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2023-06-06fprobe: Pass return address to the handlersMasami Hiramatsu (Google)
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) <mhiramat@kernel.org>
2023-03-28fprobe: Skip exit_handler if entry_handler returns !0Masami Hiramatsu (Google)
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 <revest@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-28fprobe: Pass entry_data to handlersMasami Hiramatsu (Google)
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 <revest@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-12Merge tag 'trace-v5.19-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 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
2022-07-12fprobe/samples: Make sample_probe staticsunliming
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 <lkp@intel.com> Signed-off-by: sunliming <sunliming@kylinos.cn> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-06-24fprobe, samples: Add module parameter descriptionsMasami Hiramatsu (Google)
Add module parameter descriptions for the fprobe_example module. Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/165602349520.56016.1314423560740428008.stgit@devnote2
2022-06-17fprobe, samples: Add use_trace option and show hit/missed counterMasami Hiramatsu (Google)
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) <mhiramat@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/165461826247.280167.11939123218334322352.stgit@devnote2
2022-03-17fprobe: Add sample program for fprobeMasami Hiramatsu
Add a sample program for the fprobe. The sample_fprobe puts a fprobe on kernel_clone() by default. This dump stack and some called address info at the function entry and exit. The sample_fprobe.ko gets 2 parameters. - symbol: you can specify the comma separated symbols or wildcard symbol pattern (in this case you can not use comma) - stackdump: a bool value to enable or disable stack dump in the fprobe handler. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/164735291987.1084943.4449670993752806840.stgit@devnote2