5702 Commits

Author SHA1 Message Date
Daniel Bristot de Oliveira
b9f451a902 tracing/timerlat: Notify new max thread latency
timerlat is not reporting a new tracing_max_latency for the thread
latency. The reason is that it is not calling notify_new_max_latency()
function after the new thread latency is sampled.

Call notify_new_max_latency() after computing the thread latency.

Link: https://lkml.kernel.org/r/16e18d61d69073d0192ace07bf61e405cca96e9c.1680104184.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-03 11:52:32 -04:00
Zheng Yejian
6455b6163d ring-buffer: Fix race while reader and writer are on the same page
When user reads file 'trace_pipe', kernel keeps printing following logs
that warn at "cpu_buffer->reader_page->read > rb_page_size(reader)" in
rb_get_reader_page(). It just looks like there's an infinite loop in
tracing_read_pipe(). This problem occurs several times on arm64 platform
when testing v5.10 and below.

  Call trace:
   rb_get_reader_page+0x248/0x1300
   rb_buffer_peek+0x34/0x160
   ring_buffer_peek+0xbc/0x224
   peek_next_entry+0x98/0xbc
   __find_next_entry+0xc4/0x1c0
   trace_find_next_entry_inc+0x30/0x94
   tracing_read_pipe+0x198/0x304
   vfs_read+0xb4/0x1e0
   ksys_read+0x74/0x100
   __arm64_sys_read+0x24/0x30
   el0_svc_common.constprop.0+0x7c/0x1bc
   do_el0_svc+0x2c/0x94
   el0_svc+0x20/0x30
   el0_sync_handler+0xb0/0xb4
   el0_sync+0x160/0x180

Then I dump the vmcore and look into the problematic per_cpu ring_buffer,
I found that tail_page/commit_page/reader_page are on the same page while
reader_page->read is obviously abnormal:
  tail_page == commit_page == reader_page == {
    .write = 0x100d20,
    .read = 0x8f9f4805,  // Far greater than 0xd20, obviously abnormal!!!
    .entries = 0x10004c,
    .real_end = 0x0,
    .page = {
      .time_stamp = 0x857257416af0,
      .commit = 0xd20,  // This page hasn't been full filled.
      // .data[0...0xd20] seems normal.
    }
 }

The root cause is most likely the race that reader and writer are on the
same page while reader saw an event that not fully committed by writer.

To fix this, add memory barriers to make sure the reader can see the
content of what is committed. Since commit a0fcaaed0c46 ("ring-buffer: Fix
race between reset page and reading page") has added the read barrier in
rb_get_reader_page(), here we just need to add the write barrier.

Link: https://lore.kernel.org/linux-trace-kernel/20230325021247.2923907-1-zhengyejian1@huawei.com

Cc: stable@vger.kernel.org
Fixes: 77ae365eca89 ("ring-buffer: make lockless")
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-03 11:51:38 -04:00
Tze-nan Wu
4ccf11c4e8 tracing/synthetic: Fix races on freeing last_cmd
Currently, the "last_cmd" variable can be accessed by multiple processes
asynchronously when multiple users manipulate synthetic_events node
at the same time, it could lead to use-after-free or double-free.

This patch add "lastcmd_mutex" to prevent "last_cmd" from being accessed
asynchronously.

================================================================

It's easy to reproduce in the KASAN environment by running the two
scripts below in different shells.

script 1:
        while :
        do
                echo -n -e '\x88' > /sys/kernel/tracing/synthetic_events
        done

script 2:
        while :
        do
                echo -n -e '\xb0' > /sys/kernel/tracing/synthetic_events
        done

================================================================
double-free scenario:

    process A                       process B
-------------------               ---------------
1.kstrdup last_cmd
                                  2.free last_cmd
3.free last_cmd(double-free)

================================================================
use-after-free scenario:

    process A                       process B
-------------------               ---------------
1.kstrdup last_cmd
                                  2.free last_cmd
3.tracing_log_err(use-after-free)

================================================================

Appendix 1. KASAN report double-free:

BUG: KASAN: double-free in kfree+0xdc/0x1d4
Free of addr ***** by task sh/4879
Call trace:
        ...
        kfree+0xdc/0x1d4
        create_or_delete_synth_event+0x60/0x1e8
        trace_parse_run_command+0x2bc/0x4b8
        synth_events_write+0x20/0x30
        vfs_write+0x200/0x830
        ...

Allocated by task 4879:
        ...
        kstrdup+0x5c/0x98
        create_or_delete_synth_event+0x6c/0x1e8
        trace_parse_run_command+0x2bc/0x4b8
        synth_events_write+0x20/0x30
        vfs_write+0x200/0x830
        ...

Freed by task 5464:
        ...
        kfree+0xdc/0x1d4
        create_or_delete_synth_event+0x60/0x1e8
        trace_parse_run_command+0x2bc/0x4b8
        synth_events_write+0x20/0x30
        vfs_write+0x200/0x830
        ...

================================================================
Appendix 2. KASAN report use-after-free:

BUG: KASAN: use-after-free in strlen+0x5c/0x7c
Read of size 1 at addr ***** by task sh/5483
sh: CPU: 7 PID: 5483 Comm: sh
        ...
        __asan_report_load1_noabort+0x34/0x44
        strlen+0x5c/0x7c
        tracing_log_err+0x60/0x444
        create_or_delete_synth_event+0xc4/0x204
        trace_parse_run_command+0x2bc/0x4b8
        synth_events_write+0x20/0x30
        vfs_write+0x200/0x830
        ...

Allocated by task 5483:
        ...
        kstrdup+0x5c/0x98
        create_or_delete_synth_event+0x80/0x204
        trace_parse_run_command+0x2bc/0x4b8
        synth_events_write+0x20/0x30
        vfs_write+0x200/0x830
        ...

Freed by task 5480:
        ...
        kfree+0xdc/0x1d4
        create_or_delete_synth_event+0x74/0x204
        trace_parse_run_command+0x2bc/0x4b8
        synth_events_write+0x20/0x30
        vfs_write+0x200/0x830
        ...

Link: https://lore.kernel.org/linux-trace-kernel/20230321110444.1587-1-Tze-nan.Wu@mediatek.com

Fixes: 27c888da9867 ("tracing: Remove size restriction on synthetic event cmd error logging")
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: "Tom Zanussi" <zanussi@kernel.org>
Signed-off-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-04-03 11:51:12 -04:00
Steven Rostedt (Google)
88fe1ec75f tracing: Unbreak user events
The user events was added a bit prematurely, and there were a few kernel
developers that had issues with it. The API also needed a bit of work to
make sure it would be stable. It was decided to make user events "broken"
until this was settled. Now it has a new API that appears to be as stable
as it will be without the use of a crystal ball. It's being used within
Microsoft as is, which means the API has had some testing in real world
use cases. It went through many discussions in the bi-weekly tracing
meetings, and there's been no more comments about updates.

I feel this is good to go.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:09 -04:00
Steven Rostedt (Google)
4bec284cc0 tracing/user_events: Use print_format_fields() for trace output
Currently, user events are shown using the "hex" output for "safety"
reasons as one cannot trust user events behaving nicely. But the hex
output is not the only utility for safe outputting of trace events. The
print_event_fields() is just as safe and gives user readable output.

Before:
         example-839     [001] .....    43.222244:
00000000: b1 06 00 00 47 03 00 00 00 00 00 00              ....G.......
         example-839     [001] .....    43.564433:
00000000: b1 06 00 00 47 03 00 00 01 00 00 00              ....G.......
         example-839     [001] .....    43.763917:
00000000: b1 06 00 00 47 03 00 00 02 00 00 00              ....G.......
         example-839     [001] .....    43.967929:
00000000: b1 06 00 00 47 03 00 00 03 00 00 00              ....G.......

After:

         example-837     [006] .....    55.739249: test: count=0x0 (0)
         example-837     [006] .....   111.104784: test: count=0x1 (1)
         example-837     [006] .....   111.268444: test: count=0x2 (2)
         example-837     [006] .....   111.416533: test: count=0x3 (3)
         example-837     [006] .....   111.542859: test: count=0x4 (4)

Link: https://lore.kernel.org/linux-trace-kernel/20230328151413.4770b8d7@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:09 -04:00
Beau Belgrave
a4c40c1349 tracing/user_events: Align structs with tabs for readability
Add tabs to make struct members easier to read and unify the style of
the code.

Link: https://lkml.kernel.org/r/20230328235219.203-13-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:09 -04:00
Beau Belgrave
ce58e96e9f tracing/user_events: Limit global user_event count
Operators want to be able to ensure enough tracepoints exist on the
system for kernel components as well as for user components. Since there
are only up to 64K events, by default allow up to half to be used by
user events.

Add a kernel sysctl parameter (kernel.user_events_max) to set a global
limit that is honored among all groups on the system. This ensures hard
limits can be setup to prevent user processes from consuming all event
IDs on the system.

Link: https://lkml.kernel.org/r/20230328235219.203-12-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:09 -04:00
Beau Belgrave
f9cce238ee tracing/user_events: Charge event allocs to cgroups
Operators need a way to limit how much memory cgroups use. User events need
to be included into that accounting. Fix this by using GFP_KERNEL_ACCOUNT
for allocations generated by user programs for user_event tracing.

Link: https://lkml.kernel.org/r/20230328235219.203-11-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:09 -04:00
Beau Belgrave
dcb8177c13 tracing/user_events: Add ioctl for disabling addresses
Enablements are now tracked by the lifetime of the task/mm. User
processes need to be able to disable their addresses if tracing is
requested to be turned off. Before unmapping the page would suffice.
However, we now need a stronger contract. Add an ioctl to enable this.

A new flag bit is added, freeing, to user_event_enabler to ensure that
if the event is attempted to be removed while a fault is being handled
that the remove is delayed until after the fault is reattempted.

Link: https://lkml.kernel.org/r/20230328235219.203-6-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:08 -04:00
Beau Belgrave
81f8fb6549 tracing/user_events: Fixup enable faults asyncly
When events are enabled within the various tracing facilities, such as
ftrace/perf, the event_mutex is held. As events are enabled pages are
accessed. We do not want page faults to occur under this lock. Instead
queue the fault to a workqueue to be handled in a process context safe
way without the lock.

The enable address is marked faulting while the async fault-in occurs.
This ensures that we don't attempt to fault-in more than is necessary.
Once the page has been faulted in, an address write is re-attempted.
If the page couldn't fault-in, then we wait until the next time the
event is enabled to prevent any potential infinite loops.

Link: https://lkml.kernel.org/r/20230328235219.203-5-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:08 -04:00
Beau Belgrave
7235759084 tracing/user_events: Use remote writes for event enablement
As part of the discussions for user_events aligned with user space
tracers, it was determined that user programs should register a aligned
value to set or clear a bit when an event becomes enabled. Currently a
shared page is being used that requires mmap(). Remove the shared page
implementation and move to a user registered address implementation.

In this new model during the event registration from user programs 3 new
values are specified. The first is the address to update when the event
is either enabled or disabled. The second is the bit to set/clear to
reflect the event being enabled. The third is the size of the value at
the specified address.

This allows for a local 32/64-bit value in user programs to support
both kernel and user tracers. As an example, setting bit 31 for kernel
tracers when the event becomes enabled allows for user tracers to use
the other bits for ref counts or other flags. The kernel side updates
the bit atomically, user programs need to also update these values
atomically.

User provided addresses must be aligned on a natural boundary, this
allows for single page checking and prevents odd behaviors such as a
enable value straddling 2 pages instead of a single page. Currently
page faults are only logged, future patches will handle these.

Link: https://lkml.kernel.org/r/20230328235219.203-4-beaub@linux.microsoft.com

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:08 -04:00
Beau Belgrave
e5a26a4048 tracing/user_events: Split header into uapi and kernel
The UAPI parts need to be split out from the kernel parts of user_events
now that other parts of the kernel will reference it. Do so by moving
the existing include/linux/user_events.h into
include/uapi/linux/user_events.h.

Link: https://lkml.kernel.org/r/20230328235219.203-2-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:08 -04:00
Steven Rostedt (Google)
80a76994b2 tracing: Add "fields" option to show raw trace event fields
The hex, raw and bin formats come from the old PREEMPT_RT patch set
latency tracer. That actually gave real alternatives to reading the ascii
buffer. But they have started to bit rot and they do not give a good
representation of the tracing data.

Add "fields" option that will read the trace event fields and parse the
data from how the fields are defined:

With "fields" = 0 (default)

 echo 1 > events/sched/sched_switch/enable
 cat trace
         <idle>-0       [003] d..2.   540.078653: sched_switch: prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=kworker/3:1 next_pid=83 next_prio=120
     kworker/3:1-83      [003] d..2.   540.078860: sched_switch: prev_comm=kworker/3:1 prev_pid=83 prev_prio=120 prev_state=I ==> next_comm=swapper/3 next_pid=0 next_prio=120
          <idle>-0       [003] d..2.   540.206423: sched_switch: prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=sshd next_pid=807 next_prio=120
            sshd-807     [003] d..2.   540.206531: sched_switch: prev_comm=sshd prev_pid=807 prev_prio=120 prev_state=S ==> next_comm=swapper/3 next_pid=0 next_prio=120
          <idle>-0       [001] d..2.   540.206597: sched_switch: prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=kworker/u16:4 next_pid=58 next_prio=120
   kworker/u16:4-58      [001] d..2.   540.206617: sched_switch: prev_comm=kworker/u16:4 prev_pid=58 prev_prio=120 prev_state=I ==> next_comm=bash next_pid=830 next_prio=120
            bash-830     [001] d..2.   540.206678: sched_switch: prev_comm=bash prev_pid=830 prev_prio=120 prev_state=R ==> next_comm=kworker/u16:4 next_pid=58 next_prio=120
   kworker/u16:4-58      [001] d..2.   540.206696: sched_switch: prev_comm=kworker/u16:4 prev_pid=58 prev_prio=120 prev_state=I ==> next_comm=bash next_pid=830 next_prio=120
            bash-830     [001] d..2.   540.206713: sched_switch: prev_comm=bash prev_pid=830 prev_prio=120 prev_state=R ==> next_comm=kworker/u16:4 next_pid=58 next_prio=120

 echo 1 > options/fields
           <...>-998     [002] d..2.   538.643732: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/2 prev_state=0x20 (32) prev_prio=0x78 (120) prev_pid=0x3e6 (998) prev_comm=trace-cmd
          <idle>-0       [001] d..2.   538.643806: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x0 (0) prev_comm=swapper/1
            bash-830     [001] d..2.   538.644106: sched_switch: next_prio=0x78 (120) next_pid=0x3a (58) next_comm=kworker/u16:4 prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash
   kworker/u16:4-58      [001] d..2.   538.644130: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x80 (128) prev_prio=0x78 (120) prev_pid=0x3a (58) prev_comm=kworker/u16:4
            bash-830     [001] d..2.   538.644180: sched_switch: next_prio=0x78 (120) next_pid=0x3a (58) next_comm=kworker/u16:4 prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash
   kworker/u16:4-58      [001] d..2.   538.644185: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x80 (128) prev_prio=0x78 (120) prev_pid=0x3a (58) prev_comm=kworker/u16:4
            bash-830     [001] d..2.   538.644204: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/1 prev_state=0x1 (1) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash
          <idle>-0       [003] d..2.   538.644211: sched_switch: next_prio=0x78 (120) next_pid=0x327 (807) next_comm=sshd prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x0 (0) prev_comm=swapper/3
            sshd-807     [003] d..2.   538.644340: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/3 prev_state=0x1 (1) prev_prio=0x78 (120) prev_pid=0x327 (807) prev_comm=sshd

It traces the data safely without using the trace print formatting.

Link: https://lore.kernel.org/linux-trace-kernel/20230328145156.497651be@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-29 06:52:08 -04:00
Masami Hiramatsu (Google)
39d954200b fprobe: Skip exit_handler if entry_handler returns !0
Skip hooking function return and calling exit_handler if the
entry_handler() returns !0.

Link: https://lkml.kernel.org/r/167526699798.433354.10998365726830117303.stgit@mhiramat.roam.corp.google.com

Cc: Florent Revest <revest@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-28 18:52:22 -04:00
Masami Hiramatsu (Google)
59a7a29856 fprobe: Add nr_maxactive to specify rethook_node pool size
Add nr_maxactive to specify rethook_node pool size. This means
the maximum number of actively running target functions concurrently
for probing by exit_handler. Note that if the running function is
preempted or sleep, it is still counted as 'active'.

Link: https://lkml.kernel.org/r/167526697917.433354.17779774988245113106.stgit@mhiramat.roam.corp.google.com

Cc: Florent Revest <revest@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-28 18:52:22 -04:00
Masami Hiramatsu (Google)
76d0de5729 fprobe: Pass entry_data to handlers
Pass the private entry_data to the entry and exit handlers so that
they can share the context data, something like saved function
arguments etc.
User must specify the private entry_data size by @entry_data_size
field before registering the fprobe.

Link: https://lkml.kernel.org/r/167526696173.433354.17408372048319432574.stgit@mhiramat.roam.corp.google.com

Cc: Florent Revest <revest@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-28 18:52:22 -04:00
Jakub Kicinski
dc0a7b5200 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
  6e9d51b1a5cb ("net/mlx5e: Initialize link speed to zero")
  1bffcea42926 ("net/mlx5e: Add devlink hairpin queues parameters")
https://lore.kernel.org/all/20230324120623.4ebbc66f@canb.auug.org.au/
https://lore.kernel.org/all/20230321211135.47711-1-saeed@kernel.org/

Adjacent changes:

drivers/net/phy/phy.c
  323fe43cf9ae ("net: phy: Improved PHY error reporting in state machine")
  4203d84032e2 ("net: phy: Ensure state transitions are processed from phy_stop()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-24 10:10:20 -07:00
Steven Rostedt (Google)
e11b521a7b ftrace: Show a list of all functions that have ever been enabled
When debugging a crash that appears to be related to ftrace, but not for
sure, it is useful to know if a function was ever enabled by ftrace or
not. It could be that a BPF program was attached to it, or possibly a live
patch.

We are having crashes in the field where this information is not always
known. But having ftrace set a flag if a function has ever been attached
since boot up helps tremendously in trying to know if a crash had to do
with something using ftrace.

For analyzing crashes, the use of a kdump image can have access to the
flags. When looking at issues where the kernel did not panic, the
touched_functions file can simply be used.

Link: https://lore.kernel.org/linux-trace-kernel/20230124095653.6fd1640e@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Chris Li <chriscli@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 14:00:10 -04:00
Uros Bizjak
8328e36da9 ring_buffer: Use try_cmpxchg instead of cmpxchg
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old.
x86 CMPXCHG instruction returns success in ZF flag, so this change
saves a compare after cmpxchg (and related move instruction in
front of cmpxchg).

Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg
fails. There is no need to re-read the value in the loop.

No functional change intended.

Link: https://lkml.kernel.org/r/20230305155532.5549-4-ubizjak@gmail.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:59:48 -04:00
Uros Bizjak
bc92b9562a ring_buffer: Change some static functions to bool
The return values of some functions are of boolean type. Change the
type of these function to bool and adjust their return values. Also
change type of some internal varibles to bool.

No functional change intended.

Link: https://lkml.kernel.org/r/20230305155532.5549-3-ubizjak@gmail.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:59:42 -04:00
Uros Bizjak
b4b55dfd96 ring_buffer: Change some static functions to void
The results of some static functions are not used. Change the
type of these function to void and remove unnecessary returns.

No functional change intended.

Link: https://lkml.kernel.org/r/20230305155532.5549-2-ubizjak@gmail.com

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:59:31 -04:00
Mark Rutland
fee86a4ed5 ftrace: selftest: remove broken trace_direct_tramp
The ftrace selftest code has a trace_direct_tramp() function which it
uses as a direct call trampoline. This happens to work on x86, since the
direct call's return address is in the usual place, and can be returned
to via a RET, but in general the calling convention for direct calls is
different from regular function calls, and requires a trampoline written
in assembly.

On s390, regular function calls place the return address in %r14, and an
ftrace patch-site in an instrumented function places the trampoline's
return address (which is within the instrumented function) in %r0,
preserving the original %r14 value in-place. As a regular C function
will return to the address in %r14, using a C function as the trampoline
results in the trampoline returning to the caller of the instrumented
function, skipping the body of the instrumented function.

Note that the s390 issue is not detcted by the ftrace selftest code, as
the instrumented function is trivial, and returning back into the caller
happens to be equivalent.

On arm64, regular function calls place the return address in x30, and
an ftrace patch-site in an instrumented function saves this into r9
and places the trampoline's return address (within the instrumented
function) in x30. A regular C function will return to the address in
x30, but will not restore x9 into x30. Consequently, using a C function
as the trampoline results in returning to the trampoline's return
address having corrupted x30, such that when the instrumented function
returns, it will return back into itself.

To avoid future issues in this area, remove the trace_direct_tramp()
function, and require that each architecture with direct calls provides
a stub trampoline, named ftrace_stub_direct_tramp. This can be written
to handle the architecture's trampoline calling convention, and in
future could be used elsewhere (e.g. in the ftrace ops sample, to
measure the overhead of direct calls), so we may as well always build it
in.

Link: https://lkml.kernel.org/r/20230321140424.345218-8-revest@chromium.org

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:59:29 -04:00
Florent Revest
60c8971899 ftrace: Make DIRECT_CALLS work WITH_ARGS and !WITH_REGS
Direct called trampolines can be called in two ways:
- either from the ftrace callsite. In this case, they do not access any
  struct ftrace_regs nor pt_regs
- Or, if a ftrace ops is also attached, from the end of a ftrace
  trampoline. In this case, the call_direct_funcs ops is in charge of
  setting the direct call trampoline's address in a struct ftrace_regs

Since:

commit 9705bc709604 ("ftrace: pass fregs to arch_ftrace_set_direct_caller()")

The later case no longer requires a full pt_regs. It only needs a struct
ftrace_regs so DIRECT_CALLS can work with both WITH_ARGS or WITH_REGS.
With architectures like arm64 already abandoning WITH_REGS in favor of
WITH_ARGS, it's important to have DIRECT_CALLS work WITH_ARGS only.

Link: https://lkml.kernel.org/r/20230321140424.345218-7-revest@chromium.org

Signed-off-by: Florent Revest <revest@chromium.org>
Co-developed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:43:32 -04:00
Florent Revest
dbaccb618f ftrace: Store direct called addresses in their ops
All direct calls are now registered using the register_ftrace_direct API
so each ops can jump to only one direct-called trampoline.

By storing the direct called trampoline address directly in the ops we
can save one hashmap lookup in the direct call ops and implement arm64
direct calls on top of call ops.

Link: https://lkml.kernel.org/r/20230321140424.345218-6-revest@chromium.org

Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:43:32 -04:00
Florent Revest
da8bdfbd42 ftrace: Rename _ftrace_direct_multi APIs to _ftrace_direct APIs
Now that the original _ftrace_direct APIs are gone, the "_multi"
suffixes only add confusion.

Link: https://lkml.kernel.org/r/20230321140424.345218-5-revest@chromium.org

Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:43:32 -04:00
Florent Revest
8788ca164e ftrace: Remove the legacy _ftrace_direct API
This API relies on a single global ops, used for all direct calls
registered with it. However, to implement arm64 direct calls, we need
each ops to point to a single direct call trampoline.

Link: https://lkml.kernel.org/r/20230321140424.345218-4-revest@chromium.org

Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:43:31 -04:00
Florent Revest
23edf48309 ftrace: Replace uses of _ftrace_direct APIs with _ftrace_direct_multi
The _multi API requires that users keep their own ops but can enforce
that an op is only associated to one direct call.

Link: https://lkml.kernel.org/r/20230321140424.345218-3-revest@chromium.org

Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:42:12 -04:00
Florent Revest
59495740f7 ftrace: Let unregister_ftrace_direct_multi() call ftrace_free_filter()
A common pattern when using the ftrace_direct_multi API is to unregister
the ops and also immediately free its filter. We've noticed it's very
easy for users to miss calling ftrace_free_filter().

This adds a "free_filters" argument to unregister_ftrace_direct_multi()
to both remind the user they should free filters and also to make their
life easier.

Link: https://lkml.kernel.org/r/20230321140424.345218-2-revest@chromium.org

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:42:11 -04:00
Zhen Lei
3703bd54cd kallsyms: Delete an unused parameter related to {module_}kallsyms_on_each_symbol()
The parameter 'struct module *' in the hook function associated with
{module_}kallsyms_on_each_symbol() is no longer used. Delete it.

Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-03-19 13:27:19 -07:00
Linus Torvalds
eaba52d63b Tracing fixes for 6.3:
- Fix setting affinity of hwlat threads in containers
   Using sched_set_affinity() has unwanted side effects when being
   called within a container. Use set_cpus_allowed_ptr() instead.
 
 - Fix per cpu thread management of the hwlat tracer
   * Do not start per_cpu threads if one is already running for the CPU.
   * When starting per_cpu threads, do not clear the kthread variable
     as it may already be set to running per cpu threads
 
 - Fix return value for test_gen_kprobe_cmd()
   On error the return value was overwritten by being set to
   the result of the call from kprobe_event_delete(), which would
   likely succeed, and thus have the function return success.
 
 - Fix splice() reads from the trace file that was broken by
   36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
 
 - Remove obsolete and confusing comment in ring_buffer.c
   The original design of the ring buffer used struct page flags
   for tricks to optimize, which was shortly removed due to them
   being tricks. But a comment for those tricks remained.
 
 - Set local functions and variables to static
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZBdIkBQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qti2AP49s1GM8teFgDF/CO3oa45BoYq1lMJO
 1Z+x+mS/bdUAZgEAw+3KGo8oZDuvWu/nr04JPeoy0GL1/JnbQ6JNCCjzhQc=
 =Yk66
 -----END PGP SIGNATURE-----

Merge tag 'trace-v6.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix setting affinity of hwlat threads in containers

   Using sched_set_affinity() has unwanted side effects when being
   called within a container. Use set_cpus_allowed_ptr() instead

 - Fix per cpu thread management of the hwlat tracer:
    - Do not start per_cpu threads if one is already running for the CPU
    - When starting per_cpu threads, do not clear the kthread variable
      as it may already be set to running per cpu threads

 - Fix return value for test_gen_kprobe_cmd()

   On error the return value was overwritten by being set to the result
   of the call from kprobe_event_delete(), which would likely succeed,
   and thus have the function return success

 - Fix splice() reads from the trace file that was broken by commit
   36e2c7421f02 ("fs: don't allow splice read/write without explicit
   ops")

 - Remove obsolete and confusing comment in ring_buffer.c

   The original design of the ring buffer used struct page flags for
   tricks to optimize, which was shortly removed due to them being
   tricks. But a comment for those tricks remained

 - Set local functions and variables to static

* tag 'trace-v6.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/hwlat: Replace sched_setaffinity with set_cpus_allowed_ptr
  ring-buffer: remove obsolete comment for free_buffer_page()
  tracing: Make splice_read available again
  ftrace: Set direct_ops storage-class-specifier to static
  trace/hwlat: Do not start per-cpu thread if it is already running
  trace/hwlat: Do not wipe the contents of per-cpu thread data
  tracing/osnoise: set several trace_osnoise.c variables storage-class-specifier to static
  tracing: Fix wrong return in kprobe_event_gen_test.c
2023-03-19 10:46:02 -07:00
Costa Shulyupin
71c7a30442 tracing/hwlat: Replace sched_setaffinity with set_cpus_allowed_ptr
There is a problem with the behavior of hwlat in a container,
resulting in incorrect output. A warning message is generated:
"cpumask changed while in round-robin mode, switching to mode none",
and the tracing_cpumask is ignored. This issue arises because
the kernel thread, hwlatd, is not a part of the container, and
the function sched_setaffinity is unable to locate it using its PID.
Additionally, the task_struct of hwlatd is already known.
Ultimately, the function set_cpus_allowed_ptr achieves
the same outcome as sched_setaffinity, but employs task_struct
instead of PID.

Test case:

  # cd /sys/kernel/tracing
  # echo 0 > tracing_on
  # echo round-robin > hwlat_detector/mode
  # echo hwlat > current_tracer
  # unshare --fork --pid bash -c 'echo 1 > tracing_on'
  # dmesg -c

Actual behavior:

[573502.809060] hwlat_detector: cpumask changed while in round-robin mode, switching to mode none

Link: https://lore.kernel.org/linux-trace-kernel/20230316144535.1004952-1-costa.shul@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 0330f7aa8ee63 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-19 13:23:22 -04:00
Vlastimil Babka
a98151ad53 ring-buffer: remove obsolete comment for free_buffer_page()
The comment refers to mm/slob.c which is being removed. It comes from
commit ed56829cb319 ("ring_buffer: reset buffer page when freeing") and
according to Steven the borrowed code was a page mapcount and mapping
reset, which was later removed by commit e4c2ce82ca27 ("ring_buffer:
allocate buffer page pointer"). Thus the comment is not accurate anyway,
remove it.

Link: https://lore.kernel.org/linux-trace-kernel/20230315142446.27040-1-vbabka@suse.cz

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Reported-by: Mike Rapoport <mike.rapoport@gmail.com>
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fixes: e4c2ce82ca27 ("ring_buffer: allocate buffer page pointer")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-19 13:23:22 -04:00
Sung-hun Kim
e400be674a tracing: Make splice_read available again
Since the commit 36e2c7421f02 ("fs: don't allow splice read/write
without explicit ops") is applied to the kernel, splice() and
sendfile() calls on the trace file (/sys/kernel/debug/tracing
/trace) return EINVAL.

This patch restores these system calls by initializing splice_read
in file_operations of the trace file. This patch only enables such
functionalities for the read case.

Link: https://lore.kernel.org/linux-trace-kernel/20230314013707.28814-1-sfoon.kim@samsung.com

Cc: stable@vger.kernel.org
Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Sung-hun Kim <sfoon.kim@samsung.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-19 13:16:21 -04:00
Tom Rix
8732565549 ftrace: Set direct_ops storage-class-specifier to static
smatch reports this warning
kernel/trace/ftrace.c:2594:19: warning:
  symbol 'direct_ops' was not declared. Should it be static?

The variable direct_ops is only used in ftrace.c, so it should be static

Link: https://lore.kernel.org/linux-trace-kernel/20230311135113.711824-1-trix@redhat.com

Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-19 12:20:49 -04:00
Tero Kristo
08697bca9b trace/hwlat: Do not start per-cpu thread if it is already running
The hwlatd tracer will end up starting multiple per-cpu threads with
the following script:

    #!/bin/sh
    cd /sys/kernel/debug/tracing
    echo 0 > tracing_on
    echo hwlat > current_tracer
    echo per-cpu > hwlat_detector/mode
    echo 100000 > hwlat_detector/width
    echo 200000 > hwlat_detector/window
    echo 1 > tracing_on

To fix the issue, check if the hwlatd thread for the cpu is already
running, before starting a new one. Along with the previous patch, this
avoids running multiple instances of the same CPU thread on the system.

Link: https://lore.kernel.org/all/20230302113654.2984709-1-tero.kristo@linux.intel.com/
Link: https://lkml.kernel.org/r/20230310100451.3948583-3-tero.kristo@linux.intel.com

Cc: stable@vger.kernel.org
Fixes: f46b16520a087 ("trace/hwlat: Implement the per-cpu mode")
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-19 12:20:49 -04:00
Tero Kristo
4c42f5f0d1 trace/hwlat: Do not wipe the contents of per-cpu thread data
Do not wipe the contents of the per-cpu kthread data when starting the
tracer, as this will completely forget about already running instances
and can later start new additional per-cpu threads.

Link: https://lore.kernel.org/all/20230302113654.2984709-1-tero.kristo@linux.intel.com/
Link: https://lkml.kernel.org/r/20230310100451.3948583-2-tero.kristo@linux.intel.com

Cc: stable@vger.kernel.org
Fixes: f46b16520a087 ("trace/hwlat: Implement the per-cpu mode")
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-19 12:20:48 -04:00
Tom Rix
7a025e066e tracing/osnoise: set several trace_osnoise.c variables storage-class-specifier to static
smatch reports several similar warnings
kernel/trace/trace_osnoise.c:220:1: warning:
  symbol '__pcpu_scope_per_cpu_osnoise_var' was not declared. Should it be static?
kernel/trace/trace_osnoise.c:243:1: warning:
  symbol '__pcpu_scope_per_cpu_timerlat_var' was not declared. Should it be static?
kernel/trace/trace_osnoise.c:335:14: warning:
  symbol 'interface_lock' was not declared. Should it be static?
kernel/trace/trace_osnoise.c:2242:5: warning:
  symbol 'timerlat_min_period' was not declared. Should it be static?
kernel/trace/trace_osnoise.c:2243:5: warning:
  symbol 'timerlat_max_period' was not declared. Should it be static?

These variables are only used in trace_osnoise.c, so it should be static

Link: https://lore.kernel.org/linux-trace-kernel/20230309150414.4036764-1-trix@redhat.com

Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-19 12:20:48 -04:00
Anton Gusev
bc4f359b3b tracing: Fix wrong return in kprobe_event_gen_test.c
Overwriting the error code with the deletion result may cause the
function to return 0 despite encountering an error. Commit b111545d26c0
("tracing: Remove the useless value assignment in
test_create_synth_event()") solves a similar issue by
returning the original error code, so this patch does the same.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Link: https://lore.kernel.org/linux-trace-kernel/20230131075818.5322-1-aagusev@ispras.ru

Signed-off-by: Anton Gusev <aagusev@ispras.ru>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-19 12:20:48 -04:00
Jakub Kicinski
1118aa4c70 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
net/wireless/nl80211.c
  b27f07c50a73 ("wifi: nl80211: fix puncturing bitmap policy")
  cbbaf2bb829b ("wifi: nl80211: add a command to enable/disable HW timestamping")
https://lore.kernel.org/all/20230314105421.3608efae@canb.auug.org.au

tools/testing/selftests/net/Makefile
  62199e3f1658 ("selftests: net: Add VXLAN MDB test")
  13715acf8ab5 ("selftest: Add test for bind() conflicts.")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-17 16:29:25 -07:00
Linus Torvalds
29db00c252 Tracing fixes for v6.3
- Do not allow histogram values to have modifies.
   Can cause a NULL pointer dereference if they do.
 
 - Warn if hist_field_name() is passed a NULL.
   Prevent the NULL pointer dereference mentioned above.
 
 - Fix invalid address look up race in lookup_rec()
 
 - Define ftrace_stub_graph conditionally to prevent linker errors
 
 - Always check if RCU is watching at all tracepoint locations
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZBDuTBQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qsboAP4yfrFYvIIKM5EkzkEiPI+V2hdlA12x
 bt839jO5AWCmhAEAiY8FmKatpBJQKsiGqSOab8aHOMnhGFZwltCHAPa9PAI=
 =vtA2
 -----END PGP SIGNATURE-----

Merge tag 'trace-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Do not allow histogram values to have modifies. They can cause a NULL
   pointer dereference if they do.

 - Warn if hist_field_name() is passed a NULL. Prevent the NULL pointer
   dereference mentioned above.

 - Fix invalid address look up race in lookup_rec()

 - Define ftrace_stub_graph conditionally to prevent linker errors

 - Always check if RCU is watching at all tracepoint locations

* tag 'trace-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Make tracepoint lockdep check actually test something
  ftrace,kcfi: Define ftrace_stub_graph conditionally
  ftrace: Fix invalid address access in lookup_rec() when index is 0
  tracing: Check field value in hist_field_name()
  tracing: Do not let histogram values have some modifiers
2023-03-14 17:07:54 -07:00
Jakub Kicinski
d0ddf5065f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Documentation/bpf/bpf_devel_QA.rst
  b7abcd9c656b ("bpf, doc: Link to submitting-patches.rst for general patch submission info")
  d56b0c461d19 ("bpf, docs: Fix link to netdev-FAQ target")
https://lore.kernel.org/all/20230307095812.236eb1be@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-09 22:22:11 -08:00
Chen Zhongjin
ee92fa4433 ftrace: Fix invalid address access in lookup_rec() when index is 0
KASAN reported follow problem:

 BUG: KASAN: use-after-free in lookup_rec
 Read of size 8 at addr ffff000199270ff0 by task modprobe
 CPU: 2 Comm: modprobe
 Call trace:
  kasan_report
  __asan_load8
  lookup_rec
  ftrace_location
  arch_check_ftrace_location
  check_kprobe_address_safe
  register_kprobe

When checking pg->records[pg->index - 1].ip in lookup_rec(), it can get a
pg which is newly added to ftrace_pages_start in ftrace_process_locs().
Before the first pg->index++, index is 0 and accessing pg->records[-1].ip
will cause this problem.

Don't check the ip when pg->index is 0.

Link: https://lore.kernel.org/linux-trace-kernel/20230309080230.36064-1-chenzhongjin@huawei.com

Cc: stable@vger.kernel.org
Fixes: 9644302e3315 ("ftrace: Speed up search by skipping pages by address")
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-09 22:17:06 -05:00
Steven Rostedt (Google)
9f116f76fa tracing: Check field value in hist_field_name()
The function hist_field_name() cannot handle being passed a NULL field
parameter. It should never be NULL, but due to a previous bug, NULL was
passed to the function and the kernel crashed due to a NULL dereference.
Mark Rutland reported this to me on IRC.

The bug was fixed, but to prevent future bugs from crashing the kernel,
check the field and add a WARN_ON() if it is NULL.

Link: https://lkml.kernel.org/r/20230302020810.762384440@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Fixes: c6afad49d127f ("tracing: Add hist trigger 'sym' and 'sym-offset' modifiers")
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-09 22:17:06 -05:00
Steven Rostedt (Google)
e0213434fe tracing: Do not let histogram values have some modifiers
Histogram values can not be strings, stacktraces, graphs, symbols,
syscalls, or grouped in buckets or log. Give an error if a value is set to
do so.

Note, the histogram code was not prepared to handle these modifiers for
histograms and caused a bug.

Mark Rutland reported:

 # echo 'p:copy_to_user __arch_copy_to_user n=$arg2' >> /sys/kernel/tracing/kprobe_events
 # echo 'hist:keys=n:vals=hitcount.buckets=8:sort=hitcount' > /sys/kernel/tracing/events/kprobes/copy_to_user/trigger
 # cat /sys/kernel/tracing/events/kprobes/copy_to_user/hist
[  143.694628] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[  143.695190] Mem abort info:
[  143.695362]   ESR = 0x0000000096000004
[  143.695604]   EC = 0x25: DABT (current EL), IL = 32 bits
[  143.695889]   SET = 0, FnV = 0
[  143.696077]   EA = 0, S1PTW = 0
[  143.696302]   FSC = 0x04: level 0 translation fault
[  143.702381] Data abort info:
[  143.702614]   ISV = 0, ISS = 0x00000004
[  143.702832]   CM = 0, WnR = 0
[  143.703087] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000448f9000
[  143.703407] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[  143.704137] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[  143.704714] Modules linked in:
[  143.705273] CPU: 0 PID: 133 Comm: cat Not tainted 6.2.0-00003-g6fc512c10a7c #3
[  143.706138] Hardware name: linux,dummy-virt (DT)
[  143.706723] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  143.707120] pc : hist_field_name.part.0+0x14/0x140
[  143.707504] lr : hist_field_name.part.0+0x104/0x140
[  143.707774] sp : ffff800008333a30
[  143.707952] x29: ffff800008333a30 x28: 0000000000000001 x27: 0000000000400cc0
[  143.708429] x26: ffffd7a653b20260 x25: 0000000000000000 x24: ffff10d303ee5800
[  143.708776] x23: ffffd7a6539b27b0 x22: ffff10d303fb8c00 x21: 0000000000000001
[  143.709127] x20: ffff10d303ec2000 x19: 0000000000000000 x18: 0000000000000000
[  143.709478] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
[  143.709824] x14: 0000000000000000 x13: 203a6f666e692072 x12: 6567676972742023
[  143.710179] x11: 0a230a6d6172676f x10: 000000000000002c x9 : ffffd7a6521e018c
[  143.710584] x8 : 000000000000002c x7 : 7f7f7f7f7f7f7f7f x6 : 000000000000002c
[  143.710915] x5 : ffff10d303b0103e x4 : ffffd7a653b20261 x3 : 000000000000003d
[  143.711239] x2 : 0000000000020001 x1 : 0000000000000001 x0 : 0000000000000000
[  143.711746] Call trace:
[  143.712115]  hist_field_name.part.0+0x14/0x140
[  143.712642]  hist_field_name.part.0+0x104/0x140
[  143.712925]  hist_field_print+0x28/0x140
[  143.713125]  event_hist_trigger_print+0x174/0x4d0
[  143.713348]  hist_show+0xf8/0x980
[  143.713521]  seq_read_iter+0x1bc/0x4b0
[  143.713711]  seq_read+0x8c/0xc4
[  143.713876]  vfs_read+0xc8/0x2a4
[  143.714043]  ksys_read+0x70/0xfc
[  143.714218]  __arm64_sys_read+0x24/0x30
[  143.714400]  invoke_syscall+0x50/0x120
[  143.714587]  el0_svc_common.constprop.0+0x4c/0x100
[  143.714807]  do_el0_svc+0x44/0xd0
[  143.714970]  el0_svc+0x2c/0x84
[  143.715134]  el0t_64_sync_handler+0xbc/0x140
[  143.715334]  el0t_64_sync+0x190/0x194
[  143.715742] Code: a9bd7bfd 910003fd a90153f3 aa0003f3 (f9400000)
[  143.716510] ---[ end trace 0000000000000000 ]---
Segmentation fault

Link: https://lkml.kernel.org/r/20230302020810.559462599@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: c6afad49d127f ("tracing: Add hist trigger 'sym' and 'sym-offset' modifiers")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-09 22:17:06 -05:00
Jakub Kicinski
36e5e391a2 bpf-next-for-netdev
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZAZsBwAKCRDbK58LschI
 g3W1AQCQnO6pqqX5Q2aYDAZPlZRtV2TRLjuqrQE0dHW/XLAbBgD/bgsAmiKhPSCG
 2mTt6izpTQVlZB0e8KcDIvbYd9CE3Qc=
 =EjJQ
 -----END PGP SIGNATURE-----

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2023-03-06

We've added 85 non-merge commits during the last 13 day(s) which contain
a total of 131 files changed, 7102 insertions(+), 1792 deletions(-).

The main changes are:

1) Add skb and XDP typed dynptrs which allow BPF programs for more
   ergonomic and less brittle iteration through data and variable-sized
   accesses, from Joanne Koong.

2) Bigger batch of BPF verifier improvements to prepare for upcoming BPF
   open-coded iterators allowing for less restrictive looping capabilities,
   from Andrii Nakryiko.

3) Rework RCU enforcement in the verifier, add kptr_rcu and enforce BPF
   programs to NULL-check before passing such pointers into kfunc,
   from Alexei Starovoitov.

4) Add support for kptrs in percpu hashmaps, percpu LRU hashmaps and in
   local storage maps, from Kumar Kartikeya Dwivedi.

5) Add BPF verifier support for ST instructions in convert_ctx_access()
   which will help new -mcpu=v4 clang flag to start emitting them,
   from Eduard Zingerman.

6) Make uprobe attachment Android APK aware by supporting attachment
   to functions inside ELF objects contained in APKs via function names,
   from Daniel Müller.

7) Add a new flag BPF_F_TIMER_ABS flag for bpf_timer_start() helper
   to start the timer with absolute expiration value instead of relative
   one, from Tero Kristo.

8) Add a new kfunc bpf_cgroup_from_id() to look up cgroups via id,
   from Tejun Heo.

9) Extend libbpf to support users manually attaching kprobes/uprobes
   in the legacy/perf/link mode, from Menglong Dong.

10) Implement workarounds in the mips BPF JIT for DADDI/R4000,
   from Jiaxun Yang.

11) Enable mixing bpf2bpf and tailcalls for the loongarch BPF JIT,
    from Hengqi Chen.

12) Extend BPF instruction set doc with describing the encoding of BPF
    instructions in terms of how bytes are stored under big/little endian,
    from Jose E. Marchesi.

13) Follow-up to enable kfunc support for riscv BPF JIT, from Pu Lehui.

14) Fix bpf_xdp_query() backwards compatibility on old kernels,
    from Yonghong Song.

15) Fix BPF selftest cross compilation with CLANG_CROSS_FLAGS,
    from Florent Revest.

16) Improve bpf_cpumask_ma to only allocate one bpf_mem_cache,
    from Hou Tao.

17) Fix BPF verifier's check_subprogs to not unnecessarily mark
    a subprogram with has_tail_call, from Ilya Leoshkevich.

18) Fix arm syscall regs spec in libbpf's bpf_tracing.h, from Puranjay Mohan.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (85 commits)
  selftests/bpf: Add test for legacy/perf kprobe/uprobe attach mode
  selftests/bpf: Split test_attach_probe into multi subtests
  libbpf: Add support to set kprobe/uprobe attach mode
  tools/resolve_btfids: Add /libsubcmd to .gitignore
  bpf: add support for fixed-size memory pointer returns for kfuncs
  bpf: generalize dynptr_get_spi to be usable for iters
  bpf: mark PTR_TO_MEM as non-null register type
  bpf: move kfunc_call_arg_meta higher in the file
  bpf: ensure that r0 is marked scratched after any function call
  bpf: fix visit_insn()'s detection of BPF_FUNC_timer_set_callback helper
  bpf: clean up visit_insn()'s instruction processing
  selftests/bpf: adjust log_fixup's buffer size for proper truncation
  bpf: honor env->test_state_freq flag in is_state_visited()
  selftests/bpf: enhance align selftest's expected log matching
  bpf: improve regsafe() checks for PTR_TO_{MEM,BUF,TP_BUFFER}
  bpf: improve stack slot state printing
  selftests/bpf: Disassembler tests for verifier.c:convert_ctx_access()
  selftests/bpf: test if pointer type is tracked for BPF_ST_MEM
  bpf: allow ctx writes using BPF_ST_MEM instruction
  bpf: Use separate RCU callbacks for freeing selem
  ...
====================

Link: https://lore.kernel.org/r/20230307004346.27578-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-06 20:36:39 -08:00
Linus Torvalds
9d0281b56b block-6.3-2023-03-03
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmQB57MQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgputpEADVrc1OFzHOivJq+LJ3HS3ufhLBthtgu1Lp
 sEHvDNp9tBGXMLkomuCYpAju5TBAEKC+AJTZyj9iS1j++ItoezdoP55YRIH7t2Or
 UTy8ex3rLPGkQk6k3o8roWCyajTW/ZS+4fmk+NkVYMLsQBp9I+kFbxgJa5bbREdU
 Z8b/9hcBGz58R8Kq+TEMp/bO7oCV4c8xWumrKER+MktDDx0kc5d+afWXoy7bEKFg
 jLB3gleTM9HUpa9a2GPc4fxqdb0KanQdMtiyn/oplg0JcZLMiHfRbiRnsgQkjN0O
 RVtUcdxXmOkQeFra4GXPiHmQBcIfE85wP4wxb8p/F2StYRhb1epzzeCXOhuNZvv4
 dd6OSARgtzWt3OlHka4aC63H4kzs9SxJp0F2uwuPLV0fM91TP1oOTWV+53FrQr9Z
 OQYyB8d9Il4K72NFLwU4ukJ1fPoCRHjpgAXIIkasEjaBftpJlMNnfblncTZTBumy
 XumFVdKfvqc3OFt8LLKWqLDV0j3TknVeCMPKhsbRwQ0NG4vlNOSWaLkGJCDLJ7ga
 ebf8AD5eaLCT9qyYquBuW5VBKZH5Z4rf5yHta9Dx+Omu0JTQYtTkiiM3UTdpDbtq
 SObZ31UvLoYK2dOZcVgjhE2RgM/AV5jJcx7aHhT3UptavAehHbePgiNhuEEntlKv
 L87kXJkSSQ==
 =ezrg
 -----END PGP SIGNATURE-----

Merge tag 'block-6.3-2023-03-03' of git://git.kernel.dk/linux

Pull block fixes from Jens Axboe:

 - NVMe pull request via Christoph:
      - Don't access released socket during error recovery (Akinobu
        Mita)
      - Bring back auto-removal of deleted namespaces during sequential
        scan (Christoph Hellwig)
      - Fix an error code in nvme_auth_process_dhchap_challenge (Dan
        Carpenter)
      - Show well known discovery name (Daniel Wagner)
      - Add a missing endianess conversion in effects masking (Keith
        Busch)

 - Fix for a regression introduced in blk-rq-qos during init in this
   merge window (Breno)

 - Reorder a few fields in struct blk_mq_tag_set, eliminating a few
   holes and shrinking it (Christophe)

 - Remove redundant bdev_get_queue() NULL checks (Juhyung)

 - Add sed-opal single user mode support flag (Luca)

 - Remove SQE128 check in ublk as it isn't needed, saving some memory
   (Ming)

 - Op specific segment checking for cloned requests (Uday)

 - Exclusive open partition scan fixes (Yu)

 - Loop offset/size checking before assigning them in the device (Zhong)

 - Bio polling fixes (me)

* tag 'block-6.3-2023-03-03' of git://git.kernel.dk/linux:
  blk-mq: enforce op-specific segment limits in blk_insert_cloned_request
  nvme-fabrics: show well known discovery name
  nvme-tcp: don't access released socket during error recovery
  nvme-auth: fix an error code in nvme_auth_process_dhchap_challenge()
  nvme: bring back auto-removal of deleted namespaces during sequential scan
  blk-iocost: Pass gendisk to ioc_refresh_params
  nvme: fix sparse warning on effects masking
  block: be a bit more careful in checking for NULL bdev while polling
  block: clear bio->bi_bdev when putting a bio back in the cache
  loop: loop_set_status_from_info() check before assignment
  ublk: remove check IO_URING_F_SQE128 in ublk_ch_uring_cmd
  block: remove more NULL checks after bdev_get_queue()
  blk-mq: Reorder fields in 'struct blk_mq_tag_set'
  block: fix scan partition for exclusively open device again
  block: Revert "block: Do not reread partition table on exclusively open device"
  sed-opal: add support flag for SUM in status ioctl
2023-03-03 10:21:39 -08:00
Tejun Heo
c501bf55c8 bpf: Make bpf_get_current_[ancestor_]cgroup_id() available for all program types
These helpers are safe to call from any context and there's no reason to
restrict access to them. Remove them from bpf_trace and filter lists and add
to bpf_base_func_proto() under perfmon_capable().

v2: After consulting with Andrii, relocated in bpf_base_func_proto() so that
    they require bpf_capable() but not perfomon_capable() as it doesn't read
    from or affect others on the system.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/ZAD8QyoszMZiTzBY@slm.duckdns.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-02 22:37:07 -08:00
Linus Torvalds
116b41162f probes cleanup updates for v6.3:
These are the probe events cleanup patches, no new features but improve
 readability.
 
 - Rename print_probe_args() to trace_probe_print_args() and un-inlined.
 
 - Introduce a set of default data fetch functions for dynamic probe
   events.
 
 - Extract common code of data fetch process of dynamic probe events.
 -----BEGIN PGP SIGNATURE-----
 
 iQFPBAABCgA5FiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmP40igbHG1hc2FtaS5o
 aXJhbWF0c3VAZ21haWwuY29tAAoJENv7B78FKz8b1Q4IAIdX/xWscmgnH/OjKlXK
 U/O/mzvgY4m8pGpxbTHQ0DLea6PW2SUmGuPz+9BvRMisNtJP3M/C3vpnYEZRwkY9
 Movn0lCBZ47Dw2pdwBz34XKUI+B3Tp42/Xs5J8FaKlp+/CcJNqGpsJnF0Hm05MUb
 fZyQNI2hArnXITLHP+ADNiG6lTly0Zaza5nw27P+VW+6sfJhzuSG4hl+WXgHL8ut
 M0s6972QYH08uGs7Ywnl8pMpng6861YpHnREoOLOJ+1Cg6IYA+O6XK3Q75EXp+IX
 lXl611AAKZKpvc27eX+e9ionJRS4j1C0C12HSHYX/B8DN7SzuctXm1zmKewonHd5
 r8M=
 =1Lix
 -----END PGP SIGNATURE-----

Merge tag 'probes-v6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull kprobes cleanup updates from Masami Hiramatsu:
 "These are probe events cleanups, no new features but improve
  readability:

   - Rename print_probe_args() to trace_probe_print_args() and
     un-inline it

   - Introduce a set of default data fetch functions for dynamic
     probe events

   - Extract common code of data fetch process of dynamic probe events"

* tag 'probes-v6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kernel/trace: extract common part in process_fetch_insn
  kernel/trace: Provide default impelentations defined in trace_probe_tmpl.h
  kernel/trace: Introduce trace_probe_print_args and use it in *probes
2023-02-25 13:06:28 -08:00
Linus Torvalds
e534a583cc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha
Pull alpha updates from Al Viro:
 "Mostly small janitorial fixes but there's also more important ones: a
  patch to fix loading large modules from Edward Humes, and some fixes
  from Al Viro"

[ The fixes from Al mostly came in separately through Al's trees too and
  are now duplicated..   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha:
  alpha: in_irq() cleanup
  alpha: lazy FPU switching
  alpha/boot/misc: trim unused declarations
  alpha/boot/tools/objstrip: fix the check for ELF header
  alpha/boot: fix the breakage from -isystem series...
  alpha: fix FEN fault handling
  alpha: Avoid comma separated statements
  alpha: fixed a typo in core_cia.c
  alpha: remove unused __SLOW_DOWN_IO and SLOW_DOWN_IO definitions
  alpha: update config files
  alpha: fix R_ALPHA_LITERAL reloc for large modules
  alpha: Add some spaces to ensure format specification
  alpha: replace NR_SYSCALLS by NR_syscalls
  alpha: Remove redundant local asm header redirections
  alpha: Implement "current_stack_pointer"
  alpha: remove redundant err variable
  alpha: osf_sys: reduce kernel log spamming on invalid osf_mount call typenr
2023-02-25 12:49:29 -08:00
Song Chen
bd78acc89d kernel/trace: extract common part in process_fetch_insn
Each probe has an instance of process_fetch_insn respectively,
but they have something in common.

This patch aims to extract the common part into
process_common_fetch_insn which can be shared by each probe,
and they only need to focus on their special cases.

Signed-off-by: Song Chen <chensong_2000@189.cn>
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
2023-02-24 10:04:13 +09:00