When updating instruction states, the call instruction should play a
role since it changes the register states. For simplicity, mark some
registers as caller-saved registers (should be arch-dependent), and
invalidate them all after a function call.
If the function returns something, the designated register (ret_reg)
will have the type info.
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/annotate-data.c | 54 +++++++++++++++++++++++++++++++--
1 file changed, 52 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index 2cc9f56e3eea..6bcf22e523cb 100644
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -47,10 +47,14 @@ static void pr_debug_type_name(Dwarf_Die *die)
free(str);
}
-/* Type information in a register, valid when ok is true */
+/*
+ * Type information in a register, valid when @ok is true.
+ * The @caller_saved registers are invalidated after a function call.
+ */
struct type_state_reg {
Dwarf_Die type;
bool ok;
+ bool caller_saved;
};
/* Type information in a stack location, dynamically allocated */
@@ -76,6 +80,8 @@ struct type_state {
struct type_state_reg regs[TYPE_STATE_MAX_REGS];
/* state of stack location */
struct list_head stack_vars;
+ /* return value register */
+ int ret_reg;
};
static bool has_reg_type(struct type_state *state, int reg)
@@ -91,10 +97,23 @@ void update_var_state(struct type_state *state, struct data_loc_info *dloc,
void update_insn_state(struct type_state *state, struct data_loc_info *dloc,
Dwarf_Die *cu_die, struct disasm_line *dl);
-void init_type_state(struct type_state *state, struct arch *arch __maybe_unused)
+void init_type_state(struct type_state *state, struct arch *arch)
{
memset(state, 0, sizeof(*state));
INIT_LIST_HEAD(&state->stack_vars);
+
+ if (arch__is(arch, "x86")) {
+ state->regs[0].caller_saved = true;
+ state->regs[1].caller_saved = true;
+ state->regs[2].caller_saved = true;
+ state->regs[4].caller_saved = true;
+ state->regs[5].caller_saved = true;
+ state->regs[8].caller_saved = true;
+ state->regs[9].caller_saved = true;
+ state->regs[10].caller_saved = true;
+ state->regs[11].caller_saved = true;
+ state->ret_reg = 0;
+ }
}
void exit_type_state(struct type_state *state)
@@ -500,6 +519,37 @@ static void update_insn_state_x86(struct type_state *state,
if (annotate_get_insn_location(dloc->arch, dl, &loc) < 0)
return;
+ if (ins__is_call(&dl->ins)) {
+ struct symbol *func = dl->ops.target.sym;
+
+ if (func == NULL)
+ return;
+
+ /* __fentry__ will preserve all registers */
+ if (!strcmp(func->name, "__fentry__"))
+ return;
+
+ pr_debug_dtp("call [%x] %s\n", insn_offset, func->name);
+
+ /* Otherwise invalidate caller-saved registers after call */
+ for (unsigned i = 0; i < ARRAY_SIZE(state->regs); i++) {
+ if (state->regs[i].caller_saved)
+ state->regs[i].ok = false;
+ }
+
+ /* Update register with the return type (if any) */
+ if (die_find_func_rettype(cu_die, func->name, &type_die)) {
+ tsr = &state->regs[state->ret_reg];
+ tsr->type = type_die;
+ tsr->ok = true;
+
+ pr_debug_dtp("call [%x] return -> reg%d",
+ insn_offset, state->ret_reg);
+ pr_debug_type_name(&type_die);
+ }
+ return;
+ }
+
if (strncmp(dl->ins.name, "mov", 3))
return;
--
2.44.0.291.gc1ea87d7ee-goog
|