From a5367ecb5353fbf28bfd3979fc4f61ddebec80b1 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Mon, 11 Jul 2022 12:32:05 +0300 Subject: 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: Adrian Hunter Cc: Andi Kleen Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: kvm@vger.kernel.org Link: https://lore.kernel.org/r/20220711093218.10967-23-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/data.c | 19 +++++++++++++++++++ tools/perf/util/data.h | 1 + tools/perf/util/machine.h | 1 + tools/perf/util/session.c | 2 ++ tools/perf/util/symbol.c | 6 ++++-- 5 files changed, 27 insertions(+), 2 deletions(-) (limited to 'tools/perf') diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c index 9782ccbe595d..a7f68c309545 100644 --- a/tools/perf/util/data.c +++ b/tools/perf/util/data.c @@ -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; diff --git a/tools/perf/util/data.h b/tools/perf/util/data.h index 7de53d6e2d7f..173132d502f5 100644 --- a/tools/perf/util/data.h +++ b/tools/perf/util/data.h @@ -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 */ diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h index e1476343cbb2..199807ac3c54 100644 --- a/tools/perf/util/machine.h +++ b/tools/perf/util/machine.h @@ -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; diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 7ea0b91013ea..98e16659a149 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -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; } diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index f72baf636724..a4b22caa7c24 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -2300,11 +2300,13 @@ do_kallsyms: 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. -- cgit v1.2.3-59-g8ed1b