From patchwork Thu Apr 18 08:41:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 10906895 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CC7C4922 for ; Thu, 18 Apr 2019 09:09:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B9925286A0 for ; Thu, 18 Apr 2019 09:09:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AD9D828857; Thu, 18 Apr 2019 09:09:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4AC84286A0 for ; Thu, 18 Apr 2019 09:09:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388530AbfDRJHc (ORCPT ); Thu, 18 Apr 2019 05:07:32 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:34066 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388508AbfDRJHb (ORCPT ); Thu, 18 Apr 2019 05:07:31 -0400 Received: from localhost ([127.0.0.1] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1hH30N-0001wk-9B; Thu, 18 Apr 2019 11:06:51 +0200 Message-Id: <20190418084255.275696472@linutronix.de> User-Agent: quilt/0.65 Date: Thu, 18 Apr 2019 10:41:43 +0200 From: Thomas Gleixner To: LKML Cc: Josh Poimboeuf , x86@kernel.org, Andy Lutomirski , Steven Rostedt , Alexander Potapenko , Alexey Dobriyan , Andrew Morton , Pekka Enberg , linux-mm@kvack.org, David Rientjes , Christoph Lameter , Catalin Marinas , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Mike Rapoport , Akinobu Mita , iommu@lists.linux-foundation.org, Robin Murphy , Christoph Hellwig , Marek Szyprowski , Johannes Thumshirn , David Sterba , Chris Mason , Josef Bacik , linux-btrfs@vger.kernel.org, dm-devel@redhat.com, Mike Snitzer , Alasdair Kergon , intel-gfx@lists.freedesktop.org, Joonas Lahtinen , Maarten Lankhorst , dri-devel@lists.freedesktop.org, David Airlie , Jani Nikula , Daniel Vetter , Rodrigo Vivi , linux-arch@vger.kernel.org Subject: [patch V2 24/29] tracing: Remove the last struct stack_trace usage References: <20190418084119.056416939@linutronix.de> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Simplify the stack retrieval code by using the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt (VMware) --- kernel/trace/trace_stack.c | 42 ++++++++++++++++-------------------------- 1 file changed, 16 insertions(+), 26 deletions(-) --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -23,16 +23,7 @@ static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES]; static unsigned stack_trace_index[STACK_TRACE_ENTRIES]; -/* - * Reserve one entry for the passed in ip. This will allow - * us to remove most or all of the stack size overhead - * added by the stack tracer itself. - */ -struct stack_trace stack_trace_max = { - .max_entries = STACK_TRACE_ENTRIES - 1, - .entries = &stack_dump_trace[0], -}; - +static unsigned int stack_trace_entries; static unsigned long stack_trace_max_size; static arch_spinlock_t stack_trace_max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; @@ -49,10 +40,10 @@ static void print_max_stack(void) pr_emerg(" Depth Size Location (%d entries)\n" " ----- ---- --------\n", - stack_trace_max.nr_entries); + stack_trace_entries); - for (i = 0; i < stack_trace_max.nr_entries; i++) { - if (i + 1 == stack_trace_max.nr_entries) + for (i = 0; i < stack_trace_entries; i++) { + if (i + 1 == stack_trace_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; @@ -98,13 +89,12 @@ static void check_stack(unsigned long ip stack_trace_max_size = this_size; - stack_trace_max.nr_entries = 0; - stack_trace_max.skip = 0; - - save_stack_trace(&stack_trace_max); + stack_trace_entries = stack_trace_save(stack_dump_trace, + ARRAY_SIZE(stack_dump_trace) - 1, + 0); /* Skip over the overhead of the stack tracer itself */ - for (i = 0; i < stack_trace_max.nr_entries; i++) { + for (i = 0; i < stack_trace_entries; i++) { if (stack_dump_trace[i] == ip) break; } @@ -113,7 +103,7 @@ static void check_stack(unsigned long ip * Some archs may not have the passed in ip in the dump. * If that happens, we need to show everything. */ - if (i == stack_trace_max.nr_entries) + if (i == stack_trace_entries) i = 0; /* @@ -131,13 +121,13 @@ static void check_stack(unsigned long ip * loop will only happen once. This code only takes place * on a new max, so it is far from a fast path. */ - while (i < stack_trace_max.nr_entries) { + while (i < stack_trace_entries) { int found = 0; stack_trace_index[x] = this_size; p = start; - for (; p < top && i < stack_trace_max.nr_entries; p++) { + for (; p < top && i < stack_trace_entries; p++) { /* * The READ_ONCE_NOCHECK is used to let KASAN know that * this is not a stack-out-of-bounds error. @@ -168,7 +158,7 @@ static void check_stack(unsigned long ip i++; } - stack_trace_max.nr_entries = x; + stack_trace_entries = x; if (task_stack_end_corrupted(current)) { print_max_stack(); @@ -270,7 +260,7 @@ static void * { long n = *pos - 1; - if (n >= stack_trace_max.nr_entries) + if (n >= stack_trace_entries) return NULL; m->private = (void *)n; @@ -334,7 +324,7 @@ static int t_show(struct seq_file *m, vo seq_printf(m, " Depth Size Location" " (%d entries)\n" " ----- ---- --------\n", - stack_trace_max.nr_entries); + stack_trace_entries); if (!stack_tracer_enabled && !stack_trace_max_size) print_disabled(m); @@ -344,10 +334,10 @@ static int t_show(struct seq_file *m, vo i = *(long *)v; - if (i >= stack_trace_max.nr_entries) + if (i >= stack_trace_entries) return 0; - if (i + 1 == stack_trace_max.nr_entries) + if (i + 1 == stack_trace_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1];