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-rw-r--r--tools/perf/util/annotate-data.c405
1 files changed, 405 insertions, 0 deletions
diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
new file mode 100644
index 0000000000..f22b4f1827
--- /dev/null
+++ b/tools/perf/util/annotate-data.c
@@ -0,0 +1,405 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Convert sample address to data type using DWARF debug info.
+ *
+ * Written by Namhyung Kim <namhyung@kernel.org>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <inttypes.h>
+
+#include "annotate-data.h"
+#include "debuginfo.h"
+#include "debug.h"
+#include "dso.h"
+#include "evsel.h"
+#include "evlist.h"
+#include "map.h"
+#include "map_symbol.h"
+#include "strbuf.h"
+#include "symbol.h"
+#include "symbol_conf.h"
+
+/*
+ * Compare type name and size to maintain them in a tree.
+ * I'm not sure if DWARF would have information of a single type in many
+ * different places (compilation units). If not, it could compare the
+ * offset of the type entry in the .debug_info section.
+ */
+static int data_type_cmp(const void *_key, const struct rb_node *node)
+{
+ const struct annotated_data_type *key = _key;
+ struct annotated_data_type *type;
+
+ type = rb_entry(node, struct annotated_data_type, node);
+
+ if (key->self.size != type->self.size)
+ return key->self.size - type->self.size;
+ return strcmp(key->self.type_name, type->self.type_name);
+}
+
+static bool data_type_less(struct rb_node *node_a, const struct rb_node *node_b)
+{
+ struct annotated_data_type *a, *b;
+
+ a = rb_entry(node_a, struct annotated_data_type, node);
+ b = rb_entry(node_b, struct annotated_data_type, node);
+
+ if (a->self.size != b->self.size)
+ return a->self.size < b->self.size;
+ return strcmp(a->self.type_name, b->self.type_name) < 0;
+}
+
+/* Recursively add new members for struct/union */
+static int __add_member_cb(Dwarf_Die *die, void *arg)
+{
+ struct annotated_member *parent = arg;
+ struct annotated_member *member;
+ Dwarf_Die member_type, die_mem;
+ Dwarf_Word size, loc;
+ Dwarf_Attribute attr;
+ struct strbuf sb;
+ int tag;
+
+ if (dwarf_tag(die) != DW_TAG_member)
+ return DIE_FIND_CB_SIBLING;
+
+ member = zalloc(sizeof(*member));
+ if (member == NULL)
+ return DIE_FIND_CB_END;
+
+ strbuf_init(&sb, 32);
+ die_get_typename(die, &sb);
+
+ die_get_real_type(die, &member_type);
+ if (dwarf_aggregate_size(&member_type, &size) < 0)
+ size = 0;
+
+ if (!dwarf_attr_integrate(die, DW_AT_data_member_location, &attr))
+ loc = 0;
+ else
+ dwarf_formudata(&attr, &loc);
+
+ member->type_name = strbuf_detach(&sb, NULL);
+ /* member->var_name can be NULL */
+ if (dwarf_diename(die))
+ member->var_name = strdup(dwarf_diename(die));
+ member->size = size;
+ member->offset = loc + parent->offset;
+ INIT_LIST_HEAD(&member->children);
+ list_add_tail(&member->node, &parent->children);
+
+ tag = dwarf_tag(&member_type);
+ switch (tag) {
+ case DW_TAG_structure_type:
+ case DW_TAG_union_type:
+ die_find_child(&member_type, __add_member_cb, member, &die_mem);
+ break;
+ default:
+ break;
+ }
+ return DIE_FIND_CB_SIBLING;
+}
+
+static void add_member_types(struct annotated_data_type *parent, Dwarf_Die *type)
+{
+ Dwarf_Die die_mem;
+
+ die_find_child(type, __add_member_cb, &parent->self, &die_mem);
+}
+
+static void delete_members(struct annotated_member *member)
+{
+ struct annotated_member *child, *tmp;
+
+ list_for_each_entry_safe(child, tmp, &member->children, node) {
+ list_del(&child->node);
+ delete_members(child);
+ free(child->type_name);
+ free(child->var_name);
+ free(child);
+ }
+}
+
+static struct annotated_data_type *dso__findnew_data_type(struct dso *dso,
+ Dwarf_Die *type_die)
+{
+ struct annotated_data_type *result = NULL;
+ struct annotated_data_type key;
+ struct rb_node *node;
+ struct strbuf sb;
+ char *type_name;
+ Dwarf_Word size;
+
+ strbuf_init(&sb, 32);
+ if (die_get_typename_from_type(type_die, &sb) < 0)
+ strbuf_add(&sb, "(unknown type)", 14);
+ type_name = strbuf_detach(&sb, NULL);
+ dwarf_aggregate_size(type_die, &size);
+
+ /* Check existing nodes in dso->data_types tree */
+ key.self.type_name = type_name;
+ key.self.size = size;
+ node = rb_find(&key, &dso->data_types, data_type_cmp);
+ if (node) {
+ result = rb_entry(node, struct annotated_data_type, node);
+ free(type_name);
+ return result;
+ }
+
+ /* If not, add a new one */
+ result = zalloc(sizeof(*result));
+ if (result == NULL) {
+ free(type_name);
+ return NULL;
+ }
+
+ result->self.type_name = type_name;
+ result->self.size = size;
+ INIT_LIST_HEAD(&result->self.children);
+
+ if (symbol_conf.annotate_data_member)
+ add_member_types(result, type_die);
+
+ rb_add(&result->node, &dso->data_types, data_type_less);
+ return result;
+}
+
+static bool find_cu_die(struct debuginfo *di, u64 pc, Dwarf_Die *cu_die)
+{
+ Dwarf_Off off, next_off;
+ size_t header_size;
+
+ if (dwarf_addrdie(di->dbg, pc, cu_die) != NULL)
+ return cu_die;
+
+ /*
+ * There are some kernels don't have full aranges and contain only a few
+ * aranges entries. Fallback to iterate all CU entries in .debug_info
+ * in case it's missing.
+ */
+ off = 0;
+ while (dwarf_nextcu(di->dbg, off, &next_off, &header_size,
+ NULL, NULL, NULL) == 0) {
+ if (dwarf_offdie(di->dbg, off + header_size, cu_die) &&
+ dwarf_haspc(cu_die, pc))
+ return true;
+
+ off = next_off;
+ }
+ return false;
+}
+
+/* The type info will be saved in @type_die */
+static int check_variable(Dwarf_Die *var_die, Dwarf_Die *type_die, int offset)
+{
+ Dwarf_Word size;
+
+ /* Get the type of the variable */
+ if (die_get_real_type(var_die, type_die) == NULL) {
+ pr_debug("variable has no type\n");
+ ann_data_stat.no_typeinfo++;
+ return -1;
+ }
+
+ /*
+ * It expects a pointer type for a memory access.
+ * Convert to a real type it points to.
+ */
+ if (dwarf_tag(type_die) != DW_TAG_pointer_type ||
+ die_get_real_type(type_die, type_die) == NULL) {
+ pr_debug("no pointer or no type\n");
+ ann_data_stat.no_typeinfo++;
+ return -1;
+ }
+
+ /* Get the size of the actual type */
+ if (dwarf_aggregate_size(type_die, &size) < 0) {
+ pr_debug("type size is unknown\n");
+ ann_data_stat.invalid_size++;
+ return -1;
+ }
+
+ /* Minimal sanity check */
+ if ((unsigned)offset >= size) {
+ pr_debug("offset: %d is bigger than size: %" PRIu64 "\n", offset, size);
+ ann_data_stat.bad_offset++;
+ return -1;
+ }
+
+ return 0;
+}
+
+/* The result will be saved in @type_die */
+static int find_data_type_die(struct debuginfo *di, u64 pc,
+ int reg, int offset, Dwarf_Die *type_die)
+{
+ Dwarf_Die cu_die, var_die;
+ Dwarf_Die *scopes = NULL;
+ int ret = -1;
+ int i, nr_scopes;
+
+ /* Get a compile_unit for this address */
+ if (!find_cu_die(di, pc, &cu_die)) {
+ pr_debug("cannot find CU for address %" PRIx64 "\n", pc);
+ ann_data_stat.no_cuinfo++;
+ return -1;
+ }
+
+ /* Get a list of nested scopes - i.e. (inlined) functions and blocks. */
+ nr_scopes = die_get_scopes(&cu_die, pc, &scopes);
+
+ /* Search from the inner-most scope to the outer */
+ for (i = nr_scopes - 1; i >= 0; i--) {
+ /* Look up variables/parameters in this scope */
+ if (!die_find_variable_by_reg(&scopes[i], pc, reg, &var_die))
+ continue;
+
+ /* Found a variable, see if it's correct */
+ ret = check_variable(&var_die, type_die, offset);
+ goto out;
+ }
+ if (ret < 0)
+ ann_data_stat.no_var++;
+
+out:
+ free(scopes);
+ return ret;
+}
+
+/**
+ * find_data_type - Return a data type at the location
+ * @ms: map and symbol at the location
+ * @ip: instruction address of the memory access
+ * @reg: register that holds the base address
+ * @offset: offset from the base address
+ *
+ * This functions searches the debug information of the binary to get the data
+ * type it accesses. The exact location is expressed by (ip, reg, offset).
+ * It return %NULL if not found.
+ */
+struct annotated_data_type *find_data_type(struct map_symbol *ms, u64 ip,
+ int reg, int offset)
+{
+ struct annotated_data_type *result = NULL;
+ struct dso *dso = map__dso(ms->map);
+ struct debuginfo *di;
+ Dwarf_Die type_die;
+ u64 pc;
+
+ di = debuginfo__new(dso->long_name);
+ if (di == NULL) {
+ pr_debug("cannot get the debug info\n");
+ return NULL;
+ }
+
+ /*
+ * IP is a relative instruction address from the start of the map, as
+ * it can be randomized/relocated, it needs to translate to PC which is
+ * a file address for DWARF processing.
+ */
+ pc = map__rip_2objdump(ms->map, ip);
+ if (find_data_type_die(di, pc, reg, offset, &type_die) < 0)
+ goto out;
+
+ result = dso__findnew_data_type(dso, &type_die);
+
+out:
+ debuginfo__delete(di);
+ return result;
+}
+
+static int alloc_data_type_histograms(struct annotated_data_type *adt, int nr_entries)
+{
+ int i;
+ size_t sz = sizeof(struct type_hist);
+
+ sz += sizeof(struct type_hist_entry) * adt->self.size;
+
+ /* Allocate a table of pointers for each event */
+ adt->nr_histograms = nr_entries;
+ adt->histograms = calloc(nr_entries, sizeof(*adt->histograms));
+ if (adt->histograms == NULL)
+ return -ENOMEM;
+
+ /*
+ * Each histogram is allocated for the whole size of the type.
+ * TODO: Probably we can move the histogram to members.
+ */
+ for (i = 0; i < nr_entries; i++) {
+ adt->histograms[i] = zalloc(sz);
+ if (adt->histograms[i] == NULL)
+ goto err;
+ }
+ return 0;
+
+err:
+ while (--i >= 0)
+ free(adt->histograms[i]);
+ free(adt->histograms);
+ return -ENOMEM;
+}
+
+static void delete_data_type_histograms(struct annotated_data_type *adt)
+{
+ for (int i = 0; i < adt->nr_histograms; i++)
+ free(adt->histograms[i]);
+ free(adt->histograms);
+}
+
+void annotated_data_type__tree_delete(struct rb_root *root)
+{
+ struct annotated_data_type *pos;
+
+ while (!RB_EMPTY_ROOT(root)) {
+ struct rb_node *node = rb_first(root);
+
+ rb_erase(node, root);
+ pos = rb_entry(node, struct annotated_data_type, node);
+ delete_members(&pos->self);
+ delete_data_type_histograms(pos);
+ free(pos->self.type_name);
+ free(pos);
+ }
+}
+
+/**
+ * annotated_data_type__update_samples - Update histogram
+ * @adt: Data type to update
+ * @evsel: Event to update
+ * @offset: Offset in the type
+ * @nr_samples: Number of samples at this offset
+ * @period: Event count at this offset
+ *
+ * This function updates type histogram at @ofs for @evsel. Samples are
+ * aggregated before calling this function so it can be called with more
+ * than one samples at a certain offset.
+ */
+int annotated_data_type__update_samples(struct annotated_data_type *adt,
+ struct evsel *evsel, int offset,
+ int nr_samples, u64 period)
+{
+ struct type_hist *h;
+
+ if (adt == NULL)
+ return 0;
+
+ if (adt->histograms == NULL) {
+ int nr = evsel->evlist->core.nr_entries;
+
+ if (alloc_data_type_histograms(adt, nr) < 0)
+ return -1;
+ }
+
+ if (offset < 0 || offset >= adt->self.size)
+ return -1;
+
+ h = adt->histograms[evsel->core.idx];
+
+ h->nr_samples += nr_samples;
+ h->addr[offset].nr_samples += nr_samples;
+ h->period += period;
+ h->addr[offset].period += period;
+ return 0;
+}