linux.git/kernel, branch v6.2-rc6

Merge tag 'irq_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-01-29T19:26:49+00:00

Pull irq fix from Borislav Petkov:

 - Cleanup the firmware node for the new IRQ MSI domain properly, to
   avoid leaking memory

* tag 'irq_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/msi: Free the fwnode created by msi_create_device_irq_domain()

Merge tag 'trace-v6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2023-01-28T00:03:32+00:00

Pull tracing fixes from Steven Rostedt:

 - Fix filter memory leak by calling ftrace_free_filter()

 - Initialize trace_printk() earlier so that ftrace_dump_on_oops shows
   data on early crashes.

 - Update the outdated instructions in scripts/tracing/ftrace-bisect.sh

 - Add lockdep_is_held() to fix lockdep warning

 - Add allocation failure check in create_hist_field()

 - Don't initialize pointer that gets set right away in enabled_monitors_write()

 - Update MAINTAINER entries

 - Fix help messages in Kconfigs

 - Fix kernel-doc header for update_preds()

* tag 'trace-v6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  bootconfig: Update MAINTAINERS file to add tree and mailing list
  rv: remove redundant initialization of pointer ptr
  ftrace: Maintain samples/ftrace
  tracing/filter: fix kernel-doc warnings
  lib: Kconfig: fix spellos
  trace_events_hist: add check for return value of 'create_hist_field'
  tracing/osnoise: Use built-in RCU list checking
  tracing: Kconfig: Fix spelling/grammar/punctuation
  ftrace/scripts: Update the instructions for ftrace-bisect.sh
  tracing: Make sure trace_printk() can output as soon as it can be used
  ftrace: Export ftrace_free_filter() to modules

rv: remove redundant initialization of pointer ptr

2023-01-25T15:31:02+00:00

The pointer ptr is being initialized with a value that is never read,
it is being updated later on a call to strim. Remove the extraneous
initialization.

Link: https://lkml.kernel.org/r/20230116161612.77192-1-colin.i.king@gmail.com

Cc: Daniel Bristot de Oliveira 
Cc: Masami Hiramatsu 
Signed-off-by: Colin Ian King 
Signed-off-by: Steven Rostedt (Google)

tracing/filter: fix kernel-doc warnings

2023-01-25T15:28:13+00:00

Use the 'struct' keyword for a struct's kernel-doc notation and
use the correct function parameter name to eliminate kernel-doc
warnings:

kernel/trace/trace_events_filter.c:136: warning: cannot understand function prototype: 'struct prog_entry '
kerne/trace/trace_events_filter.c:155: warning: Excess function parameter 'when_to_branch' description in 'update_preds'

Also correct some trivial punctuation problems.

Link: https://lkml.kernel.org/r/20230108021238.16398-1-rdunlap@infradead.org

Signed-off-by: Randy Dunlap 
Signed-off-by: Steven Rostedt (Google)

trace_events_hist: add check for return value of 'create_hist_field'

2023-01-24T23:19:36+00:00

Function 'create_hist_field' is called recursively at
trace_events_hist.c:1954 and can return NULL-value that's why we have
to check it to avoid null pointer dereference.

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

Link: https://lkml.kernel.org/r/20230111120409.4111-1-n.petrova@fintech.ru

Cc: stable@vger.kernel.org
Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers")
Signed-off-by: Natalia Petrova 
Signed-off-by: Steven Rostedt (Google)

tracing/osnoise: Use built-in RCU list checking

2023-01-24T23:11:41+00:00

list_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence false lockdep
warning when CONFIG_PROVE_RCU_LIST is enabled.

Execute as follow:

 [tracing]# echo osnoise > current_tracer
 [tracing]# echo 1 > tracing_on
 [tracing]# echo 0 > tracing_on

The trace_types_lock is held when osnoise_tracer_stop() or
timerlat_tracer_stop() are called in the non-RCU read side section.
So, pass lockdep_is_held(&trace_types_lock) to silence false lockdep
warning.

Link: https://lkml.kernel.org/r/20221227023036.784337-1-nashuiliang@gmail.com

Cc: Masami Hiramatsu 
Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr")
Acked-by: Daniel Bristot de Oliveira 
Signed-off-by: Chuang Wang 
Signed-off-by: Steven Rostedt (Google)

module: Don't wait for GOING modules

2023-01-24T20:52:52+00:00

During a system boot, it can happen that the kernel receives a burst of
requests to insert the same module but loading it eventually fails
during its init call. For instance, udev can make a request to insert
a frequency module for each individual CPU when another frequency module
is already loaded which causes the init function of the new module to
return an error.

Since commit 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for
modules that have finished loading"), the kernel waits for modules in
MODULE_STATE_GOING state to finish unloading before making another
attempt to load the same module.

This creates unnecessary work in the described scenario and delays the
boot. In the worst case, it can prevent udev from loading drivers for
other devices and might cause timeouts of services waiting on them and
subsequently a failed boot.

This patch attempts a different solution for the problem 6e6de3dee51a
was trying to solve. Rather than waiting for the unloading to complete,
it returns a different error code (-EBUSY) for modules in the GOING
state. This should avoid the error situation that was described in
6e6de3dee51a (user space attempting to load a dependent module because
the -EEXIST error code would suggest to user space that the first module
had been loaded successfully), while avoiding the delay situation too.

This has been tested on linux-next since December 2022 and passes
all kmod selftests except test 0009 with module compression enabled
but it has been confirmed that this issue has existed and has gone
unnoticed since prior to this commit and can also be reproduced without
module compression with a simple usleep(5000000) on tools/modprobe.c [0].
These failures are caused by hitting the kernel mod_concurrent_max and can
happen either due to a self inflicted kernel module auto-loead DoS somehow
or on a system with large CPU count and each CPU count incorrectly triggering
many module auto-loads. Both of those issues need to be fixed in-kernel.

[0] https://lore.kernel.org/all/Y9A4fiobL6IHp%2F%2FP@bombadil.infradead.org/

Fixes: 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for modules that have finished loading")
Co-developed-by: Martin Wilck 
Signed-off-by: Martin Wilck 
Signed-off-by: Petr Pavlu 
Cc: stable@vger.kernel.org
Reviewed-by: Petr Mladek 
[mcgrof: enhance commit log with testing and kmod test result interpretation ]
Signed-off-by: Luis Chamberlain

tracing: Kconfig: Fix spelling/grammar/punctuation

2023-01-24T18:22:38+00:00

Fix some editorial nits in trace Kconfig.

Link: https://lkml.kernel.org/r/20230124181647.15902-1-rdunlap@infradead.org

Signed-off-by: Randy Dunlap 
Signed-off-by: Steven Rostedt (Google)

tracing: Make sure trace_printk() can output as soon as it can be used

2023-01-24T16:27:29+00:00

Currently trace_printk() can be used as soon as early_trace_init() is
called from start_kernel(). But if a crash happens, and
"ftrace_dump_on_oops" is set on the kernel command line, all you get will
be:

  [    0.456075]   -0         0dN.2. 347519us : Unknown type 6
  [    0.456075]   -0         0dN.2. 353141us : Unknown type 6
  [    0.456075]   -0         0dN.2. 358684us : Unknown type 6

This is because the trace_printk() event (type 6) hasn't been registered
yet. That gets done via an early_initcall(), which may be early, but not
early enough.

Instead of registering the trace_printk() event (and other ftrace events,
which are not trace events) via an early_initcall(), have them registered at
the same time that trace_printk() can be used. This way, if there is a
crash before early_initcall(), then the trace_printk()s will actually be
useful.

Link: https://lkml.kernel.org/r/20230104161412.019f6c55@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu 
Fixes: e725c731e3bb1 ("tracing: Split tracing initialization into two for early initialization")
Reported-by: "Joel Fernandes (Google)" 
Tested-by: Joel Fernandes (Google) 
Signed-off-by: Steven Rostedt (Google)

ftrace: Export ftrace_free_filter() to modules

2023-01-24T16:20:58+00:00

Setting filters on an ftrace ops results in some memory being allocated
for the filter hashes, which must be freed before the ops can be freed.
This can be done by removing every individual element of the hash by
calling ftrace_set_filter_ip() or ftrace_set_filter_ips() with `remove`
set, but this is somewhat error prone as it's easy to forget to remove
an element.

Make it easier to clean this up by exporting ftrace_free_filter(), which
can be used to clean up all of the filter hashes after an ftrace_ops has
been unregistered.

Using this, fix the ftrace-direct* samples to free hashes prior to being
unloaded. All other code either removes individual filters explicitly or
is built-in and already calls ftrace_free_filter().

Link: https://lkml.kernel.org/r/20230103124912.2948963-3-mark.rutland@arm.com

Cc: stable@vger.kernel.org
Cc: Florent Revest 
Cc: Masami Hiramatsu 
Fixes: e1067a07cfbc ("ftrace/samples: Add module to test multi direct modify interface")
Fixes: 5fae941b9a6f ("ftrace/samples: Add multi direct interface test module")
Reviewed-by: Masami Hiramatsu (Google) 
Reviewed-by: Steven Rostedt (Google) 
Signed-off-by: Mark Rutland 
Signed-off-by: Steven Rostedt (Google)