for dynpointers, from Matt Bobrowski.

15) Fix bpf_session_cookie() kfunc to return __u64 instead of long pointer as
    it might lead to problems on 32-bit archs, from Jiri Olsa.

16) Enhance traffic validation and dynamic batch size support in xsk selftests,
    from Tushar Vyavahare.

bpf-next-for-netdev

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (102 commits)
  selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep
  selftests/bpf: amend for wrong bpf_wq_set_callback_impl signature
  bpf: helpers: fix bpf_wq_set_callback_impl signature
  libbpf: Add NULL checks to bpf_object__{prev_map,next_map}
  selftests/bpf: Remove exceptions tests from DENYLIST.s390x
  s390/bpf: Implement exceptions
  s390/bpf: Change seen_reg to a mask
  bpf: Remove unnecessary loop in task_file_seq_get_next()
  riscv, bpf: Optimize stack usage of trampoline
  bpf, devmap: Add .map_alloc_check
  selftests/bpf: Remove arena tests from DENYLIST.s390x
  selftests/bpf: Add UAF tests for arena atomics
  selftests/bpf: Introduce __arena_global
  s390/bpf: Support arena atomics
  s390/bpf: Enable arena
  s390/bpf: Support address space cast instruction
  s390/bpf: Support BPF_PROBE_MEM32
  s390/bpf: Land on the next JITed instruction after exception
  s390/bpf: Introduce pre- and post- probe functions
  s390/bpf: Get rid of get_probe_mem_regno()
  ...
====================

Link: https://patch.msgid.link/20240708221438.10974-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-09 17:01:46 +02:00
Masami Hiramatsu (Google)
9d8616034f tracing/kprobes: Add symbol counting check when module loads
Currently, kprobe event checks whether the target symbol name is unique
or not, so that it does not put a probe on an unexpected place. But this
skips the check if the target is on a module because the module may not
be loaded.

To fix this issue, this patch checks the number of probe target symbols
in a target module when the module is loaded. If the probe is not on the
unique name symbols in the module, it will be rejected at that point.

Note that the symbol which has a unique name in the target module,
it will be accepted even if there are same-name symbols in the
kernel or other modules,

Link: https://lore.kernel.org/all/172016348553.99543.2834679315611882137.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-06 09:27:47 +09:00
Ilya Leoshkevich
c02525a339 ftrace: unpoison ftrace_regs in ftrace_ops_list_func()
Patch series "kmsan: Enable on s390", v7.


Architectures use assembly code to initialize ftrace_regs and call
ftrace_ops_list_func().  Therefore, from the KMSAN's point of view,
ftrace_regs is poisoned on ftrace_ops_list_func entry().  This causes
KMSAN warnings when running the ftrace testsuite.

Fix by trusting the architecture-specific assembly code and always
unpoisoning ftrace_regs in ftrace_ops_list_func.

The issue was not encountered on x86_64 so far only by accident:
assembly-allocated ftrace_regs was overlapping a stale partially
unpoisoned stack frame.  Poisoning stack frames before returns [1] makes
the issue appear on x86_64 as well.

[1] https://github.com/iii-i/llvm-project/commits/msan-poison-allocas-before-returning-2024-06-12/

Link: https://lkml.kernel.org/r/20240621113706.315500-1-iii@linux.ibm.com
Link: https://lkml.kernel.org/r/20240621113706.315500-2-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:21 -07:00
Jiapeng Chong
b576d375b5 fgraph: Use str_plural() in test_graph_storage_single()
Use existing str_plural() function rather than duplicating its
implementation.

./kernel/trace/trace_selftest.c:880:56-60: opportunity for str_plural(size).

Link: https://lore.kernel.org/linux-trace-kernel/20240618072014.20855-1-jiapeng.chong@linux.alibaba.com

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9349
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-01 19:57:51 -04:00
Luis Claudio R. Goncalves
c40583e19e rtla/osnoise: set the default threshold to 1us
Change the default threshold for osnoise to 1us, so that any noise
equal or above this value is recorded. Let the user set a higher
threshold if necessary.

Link: https://lore.kernel.org/linux-trace-kernel/Zmb-QhiiiI6jM9To@uudg.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Suggested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: Clark Williams <williams@redhat.com>
Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-01 18:54:31 -04:00
Arnd Bergmann
7e1f4eb9a6 kallsyms: rework symbol lookup return codes
Building with W=1 in some configurations produces a false positive
warning for kallsyms:

kernel/kallsyms.c: In function '__sprint_symbol.isra':
kernel/kallsyms.c:503:17: error: 'strcpy' source argument is the same as destination [-Werror=restrict]
  503 |                 strcpy(buffer, name);
      |                 ^~~~~~~~~~~~~~~~~~~~

This originally showed up while building with -O3, but later started
happening in other configurations as well, depending on inlining
decisions. The underlying issue is that the local 'name' variable is
always initialized to the be the same as 'buffer' in the called functions
that fill the buffer, which gcc notices while inlining, though it could
see that the address check always skips the copy.

The calling conventions here are rather unusual, as all of the internal
lookup functions (bpf_address_lookup, ftrace_mod_address_lookup,
ftrace_func_address_lookup, module_address_lookup and
kallsyms_lookup_buildid) already use the provided buffer and either return
the address of that buffer to indicate success, or NULL for failure,
but the callers are written to also expect an arbitrary other buffer
to be returned.

Rework the calling conventions to return the length of the filled buffer
instead of its address, which is simpler and easier to follow as well
as avoiding the warning. Leave only the kallsyms_lookup() calling conventions
unchanged, since that is called from 16 different functions and
adapting this would be a much bigger change.

Link: https://lore.kernel.org/lkml/20200107214042.855757-1-arnd@arndb.de/
Link: https://lore.kernel.org/lkml/20240326130647.7bfb1d92@gandalf.local.home/
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-06-27 17:43:40 +02:00
Jiri Olsa
717d6313bb bpf: Change bpf_session_cookie return value to __u64 *
This reverts [1] and changes return value for bpf_session_cookie
in bpf selftests. Having long * might lead to problems on 32-bit
architectures.

Fixes: 2b8dd87332 ("bpf: Make bpf_session_cookie() kfunc return long *")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240619081624.1620152-1-jolsa@kernel.org
2024-06-21 19:32:36 +02:00
Steven Rostedt (Google)
63a8dfb889 function_graph: Add READ_ONCE() when accessing fgraph_array[]
In function_graph_enter() there's a loop that looks at fgraph_array[]
elements which are fgraph_ops. It first tests if it is a fgraph_stub op,
and if so skips it, as that's just there as a place holder. Then it checks
the fgraph_ops filters to see if the ops wants to trace the current
function.

But if the compiler reloads the fgraph_array[] after the check against
fgraph_stub, it could race with the fgraph_array[] being updated with the
fgraph_stub. That would cause the stub to be processed. But the stub has a
null "func_hash" field which will cause a NULL pointer dereference.

Add a READ_ONCE() so that the gops that is compared against the
fgraph_stub is also the gops that is processed later.

Link: https://lore.kernel.org/all/CA+G9fYsSVJQZH=nM=1cjTc94PgSnMF9y65BnOv6XSoCG_b6wmw@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240613095223.1f07e3a4@rorschach.local.home

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: cc60ee813b ("function_graph: Use static_call and branch to optimize entry function")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-06-14 12:37:08 -04:00
Daniel Xu
cce4c40b96 bpf: treewide: Align kfunc signatures to prog point-of-view
Previously, kfunc declarations in bpf_kfuncs.h (and others) used "user
facing" types for kfuncs prototypes while the actual kfunc definitions
used "kernel facing" types. More specifically: bpf_dynptr vs
bpf_dynptr_kern, __sk_buff vs sk_buff, and xdp_md vs xdp_buff.

It wasn't an issue before, as the verifier allows aliased types.
However, since we are now generating kfunc prototypes in vmlinux.h (in
addition to keeping bpf_kfuncs.h around), this conflict creates
compilation errors.

Fix this conflict by using "user facing" types in kfunc definitions.
This results in more casts, but otherwise has no additional runtime
cost.

Note, similar to 5b268d1ebc ("bpf: Have bpf_rdonly_cast() take a const
pointer"), we also make kfuncs take const arguments where appropriate in
order to make the kfunc more permissive.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/b58346a63a0e66bc9b7504da751b526b0b189a67.1718207789.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-12 11:01:31 -07:00
Daniel Xu
2b8dd87332 bpf: Make bpf_session_cookie() kfunc return long *
We will soon be generating kfunc prototypes from BTF. As part of that,
we need to align the manual signatures in bpf_kfuncs.h with the actual
kfunc definitions. There is currently a conflicting signature for
bpf_session_cookie() w.r.t. return type.

The original intent was to return long * and not __u64 *. You can see
evidence of that intent in a3a5113393 ("selftests/bpf: Add kprobe
session cookie test").

Fix conflict by changing kfunc definition.

Fixes: 5c919acef8 ("bpf: Add support for kprobe session cookie")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/7043e1c251ab33151d6e3830f8ea1902ed2604ac.1718207789.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-12 11:01:31 -07:00
Masami Hiramatsu (Google)
3eddb03196 tracing/kprobe: Remove cleanup code unrelated to selftest
This cleanup all kprobe events code is not related to the selftest
itself, and it can fail by the reason unrelated to this test.
If the test is successful, the generated events are cleaned up.
And if not, we cannot guarantee that the kprobe events will work
correctly. So, anyway, there is no need to clean it up.

Link: https://lore.kernel.org/all/171811265627.85078.16897867213512435822.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-12 08:46:00 +09:00
Masami Hiramatsu (Google)
41051daa38 tracing/kprobe: Integrate test warnings into WARN_ONCE
Cleanup the redundant WARN_ON_ONCE(cond) + pr_warn(msg) into
WARN_ONCE(cond, msg). Also add some WARN_ONCE() for hitcount check.
These WARN_ONCE() errors makes it easy to handle errors from ktest.

Link: https://lore.kernel.org/all/171811264685.85078.8068819097047430463.stgit@devnote2/

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-12 08:44:44 +09:00
Masami Hiramatsu (Google)
3572bd5689 tracing: Build event generation tests only as modules
The kprobes and synth event generation test modules add events and lock
(get a reference) those event file reference in module init function,
and unlock and delete it in module exit function. This is because those
are designed for playing as modules.

If we make those modules as built-in, those events are left locked in the
kernel, and never be removed. This causes kprobe event self-test failure
as below.

[   97.349708] ------------[ cut here ]------------
[   97.353453] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:2133 kprobe_trace_self_tests_init+0x3f1/0x480
[   97.357106] Modules linked in:
[   97.358488] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.9.0-g699646734ab5-dirty #14
[   97.361556] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[   97.363880] RIP: 0010:kprobe_trace_self_tests_init+0x3f1/0x480
[   97.365538] Code: a8 24 08 82 e9 ae fd ff ff 90 0f 0b 90 48 c7 c7 e5 aa 0b 82 e9 ee fc ff ff 90 0f 0b 90 48 c7 c7 2d 61 06 82 e9 8e fd ff ff 90 <0f> 0b 90 48 c7 c7 33 0b 0c 82 89 c6 e8 6e 03 1f ff 41 ff c7 e9 90
[   97.370429] RSP: 0000:ffffc90000013b50 EFLAGS: 00010286
[   97.371852] RAX: 00000000fffffff0 RBX: ffff888005919c00 RCX: 0000000000000000
[   97.373829] RDX: ffff888003f40000 RSI: ffffffff8236a598 RDI: ffff888003f40a68
[   97.375715] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
[   97.377675] R10: ffffffff811c9ae5 R11: ffffffff8120c4e0 R12: 0000000000000000
[   97.379591] R13: 0000000000000001 R14: 0000000000000015 R15: 0000000000000000
[   97.381536] FS:  0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000
[   97.383813] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   97.385449] CR2: 0000000000000000 CR3: 0000000002244000 CR4: 00000000000006b0
[   97.387347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   97.389277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   97.391196] Call Trace:
[   97.391967]  <TASK>
[   97.392647]  ? __warn+0xcc/0x180
[   97.393640]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.395181]  ? report_bug+0xbd/0x150
[   97.396234]  ? handle_bug+0x3e/0x60
[   97.397311]  ? exc_invalid_op+0x1a/0x50
[   97.398434]  ? asm_exc_invalid_op+0x1a/0x20
[   97.399652]  ? trace_kprobe_is_busy+0x20/0x20
[   97.400904]  ? tracing_reset_all_online_cpus+0x15/0x90
[   97.402304]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.403773]  ? init_kprobe_trace+0x50/0x50
[   97.404972]  do_one_initcall+0x112/0x240
[   97.406113]  do_initcall_level+0x95/0xb0
[   97.407286]  ? kernel_init+0x1a/0x1a0
[   97.408401]  do_initcalls+0x3f/0x70
[   97.409452]  kernel_init_freeable+0x16f/0x1e0
[   97.410662]  ? rest_init+0x1f0/0x1f0
[   97.411738]  kernel_init+0x1a/0x1a0
[   97.412788]  ret_from_fork+0x39/0x50
[   97.413817]  ? rest_init+0x1f0/0x1f0
[   97.414844]  ret_from_fork_asm+0x11/0x20
[   97.416285]  </TASK>
[   97.417134] irq event stamp: 13437323
[   97.418376] hardirqs last  enabled at (13437337): [<ffffffff8110bc0c>] console_unlock+0x11c/0x150
[   97.421285] hardirqs last disabled at (13437370): [<ffffffff8110bbf1>] console_unlock+0x101/0x150
[   97.423838] softirqs last  enabled at (13437366): [<ffffffff8108e17f>] handle_softirqs+0x23f/0x2a0
[   97.426450] softirqs last disabled at (13437393): [<ffffffff8108e346>] __irq_exit_rcu+0x66/0xd0
[   97.428850] ---[ end trace 0000000000000000 ]---

And also, since we can not cleanup dynamic_event file, ftracetest are
failed too.

To avoid these issues, build these tests only as modules.

Link: https://lore.kernel.org/all/171811263754.85078.5877446624311852525.stgit@devnote2/

Fixes: 9fe41efaca ("tracing: Add synth event generation test module")
Fixes: 64836248dd ("tracing: Add kprobe event command generation test module")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-12 08:43:12 +09:00
Marilene A Garcia
9b5a45eb63 ftrace: Add missing kerneldoc parameters to unregister_ftrace_direct()
Add the description to the parameters addr and free_filters
of the function unregister_ftrace_direct().

Link: https://lore.kernel.org/linux-trace-kernel/20240606132520.1397567-1-marilene.agarcia@gmail.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Signed-off-by: Marilene A Garcia <marilene.agarcia@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-11 11:18:24 -04:00
Steven Rostedt (Google)
5f7fb89a11 function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove it
All architectures that implement function graph also implements
HAVE_FUNCTION_GRAPH_RET_ADDR_PTR. Remove it, as it is no longer a
differentiator.

Link: https://lore.kernel.org/linux-trace-kernel/20240611031737.982047614@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-11 11:18:24 -04:00
Steven Rostedt (Google)
29c1c24a27 function_graph: Fix up ftrace_graph_ret_addr()
Yang Li sent a patch to fix the kerneldoc of ftrace_graph_ret_addr().
While reviewing it, I realized that the comments in the entire function
header needed a rewrite. When doing that, I realized that @idx parameter
was being ignored. Every time this was called by the unwinder, it would
start the loop at the top of the shadow stack and look for the matching
stack pointer. When it found it, it would return it. When the unwinder
asked for the next function, it would search from the beginning again.

In reality, it should start from where it left off. That was the reason
for the @idx parameter in the first place. The first time the unwinder
calls this function, the @idx pointer would contain zero. That would mean
to start from the top of the stack. The function was supposed to update
the @idx with the index where it found the return address, so that the
next time the unwinder calls this function it doesn't have to search
through the previous addresses it found (making it O(n^2)!).

This speeds up the unwinder's use of ftrace_graph_ret_addr() by an order
of magnitude.

Link: https://lore.kernel.org/linux-trace-kernel/20240610181746.656e3759@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20240611031737.821995106@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Reported-by: Yang Li <yang.lee@linux.alibaba.com>
Fixes: 7aa1eaef9f ("function_graph: Allow multiple users to attach to function graph")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-11 11:18:24 -04:00
Steven Rostedt (Google)
4267fda4af function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACE
When CONFIG_DYNAMIC_FTRACE is not set, the function
fgraph_update_pid_func() doesn't do anything. Currently, most of its logic
is within a "#ifdef CONFIG_DYNAMIC_FTRACE" block, but its variables were
declared outside that, and when DYNAMIC_FTRACE is not set, it produces
unused variable warnings.

Instead, just place it (and the helper function fgraph_pid_func()) within
the #ifdef block and have the header file use a empty stub function for
when DYNAMIC_FTRACE is not defined.

Link: https://lore.kernel.org/linux-trace-kernel/20240607094833.6a787d73@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406071806.BRjaC5FF-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-10 18:08:23 -04:00
Steven Rostedt (Google)
2f6b884dfc function_graph: Rename BYTE_NUMBER to CHAR_NUMBER in selftests
The function_graph selftests checks various size variables to pass from
the entry of the function to the exit. It tests 1, 2, 4 and 8 byte words.
The 1 byte macro was called BYTE_NUMBER but that is used in the sh
architecture: arch/sh/include/asm/bitops-op32.h

Just rename the macro to CHAR_NUMBER.

Link: https://lore.kernel.org/linux-trace-kernel/20240606081846.4cb82dc4@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 47c3c70aa3 ("function_graph: Add selftest for passing local variables")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406061744.rZDXfRrG-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:19 -04:00
Jiapeng Chong
9a2a3aab73 fgraph: Remove some unused functions
These functions are defined in the fgraph.c file, but not
called elsewhere, so delete these unused functions.

kernel/trace/fgraph.c:273:1: warning: unused function 'set_bitmap_bits'.
kernel/trace/fgraph.c:259:19: warning: unused function 'get_fgraph_type'.

Link: https://lore.kernel.org/linux-trace-kernel/20240606021053.27783-1-jiapeng.chong@linux.alibaba.com

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9289
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:19 -04:00
Tatsuya S
6c1f7f0aca ftrace: Hide one more entry in stack trace when ftrace_pid is enabled
On setting set_ftrace_pid, a extra entry generated by ftrace_pid_func()
is shown on stack trace(CONFIG_UNWINDER_FRAME_POINTER=y).

        [004] .....    68.459382: <stack trace>
 => 0xffffffffa00090af
 => ksys_read
 => __x64_sys_read
 => x64_sys_call
 => do_syscall_64
 => entry_SYSCALL_64_after_hwframe

To resolve this issue, increment skip count
in function_stack_trace_call() if pids are set.

Link: https://lore.kernel.org/linux-trace-kernel/20240528032604.6813-3-tatsuya.s2862@gmail.com

Signed-off-by: Tatsuya S <tatsuya.s2862@gmail.com>
[ Rebased to current tree ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
4057fd2cdd function_graph: Do not update pid func if CONFIG_DYNAMIC_FTRACE not enabled
The ftrace subops is only defined if CONFIG_DYNAMIC_FTRACE is enabled. If
it is not, function tracing is extremely limited, and the subops in the
ftrace_ops structure is not defined (and will fail to compile). If
DYNAMIC_FTRACE is not enabled, then function graph filtering will not
work (as it shouldn't).

Link: https://lore.kernel.org/linux-trace-kernel/20240605202709.096020676@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: df3ec5da6a ("function_graph: Add pid tracing back to function graph tracer")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406051855.9VIYXbTB-lkp@intel.com/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
0c4d8cbb2c function_graph: Make fgraph_do_direct static key static
The static branch key "fgraph_do_direct" was not declared static but is
only used in one file. Change it to a static variable.

Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.936515302@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: cc60ee813b ("function_graph: Use static_call and branch to optimize entry function")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406051711.dS1sQZ9n-lkp@intel.com/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
86b49970e0 ftrace: Fix prototypes for ftrace_startup/shutdown_subops()
The ftrace_startup_subops() was in the wrong header, and both functions
were not defined on !CONFIG_DYNAMIC_FTRACE.

Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.773583114@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 5fccc7552c ("ftrace: Add subops logic to allow one ops to manage many")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406051524.a12JqLqx-lkp@intel.com/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
0ddef5d601 ftrace: Assign RCU list variable with rcu_assign_ptr()
Use rcu_assign_ptr() to assign the list pointer as it is marked as RCU,
and this quiets the sparse warning:

   kernel/trace/ftrace.c:313:23: warning: incorrect type in assignment (different address spaces)
   kernel/trace/ftrace.c:313:23:    expected struct ftrace_ops [noderef] __rcu *
   kernel/trace/ftrace.c:313:23:    got struct ftrace_ops *

Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.613471310@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
1f51ba905e ftrace: Assign ftrace_list_end to ftrace_ops_list type cast to RCU
Use a type cast to convert ftrace_list_end to RCU when assigning
ftrace_ops_list. This will quiet the sparse warning:

 kernel/trace/ftrace.c:125:59: warning: incorrect type in initializer (different address spaces)
 kernel/trace/ftrace.c:125:59:    expected struct ftrace_ops [noderef] __rcu *[addressable] [toplevel] ftrace_ops_list
 kernel/trace/ftrace.c:125:59:    got struct ftrace_ops *

Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.450784356@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
d66bb33479 ftrace: Add comments to ftrace_hash_move() and friends
Describe what ftrace_hash_move() does and add some more comments to some
other functions to make it easier to understand.

Link: https://lore.kernel.org/linux-trace-kernel/20240605180409.179520305@goodmis.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:03 -04:00
Steven Rostedt (Google)
1a88c07167 ftrace: Convert "inc" parameter to bool in ftrace_hash_rec_update_modify()
The parameter "inc" in the function ftrace_hash_rec_update_modify() is
boolean. Change it to be such.

Also add documentation to what the function does.

Link: https://lore.kernel.org/linux-trace-kernel/20240605180409.021080462@goodmis.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:21:28 -04:00
Steven Rostedt (Google)
da73f6d490 ftrace: Add comments to ftrace_hash_rec_disable/enable()
Add comments to describe what the functions ftrace_hash_rec_disable() and
ftrace_hash_rec_enable() do. Also change the passing of the "inc" variable
to __ftrace_hash_rec_update() to a boolean value as that is what it is
supposed to take.

Link: https://lore.kernel.org/linux-trace-kernel/20240605180408.857333430@goodmis.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:21:25 -04:00
Steven Rostedt (Google)
07bbe0833e ftrace: Remove "filter_hash" parameter from __ftrace_hash_rec_update()
While adding comments to the function __ftrace_hash_rec_update() and
trying to describe in detail what the parameter for "filter_hash" does, I
realized that it basically does exactly the same thing (but differently)
if it is set or not!

If it is set, the idea was the ops->filter_hash was being updated, and the
code should focus on the functions that are in the ops->filter_hash and
add them. But it still had to pay attention to the functions in the
ops->notrace_hash, to ignore them.

If it was cleared, it focused on the ops->notrace_hash, and would add
functions that were not in the ops->notrace_hash but would still keep
functions in the "ops->filter_hash". Basically doing the same thing.

In reality, the __ftrace_hash_rec_update() only needs to either remove the
functions associated to the give ops (if "inc" is set) or remove them (if
"inc" is cleared). It has to pay attention to both the filter_hash and
notrace_hash regardless.

Remove the "filter_hash" parameter from __filter_hash_rec_update() and
comment the function for what it really is doing.

Link: https://lore.kernel.org/linux-trace-kernel/20240605180408.691995506@goodmis.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:20:27 -04:00