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| author |   Masami Hiramatsu <mhiramat@kernel.org> | 2018-07-30 19:20:14 +0900 |
|---|---|---|
| committer |   Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-07-30 18:28:52 -0400 |
| commit | 45408c4f92506dbdfef1721f2613e1426de00894 (patch) | |
| tree | 0deca678bf0954a7224acd62f4a805d8d6eb1788 /kernel/trace/Kconfig | |
| parent | tracing: preemptirq_delay_run() can be static (diff) | |
| download | linux-dev-45408c4f92506dbdfef1721f2613e1426de00894.tar.xz linux-dev-45408c4f92506dbdfef1721f2613e1426de00894.zip | |
tracing: kprobes: Prohibit probing on notrace function
Prohibit kprobe-events probing on notrace functions. Since probing on a
notrace function can cause a recursive event call. In most cases those are just
skipped, but in some cases it falls into an infinite recursive call.
This protection can be disabled by the kconfig
CONFIG_KPROBE_EVENTS_ON_NOTRACE=y, but it is highly recommended to keep it
"n" for normal kernel builds. Note that this is only available if "kprobes on
ftrace" has been implemented on the target arch and CONFIG_KPROBES_ON_FTRACE=y.
Link: http://lkml.kernel.org/r/153294601436.32740.10557881188933661239.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Francis Deslauriers <francis.deslauriers@efficios.com>
[ Slight grammar and spelling fixes ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/Kconfig')
| -rw-r--r-- | kernel/trace/Kconfig | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index e15fadbe5dfb..4d4eb15cc7fd 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -456,6 +456,26 @@ config KPROBE_EVENTS This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. +config KPROBE_EVENTS_ON_NOTRACE + bool "Do NOT protect notrace function from kprobe events" + depends on KPROBE_EVENTS + depends on KPROBES_ON_FTRACE + default n + help + This is only for the developers who want to debug ftrace itself + using kprobe events. + + If kprobes can use ftrace instead of breakpoint, ftrace related + functions are protected from kprobe-events to prevent an infinit + recursion or any unexpected execution path which leads to a kernel + crash. + + This option disables such protection and allows you to put kprobe + events on ftrace functions for debugging ftrace by itself. + Note that this might let you shoot yourself in the foot. + + If unsure, say N. + config UPROBE_EVENTS bool "Enable uprobes-based dynamic events" depends on ARCH_SUPPORTS_UPROBES |