[PATCH 12/21] perf trace: Introduce syscall arg formatters

From: Arnaldo Carvalho de Melo
Date: Wed Aug 28 2013 - 11:01:12 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

Starting with one for printing pointers in hexadecimal, using the
information in the syscall tracepoint format.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-c4y4jy7qqkn8wsd8q6j1g7zh@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-trace.c | 39 ++++++++++++++++++++++++++++++++++++---
1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index c3caabb..86568ed 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -12,6 +12,11 @@
#include <libaudit.h>
#include <stdlib.h>

+static size_t syscall_arg__scnprintf_hex(char *bf, size_t size, unsigned long arg)
+{
+ return scnprintf(bf, size, "%#lx", arg);
+}
+
static struct syscall_fmt {
const char *name;
const char *alias;
@@ -51,6 +56,7 @@ struct syscall {
const char *name;
bool filtered;
struct syscall_fmt *fmt;
+ size_t (**arg_scnprintf)(char *bf, size_t size, unsigned long arg);
};

static size_t fprintf_duration(unsigned long t, FILE *fp)
@@ -207,6 +213,24 @@ static int trace__symbols_init(struct trace *trace, struct perf_evlist *evlist)
return err;
}

+static int syscall__set_arg_fmts(struct syscall *sc)
+{
+ struct format_field *field;
+ int idx = 0;
+
+ sc->arg_scnprintf = calloc(sc->tp_format->format.nr_fields - 1, sizeof(void *));
+ if (sc->arg_scnprintf == NULL)
+ return -1;
+
+ for (field = sc->tp_format->format.fields->next; field; field = field->next) {
+ if (field->flags & FIELD_IS_POINTER)
+ sc->arg_scnprintf[idx] = syscall_arg__scnprintf_hex;
+ ++idx;
+ }
+
+ return 0;
+}
+
static int trace__read_syscall_info(struct trace *trace, int id)
{
char tp_name[128];
@@ -259,7 +283,10 @@ static int trace__read_syscall_info(struct trace *trace, int id)
sc->tp_format = event_format__new("syscalls", tp_name);
}

- return sc->tp_format != NULL ? 0 : -1;
+ if (sc->tp_format == NULL)
+ return -1;
+
+ return syscall__set_arg_fmts(sc);
}

static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size,
@@ -273,8 +300,14 @@ static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size,

for (field = sc->tp_format->format.fields->next; field; field = field->next) {
printed += scnprintf(bf + printed, size - printed,
- "%s%s: %ld", printed ? ", " : "",
- field->name, args[i++]);
+ "%s%s: ", printed ? ", " : "", field->name);
+
+ if (sc->arg_scnprintf && sc->arg_scnprintf[i])
+ printed += sc->arg_scnprintf[i](bf + printed, size - printed, args[i]);
+ else
+ printed += scnprintf(bf + printed, size - printed,
+ "%ld", args[i]);
+ ++i;
}
} else {
while (i < 6) {
--
1.8.1.4

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