From patchwork Mon Oct 21 16:34:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 177121 Delivered-To: patch@linaro.org Received: by 2002:a92:409a:0:0:0:0:0 with SMTP id d26csp3646690ill; Mon, 21 Oct 2019 09:35:08 -0700 (PDT) X-Google-Smtp-Source: APXvYqyL2j+EUbZwFtVJqMQi0ovzHr2e/rcb4MHrJdXTuyMF/u4ejcOtptA3keVv+REvKGugvWcD X-Received: by 2002:a17:906:2410:: with SMTP id z16mr23090482eja.120.1571675708255; Mon, 21 Oct 2019 09:35:08 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1571675708; cv=none; d=google.com; s=arc-20160816; b=nXcfveucE3mH5II9zDYLiG8CH9+CCziwDTpLDAtxVkFhmgHuQLposQyF9mS3bdDjs5 wApfoyGRK1yJET5QhvgWjXsUEa6cGEydyLnoz6eOMIgI4I6QKXULaPgm64Xgnd0YO8IA kbqyKhMlxYgKzedhgl5CCQ4NMW73ol2hjVjT/kGcGonxk4nxrCNB0Pd6mfAjQ/a3MMf7 EKbfu0lp1Axk9BGXV4dwFFQcJjJ+1JE6wTALabNIVgV8e0c3N6Q3YTcmW861TB1g+BI1 KVDZ59hCxm8X2ricdmV1nwoQWMmoe5UORZf8W9NrArFUVspf5ERWuhKHWaeMhmCf0AGj w/3w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from; bh=jvFXUJlwlpWO7N456I9AmiIqVSOX5vUOXbDlNZT2qus=; b=up54KVp8QXEtREtXmkXV4AMplpxvybdFIY31DM/mL6oCJzIo997bnP0YlhIeu2H/g4 IkewHt9s8hVnZDDgxWjGJn0EoHkTpQdappmapo15tn95gUOA/8K9z9TlMjaw/EL9HZx1 OqNaLbToWZSyFbdUbIPiNlUdko8HgOPS8HKVXg9KAKpwOJ3WVgP7Kl3NmpZjD4OFMnW8 q+l2o603NOBGx+Vgl+5Qth6CKfTx0sbwcteCzsW00choNj9S9fqSGUcJoJf1973ze4p9 p5ODjxfCif4vlGbuDaHWgjf4GdYR1BCb+FwSJKDB5cNtbRIKwmbTpBg8GV0tZ1KASBm0 GAEw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id t49si10873239edd.198.2019.10.21.09.35.08; Mon, 21 Oct 2019 09:35:08 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729379AbfJUQfG (ORCPT + 26 others); Mon, 21 Oct 2019 12:35:06 -0400 Received: from [217.140.110.172] ([217.140.110.172]:57526 "EHLO foss.arm.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1726289AbfJUQfE (ORCPT ); Mon, 21 Oct 2019 12:35:04 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3AA221042; Mon, 21 Oct 2019 09:34:37 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 02B233F71F; Mon, 21 Oct 2019 09:34:34 -0700 (PDT) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: amit.kachhap@arm.com, ard.biesheuvel@linaro.org, catalin.marinas@arm.com, deller@gmx.de, duwe@suse.de, james.morse@arm.com, jeyu@kernel.org, jpoimboe@redhat.com, jthierry@redhat.com, mark.rutland@arm.com, mingo@redhat.com, peterz@infradead.org, rostedt@goodmis.org, svens@stackframe.org, takahiro.akashi@linaro.org, will@kernel.org Subject: [PATCH 1/8] ftrace: add ftrace_init_nop() Date: Mon, 21 Oct 2019 17:34:19 +0100 Message-Id: <20191021163426.9408-2-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20191021163426.9408-1-mark.rutland@arm.com> References: <20191021163426.9408-1-mark.rutland@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Architectures may need to perform special initialization of ftrace callsites, and today they do so by special-casing ftrace_make_nop() when the expected branch address is MCOUNT_ADDR. In some cases (e.g. for patchable-function-entry), we don't have an mcount-like symbol and don't want a synthetic MCOUNT_ADDR, but we may need to perform some initialization of callsites. To make it possible to separate initialization from runtime modification, and to handle cases without an mcount-like symbol, this patch adds an optional ftrace_init_nop() function that architectures can implement, which does not pass a branch address. Where an architecture does not provide ftrace_init_nop(), we will fall back to the existing behaviour of calling ftrace_make_nop() with MCOUNT_ADDR. At the same time, ftrace_code_disable() is renamed to ftrace_code_init_disabled() to make it clearer that it is intended to intialize a callsite into a disabled state, and is not for disabling a callsite that has been runtime enabled. Signed-off-by: Mark Rutland Cc: Ingo Molnar Cc: Steven Rostedt Cc: Torsten Duwe --- kernel/trace/ftrace.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) -- 2.11.0 diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f296d89be757..afd7e210e595 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2493,15 +2493,22 @@ struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) return &iter->pg->records[iter->index]; } +#ifndef ftrace_init_nop +static int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) +{ + return ftrace_make_nop(mod, rec, MCOUNT_ADDR); +} +#endif + static int -ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) +ftrace_code_init_disabled(struct module *mod, struct dyn_ftrace *rec) { int ret; if (unlikely(ftrace_disabled)) return 0; - ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); + ret = ftrace_init_nop(mod, rec); if (ret) { ftrace_bug_type = FTRACE_BUG_INIT; ftrace_bug(ret, rec); @@ -2943,7 +2950,7 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) * to the NOP instructions. */ if (!__is_defined(CC_USING_NOP_MCOUNT) && - !ftrace_code_disable(mod, p)) + !ftrace_code_init_disabled(mod, p)) break; update_cnt++;