diff options
| author | Josef Bacik <jbacik@fb.com> | 2017-12-11 11:36:48 -0500 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2017-12-12 09:02:34 -0800 |
| commit | 9802d86585db91655c7d1929a4f6bbe0952ea88e (patch) | |
| tree | 53b334864518dd27b243eafc9ab510ac56ee3b74 /kernel/trace/Kconfig | |
| parent | 8556e50994c8a8f5282fea008ae084d6d080648a (diff) | |
bpf: add a bpf_override_function helper
Error injection is sloppy and very ad-hoc. BPF could fill this niche
perfectly with it's kprobe functionality. We could make sure errors are
only triggered in specific call chains that we care about with very
specific situations. Accomplish this with the bpf_override_funciton
helper. This will modify the probe'd callers return value to the
specified value and set the PC to an override function that simply
returns, bypassing the originally probed function. This gives us a nice
clean way to implement systematic error injection for all of our code
paths.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/trace/Kconfig')
| -rw-r--r-- | kernel/trace/Kconfig | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index af7dad126c13..3e6fd580fe7f 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -529,6 +529,17 @@ config FUNCTION_PROFILER If in doubt, say N. +config BPF_KPROBE_OVERRIDE + bool "Enable BPF programs to override a kprobed function" + depends on BPF_EVENTS + depends on KPROBES_ON_FTRACE + depends on HAVE_KPROBE_OVERRIDE + depends on DYNAMIC_FTRACE_WITH_REGS + default n + help + Allows BPF to override the execution of a probed function and + set a different return value. This is used for error injection. + config FTRACE_MCOUNT_RECORD def_bool y depends on DYNAMIC_FTRACE |