linux.git/samples/fprobe/fprobe_example.c, branch v6.18.21

fprobe: Use ftrace_regs in fprobe exit handler

2024-12-26T15:50:03+00:00

Change the fprobe exit handler to use ftrace_regs structure instead of
pt_regs. This also introduce HAVE_FTRACE_REGS_HAVING_PT_REGS which
means the ftrace_regs is including the pt_regs so that ftrace_regs
can provide pt_regs without memory allocation.
Fprobe introduces a new dependency with that.

Signed-off-by: Masami Hiramatsu (Google) 
Acked-by: Heiko Carstens  # s390
Cc: Huacai Chen 
Cc: Alexei Starovoitov 
Cc: Florent Revest 
Cc: bpf 
Cc: Alan Maguire 
Cc: Heiko Carstens 
Cc: WANG Xuerui 
Cc: Vasily Gorbik 
Cc: Alexander Gordeev 
Cc: Christian Borntraeger 
Cc: Sven Schnelle 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Song Liu 
Cc: Jiri Olsa 
Cc: KP Singh 
Cc: Matt Bobrowski 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Andrii Nakryiko 
Cc: Martin KaFai Lau 
Cc: Eduard Zingerman 
Cc: Yonghong Song 
Cc: John Fastabend 
Cc: Stanislav Fomichev 
Cc: Hao Luo 
Cc: Andrew Morton 
Link: https://lore.kernel.org/173518995092.391279.6765116450352977627.stgit@devnote2
Signed-off-by: Steven Rostedt (Google)

fprobe: Use ftrace_regs in fprobe entry handler

2024-12-26T15:50:03+00:00

This allows fprobes to be available with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
instead of CONFIG_DYNAMIC_FTRACE_WITH_REGS, then we can enable fprobe
on arm64.

Cc: Alexei Starovoitov 
Cc: Martin KaFai Lau 
Cc: bpf 
Cc: Alexei Starovoitov 
Cc: Jiri Olsa 
Cc: Alan Maguire 
Cc: Mark Rutland 
Link: https://lore.kernel.org/173518994037.391279.2786805566359674586.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) 
Acked-by: Florent Revest 
Signed-off-by: Steven Rostedt (Google)

fprobe: add missing MODULE_DESCRIPTION() macro

2024-06-11T23:44:27+00:00

make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/fprobe/fprobe_example.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.

Link: https://lore.kernel.org/all/20240601-md-samples-fprobe-v1-1-5d256a956612@quicinc.com/

Signed-off-by: Jeff Johnson 
Signed-off-by: Masami Hiramatsu (Google)

fprobe: Pass return address to the handlers

2023-06-06T12:39:55+00:00

Pass return address as 'ret_ip' to the fprobe entry and return handlers
so that the fprobe user handler can get the reutrn address without
analyzing arch-dependent pt_regs.

Link: https://lore.kernel.org/all/168507467664.913472.11642316698862778600.stgit@mhiramat.roam.corp.google.com/

Signed-off-by: Masami Hiramatsu (Google)

fprobe: Skip exit_handler if entry_handler returns !0

2023-03-28T22:52:22+00:00

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 
Cc: Mark Rutland 
Cc: Will Deacon 
Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Steven Rostedt (Google)

fprobe: Pass entry_data to handlers

2023-03-28T22:52:22+00:00

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 
Cc: Mark Rutland 
Cc: Will Deacon 
Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Steven Rostedt (Google)

Merge tag 'trace-v5.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2022-07-12T23:17:40+00:00

Pull tracing fixes from Steven Rostedt:
 "Fixes and minor clean ups for tracing:

   - Fix memory leak by reverting what was thought to be a double free.

     A static tool had gave a false positive that a double free was
     possible in the error path, but it was actually a different
     location that confused the static analyzer (and those of us that
     reviewed it).

   - Move use of static buffers by ftrace_dump() to a location that can
     be used by kgdb's ftdump(), as it needs it for the same reasons.

   - Clarify in the Kconfig description that function tracing has
     negligible impact on x86, but may have a bit bigger impact on other
     architectures.

   - Remove unnecessary extra semicolon in trace event.

   - Make a local variable static that is used in the fprobes sample

   - Use KSYM_NAME_LEN for length of function in kprobe sample and get
     rid of unneeded macro for the same purpose"

* tag 'trace-v5.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  samples: Use KSYM_NAME_LEN for kprobes
  fprobe/samples: Make sample_probe static
  blk-iocost: tracing: atomic64_read(&ioc->vtime_rate) is assigned an extra semicolon
  ftrace: Be more specific about arch impact when function tracer is enabled
  tracing: Fix sleeping while atomic in kdb ftdump
  tracing/histograms: Fix memory leak problem

fprobe/samples: Make sample_probe static

2022-07-12T20:36:43+00:00

This symbol is not used outside of fprobe_example.c, so marks it static.

Fixes the following warning:

sparse warnings: (new ones prefixed by >>)
>> samples/fprobe/fprobe_example.c:23:15: sparse: sparse: symbol 'sample_probe'
was not declared. Should it be static?

Link: https://lkml.kernel.org/r/20220606075659.674556-1-sunliming@kylinos.cn

Reported-by: kernel test robot 
Signed-off-by: sunliming 
Acked-by: Masami Hiramatsu (Google) 
Signed-off-by: Steven Rostedt (Google)

fprobe, samples: Add module parameter descriptions

2022-06-24T22:23:04+00:00

Add module parameter descriptions for the fprobe_example module.

Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/165602349520.56016.1314423560740428008.stgit@devnote2

fprobe, samples: Add use_trace option and show hit/missed counter

2022-06-17T19:53:29+00:00

Add use_trace option to use trace_printk() instead of pr_info()
so that the handler doesn't involve the RCU operations.
And show the hit and missed counter so that the user can check
how many times the probe handler hit and missed.

Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Daniel Borkmann 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/165461826247.280167.11939123218334322352.stgit@devnote2