From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752621AbbKYTrW (ORCPT ); Wed, 25 Nov 2015 14:47:22 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:33996 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752478AbbKYTrT (ORCPT ); Wed, 25 Nov 2015 14:47:19 -0500 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Masami Hiramatsu , Adrian Hunter , David Ahern , Jiri Olsa , Namhyung Kim , Peter Zijlstra , Wang Nan , Arnaldo Carvalho de Melo Subject: [PATCH 2/4] perf probe: Fix to free temporal Dwarf_Frame correctly Date: Wed, 25 Nov 2015 16:47:00 -0300 Message-Id: <1448480822-19140-3-git-send-email-acme@kernel.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1448480822-19140-1-git-send-email-acme@kernel.org> References: <1448480822-19140-1-git-send-email-acme@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Hiramatsu The commit 05c8d802fa52 ("perf probe: Fix to free temporal Dwarf_Frame") tried to fix the memory leak of Dwarf_Frame, but it released the frame at wrong point. Since the dwarf_frame_cfa(frame, &pf->fb_ops, &nops) can return an address inside the frame data structure to pf->fb_ops, we can not release the frame before using pf->fb_ops. This reverts the commit and releases the frame afterwards (right before returning from call_probe_finder) correctly. Reported-and-Tested-by: Arnaldo Carvalho de Melo Reported-by: Michael Petlan Signed-off-by: Masami Hiramatsu Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Fixes: 05c8d802fa52 ("perf probe: Fix to free temporal Dwarf_Frame") LPU-Reference: 20151125103432.1473.31009.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-finder.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 1cab05a3831e..2be10fb27172 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -654,6 +654,7 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod, static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf) { Dwarf_Attribute fb_attr; + Dwarf_Frame *frame = NULL; size_t nops; int ret; @@ -683,26 +684,24 @@ static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf) ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1); if (ret <= 0 || nops == 0) { pf->fb_ops = NULL; - ret = 0; #if _ELFUTILS_PREREQ(0, 142) } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa && pf->cfi != NULL) { - Dwarf_Frame *frame = NULL; if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 || dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) { pr_warning("Failed to get call frame on 0x%jx\n", (uintmax_t)pf->addr); - ret = -ENOENT; + free(frame); + return -ENOENT; } - free(frame); #endif } /* Call finder's callback handler */ - if (ret >= 0) - ret = pf->callback(sc_die, pf); + ret = pf->callback(sc_die, pf); - /* *pf->fb_ops will be cached in libdw. Don't free it. */ + /* Since *pf->fb_ops can be a part of frame. we should free it here. */ + free(frame); pf->fb_ops = NULL; return ret; -- 2.1.0