iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

perf annotate-data: Handle call instructions

Browse Source 
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@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240319055115.4063940-14-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2024-03-18 22:51:05 -07:00 committed by Arnaldo Carvalho de Melo
parent 0a41e5d684
commit cffb7910af
1 changed files with 52 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
tools/perf/util/annotate-data.c
View File

@ -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;