From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 06/28] perf annotate browser: Be more robust when drawing jump arrows Date: Mon, 5 Mar 2018 11:29:10 -0300 Message-ID: <20180305142932.16921-7-acme@kernel.org> References: <20180305142932.16921-1-acme@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20180305142932.16921-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , David Ahern , Jiri Olsa , Namhyung Kim , Wang Nan , Jin Yao , Kan Liang List-Id: linux-perf-users.vger.kernel.org From: Arnaldo Carvalho de Melo This first happened with a gcc function, _cpp_lex_token, that has the usual jumps: │1159e6c: ↓ jne 115aa32 <_cpp_lex_token@@Base+0xf92> I.e. jumps to a label inside that function (_cpp_lex_token), and those works, but also this kind: │1159e8b: ↓ jne c469be I.e. jumps to another function, outside _cpp_lex_token, which are not being correctly handled generating as a side effect references to ab->offset[] entries that are set to NULL, so to make this code more robust, check that here. A proper fix for will be put in place, looking at the function name right after the '<' token and probably treating this like a 'call' instruction. For now just don't draw the arrow. Reported-by: Ingo Molnar Reported-by: Linus Torvalds Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Cc: Jin Yao Cc: Kan Liang Link: https://lkml.kernel.org/n/tip-5tzvb875ep2sel03aeefgmud@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/ui/browsers/annotate.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c index e2f666391ac4..6ff6839558b0 100644 --- a/tools/perf/ui/browsers/annotate.c +++ b/tools/perf/ui/browsers/annotate.c @@ -328,7 +328,32 @@ static void annotate_browser__draw_current_jump(struct ui_browser *browser) if (!disasm_line__is_valid_jump(cursor, sym)) return; + /* + * This first was seen with a gcc function, _cpp_lex_token, that + * has the usual jumps: + * + * │1159e6c: ↓ jne 115aa32 <_cpp_lex_token@@Base+0xf92> + * + * I.e. jumps to a label inside that function (_cpp_lex_token), and + * those works, but also this kind: + * + * │1159e8b: ↓ jne c469be + * + * I.e. jumps to another function, outside _cpp_lex_token, which + * are not being correctly handled generating as a side effect references + * to ab->offset[] entries that are set to NULL, so to make this code + * more robust, check that here. + * + * A proper fix for will be put in place, looking at the function + * name right after the '<' token and probably treating this like a + * 'call' instruction. + */ target = ab->offsets[cursor->ops.target.offset]; + if (target == NULL) { + ui_helpline__printf("WARN: jump target inconsistency, press 'o', ab->offsets[%#x] = NULL\n", + cursor->ops.target.offset); + return; + } bcursor = browser_line(&cursor->al); btarget = browser_line(target); -- 2.14.3