1 files changed, 94 insertions, 41 deletions

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index e11ddf86f2b3..0f1b77275a86 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -768,7 +768,7 @@ dso_cache__free(struct dso *dso)
 	pthread_mutex_unlock(&dso->lock);
 }
 
-static struct dso_cache *dso_cache__find(struct dso *dso, u64 offset)
+static struct dso_cache *__dso_cache__find(struct dso *dso, u64 offset)
 {
 	const struct rb_root *root = &dso->data.cache;
 	struct rb_node * const *p = &root->rb_node;
@@ -827,14 +827,16 @@ out:
 	return cache;
 }
 
-static ssize_t
-dso_cache__memcpy(struct dso_cache *cache, u64 offset,
-		  u8 *data, u64 size)
+static ssize_t dso_cache__memcpy(struct dso_cache *cache, u64 offset, u8 *data,
+				 u64 size, bool out)
 {
 	u64 cache_offset = offset - cache->offset;
 	u64 cache_size   = min(cache->size - cache_offset, size);
 
-	memcpy(data, cache->data + cache_offset, cache_size);
+	if (out)
+		memcpy(data, cache->data + cache_offset, cache_size);
+	else
+		memcpy(cache->data + cache_offset, data, cache_size);
 	return cache_size;
 }
 
@@ -863,63 +865,73 @@ out:
 	return ret;
 }
 
-static ssize_t
-dso_cache__read(struct dso *dso, struct machine *machine,
-		u64 offset, u8 *data, ssize_t size)
+static struct dso_cache *dso_cache__populate(struct dso *dso,
+					     struct machine *machine,
+					     u64 offset, ssize_t *ret)
 {
 	u64 cache_offset = offset & DSO__DATA_CACHE_MASK;
 	struct dso_cache *cache;
 	struct dso_cache *old;
-	ssize_t ret;
 
 	cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
-	if (!cache)
-		return -ENOMEM;
+	if (!cache) {
+		*ret = -ENOMEM;
+		return NULL;
+	}
 
 	if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO)
-		ret = bpf_read(dso, cache_offset, cache->data);
+		*ret = bpf_read(dso, cache_offset, cache->data);
 	else
-		ret = file_read(dso, machine, cache_offset, cache->data);
+		*ret = file_read(dso, machine, cache_offset, cache->data);
 
-	if (ret > 0) {
-		cache->offset = cache_offset;
-		cache->size   = ret;
+	if (*ret <= 0) {
+		free(cache);
+		return NULL;
+	}
 
-		old = dso_cache__insert(dso, cache);
-		if (old) {
-			/* we lose the race */
-			free(cache);
-			cache = old;
-		}
+	cache->offset = cache_offset;
+	cache->size   = *ret;
 
-		ret = dso_cache__memcpy(cache, offset, data, size);
+	old = dso_cache__insert(dso, cache);
+	if (old) {
+		/* we lose the race */
+		free(cache);
+		cache = old;
 	}
 
-	if (ret <= 0)
-		free(cache);
+	return cache;
+}
 
-	return ret;
+static struct dso_cache *dso_cache__find(struct dso *dso,
+					 struct machine *machine,
+					 u64 offset,
+					 ssize_t *ret)
+{
+	struct dso_cache *cache = __dso_cache__find(dso, offset);
+
+	return cache ? cache : dso_cache__populate(dso, machine, offset, ret);
 }
 
-static ssize_t dso_cache_read(struct dso *dso, struct machine *machine,
-			      u64 offset, u8 *data, ssize_t size)
+static ssize_t dso_cache_io(struct dso *dso, struct machine *machine,
+			    u64 offset, u8 *data, ssize_t size, bool out)
 {
 	struct dso_cache *cache;
+	ssize_t ret = 0;
 
-	cache = dso_cache__find(dso, offset);
-	if (cache)
-		return dso_cache__memcpy(cache, offset, data, size);
-	else
-		return dso_cache__read(dso, machine, offset, data, size);
+	cache = dso_cache__find(dso, machine, offset, &ret);
+	if (!cache)
+		return ret;
+
+	return dso_cache__memcpy(cache, offset, data, size, out);
 }
 
 /*
  * Reads and caches dso data DSO__DATA_CACHE_SIZE size chunks
  * in the rb_tree. Any read to already cached data is served
- * by cached data.
+ * by cached data. Writes update the cache only, not the backing file.
  */
-static ssize_t cached_read(struct dso *dso, struct machine *machine,
-			   u64 offset, u8 *data, ssize_t size)
+static ssize_t cached_io(struct dso *dso, struct machine *machine,
+			 u64 offset, u8 *data, ssize_t size, bool out)
 {
 	ssize_t r = 0;
 	u8 *p = data;
@@ -927,7 +939,7 @@ static ssize_t cached_read(struct dso *dso, struct machine *machine,
 	do {
 		ssize_t ret;
 
-		ret = dso_cache_read(dso, machine, offset, p, size);
+		ret = dso_cache_io(dso, machine, offset, p, size, out);
 		if (ret < 0)
 			return ret;
 
@@ -1011,8 +1023,9 @@ off_t dso__data_size(struct dso *dso, struct machine *machine)
 	return dso->data.file_size;
 }
 
-static ssize_t data_read_offset(struct dso *dso, struct machine *machine,
-				u64 offset, u8 *data, ssize_t size)
+static ssize_t data_read_write_offset(struct dso *dso, struct machine *machine,
+				      u64 offset, u8 *data, ssize_t size,
+				      bool out)
 {
 	if (dso__data_file_size(dso, machine))
 		return -1;
@@ -1024,7 +1037,7 @@ static ssize_t data_read_offset(struct dso *dso, struct machine *machine,
 	if (offset + size < offset)
 		return -1;
 
-	return cached_read(dso, machine, offset, data, size);
+	return cached_io(dso, machine, offset, data, size, out);
 }
 
 /**
@@ -1044,7 +1057,7 @@ ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
 	if (dso->data.status == DSO_DATA_STATUS_ERROR)
 		return -1;
 
-	return data_read_offset(dso, machine, offset, data, size);
+	return data_read_write_offset(dso, machine, offset, data, size, true);
 }
 
 /**
@@ -1065,6 +1078,46 @@ ssize_t dso__data_read_addr(struct dso *dso, struct map *map,
 	return dso__data_read_offset(dso, machine, offset, data, size);
 }
 
+/**
+ * dso__data_write_cache_offs - Write data to dso data cache at file offset
+ * @dso: dso object
+ * @machine: machine object
+ * @offset: file offset
+ * @data: buffer to write
+ * @size: size of the @data buffer
+ *
+ * Write into the dso file data cache, but do not change the file itself.
+ */
+ssize_t dso__data_write_cache_offs(struct dso *dso, struct machine *machine,
+				   u64 offset, const u8 *data_in, ssize_t size)
+{
+	u8 *data = (u8 *)data_in; /* cast away const to use same fns for r/w */
+
+	if (dso->data.status == DSO_DATA_STATUS_ERROR)
+		return -1;
+
+	return data_read_write_offset(dso, machine, offset, data, size, false);
+}
+
+/**
+ * dso__data_write_cache_addr - Write data to dso data cache at dso address
+ * @dso: dso object
+ * @machine: machine object
+ * @add: virtual memory address
+ * @data: buffer to write
+ * @size: size of the @data buffer
+ *
+ * External interface to write into the dso file data cache, but do not change
+ * the file itself.
+ */
+ssize_t dso__data_write_cache_addr(struct dso *dso, struct map *map,
+				   struct machine *machine, u64 addr,
+				   const u8 *data, ssize_t size)
+{
+	u64 offset = map->map_ip(map, addr);
+	return dso__data_write_cache_offs(dso, machine, offset, data, size);
+}
+
 struct map *dso__new_map(const char *name)
 {
 	struct map *map = NULL;