[for-next][PATCH 01/18] tracing: probeevent: Cleanup print argument functions

From: Steven Rostedt
Date: Sun Oct 28 2018 - 03:31:58 EST


From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

Cleanup the print-argument function to decouple it into
print-name and print-value, so that it can support more
flexible expression, like array type.

Link: http://lkml.kernel.org/r/152465859635.26224.13452846788717102315.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 20 ++++++--------------
kernel/trace/trace_probe.c | 12 +++++-------
kernel/trace/trace_probe.h | 19 ++++++++++++++++---
kernel/trace/trace_uprobe.c | 9 ++-------
4 files changed, 29 insertions(+), 31 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 508396edc56a..6326c71181aa 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1136,8 +1136,6 @@ print_kprobe_event(struct trace_iterator *iter, int flags,
struct kprobe_trace_entry_head *field;
struct trace_seq *s = &iter->seq;
struct trace_probe *tp;
- u8 *data;
- int i;

field = (struct kprobe_trace_entry_head *)iter->ent;
tp = container_of(event, struct trace_probe, call.event);
@@ -1149,11 +1147,9 @@ print_kprobe_event(struct trace_iterator *iter, int flags,

trace_seq_putc(s, ')');

- data = (u8 *)&field[1];
- for (i = 0; i < tp->nr_args; i++)
- if (!tp->args[i].type->print(s, tp->args[i].name,
- data + tp->args[i].offset, field))
- goto out;
+ if (print_probe_args(s, tp->args, tp->nr_args,
+ (u8 *)&field[1], field) < 0)
+ goto out;

trace_seq_putc(s, '\n');
out:
@@ -1167,8 +1163,6 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
struct kretprobe_trace_entry_head *field;
struct trace_seq *s = &iter->seq;
struct trace_probe *tp;
- u8 *data;
- int i;

field = (struct kretprobe_trace_entry_head *)iter->ent;
tp = container_of(event, struct trace_probe, call.event);
@@ -1185,11 +1179,9 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,

trace_seq_putc(s, ')');

- data = (u8 *)&field[1];
- for (i = 0; i < tp->nr_args; i++)
- if (!tp->args[i].type->print(s, tp->args[i].name,
- data + tp->args[i].offset, field))
- goto out;
+ if (print_probe_args(s, tp->args, tp->nr_args,
+ (u8 *)&field[1], field) < 0)
+ goto out;

trace_seq_putc(s, '\n');

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index e99c3ce7aa65..e2c184eaa7db 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -26,10 +26,9 @@ const char *reserved_field_names[] = {

/* Printing in basic type function template */
#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
-int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, const char *name, \
- void *data, void *ent) \
+int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
{ \
- trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \
+ trace_seq_printf(s, fmt, *(type *)data); \
return !trace_seq_has_overflowed(s); \
} \
const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; \
@@ -49,15 +48,14 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")

/* Print type function for string type */
-int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name,
- void *data, void *ent)
+int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
{
int len = *(u32 *)data >> 16;

if (!len)
- trace_seq_printf(s, " %s=(fault)", name);
+ trace_seq_puts(s, "(fault)");
else
- trace_seq_printf(s, " %s=\"%s\"", name,
+ trace_seq_printf(s, "\"%s\"",
(const char *)get_loc_data(data, ent));
return !trace_seq_has_overflowed(s);
}
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 03b10f3201a5..8254a061ac35 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -82,7 +82,7 @@ static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
/* Data fetch function type */
typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
/* Printing function type */
-typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
+typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);

/* Fetch types */
enum {
@@ -124,8 +124,7 @@ typedef u32 string_size;

/* Printing in basic type function template */
#define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \
-int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \
- void *data, void *ent); \
+int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
extern const char PRINT_TYPE_FMT_NAME(type)[]

DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
@@ -403,6 +402,20 @@ store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
}
}

+static inline int
+print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
+ u8 *data, void *field)
+{
+ int i;
+
+ for (i = 0; i < nr_args; i++) {
+ trace_seq_printf(s, " %s=", args[i].name);
+ if (!args[i].type->print(s, data + args[i].offset, field))
+ return -ENOMEM;
+ }
+ return 0;
+}
+
extern int set_print_fmt(struct trace_probe *tp, bool is_return);

#ifdef CONFIG_PERF_EVENTS
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index d09638706fe0..c55753e1079e 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -892,7 +892,6 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
struct trace_seq *s = &iter->seq;
struct trace_uprobe *tu;
u8 *data;
- int i;

entry = (struct uprobe_trace_entry_head *)iter->ent;
tu = container_of(event, struct trace_uprobe, tp.call.event);
@@ -909,12 +908,8 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
data = DATAOF_TRACE_ENTRY(entry, false);
}

- for (i = 0; i < tu->tp.nr_args; i++) {
- struct probe_arg *parg = &tu->tp.args[i];
-
- if (!parg->type->print(s, parg->name, data + parg->offset, entry))
- goto out;
- }
+ if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
+ goto out;

trace_seq_putc(s, '\n');

--
2.19.0