From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760866AbbA3Jlq (ORCPT ); Fri, 30 Jan 2015 04:41:46 -0500 Received: from mail9.hitachi.co.jp ([133.145.228.44]:51722 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760003AbbA3JiJ (ORCPT ); Fri, 30 Jan 2015 04:38:09 -0500 X-AuditID: 85900ec0-bfcf5b9000002d32-2d-54cb50d06c71 Subject: [PATCH perf/core 1/2] [BUGFIX] perf-probe: Fix to handle optimized not-inlined but has no instance From: Masami Hiramatsu To: Arnaldo Carvalho de Melo Cc: Peter Zijlstra , namhyung@kernel.org, Ingo Molnar , Linux Kernel Mailing List Date: Fri, 30 Jan 2015 18:37:44 +0900 Message-ID: <20150130093744.30575.43290.stgit@localhost.localdomain> In-Reply-To: <20150130093741.30575.41526.stgit@localhost.localdomain> References: <20150130093741.30575.41526.stgit@localhost.localdomain> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix to handle optimized no-inline functions which have only function definition but no actual instance at that point. To fix this problem, we need to find actual instance of the function. Without this patch: ---- # perf probe -a __up Failed to get entry address of __up. Error: Failed to add events. # perf probe -L __up Specified source line is not found. Error: Failed to show lines. ---- With this patch: ---- # perf probe -a __up Added new event: probe:__up (on __up) You can now use it in all perf tools, such as: perf record -e probe:__up -aR sleep 1 # perf probe -L __up <__up@/home/fedora/ksrc/linux-3/kernel/locking/semaphore.c:0> 0 static noinline void __sched __up(struct semaphore *sem) { struct semaphore_waiter *waiter = list_first_entry(&sem->wait_ struct semaphore_waite 4 list_del(&waiter->list); 5 waiter->up = true; 6 wake_up_process(waiter->task); 7 } ---- Signed-off-by: Masami Hiramatsu --- tools/perf/util/dwarf-aux.c | 15 +++++++++++++++ tools/perf/util/dwarf-aux.h | 3 +++ tools/perf/util/probe-finder.c | 12 ++++-------- 3 files changed, 22 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index cc66c40..780b2bc 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -278,6 +278,21 @@ bool die_is_func_def(Dwarf_Die *dw_die) } /** + * die_is_func_instance - Ensure that this DIE is an instance of a subprogram + * @dw_die: a DIE + * + * Ensure that this DIE is an instance (which has an entry address). + * This returns true if @dw_die is a function instance. If not, you need to + * call die_walk_instances() to find actual instances. + **/ +bool die_is_func_instance(Dwarf_Die *dw_die) +{ + Dwarf_Addr tmp; + + /* Actually gcc optimizes non-inline as like as inlined */ + return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0; +} +/** * die_get_data_member_location - Get the data-member offset * @mb_die: a DIE of a member of a data structure * @offs: The offset of the member in the data structure diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h index b4fe90c..af7dbcd 100644 --- a/tools/perf/util/dwarf-aux.h +++ b/tools/perf/util/dwarf-aux.h @@ -41,6 +41,9 @@ extern int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr, /* Ensure that this DIE is a subprogram and definition (not declaration) */ extern bool die_is_func_def(Dwarf_Die *dw_die); +/* Ensure that this DIE is an instance of a subprogram */ +extern bool die_is_func_instance(Dwarf_Die *dw_die); + /* Compare diename and tname */ extern bool die_compare_name(Dwarf_Die *dw_die, const char *tname); diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index b5247d7..d141935 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -915,17 +915,13 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) dwarf_decl_line(sp_die, &pf->lno); pf->lno += pp->line; param->retval = find_probe_point_by_line(pf); - } else if (!dwarf_func_inline(sp_die)) { + } else if (die_is_func_instance(sp_die)) { + /* Instances always have the entry address */ + dwarf_entrypc(sp_die, &pf->addr); /* Real function */ if (pp->lazy_line) param->retval = find_probe_point_lazy(sp_die, pf); else { - if (dwarf_entrypc(sp_die, &pf->addr) != 0) { - pr_warning("Failed to get entry address of " - "%s.\n", dwarf_diename(sp_die)); - param->retval = -ENOENT; - return DWARF_CB_ABORT; - } pf->addr += pp->offset; /* TODO: Check the address in this function */ param->retval = call_probe_finder(sp_die, pf); @@ -1536,7 +1532,7 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data) pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e); lr->start = lf->lno_s; lr->end = lf->lno_e; - if (dwarf_func_inline(sp_die)) + if (!die_is_func_instance(sp_die)) param->retval = die_walk_instances(sp_die, line_range_inline_cb, lf); else