[PATCH v6 4/5] perf callchain: Refactor callchain option parsing

Ian Rogers
2026-03-17T17:56:56Z

record_opts__parse_callchain is shared by builtin-record and
builtin-trace, it is declared in callchain.h. Move the declaration to
callchain.c for consistency with the header. In other cases make the
option callback a small static stub that then calls into callchain.c.

Make the no argument '-g' callchain option just a short-cut for
'--call-graph fp' so that there is consistency in how the arguments
are handled. This requires the const char* string to be strdup-ed in
__parse_callchain_report_opt. For consistency also make
parse_callchain_record use strdup and remove some unnecessary
casts. Also, be more explicit with comments about the '-g' behavior if
there is a .perfconfig file setting.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/builtin-record.c | 60 +++++-------------------------
tools/perf/builtin-top.c | 20 ++++++----
tools/perf/builtin-trace.c | 9 ++++-
tools/perf/util/callchain.c | 73 ++++++++++++++++++++++++++++++-------
tools/perf/util/callchain.h | 12 ++----
5 files changed, 94 insertions(+), 80 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 40917a0be238..26223f9505c2 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -2975,65 +2975,25 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
return status;
}

-static void callchain_debug(struct callchain_param *callchain)
-{
- static const char *str[CALLCHAIN_MAX] = { "NONE", "FP", "DWARF", "LBR" };
-
- pr_debug("callchain: type %s\n", str[callchain->record_mode]);
-
- if (callchain->record_mode == CALLCHAIN_DWARF)
- pr_debug("callchain: stack dump size %d\n",
- callchain->dump_size);
-}
-
-int record_opts__parse_callchain(struct record_opts *record,
- struct callchain_param *callchain,
- const char *arg, bool unset)
-{
- int ret;
- callchain->enabled = !unset;
-
- /* --no-call-graph */
- if (unset) {
- callchain->record_mode = CALLCHAIN_NONE;
- pr_debug("callchain: disabled\n");
- return 0;
- }
-
- ret = parse_callchain_record_opt(arg, callchain);
- if (!ret) {
- /* Enable data address sampling for DWARF unwind. */
- if (callchain->record_mode == CALLCHAIN_DWARF &&
- !record->record_data_mmap_set)
- record->record_data_mmap = true;
- callchain_debug(callchain);
- }
-
- return ret;
-}
-
-int record_parse_callchain_opt(const struct option *opt,
+static int record_parse_callchain_opt(const struct option *opt,
const char *arg,
int unset)
{
return record_opts__parse_callchain(opt->value, &callchain_param, arg, unset);
}

-int record_callchain_opt(const struct option *opt,
- const char *arg __maybe_unused,
- int unset __maybe_unused)
+static int record_callchain_opt(const struct option *opt,
+ const char *arg __maybe_unused,
+ int unset)
{
- struct callchain_param *callchain = opt->value;
-
- callchain->enabled = true;
-
- if (callchain->record_mode == CALLCHAIN_NONE)
- callchain->record_mode = CALLCHAIN_FP;
+ /* The -g option only sets the callchain if not already configure by .perfconfig. */
+ if (callchain_param.record_mode != CALLCHAIN_NONE)
+ return 0;

- callchain_debug(callchain);
- return 0;
+ return record_opts__parse_callchain(opt->value, &callchain_param, "fp", unset);
}

+
static int perf_record_config(const char *var, const char *value, void *cb)
{
struct record *rec = cb;
@@ -3525,7 +3485,7 @@ static struct option __record_options[] = {
OPT_CALLBACK(0, "mmap-flush", &record.opts, "number",
"Minimal number of bytes that is extracted from mmap data pages (default: 1)",
record__mmap_flush_parse),
- OPT_CALLBACK_NOOPT('g', NULL, &callchain_param,
+ OPT_CALLBACK_NOOPT('g', NULL, &record.opts,
NULL, "enables call-graph recording" ,
&record_callchain_opt),
OPT_CALLBACK(0, "call-graph", &record.opts,
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 710604c4f6f6..5d2587228975 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1386,13 +1386,6 @@ static int __cmd_top(struct perf_top *top)
return ret;
}

-static int
-callchain_opt(const struct option *opt, const char *arg, int unset)
-{
- symbol_conf.use_callchain = true;
- return record_callchain_opt(opt, arg, unset);
-}
-
static int
parse_callchain_opt(const struct option *opt, const char *arg, int unset)
{
@@ -1413,6 +1406,19 @@ parse_callchain_opt(const struct option *opt, const char *arg, int unset)
return parse_callchain_top_opt(arg);
}

+static int
+callchain_opt(const struct option *opt, const char *arg __maybe_unused, int unset)
+{
+ struct callchain_param *callchain = opt->value;
+
+ /* The -g option only sets the callchain if not already configure by .perfconfig. */
+ if (callchain->record_mode != CALLCHAIN_NONE)
+ return 0;
+
+ return parse_callchain_opt(opt, "fp", unset);
+}
+
+
static int perf_top_config(const char *var, const char *value, void *cb __maybe_unused)
{
if (!strcmp(var, "top.call-graph")) {
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 1c38f3d16a31..f487fbaa0ad6 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -5300,6 +5300,13 @@ static int trace__parse_summary_mode(const struct option *opt, const char *str,
return 0;
}

+static int trace_parse_callchain_opt(const struct option *opt,
+ const char *arg,
+ int unset)
+{
+ return record_opts__parse_callchain(opt->value, &callchain_param, arg, unset);
+}
+
static int trace__config(const char *var, const char *value, void *arg)
{
struct trace *trace = arg;
@@ -5447,7 +5454,7 @@ int cmd_trace(int argc, const char **argv)
OPT_BOOLEAN('f', "force", &trace.force, "don't complain, do it"),
OPT_CALLBACK(0, "call-graph", &trace.opts,
"record_mode[,record_size]", record_callchain_help,
- &record_parse_callchain_opt),
+ &trace_parse_callchain_opt),
OPT_BOOLEAN(0, "libtraceevent_print", &trace.libtraceevent_print,
"Use libtraceevent to print the tracepoint arguments."),
OPT_BOOLEAN(0, "kernel-syscall-graph", &trace.kernel_syscallchains,
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 8ff0898799ee..f879b84f8ff9 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -30,6 +30,7 @@
#include "map.h"
#include "callchain.h"
#include "branch.h"
+#include "record.h"
#include "symbol.h"
#include "thread.h"
#include "util.h"
@@ -170,7 +171,7 @@ static int get_stack_size(const char *str, unsigned long *_size)
static int
__parse_callchain_report_opt(const char *arg, bool allow_record_opt)
{
- char *tok;
+ char *tok, *arg_copy;
char *endptr, *saveptr = NULL;
bool minpcnt_set = false;
bool record_opt_set = false;
@@ -182,12 +183,17 @@ __parse_callchain_report_opt(const char *arg, bool allow_record_opt)
if (!arg)
return 0;

- while ((tok = strtok_r((char *)arg, ",", &saveptr)) != NULL) {
+ arg_copy = strdup(arg);
+ if (!arg_copy)
+ return -ENOMEM;
+
+ tok = strtok_r(arg_copy, ",", &saveptr);
+ while (tok) {
if (!strncmp(tok, "none", strlen(tok))) {
callchain_param.mode = CHAIN_NONE;
callchain_param.enabled = false;
symbol_conf.use_callchain = false;
- return 0;
+ goto out;
}

if (!parse_callchain_mode(tok) ||
@@ -214,30 +220,35 @@ __parse_callchain_report_opt(const char *arg, bool allow_record_opt)
unsigned long size = 0;

if (get_stack_size(tok, &size) < 0)
- return -1;
+ goto err_out;
callchain_param.dump_size = size;
try_stack_size = false;
} else if (!minpcnt_set) {
/* try to get the min percent */
callchain_param.min_percent = strtod(tok, &endptr);
if (tok == endptr)
- return -1;
+ goto err_out;
minpcnt_set = true;
} else {
/* try print limit at last */
callchain_param.print_limit = strtoul(tok, &endptr, 0);
if (tok == endptr)
- return -1;
+ goto err_out;
}
next:
- arg = NULL;
+ tok = strtok_r(NULL, ",", &saveptr);
}

if (callchain_register_param(&callchain_param) < 0) {
pr_err("Can't register callchain params\n");
- return -1;
+ goto err_out;
}
+out:
+ free(arg_copy);
return 0;
+err_out:
+ free(arg_copy);
+ return -1;
}

int parse_callchain_report_opt(const char *arg)
@@ -257,14 +268,12 @@ int parse_callchain_record(const char *arg, struct callchain_param *param)
int ret = -1;

/* We need buffer that we know we can write to. */
- buf = malloc(strlen(arg) + 1);
+ buf = strdup(arg);
if (!buf)
return -ENOMEM;

- strcpy(buf, arg);
-
- tok = strtok_r((char *)buf, ",", &saveptr);
- name = tok ? : (char *)buf;
+ tok = strtok_r(buf, ",", &saveptr);
+ name = tok ? : buf;

do {
/* Framepointer style */
@@ -328,6 +337,44 @@ int parse_callchain_record(const char *arg, struct callchain_param *param)
return ret;
}

+static void callchain_debug(const struct callchain_param *callchain)
+{
+ static const char *str[CALLCHAIN_MAX] = { "NONE", "FP", "DWARF", "LBR" };
+
+ pr_debug("callchain: type %s\n", str[callchain->record_mode]);
+
+ if (callchain->record_mode == CALLCHAIN_DWARF)
+ pr_debug("callchain: stack dump size %d\n",
+ callchain->dump_size);
+}
+
+int record_opts__parse_callchain(struct record_opts *record,
+ struct callchain_param *callchain,
+ const char *arg, bool unset)
+{
+ int ret;
+
+ callchain->enabled = !unset;
+
+ /* --no-call-graph */
+ if (unset) {
+ callchain->record_mode = CALLCHAIN_NONE;
+ pr_debug("callchain: disabled\n");
+ return 0;
+ }
+
+ ret = parse_callchain_record_opt(arg, callchain);
+ if (!ret) {
+ /* Enable data address sampling for DWARF unwind. */
+ if (callchain->record_mode == CALLCHAIN_DWARF &&
+ !record->record_data_mmap_set)
+ record->record_data_mmap = true;
+ callchain_debug(callchain);
+ }
+
+ return ret;
+}
+
int perf_callchain_config(const char *var, const char *value)
{
char *endptr;
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index df54ddb8c0cb..06d463ccc7a0 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -9,11 +9,13 @@

struct addr_location;
struct evsel;
+struct hist_entry;
+struct hists;
struct ip_callchain;
struct map;
struct perf_sample;
+struct record_opts;
struct thread;
-struct hists;

#define HELP_PAD "\t\t\t\t"

@@ -237,14 +239,6 @@ struct callchain_cursor *get_tls_callchain_cursor(void);
int callchain_cursor__copy(struct callchain_cursor *dst,
struct callchain_cursor *src);

-struct option;
-struct hist_entry;
-
-int record_parse_callchain_opt(const struct option *opt, const char *arg, int unset);
-int record_callchain_opt(const struct option *opt, const char *arg, int unset);
-
-struct record_opts;
-
int record_opts__parse_callchain(struct record_opts *record,
struct callchain_param *callchain,
const char *arg, bool unset);
--
2.53.0.851.ga537e3e6e9-goog