[PATCH RFC 08/11] perf dlfilter: Add insn() to perf_dlfilter_fns

From: Adrian Hunter
Date: Mon Jun 21 2021 - 11:05:41 EST


Add a function, for use by dlfilters, to return instruction bytes.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/Documentation/perf-dlfilter.txt | 5 +++-
tools/perf/util/dlfilter.c | 32 ++++++++++++++++++++++
tools/perf/util/perf_dlfilter.h | 4 ++-
3 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Documentation/perf-dlfilter.txt b/tools/perf/Documentation/perf-dlfilter.txt
index c3fe3bc02819..5ed64bbf084e 100644
--- a/tools/perf/Documentation/perf-dlfilter.txt
+++ b/tools/perf/Documentation/perf-dlfilter.txt
@@ -110,7 +110,8 @@ struct perf_dlfilter_fns {
const struct perf_dlfilter_al *(*resolve_ip)(void *ctx);
const struct perf_dlfilter_al *(*resolve_addr)(void *ctx);
__s32 (*resolve_address)(void *ctx, __u64 address, struct perf_dlfilter_al *al);
- void *(*reserved[125])(void *);
+ const __u8 *(*insn)(void *ctx, __u32 *length);
+ void *(*reserved[124])(void *);
};
----

@@ -121,6 +122,8 @@ struct perf_dlfilter_fns {
'resolve_address' provides information about 'address'. al->size must be set
before calling. Returns 0 on success, -1 otherwise.

+'insn' returns instruction bytes and length.
+
The perf_dlfilter_al structure
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

diff --git a/tools/perf/util/dlfilter.c b/tools/perf/util/dlfilter.c
index 3b29bf9f2bd3..375fb01bdeb8 100644
--- a/tools/perf/util/dlfilter.c
+++ b/tools/perf/util/dlfilter.c
@@ -15,6 +15,7 @@
#include "dso.h"
#include "map.h"
#include "thread.h"
+#include "trace-event.h"
#include "symbol.h"
#include "dlfilter.h"
#include "perf_dlfilter.h"
@@ -159,10 +160,41 @@ static __s32 dlfilter__resolve_address(void *ctx, __u64 address, struct perf_dlf
return 0;
}

+static const __u8 *dlfilter__insn(void *ctx, __u32 *len)
+{
+ struct dlfilter *d = (struct dlfilter *)ctx;
+
+ if (!len)
+ return NULL;
+
+ *len = 0;
+
+ if (!d->ctx_valid)
+ return NULL;
+
+ if (d->sample->ip && !d->sample->insn_len) {
+ struct addr_location *al = d->al;
+
+ if (!al->thread && machine__resolve(d->machine, al, d->sample) < 0)
+ return NULL;
+
+ if (al->thread->maps && al->thread->maps->machine)
+ script_fetch_insn(d->sample, al->thread, al->thread->maps->machine);
+ }
+
+ if (!d->sample->insn_len)
+ return NULL;
+
+ *len = d->sample->insn_len;
+
+ return (__u8 *)d->sample->insn;
+}
+
static const struct perf_dlfilter_fns perf_dlfilter_fns = {
.resolve_ip = dlfilter__resolve_ip,
.resolve_addr = dlfilter__resolve_addr,
.resolve_address = dlfilter__resolve_address,
+ .insn = dlfilter__insn,
};

#define CHECK_FLAG(x) BUILD_BUG_ON((u64)PERF_DLFILTER_FLAG_ ## x != (u64)PERF_IP_FLAG_ ## x)
diff --git a/tools/perf/util/perf_dlfilter.h b/tools/perf/util/perf_dlfilter.h
index 97bceb625b54..913b773af268 100644
--- a/tools/perf/util/perf_dlfilter.h
+++ b/tools/perf/util/perf_dlfilter.h
@@ -95,8 +95,10 @@ struct perf_dlfilter_fns {
* calling). Returns 0 on success, -1 otherwise.
*/
__s32 (*resolve_address)(void *ctx, __u64 address, struct perf_dlfilter_al *al);
+ /* Return instruction bytes and length */
+ const __u8 *(*insn)(void *ctx, __u32 *length);
/* Reserved */
- void *(*reserved[125])(void *);
+ void *(*reserved[124])(void *);
};

/*
--
2.17.1