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authorMasami Hiramatsu <mhiramat@kernel.org>2018-08-29 01:18:43 +0900
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2018-10-10 22:19:12 -0400
commita6682814f37124ec1e708cca8f44968445fa9dd7 (patch)
tree15e0eb29bad333cb4f69eaec38172680a4393ed7 /kernel/trace/trace_kprobe.c
parent59158ec4aef7d44be51a6f3e7e17fc64c32604eb (diff)
tracing/kprobes: Allow kprobe-events to record module symbol
Allow kprobe-events to record module symbols. Since data symbols in a non-loaded module doesn't exist, it fails to define such symbol as an argument of kprobe-event. But if the kprobe event is defined on that module, we can defer to resolve the symbol address. Note that if given symbol is not found, the event is kept unavailable. User can enable it but the event is not recorded. Link: http://lkml.kernel.org/r/153547312336.26502.11432902826345374463.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
-rw-r--r--kernel/trace/trace_kprobe.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 4727a13824f0..fec67188c4d2 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -366,7 +366,7 @@ static bool within_notrace_func(struct trace_kprobe *tk)
/* Internal register function - just handle k*probes and flags */
static int __register_trace_kprobe(struct trace_kprobe *tk)
{
- int ret;
+ int i, ret;
if (trace_probe_is_registered(&tk->tp))
return -EINVAL;
@@ -377,6 +377,12 @@ static int __register_trace_kprobe(struct trace_kprobe *tk)
return -EINVAL;
}
+ for (i = 0; i < tk->tp.nr_args; i++) {
+ ret = traceprobe_update_arg(&tk->tp.args[i]);
+ if (ret)
+ return ret;
+ }
+
/* Set/clear disabled flag according to tp->flag */
if (trace_probe_is_enabled(&tk->tp))
tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
@@ -928,6 +934,7 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
{
unsigned long val;
+retry:
/* 1st stage: get value from context */
switch (code->op) {
case FETCH_OP_REG:
@@ -953,6 +960,9 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
val = regs_get_kernel_argument(regs, code->param);
break;
#endif
+ case FETCH_NOP_SYMBOL: /* Ignore a place holder */
+ code++;
+ goto retry;
default:
return -EILSEQ;
}