Re: [PATCH v4 0/2] tracing: Move non-trace_printk prototypes into trace_controls.h

Re: [PATCH v4 0/2] tracing: Move non-trace_printk prototypes into trace_controls.h

[Jani Nikula]

On Thu, 25 Jun 2026, Steven Rostedt <rostedt@kernel.org> wrote:
> Remove trace_printk.h by creating a trace_controls.h for those places that
> need access to tracing prototypes like tracing_off() and for the places that
> need trace_printk() directly, to have it included directly.
>
> Changse since v3: https://lore.kernel.org/all/20260624081806.120105649@kernel.org/
>
> - Always include trace_controls.h in rcu.h (kernel test robot)
>
>   There are other configs that may include tracing_off() in rcu.h besides
>   the one that had the include of trace_controls.h. Just always include
>   it in that header to be safe.
>
> Steven Rostedt (2):
>       tracing: Move non-trace_printk prototypes into trace_controls.h
>       tracing: Remove trace_printk.h from kernel.h
>
> ----
>  arch/powerpc/kvm/book3s_xics.c         |  1 +
>  arch/powerpc/xmon/xmon.c               |  1 +
>  arch/s390/kernel/ipl.c                 |  1 +
>  arch/s390/kernel/machine_kexec.c       |  1 +
>  drivers/gpu/drm/i915/gt/intel_gtt.h    |  1 +
>  drivers/gpu/drm/i915/i915_gem.h        |  2 ++

For the i915 parts,

Acked-by: Jani Nikula <jani.nikula@intel.com>

for merging via whichever tree.

>  drivers/hwtracing/stm/dummy_stm.c      |  1 +
>  drivers/infiniband/hw/hfi1/trace_dbg.h |  1 +
>  drivers/tty/sysrq.c                    |  1 +
>  drivers/usb/early/xhci-dbc.c           |  1 +
>  fs/ext4/inline.c                       |  1 +
>  include/linux/ftrace.h                 |  2 ++
>  include/linux/kernel.h                 |  1 -
>  include/linux/sunrpc/debug.h           |  1 +
>  include/linux/trace_controls.h         | 54 ++++++++++++++++++++++++++++++++
>  include/linux/trace_printk.h           | 56 ++--------------------------------
>  kernel/debug/debug_core.c              |  1 +
>  kernel/panic.c                         |  1 +
>  kernel/rcu/rcu.h                       |  1 +
>  kernel/rcu/rcutorture.c                |  1 +
>  kernel/trace/ring_buffer_benchmark.c   |  1 +
>  kernel/trace/trace.h                   |  1 +
>  kernel/trace/trace_benchmark.c         |  1 +
>  lib/sys_info.c                         |  1 +
>  samples/fprobe/fprobe_example.c        |  1 +
>  samples/ftrace/ftrace-direct-too.c     |  1 -
>  samples/trace_printk/trace-printk.c    |  1 +
>  27 files changed, 82 insertions(+), 55 deletions(-)
>  create mode 100644 include/linux/trace_controls.h

-- 
Jani Nikula, Intel

Re: [PATCH v4 2/2] tracing: Remove trace_printk.h from kernel.h

[Nathan Chancellor]

Hi Steve,

On Thu, Jun 25, 2026 at 06:40:09AM -0400, Steven Rostedt wrote:
> From: Steven Rostedt <rostedt@goodmis.org>
> 
> There have been complaints about trace_printk.h causing more build time
> for being in kernel.h if it changes. There is also an effort to clean up
> kernel.h to have it not include unneeded header files. Move trace_printk.h
> out of kernel.h and place it in the headers and C files that use it.
> 
> Link: https://lore.kernel.org/all/CAHk-=wikCBeVFjVXiY4o-oepdbjAoir5+TcAgtL12c4u1TpZLQ@mail.gmail.com/
> 
> Suggested-by: Yury Norov <yury.norov@gmail.com>
> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

This patch breaks lib/test_context-analysis.c for me in several
configurations:

  In file included from lib/test_context-analysis.c:9:
  In file included from include/linux/local_lock.h:5:
  include/linux/local_lock_internal.h:46:2: error: use of undeclared identifier '_THIS_IP_'
     46 |         lock_map_acquire(&l->dep_map);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  include/linux/lockdep.h:541:69: note: expanded from macro 'lock_map_acquire'
    541 | #define lock_map_acquire(l)                     lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
        |                                                                                       ^~~~~~~~~
  In file included from lib/test_context-analysis.c:9:
  In file included from include/linux/local_lock.h:5:
  include/linux/local_lock_internal.h:53:2: error: use of undeclared identifier '_THIS_IP_'
     53 |         lock_map_acquire_try(&l->dep_map);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  include/linux/lockdep.h:542:73: note: expanded from macro 'lock_map_acquire_try'
    542 | #define lock_map_acquire_try(l)                 lock_acquire_exclusive(l, 0, 1, NULL, _THIS_IP_)
        |                                                                                       ^~~~~~~~~
  In file included from lib/test_context-analysis.c:9:
  In file included from include/linux/local_lock.h:5:
  include/linux/local_lock_internal.h:62:2: error: use of undeclared identifier '_THIS_IP_'
     62 |         lock_map_release(&l->dep_map);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  include/linux/lockdep.h:545:47: note: expanded from macro 'lock_map_release'
    545 | #define lock_map_release(l)                     lock_release(l, _THIS_IP_)
        |                                                                 ^~~~~~~~~
  3 errors generated.

The following diff resolves it for me, should I send it as a separate
patch or do you want to just fold it in with a note?

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 621566345406..2301a701ffbb 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -10,6 +10,7 @@
 #ifndef __LINUX_LOCKDEP_H
 #define __LINUX_LOCKDEP_H
 
+#include <linux/instruction_pointer.h>
 #include <linux/lockdep_types.h>
 #include <linux/smp.h>
 #include <asm/percpu.h>
-- 
Cheers,
Nathan

Re: [PATCH v4 2/2] tracing: Remove trace_printk.h from kernel.h

[Nathan Chancellor]

On Fri, Jun 26, 2026 at 04:51:19AM -0400, Steven Rostedt wrote:
> On Thu, 25 Jun 2026 16:41:58 -0700
> Nathan Chancellor <nathan@kernel.org> wrote:
> 
> 
> > The following diff resolves it for me, should I send it as a separate
> > patch or do you want to just fold it in with a note?
> > 
> > diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
> > index 621566345406..2301a701ffbb 100644
> > --- a/include/linux/lockdep.h
> > +++ b/include/linux/lockdep.h
> > @@ -10,6 +10,7 @@
> >  #ifndef __LINUX_LOCKDEP_H
> >  #define __LINUX_LOCKDEP_H
> >  
> > +#include <linux/instruction_pointer.h>
> 
> Ah, so the reason for this breakage is because lockdep was relying on
> instruction_pointer.h, that just happened to be included in kernel.h
> via trace_printk.h.

Correct.

> This is a separate issue, so it should be a separate patch. I'll add it
> as patch 1 of this series.

Sounds good, thanks!

> Can you send me the config you used. This didn't trigger in my tests.

It is a plain allmodconfig, for example on arm:

  $ make -skj"$(nproc)" ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- allmodconfig lib/test_context-analysis.o
  In file included from include/linux/local_lock_internal.h:8,
                   from include/linux/local_lock.h:5,
                   from lib/test_context-analysis.c:9:
  include/linux/local_lock_internal.h: In function 'local_lock_acquire':
  include/linux/lockdep.h:541:87: error: '_THIS_IP_' undeclared (first use in this function)
    541 | #define lock_map_acquire(l)                     lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
        |                                                                                       ^~~~~~~~~
  include/linux/lockdep.h:509:88: note: in definition of macro 'lock_acquire_exclusive'
    509 | #define lock_acquire_exclusive(l, s, t, n, i)           lock_acquire(l, s, t, 0, 1, n, i)
        |                                                                                        ^
  include/linux/local_lock_internal.h:46:9: note: in expansion of macro 'lock_map_acquire'
     46 |         lock_map_acquire(&l->dep_map);
        |         ^~~~~~~~~~~~~~~~
  include/linux/lockdep.h:541:87: note: each undeclared identifier is reported only once for each function it appears in
  ...

I also reproduced it on top of allnoconfig:

  $ cat allno.config
  CONFIG_CONTEXT_ANALYSIS_TEST=y
  CONFIG_DEBUG_KERNEL=y
  CONFIG_DEBUG_LOCK_ALLOC=y
  CONFIG_EXPERT=y
  CONFIG_MMU=y
  CONFIG_RUNTIME_TESTING_MENU=y

  $ make -skj"$(nproc)" ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- KCONFIG_ALLCONFIG=1 clean allnoconfig lib/test_context-analysis.o
  <same error as above>

-- 
Cheers,
Nathan