From 1a8ac29cbffc261f6d7c92e573878110a7dcbd94 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Fri, 2 Oct 2015 21:58:32 +0900 Subject: perf probe: Allow probing on kmodules without dwarf Allow probing on kernel modules when 'perf' is built without debuginfo support. Currently perf-probe --module requires linking with libdw, but this doesn't make sense. E.g. ---- # make NO_DWARF=1 # ./perf probe -m pcspkr pcspkr_event%return Error: unknown switch `m' ---- With this patch ---- # ./perf probe -m pcspkr pcspkr_event%return Added new event: probe:pcspkr_event (on pcspkr_event%return in pcspkr) You can now use it in all perf tools, such as: perf record -e probe:pcspkr_event -aR sleep 1 ---- Signed-off-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/20151002125832.18617.78721.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c index f7882ae..530c3a2 100644 --- a/tools/perf/builtin-probe.c +++ b/tools/perf/builtin-probe.c @@ -182,10 +182,8 @@ static int opt_set_target(const struct option *opt, const char *str, if (str) { if (!strcmp(opt->long_name, "exec")) params.uprobes = true; -#ifdef HAVE_DWARF_SUPPORT else if (!strcmp(opt->long_name, "module")) params.uprobes = false; -#endif else return ret; @@ -490,9 +488,6 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused) "file", "vmlinux pathname"), OPT_STRING('s', "source", &symbol_conf.source_prefix, "directory", "path to kernel source"), - OPT_CALLBACK('m', "module", NULL, "modname|path", - "target module name (for online) or path (for offline)", - opt_set_target), OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines, "Don't search inlined functions"), #endif @@ -509,6 +504,9 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused) opt_set_filter), OPT_CALLBACK('x', "exec", NULL, "executable|path", "target executable name or path", opt_set_target), + OPT_CALLBACK('m', "module", NULL, "modname|path", + "target module name (for online) or path (for offline)", + opt_set_target), OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle, "Enable symbol demangling"), OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel, diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 3010abc..b51a8bf 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -2543,7 +2543,8 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, goto out; } - if (!pev->uprobes && !pp->retprobe) { + /* Note that the symbols in the kmodule are not relocated */ + if (!pev->uprobes && !pp->retprobe && !pev->target) { reloc_sym = kernel_get_ref_reloc_sym(); if (!reloc_sym) { pr_warning("Relocated base symbol is not found!\n"); @@ -2580,8 +2581,9 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, } /* Add one probe point */ tp->address = map->unmap_ip(map, sym->start) + pp->offset; - /* If we found a wrong one, mark it by NULL symbol */ - if (!pev->uprobes && + + /* Check the kprobe (not in module) is within .text */ + if (!pev->uprobes && !pev->target && kprobe_warn_out_range(sym->name, tp->address)) { tp->symbol = NULL; /* Skip it */ skipped++; -- cgit v0.10.2