Support up to 128 arguments for each kprobes event.
Signed-off-by: Masami Hiramatsu <[email protected]>
Cc: Ananth N Mavinakayanahalli <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Tom Zanussi <[email protected]>
---
Documentation/trace/kprobetrace.txt | 2 +-
kernel/trace/trace_kprobe.c | 21 +++++++++++++--------
2 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/Documentation/trace/kprobetrace.txt
b/Documentation/trace/kprobetrace.txt
index 9ad907c..b29a54b 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -32,7 +32,7 @@ Synopsis of kprobe_events
SYMBOL[+offs|-offs] : Symbol+offset where the probe is inserted.
MEMADDR : Address where the probe is inserted.
- FETCHARGS : Arguments.
+ FETCHARGS : Arguments. Each probe can have up to 128 args.
%REG : Fetch register REG
sN : Fetch Nth entry of stack (N >= 0)
@ADDR : Fetch memory at ADDR (ADDR should be in kernel)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 39491f0..e78c4ea 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -32,7 +32,7 @@
#include "trace.h"
#include "trace_output.h"
-#define TRACE_KPROBE_ARGS 6
+#define MAX_TRACE_ARGS 128
#define MAX_ARGSTR_LEN 63
/* currently, trace_kprobe only supports X86. */
@@ -178,11 +178,15 @@ struct trace_probe {
struct kretprobe rp;
};
const char *symbol; /* symbol name */
- unsigned int nr_args;
- struct fetch_func args[TRACE_KPROBE_ARGS];
struct ftrace_event_call call;
+ unsigned int nr_args;
+ struct fetch_func args[];
};
+#define SIZEOF_TRACE_PROBE(n) \
+ (offsetof(struct trace_probe, args) + \
+ (sizeof(struct fetch_func) * (n)))
+
static int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs);
static int kretprobe_trace_func(struct kretprobe_instance *ri,
struct pt_regs *regs);
@@ -255,11 +259,11 @@ static DEFINE_MUTEX(probe_lock);
static LIST_HEAD(probe_list);
static struct trace_probe *alloc_trace_probe(const char *symbol,
- const char *event)
+ const char *event, int nargs)
{
struct trace_probe *tp;
- tp = kzalloc(sizeof(struct trace_probe), GFP_KERNEL);
+ tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
if (!tp)
return ERR_PTR(-ENOMEM);
@@ -559,9 +563,10 @@ static int create_trace_probe(int argc, char **argv)
if (offset && is_return)
return -EINVAL;
}
+ argc -= 2; argv += 2;
/* setup a probe */
- tp = alloc_trace_probe(symbol, event);
+ tp = alloc_trace_probe(symbol, event, argc);
if (IS_ERR(tp))
return PTR_ERR(tp);
@@ -580,8 +585,8 @@ static int create_trace_probe(int argc, char **argv)
kp->addr = addr;
/* parse arguments */
- argc -= 2; argv += 2; ret = 0;
- for (i = 0; i < argc && i < TRACE_KPROBE_ARGS; i++) {
+ ret = 0;
+ for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
if (strlen(argv[i]) > MAX_ARGSTR_LEN) {
pr_info("Argument%d(%s) is too long.\n", i, argv[i]);
ret = -ENOSPC;
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division
e-mail: [email protected]
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