From 419e87382873b11b17cb31e2f21859570a32e0d1 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 27 May 2015 17:37:18 +0900 Subject: [PATCH] perf probe: Show the error reason comes from invalid DSO Show the reason of error when dso__load* fails. This shows when user gives wrong kernel image or wrong path. Without this, perf probe shows an obscure message: ---- $ perf probe -k ~/kbin/linux-3.x86_64/vmlinux -L vfs_read Failed to find path of kernel module. Error: Failed to show lines. ---- With this, perf shows appropriate error message: ---- $ perf probe -k ~/kbin/linux-3.x86_64/vmlinux -L vfs_read Failed to find the path for kernel: Mismatching build id Error: Failed to show lines. ---- And: ---- $ perf probe -k /non-exist/kernel/vmlinux -L vfs_read Failed to find the path for kernel: No such file or directory Error: Failed to show lines. ---- Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Richard Weinberger Link: http://lkml.kernel.org/r/20150527083718.23880.84100.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 47 ++++++++++++++++++----------------- tools/perf/util/probe-event.h | 3 --- 2 files changed, 24 insertions(+), 26 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 092256516262..f5be411bc69c 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -200,11 +200,12 @@ static void put_target_map(struct map *map, bool user) } -static struct dso *kernel_get_module_dso(const char *module) +static int kernel_get_module_dso(const char *module, struct dso **pdso) { struct dso *dso; struct map *map; const char *vmlinux_name; + int ret = 0; if (module) { list_for_each_entry(dso, &host_machine->kernel_dsos.head, @@ -214,30 +215,21 @@ static struct dso *kernel_get_module_dso(const char *module) goto found; } pr_debug("Failed to find module %s.\n", module); - return NULL; + return -ENOENT; } map = host_machine->vmlinux_maps[MAP__FUNCTION]; dso = map->dso; vmlinux_name = symbol_conf.vmlinux_name; - if (vmlinux_name) { - if (dso__load_vmlinux(dso, map, vmlinux_name, false, NULL) <= 0) - return NULL; - } else { - if (dso__load_vmlinux_path(dso, map, NULL) <= 0) { - pr_debug("Failed to load kernel map.\n"); - return NULL; - } - } + dso->load_errno = 0; + if (vmlinux_name) + ret = dso__load_vmlinux(dso, map, vmlinux_name, false, NULL); + else + ret = dso__load_vmlinux_path(dso, map, NULL); found: - return dso; -} - -const char *kernel_get_module_path(const char *module) -{ - struct dso *dso = kernel_get_module_dso(module); - return (dso) ? dso->long_name : NULL; + *pdso = dso; + return ret; } static int convert_exec_to_group(const char *exec, char **result) @@ -389,16 +381,25 @@ static int get_alternative_line_range(struct debuginfo *dinfo, static struct debuginfo *open_debuginfo(const char *module, bool silent) { const char *path = module; - struct debuginfo *ret; + char reason[STRERR_BUFSIZE]; + struct debuginfo *ret = NULL; + struct dso *dso = NULL; + int err; if (!module || !strchr(module, '/')) { - path = kernel_get_module_path(module); - if (!path) { + err = kernel_get_module_dso(module, &dso); + if (err < 0) { + if (!dso || dso->load_errno == 0) { + if (!strerror_r(-err, reason, STRERR_BUFSIZE)) + strcpy(reason, "(unknown)"); + } else + dso__strerror_load(dso, reason, STRERR_BUFSIZE); if (!silent) - pr_err("Failed to find path of %s module.\n", - module ?: "kernel"); + pr_err("Failed to find the path for %s: %s\n", + module ?: "kernel", reason); return NULL; } + path = dso->long_name; } ret = debuginfo__new(path); if (!ret && !silent) { diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index 537eb329c2cf..31db6ee7db54 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -131,9 +131,6 @@ extern void line_range__clear(struct line_range *lr); /* Initialize line range */ extern int line_range__init(struct line_range *lr); -/* Internal use: Return kernel/module path */ -extern const char *kernel_get_module_path(const char *module); - extern int add_perf_probe_events(struct perf_probe_event *pevs, int npevs); extern int del_perf_probe_events(struct strfilter *filter); extern int show_perf_probe_events(struct strfilter *filter); -- GitLab