mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
* [for-linus][PATCH 0/4] tracing: Fixes for v6.15
@ 2025-05-02 14:46 Steven Rostedt
  2025-05-02 14:46 ` [for-linus][PATCH 1/4] tracing: Fix oob write in trace_seq_to_buffer() Steven Rostedt
                   ` (3 more replies)
  0 siblings, 4 replies; 6+ messages in thread
From: Steven Rostedt @ 2025-05-02 14:46 UTC (permalink / raw)
  To: linux-kernel
  Cc: Masami Hiramatsu, Mark Rutland, Mathieu Desnoyers, Andrew Morton


tracing updates for v6.15

- Fix read out of bounds bug in tracing_splice_read_pipe()

  The size of the sub page being read can now be greater than a page. But
  the buffer used in tracing_splice_read_pipe() only allocates a page size.
  The data copied to the buffer is the amount in sub buffer which can
  overflow the buffer. Use min((size_t)trace_seq_used(&iter->seq), PAGE_SIZE)
  to limit the amount copied to the buffer to a max of PAGE_SIZE.

- Fix the test for NULL from "!filter_hash" to "!*filter_hash"

  The add_next_hash() function checked for NULL at the wrong pointer level.

- Do not use the array in trace_adjust_address() if there are no elements

  The trace_adjust_address() finds the offset of a module that was stored in
  the persistent buffer when reading the previous boot buffer to see if the
  address belongs to a module that was loaded in the previous boot. An array
  is created that matches currently loaded modules with previously loaded
  modules. The trace_adjust_address() uses that array to find the new offset
  of the address that's in the previous buffer.  But if no module was
  loaded, it ends up reading the last element in an array that was never
  allocated. Check if nr_entries is zero and exit out early if it is.

- Remove nested lock of trace_event_sem in print_event_fields()

  The print_event_fields() function iterates over the ftrace_events list and
  requires the trace_event_sem semaphore held for read. But this function is
  always called with that semaphore held for read. Remove the taking of the
  semaphore and replace it with lockdep_assert_held_read(&trace_event_sem);

  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/fixes

Head SHA1: 0a8f11f8569e7ed16cbcedeb28c4350f6378fea6


Colin Ian King (1):
      ftrace: Fix NULL memory allocation check

Jeongjun Park (1):
      tracing: Fix oob write in trace_seq_to_buffer()

Steven Rostedt (2):
      tracing: Fix trace_adjust_address() when there is no modules in scratch area
      tracing: Do not take trace_event_sem in print_event_fields()

----
 kernel/trace/ftrace.c       | 2 +-
 kernel/trace/trace.c        | 9 ++++++---
 kernel/trace/trace_output.c | 4 ++--
 3 files changed, 9 insertions(+), 6 deletions(-)

^ permalink raw reply	[flat|nested] 6+ messages in thread
* [for-linus][PATCH 0/4] tracing: Fixes for v6.15
@ 2025-05-14 13:38 Steven Rostedt
  0 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2025-05-14 13:38 UTC (permalink / raw)
  To: linux-kernel
  Cc: Masami Hiramatsu, Mark Rutland, Mathieu Desnoyers, Andrew Morton

tracing fixes for 6.15:

- Fix sample code that uses trace_array_printk()

  The sample code for in kernel use of trace_array (that creates an instance
  for use within the kernel) and shows how to use trace_array_printk() that
  writes into the created instance, used trace_printk_init_buffers(). But
  that function is used to initialize normal trace_printk() and produces the
  NOTICE banner which is not needed for use of trace_array_printk(). The
  function to initialize that is trace_array_init_printk() that takes the
  created trace array instance as a parameter.

  Update the sample code to reflect the proper usage.

- Fix preemption count output for stacktrace event

  The tracing buffer shows the preempt count level when an event executes.
  Because writing the event itself disables preemption, this needs to be
  accounted for when recording. The stacktrace event did not account for
  this so the output of the stacktrace event showed preemption was disabled
  while the event that triggered the stacktrace shows preemption is enabled
  and this leads to confusion. Account for preemption being disabled for the
  stacktrace event.

  The same happened for stack traces triggered by function tracer.

- Fix persistent ring buffer when trace_pipe is used

  The ring buffer swaps the reader page with the next page to read from the
  write buffer when trace_pipe is used. If there's only a page of data in
  the ring buffer, this swap will cause the "commit" pointer (last data
  written) to be on the reader page. If more data is written to the buffer,
  it is added to the reader page until it falls off back into the write
  buffer.

  If the system reboots and the commit pointer is still on the reader page,
  even if new data was written, the persistent buffer validator will miss
  finding the commit pointer because it only checks the write buffer and
  does not check the reader page. This causes the validator to fail the
  validation and clear the buffer, where the new data is lost.

  There was a check for this, but it checked the "head pointer", which was
  incorrect, because the "head pointer" always stays on the write buffer and
  is the next page to swap out for the reader page. Fix the logic to catch
  this case and allow the user to still read the data after reboot.


  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/fixes

Head SHA1: 2285fb6d4d72a833d6e5ffbbe2f5ff594f0398cc


Steven Rostedt (2):
      tracing: samples: Initialize trace_array_printk() with the correct function
      ring-buffer: Fix persistent buffer when commit page is the reader page

pengdonglin (2):
      ftrace: Fix preemption acounting for stacktrace trigger command
      ftrace: Fix preemption accounting for stacktrace filter command

----
 kernel/trace/ring_buffer.c          | 8 +++++---
 kernel/trace/trace_events_trigger.c | 2 +-
 kernel/trace/trace_functions.c      | 6 +-----
 samples/ftrace/sample-trace-array.c | 2 +-
 4 files changed, 8 insertions(+), 10 deletions(-)

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2025-05-14 13:39 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2025-05-02 14:46 [for-linus][PATCH 0/4] tracing: Fixes for v6.15 Steven Rostedt
2025-05-02 14:46 ` [for-linus][PATCH 1/4] tracing: Fix oob write in trace_seq_to_buffer() Steven Rostedt
2025-05-02 14:46 ` [for-linus][PATCH 2/4] ftrace: Fix NULL memory allocation check Steven Rostedt
2025-05-02 14:46 ` [for-linus][PATCH 3/4] tracing: Fix trace_adjust_address() when there is no modules in scratch area Steven Rostedt
2025-05-02 14:46 ` [for-linus][PATCH 4/4] tracing: Do not take trace_event_sem in print_event_fields() Steven Rostedt
2025-05-14 13:38 [for-linus][PATCH 0/4] tracing: Fixes for v6.15 Steven Rostedt

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®