Commit a5367ecb authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf tools: Automatically use guest kcore_dir if present 



When registering a guest machine using machine_pid from the id index,
check perf.data for a matching kcore_dir subdirectory and set the
kallsyms file name accordingly. If set, use it to find the machine's
kernel symbols and object code (from kcore).

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20220711093218.10967-23-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 65691e9f

tools/perf/util/data.c

+19 −0
Original line number Diff line number Diff line
@@ -518,6 +518,25 @@ char *perf_data__kallsyms_name(struct perf_data *data) 
	return kallsyms_name;

}



char *perf_data__guest_kallsyms_name(struct perf_data *data, pid_t machine_pid)

{

	char *kallsyms_name;

	struct stat st;



	if (!data->is_dir)

		return NULL;



	if (asprintf(&kallsyms_name, "%s/kcore_dir__%d/kallsyms", data->path, machine_pid) < 0)

		return NULL;



	if (stat(kallsyms_name, &st)) {

		free(kallsyms_name);

		return NULL;

	}



	return kallsyms_name;

}



bool is_perf_data(const char *path)

{

	bool ret = false;

tools/perf/util/data.h

+1 −0
Original line number Diff line number Diff line
@@ -101,5 +101,6 @@ unsigned long perf_data__size(struct perf_data *data); 
int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz);

bool has_kcore_dir(const char *path);

char *perf_data__kallsyms_name(struct perf_data *data);

char *perf_data__guest_kallsyms_name(struct perf_data *data, pid_t machine_pid);

bool is_perf_data(const char *path);

#endif /* __PERF_DATA_H */

tools/perf/util/machine.h

+1 −0
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ struct machine { 
	bool		  single_address_space;

	char		  *root_dir;

	char		  *mmap_name;

	char		  *kallsyms_filename;

	struct threads    threads[THREADS__TABLE_SIZE];

	struct vdso_info  *vdso_info;

	struct perf_env   *env;

tools/perf/util/session.c

+2 −0
Original line number Diff line number Diff line
@@ -2772,6 +2772,8 @@ static int perf_session__register_guest(struct perf_session *session, pid_t mach 
		return -ENOMEM;

	thread__put(thread);



	machine->kallsyms_filename = perf_data__guest_kallsyms_name(session->data, machine_pid);



	return 0;

}

tools/perf/util/symbol.c

+4 −2
Original line number Diff line number Diff line
@@ -2300,11 +2300,13 @@ static int dso__load_kernel_sym(struct dso *dso, struct map *map) 
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)

{

	int err;

	const char *kallsyms_filename = NULL;

	const char *kallsyms_filename;

	struct machine *machine = map__kmaps(map)->machine;

	char path[PATH_MAX];



	if (machine__is_default_guest(machine)) {

	if (machine->kallsyms_filename) {

		kallsyms_filename = machine->kallsyms_filename;

	} else if (machine__is_default_guest(machine)) {

		/*

		 * if the user specified a vmlinux filename, use it and only

		 * it, reporting errors to the user if it cannot be used.