Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751631AbdIKLO2 (ORCPT ); Mon, 11 Sep 2017 07:14:28 -0400 Received: from mail.kdab.com ([176.9.126.58]:57342 "EHLO mail.kdab.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751224AbdIKLO0 (ORCPT ); Mon, 11 Sep 2017 07:14:26 -0400 From: Milian Wolff To: acme@kernel.org Cc: Linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Milian Wolff , Arnaldo Carvalho de Melo , David Ahern , Namhyung Kim , Peter Zijlstra , Yao Jin Subject: [PATCH] perf: support running perf binaries with a dash in their name Date: Mon, 11 Sep 2017 13:14:22 +0200 Message-Id: <20170911111422.31903-1-milian.wolff@kdab.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2199 Lines: 64 Previously the part behind "perf-" was interpreted as an internal perf command. If the suffix could not be handled, the execution was stopped. This makes it impossible to launch perf binaries that got renamed to have the `perf-` prefix. This is e.g. the case for appimages (e.g. "perf-x86_64.AppImage"), but would also apply to all other scenarios where users symlink or rename perf themselves: Status quo with the broken behavior: ~~~~~ $ ln -s ./perf ./perf-custom-suffix $ ./perf-custom-suffix list cannot handle custom-suffix internally$ ~~~~~ Also note the missing newline at the end of the error message. With this patch applied, the above works properly: ~~~~~ $ ./perf-custom-suffix list List of pre-defined events (to be used in -e): ... ~~~~~ Cc: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Yao Jin Signed-off-by: Milian Wolff --- tools/perf/perf.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/tools/perf/perf.c b/tools/perf/perf.c index e0279babe0c0..7a3a39014446 100644 --- a/tools/perf/perf.c +++ b/tools/perf/perf.c @@ -467,15 +467,19 @@ int main(int argc, const char **argv) * - cannot execute it externally (since it would just do * the same thing over again) * - * So we just directly call the internal command handler, and - * die if that one cannot handle it. + * So we just directly call the internal command handler. If that one + * fails to handle this, then maybe we just run a renamed perf binary + * that contains a dash in its name. To handle this scenario, we just + * fall through and ignore the "xxxx" part of the command string. */ if (strstarts(cmd, "perf-")) { cmd += 5; argv[0] = cmd; handle_internal_command(argc, argv); - fprintf(stderr, "cannot handle %s internally", cmd); - goto out; + // if the command is handled, the above function does not return + // undo changes and fall through in such a case + cmd -= 5; + argv[0] = cmd; } if (strstarts(cmd, "trace")) { #ifdef HAVE_LIBAUDIT_SUPPORT -- 2.14.1