[PATCH V2 10/10] perf dlfilter: Add object_code() to perf_dlfilter_fns

Adrian Hunter
2021-06-27T13:18:41Z

Add a function, for use by dlfilters, to read object code.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/Documentation/perf-dlfilter.txt | 5 +++-
tools/perf/util/dlfilter.c | 34 ++++++++++++++++++++++
tools/perf/util/perf_dlfilter.h | 4 ++-
3 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Documentation/perf-dlfilter.txt b/tools/perf/Documentation/perf-dlfilter.txt
index 6b1d9da16feb..02842cb4cf90 100644
--- a/tools/perf/Documentation/perf-dlfilter.txt
+++ b/tools/perf/Documentation/perf-dlfilter.txt
@@ -127,7 +127,8 @@ struct perf_dlfilter_fns {
const __u8 *(*insn)(void *ctx, __u32 *length);
const char *(*srcline)(void *ctx, __u32 *line_number);
struct perf_event_attr *(*attr)(void *ctx);
- void *(*reserved[121])(void *);
+ __s32 (*object_code)(void *ctx, __u64 ip, void *buf, __u32 len);
+ void *(*reserved[120])(void *);
};
----

@@ -146,6 +147,8 @@ before calling. Returns 0 on success, -1 otherwise.

'attr' returns perf_event_attr, refer <linux/perf_event.h>.

+'object_code' reads object code and returns the number of bytes read.
+
The perf_dlfilter_al structure
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

diff --git a/tools/perf/util/dlfilter.c b/tools/perf/util/dlfilter.c
index e50d524906d6..ca33fbc5efde 100644
--- a/tools/perf/util/dlfilter.c
+++ b/tools/perf/util/dlfilter.c
@@ -245,6 +245,39 @@ static struct perf_event_attr *dlfilter__attr(void *ctx)
return &d->evsel->core.attr;
}

+static __s32 dlfilter__object_code(void *ctx, __u64 ip, void *buf, __u32 len)
+{
+ struct dlfilter *d = (struct dlfilter *)ctx;
+ struct addr_location *al;
+ struct addr_location a;
+ struct map *map;
+ u64 offset;
+
+ if (!d->ctx_valid)
+ return -1;
+
+ al = get_al(d);
+ if (!al)
+ return -1;
+
+ map = al->map;
+
+ if (map && ip >= map->start && ip < map->end &&
+ machine__kernel_ip(d->machine, ip) == machine__kernel_ip(d->machine, d->sample->ip))
+ goto have_map;
+
+ thread__find_map_fb(al->thread, d->sample->cpumode, ip, &a);
+ if (!a.map)
+ return -1;
+
+ map = a.map;
+have_map:
+ offset = map->map_ip(map, ip);
+ if (ip + len >= map->end)
+ len = map->end - ip;
+ return dso__data_read_offset(map->dso, d->machine, offset, buf, len);
+}
+
static const struct perf_dlfilter_fns perf_dlfilter_fns = {
.resolve_ip = dlfilter__resolve_ip,
.resolve_addr = dlfilter__resolve_addr,
@@ -253,6 +286,7 @@ static const struct perf_dlfilter_fns perf_dlfilter_fns = {
.insn = dlfilter__insn,
.srcline = dlfilter__srcline,
.attr = dlfilter__attr,
+ .object_code = dlfilter__object_code,
};

static char *find_dlfilter(const char *file)
diff --git a/tools/perf/util/perf_dlfilter.h b/tools/perf/util/perf_dlfilter.h
index f3fc92fcb3c0..3eef03d661b4 100644
--- a/tools/perf/util/perf_dlfilter.h
+++ b/tools/perf/util/perf_dlfilter.h
@@ -103,8 +103,10 @@ struct perf_dlfilter_fns {
const char *(*srcline)(void *ctx, __u32 *line_number);
/* Return perf_event_attr, refer <linux/perf_event.h> */
struct perf_event_attr *(*attr)(void *ctx);
+ /* Read object code, return numbers of bytes read */
+ __s32 (*object_code)(void *ctx, __u64 ip, void *buf, __u32 len);
/* Reserved */
- void *(*reserved[121])(void *);
+ void *(*reserved[120])(void *);
};

/*
--
2.17.1