[PATCH 04/12] perf tools: Add bpf dso read and size hooks

Jiri Olsa
2019-05-08T13:21:08Z

Adding bpf related code into dso reading paths to return
size (bpf_size) and read the bpf code (bpf_read).

Link: http://lkml.kernel.org/n/tip-ql6jpegvv5823yc87u0hlzfa@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/perf/util/dso.c | 49 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 48 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 1e6a045adb8c..2c9289621efd 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -9,6 +9,8 @@
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
+#include <bpf/libbpf.h>
+#include "bpf-event.h"
#include "compress.h"
#include "namespaces.h"
#include "path.h"
@@ -706,6 +708,44 @@ bool dso__data_status_seen(struct dso *dso, enum dso_data_status_seen by)
return false;
}

+static ssize_t bpf_read(struct dso *dso, u64 offset, char *data)
+{
+ struct bpf_prog_info_node *node;
+ ssize_t size = DSO__DATA_CACHE_SIZE;
+ u64 len;
+ u8 *buf;
+
+ node = perf_env__find_bpf_prog_info(dso->bpf_prog.env, dso->bpf_prog.id);
+ if (!node || !node->info_linear) {
+ dso->data.status = DSO_DATA_STATUS_ERROR;
+ return -1;
+ }
+
+ len = node->info_linear->info.jited_prog_len;
+ buf = (u8 *) node->info_linear->info.jited_prog_insns;
+
+ if (offset >= len)
+ return -1;
+
+ size = (ssize_t) min(len - offset, (u64) size);
+ memcpy(data, buf + offset, size);
+ return size;
+}
+
+static int bpf_size(struct dso *dso)
+{
+ struct bpf_prog_info_node *node;
+
+ node = perf_env__find_bpf_prog_info(dso->bpf_prog.env, dso->bpf_prog.id);
+ if (!node || !node->info_linear) {
+ dso->data.status = DSO_DATA_STATUS_ERROR;
+ return -1;
+ }
+
+ dso->data.file_size = node->info_linear->info.jited_prog_len;
+ return 0;
+}
+
static void
dso_cache__free(struct dso *dso)
{
@@ -832,7 +872,11 @@ dso_cache__read(struct dso *dso, struct machine *machine,
if (!cache)
return -ENOMEM;

- ret = file_read(dso, machine, cache_offset, cache->data);
+ if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO)
+ ret = bpf_read(dso, cache_offset, cache->data);
+ else
+ ret = file_read(dso, machine, cache_offset, cache->data);
+
if (ret > 0) {
cache->offset = cache_offset;
cache->size = ret;
@@ -941,6 +985,9 @@ int dso__data_file_size(struct dso *dso, struct machine *machine)
if (dso->data.status == DSO_DATA_STATUS_ERROR)
return -1;

+ if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO)
+ return bpf_size(dso);
+
return file_size(dso, machine);
}

--
2.20.1