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tracing/probe: Change traceprobe_set_print_fmt() to take a type

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Instead of a boolean "is_return" have traceprobe_set_print_fmt() take a
type (currently just PROBE_PRINT_NORMAL and PROBE_PRINT_RETURN). This will
simplify adding different types. For example, the development of the
event_probe, will need its own type as it prints an event, and not an IP.

Link: https://lkml.kernel.org/r/20210819041842.104626301@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (VMware) 2021-08-19 00:13:27 -04:00
parent 845cbf3e11
commit 007517a019
4 changed files with 31 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
kernel/trace/trace_kprobe.c
View File

@ -742,6 +742,7 @@ static int __trace_kprobe_create(int argc, const char *argv[])
bool is_return = false;
char *symbol = NULL, *tmp = NULL;
const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
enum probe_print_type ptype;
int maxactive = 0;
long offset = 0;
void *addr = NULL;
@ -875,7 +876,8 @@ static int __trace_kprobe_create(int argc, const char *argv[])
goto error; /* This can be -ENOMEM */
}
ret = traceprobe_set_print_fmt(&tk->tp, is_return);
ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
ret = traceprobe_set_print_fmt(&tk->tp, ptype);
if (ret < 0)
goto error;
@ -1799,6 +1801,7 @@ struct trace_event_call *
create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
bool is_return)
{
enum probe_print_type ptype;
struct trace_kprobe *tk;
int ret;
char *event;
@ -1822,7 +1825,9 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
init_trace_event_call(tk);
if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
ptype = trace_kprobe_is_return(tk) ?
PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) {
ret = -ENOMEM;
goto error;
}

18
kernel/trace/trace_probe.c
View File

@ -851,19 +851,25 @@ int traceprobe_update_arg(struct probe_arg *arg)
/* When len=0, we just calculate the needed length */
#define LEN_OR_ZERO (len ? len - pos : 0)
static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
bool is_return)
enum probe_print_type ptype)
{
struct probe_arg *parg;
int i, j;
int pos = 0;
const char *fmt, *arg;
if (!is_return) {
switch (ptype) {
case PROBE_PRINT_NORMAL:
fmt = "(%lx)";
arg = "REC->" FIELD_STRING_IP;
} else {
break;
case PROBE_PRINT_RETURN:
fmt = "(%lx <- %lx)";
arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
break;
default:
WARN_ON_ONCE(1);
return 0;
}
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
@ -912,20 +918,20 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
}
#undef LEN_OR_ZERO
int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)
int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype)
{
struct trace_event_call *call = trace_probe_event_call(tp);
int len;
char *print_fmt;
/* First: called with 0 length to calculate the needed length */
len = __set_print_fmt(tp, NULL, 0, is_return);
len = __set_print_fmt(tp, NULL, 0, ptype);
print_fmt = kmalloc(len + 1, GFP_KERNEL);
if (!print_fmt)
return -ENOMEM;
/* Second: actually write the @print_fmt */
__set_print_fmt(tp, print_fmt, len + 1, is_return);
__set_print_fmt(tp, print_fmt, len + 1, ptype);
call->print_fmt = print_fmt;
return 0;

7
kernel/trace/trace_probe.h
View File

@ -363,7 +363,12 @@ extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
char *buf, int offset);
extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);
enum probe_print_type {
PROBE_PRINT_NORMAL,
PROBE_PRINT_RETURN,
};
extern int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype);
#ifdef CONFIG_PERF_EVENTS
extern struct trace_event_call *

8
kernel/trace/trace_uprobe.c
View File

@ -536,6 +536,7 @@ static int __trace_uprobe_create(int argc, const char **argv)
const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
char *arg, *filename, *rctr, *rctr_end, *tmp;
char buf[MAX_EVENT_NAME_LEN];
enum probe_print_type ptype;
struct path path;
unsigned long offset, ref_ctr_offset;
bool is_return = false;
@ -687,7 +688,8 @@ static int __trace_uprobe_create(int argc, const char **argv)
goto error;
}
ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu));
ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
ret = traceprobe_set_print_fmt(&tu->tp, ptype);
if (ret < 0)
goto error;
@ -1578,6 +1580,7 @@ struct trace_event_call *
create_local_trace_uprobe(char *name, unsigned long offs,
unsigned long ref_ctr_offset, bool is_return)
{
enum probe_print_type ptype;
struct trace_uprobe *tu;
struct path path;
int ret;
@ -1612,7 +1615,8 @@ create_local_trace_uprobe(char *name, unsigned long offs,
tu->filename = kstrdup(name, GFP_KERNEL);
init_trace_event_call(tu);
if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
ret = -ENOMEM;
goto error;
}