On 5/17/15 10:30 PM, He Kuang wrote:
Add new structure bpf_pt_regs, which contains both original
'ctx'(pt_regs) and trabe_probe pointer, and pass this new pointer to bpf
prog for variable fetching.
Signed-off-by: He Kuang <heku...@huawei.com>
---
kernel/trace/trace_kprobe.c | 11 +++++++++--
kernel/trace/trace_probe.h | 5 +++++
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index d0ce590..cee0b28 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1141,8 +1141,15 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs
*regs)
int size, __size, dsize;
int rctx;
- if (prog && !trace_call_bpf(prog, regs))
- return;
+ if (prog) {
+ struct bpf_pt_regs bpf_pt_regs;
+
+ bpf_pt_regs.pt_regs = *regs;
+ bpf_pt_regs.tp = &tk->tp;
...
+struct bpf_pt_regs {
+ struct pt_regs pt_regs;
+ struct trace_probe *tp;
+};
that is a massive overhead.
On x64 it means copying 168 bytes for every call.
imo that's a wrong trade off.
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