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tracing/kprobes: Add argument name support

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Add argument name assignment support and remove "alias" lines from format.
This allows user to assign unique name to each argument. For example,

$ echo p do_sys_open dfd=a0 filename=a1 flags=a2 mode=a3 > kprobe_events

This assigns dfd, filename, flags, and mode to 1st - 4th arguments
respectively. Trace buffer shows those names too.

	<...>-1439  [000] 1200885.933147: do_sys_open+0x0/0xdf: dfd=ffffff9c filename=bfa898ac flags=8000 mode=0

This helps users to know what each value means.

Users can filter each events by these names too. Note that you can not
filter by argN anymore.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235337.22412.77383.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This commit is contained in:
Masami Hiramatsu
2009-09-10 19:53:38 -04:00
committed by Frederic Weisbecker
parent e08d1c657f
commit eca0d916f6
2 changed files with 84 additions and 90 deletions
Download Patch File Download Diff File Expand all files Collapse all files

128
kernel/trace/trace_kprobe.c
View File

@@ -176,9 +176,14 @@ static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data)
}
/**
* kprobe_trace_core
* Kprobe tracer core functions
*/
struct probe_arg {
struct fetch_func fetch;
const char *name;
};
struct trace_probe {
struct list_head list;
struct kretprobe rp; /* Use rp.kp for kprobe use */
@@ -187,12 +192,12 @@ struct trace_probe {
struct ftrace_event_call call;
struct trace_event event;
unsigned int nr_args;
struct fetch_func args[];
struct probe_arg args[];
};
#define SIZEOF_TRACE_PROBE(n) \
(offsetof(struct trace_probe, args) + \
(sizeof(struct fetch_func) * (n)))
(sizeof(struct probe_arg) * (n)))
static int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs);
static int kretprobe_trace_func(struct kretprobe_instance *ri,
@@ -301,15 +306,21 @@ error:
return ERR_PTR(-ENOMEM);
}
static void free_probe_arg(struct probe_arg *arg)
{
if (arg->fetch.func == fetch_symbol)
free_symbol_cache(arg->fetch.data);
else if (arg->fetch.func == fetch_indirect)
free_indirect_fetch_data(arg->fetch.data);
kfree(arg->name);
}
static void free_trace_probe(struct trace_probe *tp)
{
int i;
for (i = 0; i < tp->nr_args; i++)
if (tp->args[i].func == fetch_symbol)
free_symbol_cache(tp->args[i].data);
else if (tp->args[i].func == fetch_indirect)
free_indirect_fetch_data(tp->args[i].data);
free_probe_arg(&tp->args[i]);
kfree(tp->call.name);
kfree(tp->symbol);
@@ -532,11 +543,13 @@ static int create_trace_probe(int argc, char **argv)
* %REG : fetch register REG
* Indirect memory fetch:
* +|-offs(ARG) : fetch memory at ARG +|- offs address.
* Alias name of args:
* NAME=FETCHARG : set NAME as alias of FETCHARG.
*/
struct trace_probe *tp;
int i, ret = 0;
int is_return = 0;
char *symbol = NULL, *event = NULL;
char *symbol = NULL, *event = NULL, *arg = NULL;
unsigned long offset = 0;
void *addr = NULL;
char buf[MAX_EVENT_NAME_LEN];
@@ -596,12 +609,21 @@ static int create_trace_probe(int argc, char **argv)
/* parse arguments */
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]);
/* Parse argument name */
arg = strchr(argv[i], '=');
if (arg)
*arg++ = '\0';
else
arg = argv[i];
tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
/* Parse fetch argument */
if (strlen(arg) > MAX_ARGSTR_LEN) {
pr_info("Argument%d(%s) is too long.\n", i, arg);
ret = -ENOSPC;
goto error;
}
ret = parse_probe_arg(argv[i], &tp->args[i], is_return);
ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
if (ret)
goto error;
}
@@ -664,12 +686,12 @@ static int probes_seq_show(struct seq_file *m, void *v)
seq_printf(m, " 0x%p", tp->rp.kp.addr);
for (i = 0; i < tp->nr_args; i++) {
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]);
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
if (ret < 0) {
pr_warning("Argument%d decoding error(%d).\n", i, ret);
return ret;
}
seq_printf(m, " %s", buf);
seq_printf(m, " %s=%s", tp->args[i].name, buf);
}
seq_printf(m, "\n");
return 0;
@@ -824,7 +846,7 @@ static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
entry->nargs = tp->nr_args;
entry->ip = (unsigned long)kp->addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i], regs);
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
if (!filter_current_check_discard(buffer, call, entry, event))
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
@@ -858,7 +880,7 @@ static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri,
entry->func = (unsigned long)tp->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i], regs);
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
if (!filter_current_check_discard(buffer, call, entry, event))
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
@@ -872,9 +894,13 @@ print_kprobe_event(struct trace_iterator *iter, int flags)
{
struct kprobe_trace_entry *field;
struct trace_seq *s = &iter->seq;
struct trace_event *event;
struct trace_probe *tp;
int i;
field = (struct kprobe_trace_entry *)iter->ent;
event = ftrace_find_event(field->ent.type);
tp = container_of(event, struct trace_probe, event);
if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
goto partial;
@@ -883,7 +909,8 @@ print_kprobe_event(struct trace_iterator *iter, int flags)
goto partial;
for (i = 0; i < field->nargs; i++)
if (!trace_seq_printf(s, " 0x%lx", field->args[i]))
if (!trace_seq_printf(s, " %s=%lx",
tp->args[i].name, field->args[i]))
goto partial;
if (!trace_seq_puts(s, "\n"))
@@ -899,9 +926,13 @@ print_kretprobe_event(struct trace_iterator *iter, int flags)
{
struct kretprobe_trace_entry *field;
struct trace_seq *s = &iter->seq;
struct trace_event *event;
struct trace_probe *tp;
int i;
field = (struct kretprobe_trace_entry *)iter->ent;
event = ftrace_find_event(field->ent.type);
tp = container_of(event, struct trace_probe, event);
if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
goto partial;
@@ -916,7 +947,8 @@ print_kretprobe_event(struct trace_iterator *iter, int flags)
goto partial;
for (i = 0; i < field->nargs; i++)
if (!trace_seq_printf(s, " 0x%lx", field->args[i]))
if (!trace_seq_printf(s, " %s=%lx",
tp->args[i].name, field->args[i]))
goto partial;
if (!trace_seq_puts(s, "\n"))
@@ -972,7 +1004,6 @@ static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
{
int ret, i;
struct kprobe_trace_entry field;
char buf[MAX_ARGSTR_LEN + 1];
struct trace_probe *tp = (struct trace_probe *)event_call->data;
ret = trace_define_common_fields(event_call);
@@ -981,16 +1012,9 @@ static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
DEFINE_FIELD(unsigned long, ip, "ip", 0);
DEFINE_FIELD(int, nargs, "nargs", 1);
for (i = 0; i < tp->nr_args; i++) {
/* Set argN as a field */
sprintf(buf, "arg%d", i);
DEFINE_FIELD(unsigned long, args[i], buf, 0);
/* Set argument string as an alias field */
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]);
if (ret < 0)
return ret;
DEFINE_FIELD(unsigned long, args[i], buf, 0);
}
/* Set argument names as fields */
for (i = 0; i < tp->nr_args; i++)
DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
return 0;
}
@@ -998,7 +1022,6 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
{
int ret, i;
struct kretprobe_trace_entry field;
char buf[MAX_ARGSTR_LEN + 1];
struct trace_probe *tp = (struct trace_probe *)event_call->data;
ret = trace_define_common_fields(event_call);
@@ -1008,16 +1031,9 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
DEFINE_FIELD(unsigned long, func, "func", 0);
DEFINE_FIELD(unsigned long, ret_ip, "ret_ip", 0);
DEFINE_FIELD(int, nargs, "nargs", 1);
for (i = 0; i < tp->nr_args; i++) {
/* Set argN as a field */
sprintf(buf, "arg%d", i);
DEFINE_FIELD(unsigned long, args[i], buf, 0);
/* Set argument string as an alias field */
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]);
if (ret < 0)
return ret;
DEFINE_FIELD(unsigned long, args[i], buf, 0);
}
/* Set argument names as fields */
for (i = 0; i < tp->nr_args; i++)
DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
return 0;
}
@@ -1025,31 +1041,21 @@ static int __probe_event_show_format(struct trace_seq *s,
struct trace_probe *tp, const char *fmt,
const char *arg)
{
int i, ret;
char buf[MAX_ARGSTR_LEN + 1];
int i;
/* Show aliases */
for (i = 0; i < tp->nr_args; i++) {
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]);
if (ret < 0)
return ret;
if (!trace_seq_printf(s, "\talias: %s;\toriginal: arg%d;\n",
buf, i))
return 0;
}
/* Show format */
if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt))
return 0;
for (i = 0; i < tp->nr_args; i++)
if (!trace_seq_puts(s, " 0x%lx"))
if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name))
return 0;
if (!trace_seq_printf(s, "\", %s", arg))
return 0;
for (i = 0; i < tp->nr_args; i++)
if (!trace_seq_printf(s, ", arg%d", i))
if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name))
return 0;
return trace_seq_puts(s, "\n");
@@ -1071,17 +1077,14 @@ static int kprobe_event_show_format(struct ftrace_event_call *call,
{
struct kprobe_trace_entry field __attribute__((unused));
int ret, i;
char buf[8];
struct trace_probe *tp = (struct trace_probe *)call->data;
SHOW_FIELD(unsigned long, ip, "ip");
SHOW_FIELD(int, nargs, "nargs");
/* Show fields */
for (i = 0; i < tp->nr_args; i++) {
sprintf(buf, "arg%d", i);
SHOW_FIELD(unsigned long, args[i], buf);
}
for (i = 0; i < tp->nr_args; i++)
SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
trace_seq_puts(s, "\n");
return __probe_event_show_format(s, tp, "%lx:", "ip");
@@ -1092,7 +1095,6 @@ static int kretprobe_event_show_format(struct ftrace_event_call *call,
{
struct kretprobe_trace_entry field __attribute__((unused));
int ret, i;
char buf[8];
struct trace_probe *tp = (struct trace_probe *)call->data;
SHOW_FIELD(unsigned long, func, "func");
@@ -1100,10 +1102,8 @@ static int kretprobe_event_show_format(struct ftrace_event_call *call,
SHOW_FIELD(int, nargs, "nargs");
/* Show fields */
for (i = 0; i < tp->nr_args; i++) {
sprintf(buf, "arg%d", i);
SHOW_FIELD(unsigned long, args[i], buf);
}
for (i = 0; i < tp->nr_args; i++)
SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
trace_seq_puts(s, "\n");
return __probe_event_show_format(s, tp, "%lx <- %lx:",
@@ -1140,7 +1140,7 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp,
entry->nargs = tp->nr_args;
entry->ip = (unsigned long)kp->addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i], regs);
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
perf_tpcounter_event(call->id, entry->ip, 1, entry, size);
} while (0);
return 0;
@@ -1175,7 +1175,7 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
entry->func = (unsigned long)tp->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i], regs);
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
perf_tpcounter_event(call->id, entry->ret_ip, 1, entry, size);
} while (0);
return 0;