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authorJosef Bacik <jbacik@fb.com>2017-12-11 11:36:48 -0500
committerAlexei Starovoitov <ast@kernel.org>2017-12-12 09:02:34 -0800
commit9802d86585db91655c7d1929a4f6bbe0952ea88e (patch)
tree53b334864518dd27b243eafc9ab510ac56ee3b74 /include/linux/trace_events.h
parent8556e50994c8a8f5282fea008ae084d6d080648a (diff)
downloadlwn-9802d86585db91655c7d1929a4f6bbe0952ea88e.tar.gz
lwn-9802d86585db91655c7d1929a4f6bbe0952ea88e.zip
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 'include/linux/trace_events.h')
-rw-r--r--include/linux/trace_events.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index af44e7c2d577..5fea451f6e28 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -528,6 +528,7 @@ do { \
struct perf_event;
DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
+DECLARE_PER_CPU(int, bpf_kprobe_override);
extern int perf_trace_init(struct perf_event *event);
extern void perf_trace_destroy(struct perf_event *event);