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Message-ID: <20231012035111.676789-40-namhyung@kernel.org>
Date: Wed, 11 Oct 2023 20:51:02 -0700
From: Namhyung Kim <namhyung@...nel.org>
To: Arnaldo Carvalho de Melo <acme@...nel.org>,
Jiri Olsa <jolsa@...nel.org>,
Peter Zijlstra <peterz@...radead.org>
Cc: Ian Rogers <irogers@...gle.com>,
Adrian Hunter <adrian.hunter@...el.com>,
Ingo Molnar <mingo@...nel.org>,
LKML <linux-kernel@...r.kernel.org>,
linux-perf-users@...r.kernel.org,
Linus Torvalds <torvalds@...ux-foundation.org>,
Stephane Eranian <eranian@...gle.com>,
Masami Hiramatsu <mhiramat@...nel.org>,
linux-toolchains@...r.kernel.org, linux-trace-devel@...r.kernel.org
Subject: [PATCH 39/48] perf annotate-data: Maintain variable type info
As it collected basic block and variable information in each scope, it
now can build a state table to find matching variable at the location.
The struct type_state is to keep the type info saved in each register
and stack slot. The update_var_state() updates the table when it finds
variables in the current address. It expects die_collect_vars() filled
a list of variables with type info and starting address.
Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
tools/perf/util/annotate-data.c | 155 ++++++++++++++++++++++++++++++++
tools/perf/util/annotate-data.h | 29 ++++++
tools/perf/util/dwarf-aux.c | 4 +
3 files changed, 188 insertions(+)
diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index 90793cbb6aa0..a88d2cdafa08 100644
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -40,6 +40,57 @@ struct annotated_data_type stackop_type = {
/* Data type collection debug statistics */
struct annotated_data_stat ann_data_stat;
+/* Type information in a register, valid when ok is true */
+struct type_state_reg {
+ Dwarf_Die type;
+ bool ok;
+ bool scratch;
+};
+
+/* Type information in a stack location, dynamically allocated */
+struct type_state_stack {
+ struct list_head list;
+ Dwarf_Die type;
+ int offset;
+ int size;
+ bool compound;
+};
+
+/* FIXME: This should be arch-dependent */
+#define TYPE_STATE_MAX_REGS 16
+
+/*
+ * State table to maintain type info in each register and stack location.
+ * It'll be updated when new variable is allocated or type info is moved
+ * to a new location (register or stack). As it'd be used with the
+ * shortest path of basic blocks, it only maintains a single table.
+ */
+struct type_state {
+ struct type_state_reg regs[TYPE_STATE_MAX_REGS];
+ struct list_head stack_vars;
+};
+
+static bool has_reg_type(struct type_state *state, int reg)
+{
+ return (unsigned)reg < ARRAY_SIZE(state->regs);
+}
+
+void init_type_state(struct type_state *state, struct arch *arch __maybe_unused)
+{
+ memset(state, 0, sizeof(*state));
+ INIT_LIST_HEAD(&state->stack_vars);
+}
+
+void exit_type_state(struct type_state *state)
+{
+ struct type_state_stack *stack, *tmp;
+
+ list_for_each_entry_safe(stack, tmp, &state->stack_vars, list) {
+ list_del(&stack->list);
+ free(stack);
+ }
+}
+
/*
* 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
@@ -255,6 +306,110 @@ static int check_variable(Dwarf_Die *var_die, Dwarf_Die *type_die, int offset,
return 0;
}
+static struct type_state_stack *find_stack_state(struct type_state *state,
+ int offset)
+{
+ struct type_state_stack *stack;
+
+ list_for_each_entry(stack, &state->stack_vars, list) {
+ if (offset == stack->offset)
+ return stack;
+
+ if (stack->compound && stack->offset < offset &&
+ offset < stack->offset + stack->size)
+ return stack;
+ }
+ return NULL;
+}
+
+static void set_stack_state(struct type_state_stack *stack, int offset,
+ Dwarf_Die *type_die)
+{
+ int tag;
+ Dwarf_Word size;
+
+ if (dwarf_aggregate_size(type_die, &size) < 0)
+ size = 0;
+
+ tag = dwarf_tag(type_die);
+
+ stack->type = *type_die;
+ stack->size = size;
+ stack->offset = offset;
+
+ switch (tag) {
+ case DW_TAG_structure_type:
+ case DW_TAG_union_type:
+ stack->compound = true;
+ break;
+ default:
+ stack->compound = false;
+ break;
+ }
+}
+
+static struct type_state_stack *findnew_stack_state(struct type_state *state,
+ int offset, Dwarf_Die *type_die)
+{
+ struct type_state_stack *stack = find_stack_state(state, offset);
+
+ if (stack) {
+ set_stack_state(stack, offset, type_die);
+ return stack;
+ }
+
+ stack = malloc(sizeof(*stack));
+ if (stack) {
+ set_stack_state(stack, offset, type_die);
+ list_add(&stack->list, &state->stack_vars);
+ }
+ return stack;
+}
+
+/**
+ * update_var_state - Update type state using given variables
+ * @state: type state table
+ * @dloc: data location info
+ * @addr: instruction address to update
+ * @var_types: list of variables with type info
+ *
+ * This function fills the @state table using @var_types info. Each variable
+ * is used only at the given location and updates an entry in the table.
+ */
+void update_var_state(struct type_state *state, struct data_loc_info *dloc,
+ u64 addr, struct die_var_type *var_types)
+{
+ Dwarf_Die mem_die;
+ struct die_var_type *var;
+ int fbreg = dloc->fbreg;
+ int fb_offset = 0;
+
+ if (dloc->fb_cfa) {
+ if (die_get_cfa(dloc->di->dbg, addr, &fbreg, &fb_offset) < 0)
+ fbreg = -1;
+ }
+
+ for (var = var_types; var != NULL; var = var->next) {
+ if (var->addr != addr)
+ continue;
+ /* Get the type DIE using the offset */
+ if (!dwarf_offdie(dloc->di->dbg, var->die_off, &mem_die))
+ continue;
+
+ if (var->reg == DWARF_REG_FB) {
+ findnew_stack_state(state, var->offset, &mem_die);
+ } else if (var->reg == fbreg) {
+ findnew_stack_state(state, var->offset - fb_offset, &mem_die);
+ } else if (has_reg_type(state, var->reg)) {
+ struct type_state_reg *reg;
+
+ reg = &state->regs[var->reg];
+ reg->type = mem_die;
+ reg->ok = true;
+ }
+ }
+}
+
/* The result will be saved in @type_die */
static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die)
{
diff --git a/tools/perf/util/annotate-data.h b/tools/perf/util/annotate-data.h
index ad6493ea2c8e..7fbb9eb2e96f 100644
--- a/tools/perf/util/annotate-data.h
+++ b/tools/perf/util/annotate-data.h
@@ -8,9 +8,12 @@
#include <linux/types.h>
struct annotated_op_loc;
+struct arch;
struct debuginfo;
+struct die_var_type;
struct evsel;
struct map_symbol;
+struct type_state;
/**
* struct annotated_member - Type of member field
@@ -146,6 +149,16 @@ int annotated_data_type__update_samples(struct annotated_data_type *adt,
/* Release all data type information in the tree */
void annotated_data_type__tree_delete(struct rb_root *root);
+/* Initialize type state table */
+void init_type_state(struct type_state *state, struct arch *arch);
+
+/* Destroy type state table */
+void exit_type_state(struct type_state *state);
+
+/* Update type state table using variables */
+void update_var_state(struct type_state *state, struct data_loc_info *dloc,
+ u64 addr, struct die_var_type *var_types);
+
#else /* HAVE_DWARF_SUPPORT */
static inline struct annotated_data_type *
@@ -168,6 +181,22 @@ static inline void annotated_data_type__tree_delete(struct rb_root *root __maybe
{
}
+static inline void init_type_state(struct type_state *state __maybe_unused,
+ struct arch *arch __maybe_unused)
+{
+}
+
+static inline void exit_type_state(struct type_state *state __maybe_unused)
+{
+}
+
+static inline void update_var_state(struct type_state *state __maybe_unused,
+ struct data_loc_info *dloc __maybe_unused,
+ u64 addr __maybe_unused,
+ struct die_var_type *var_types __maybe_unused)
+{
+}
+
#endif /* HAVE_DWARF_SUPPORT */
#endif /* _PERF_ANNOTATE_DATA_H */
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index 5ec895e0a069..923e974ad18e 100644
--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -9,6 +9,7 @@
#include <stdlib.h>
#include "debug.h"
#include "dwarf-aux.h"
+#include "dwarf-regs.h"
#include "strbuf.h"
#include "string2.h"
@@ -1490,6 +1491,8 @@ static int reg_from_dwarf_op(Dwarf_Op *op)
case DW_OP_regx:
case DW_OP_bregx:
return op->number;
+ case DW_OP_fbreg:
+ return DWARF_REG_FB;
default:
break;
}
@@ -1503,6 +1506,7 @@ static int offset_from_dwarf_op(Dwarf_Op *op)
case DW_OP_regx:
return 0;
case DW_OP_breg0 ... DW_OP_breg31:
+ case DW_OP_fbreg:
return op->number;
case DW_OP_bregx:
return op->number2;
--
2.42.0.655.g421f12c284-goog
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