From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 6/6] perf probe: Do not depend on dwfl_module_addrsym() Date: Mon, 9 Mar 2020 15:53:23 -0300 Message-ID: <20200309185323.22583-7-acme@kernel.org> References: <20200309185323.22583-1-acme@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200309185323.22583-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Masami Hiramatsu , Alexandre Ghiti , Alexander Shishkin , Greg Kroah-Hartman , Jiri Olsa , Peter Zijlstra , Sasha Levin , Arnaldo Carvalho de Melo List-Id: linux-perf-users.vger.kernel.org From: Masami Hiramatsu Do not depend on dwfl_module_addrsym() because it can fail on user-space shared libraries. Actually, same bug was fixed by commit 664fee3dc379 ("perf probe: Do not use dwfl_module_addrsym if dwarf_diename finds symbol name"), but commit 07d369857808 ("perf probe: Fix wrong address verification) reverted to get actual symbol address from symtab. This fixes it again by getting symbol address from DIE, and only if the DIE has only address range, it uses dwfl_module_addrsym(). Fixes: 07d369857808 ("perf probe: Fix wrong address verification) Reported-by: Alexandre Ghiti Signed-off-by: Masami Hiramatsu Tested-by: Alexandre Ghiti Cc: Alexander Shishkin Cc: Greg Kroah-Hartman Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sasha Levin Link: http://lore.kernel.org/lkml/158281812176.476.14164573830975116234.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-finder.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 1c817add6ca4..e4cff49384f4 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -637,14 +637,19 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod, return -EINVAL; } - /* Try to get actual symbol name from symtab */ - symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL); + if (dwarf_entrypc(sp_die, &eaddr) == 0) { + /* If the DIE has entrypc, use it. */ + symbol = dwarf_diename(sp_die); + } else { + /* Try to get actual symbol name and address from symtab */ + symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL); + eaddr = sym.st_value; + } if (!symbol) { pr_warning("Failed to find symbol at 0x%lx\n", (unsigned long)paddr); return -ENOENT; } - eaddr = sym.st_value; tp->offset = (unsigned long)(paddr - eaddr); tp->address = (unsigned long)paddr; -- 2.21.1