linux.git/arch/parisc/kernel/ftrace.c, branch v6.2

Merge tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2021-11-02T03:05:19+00:00

Pull tracing updates from Steven Rostedt:

 - kprobes: Restructured stack unwinder to show properly on x86 when a
   stack dump happens from a kretprobe callback.

 - Fix to bootconfig parsing

 - Have tracefs allow owner and group permissions by default (only
   denying others). There's been pressure to allow non root to tracefs
   in a controlled fashion, and using groups is probably the safest.

 - Bootconfig memory managament updates.

 - Bootconfig clean up to have the tools directory be less dependent on
   changes in the kernel tree.

 - Allow perf to be traced by function tracer.

 - Rewrite of function graph tracer to be a callback from the function
   tracer instead of having its own trampoline (this change will happen
   on an arch by arch basis, and currently only x86_64 implements it).

 - Allow multiple direct trampolines (bpf hooks to functions) be batched
   together in one synchronization.

 - Allow histogram triggers to add variables that can perform
   calculations against the event's fields.

 - Use the linker to determine architecture callbacks from the ftrace
   trampoline to allow for proper parameter prototypes and prevent
   warnings from the compiler.

 - Extend histogram triggers to key off of variables.

 - Have trace recursion use bit magic to determine preempt context over
   if branches.

 - Have trace recursion disable preemption as all use cases do anyway.

 - Added testing for verification of tracing utilities.

 - Various small clean ups and fixes.

* tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits)
  tracing/histogram: Fix semicolon.cocci warnings
  tracing/histogram: Fix documentation inline emphasis warning
  tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together
  tracing: Show size of requested perf buffer
  bootconfig: Initialize ret in xbc_parse_tree()
  ftrace: do CPU checking after preemption disabled
  ftrace: disable preemption when recursion locked
  tracing/histogram: Document expression arithmetic and constants
  tracing/histogram: Optimize division by a power of 2
  tracing/histogram: Covert expr to const if both operands are constants
  tracing/histogram: Simplify handling of .sym-offset in expressions
  tracing: Fix operator precedence for hist triggers expression
  tracing: Add division and multiplication support for hist triggers
  tracing: Add support for creating hist trigger variables from literal
  selftests/ftrace: Stop tracing while reading the trace file by default
  MAINTAINERS: Update KPROBES and TRACING entries
  test_kprobes: Move it from kernel/ to lib/
  docs, kprobes: Remove invalid URL and add new reference
  samples/kretprobes: Fix return value if register_kretprobe() failed
  lib/bootconfig: Fix the xbc_get_info kerneldoc
  ...

parisc/ftrace: use static key to enable/disable function graph tracer

2021-11-01T06:36:01+00:00

This avoids using dereference_function_descriptor in the ftrace code
path, and it's also faster.

Signed-off-by: Sven Schnelle 
Signed-off-by: Helge Deller

parisc/ftrace: set function trace function

2021-11-01T06:36:01+00:00

With DYNAMIC_FTRACE, we need to implement ftrace_update_trace_func
and not call ftrace_trace_function() directly, as ftrace doesn't
expect calls to this function during code patching.

Signed-off-by: Sven Schnelle 
Signed-off-by: Helge Deller

ftrace: disable preemption when recursion locked

2021-10-27T15:21:49+00:00

As the documentation explained, ftrace_test_recursion_trylock()
and ftrace_test_recursion_unlock() were supposed to disable and
enable preemption properly, however currently this work is done
outside of the function, which could be missing by mistake.

And since the internal using of trace_test_and_set_recursion()
and trace_clear_recursion() also require preemption disabled, we
can just merge the logical.

This patch will make sure the preemption has been disabled when
trace_test_and_set_recursion() return bit >= 0, and
trace_clear_recursion() will enable the preemption if previously
enabled.

Link: https://lkml.kernel.org/r/13bde807-779c-aa4c-0672-20515ae365ea@linux.alibaba.com

CC: Petr Mladek 
Cc: Guo Ren 
Cc: Ingo Molnar 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Paul Walmsley 
Cc: Palmer Dabbelt 
Cc: Albert Ou 
Cc: Thomas Gleixner 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: Josh Poimboeuf 
Cc: Jiri Kosina 
Cc: Joe Lawrence 
Cc: Masami Hiramatsu 
Cc: Nicholas Piggin 
Cc: Jisheng Zhang 
CC: Steven Rostedt 
CC: Miroslav Benes 
Reported-by: Abaci 
Suggested-by: Peter Zijlstra 
Signed-off-by: Michael Wang 
[ Removed extra line in comment - SDR ]
Signed-off-by: Steven Rostedt (VMware)

ftrace: Cleanup ftrace_dyn_arch_init()

2021-10-08T23:41:39+00:00

Most of ARCHs use empty ftrace_dyn_arch_init(), introduce a weak common
ftrace_dyn_arch_init() to cleanup them.

Link: https://lkml.kernel.org/r/20210909090216.1955240-1-o451686892@gmail.com

Acked-by: Heiko Carstens  (s390)
Acked-by: Helge Deller  (parisc)
Signed-off-by: Weizhao Ouyang 
Signed-off-by: Steven Rostedt (VMware)

ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs

2020-11-13T17:14:55+00:00

In preparation to have arguments of a function passed to callbacks attached
to functions as default, change the default callback prototype to receive a
struct ftrace_regs as the forth parameter instead of a pt_regs.

For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they
will now need to get the pt_regs via a ftrace_get_regs() helper call. If
this is called by a callback that their ftrace_ops did not have a
FL_SAVE_REGS flag set, it that helper function will return NULL.

This will allow the ftrace_regs to hold enough just to get the parameters
and stack pointer, but without the worry that callbacks may have a pt_regs
that is not completely filled.

Acked-by: Peter Zijlstra (Intel) 
Reviewed-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

ftrace: Add recording of functions that caused recursion

2020-11-06T13:42:26+00:00

This adds CONFIG_FTRACE_RECORD_RECURSION that will record to a file
"recursed_functions" all the functions that caused recursion while a
callback to the function tracer was running.

Link: https://lkml.kernel.org/r/20201106023548.102375687@goodmis.org

Cc: Masami Hiramatsu 
Cc: Andrew Morton 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Jonathan Corbet 
Cc: Guo Ren 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Cc: Thomas Gleixner 
Cc: Borislav Petkov 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Cc: Kees Cook 
Cc: Anton Vorontsov 
Cc: Colin Cross 
Cc: Tony Luck 
Cc: Josh Poimboeuf 
Cc: Jiri Kosina 
Cc: Miroslav Benes 
Cc: Petr Mladek 
Cc: Joe Lawrence 
Cc: Kamalesh Babulal 
Cc: Mauro Carvalho Chehab 
Cc: Sebastian Andrzej Siewior 
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-csky@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: live-patching@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware)

kprobes/ftrace: Add recursion protection to the ftrace callback

2020-11-06T13:35:44+00:00

If a ftrace callback does not supply its own recursion protection and
does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will
make a helper trampoline to do so before calling the callback instead of
just calling the callback directly.

The default for ftrace_ops is going to change. It will expect that handlers
provide their own recursion protection, unless its ftrace_ops states
otherwise.

Link: https://lkml.kernel.org/r/20201028115613.140212174@goodmis.org
Link: https://lkml.kernel.org/r/20201106023546.944907560@goodmis.org

Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Josh  Poimboeuf 
Cc: Jiri Kosina 
Cc: Miroslav Benes 
Cc: Petr Mladek 
Cc: Andrew Morton 
Cc: Guo Ren 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Cc: Thomas Gleixner 
Cc: Borislav Petkov 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Cc: "Naveen N. Rao" 
Cc: Anil S Keshavamurthy 
Cc: "David S. Miller" 
Cc: linux-csky@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Acked-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

treewide: Convert macro and uses of section(foo) to section("foo")

2020-10-25T21:51:49+00:00

Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches 
Reviewed-by: Nick Desaulniers 
Reviewed-by: Miguel Ojeda 
Signed-off-by: Linus Torvalds

parisc/kernel/ftrace: Remove function callback casts

2020-08-11T10:06:39+00:00

In an effort to enable -Wcast-function-type in the top-level Makefile to
support Control Flow Integrity builds, remove all the function callback
casts.

Co-developed-by: Helge Deller 
Signed-off-by: Oscar Carter 
Signed-off-by: Helge Deller