From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C6FAC48BDF for ; Fri, 18 Jun 2021 15:20:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F42F613F2 for ; Fri, 18 Jun 2021 15:20:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235069AbhFRPW6 (ORCPT ); Fri, 18 Jun 2021 11:22:58 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:56328 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235043AbhFRPVy (ORCPT ); Fri, 18 Jun 2021 11:21:54 -0400 Message-Id: <20210618143446.797089970@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1624029584; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=Z44UcUFaoETlK2Z+lyZln3W5ENZj+2o+D1dsWdv0UTU=; b=JcxddxfPxhK4ikGIamwLOMMiIMjiUJ3zamUWDHgoJCiTpPtcDimrIBYEaAoLe1GYBVpHP2 1RZZkcJgGSlZH0DHoZ6qgYBhOCHtZ7nzOVQRKrvP+COQ6NBoHSGeMSJ8ZfFzJPo79RtCX1 KBNI5DeUhvUl9ntq+ySYmiaX3M23eeUnV92Da9/kfWAUKPjKoHYqlO0isB4aYdLvvlamdX F/Mmye6v9qaKfqdVsznqt7l1YdzF56wj3OhYCBY0vOhu8qH5ipoPjn4Yf17voWUSbQZvC9 67SplRzIm6UuDqM+5stqrn+nKshKhDxJ1x9uzZI0jCbClcfvCWr8GhwprsrixA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1624029584; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=Z44UcUFaoETlK2Z+lyZln3W5ENZj+2o+D1dsWdv0UTU=; b=BZnGtb1beWuCUCB+nkIwTzH/mPPiGiYT8beeOulQYJR7LL3+EZUAKzFCOIcQCNiKRDGjim v+Ye29PEdZfHPPAw== Date: Fri, 18 Jun 2021 16:18:44 +0200 From: Thomas Gleixner To: LKML Cc: Andy Lutomirski , Dave Hansen , Fenghua Yu , Tony Luck , Yu-cheng Yu , Sebastian Andrzej Siewior , Borislav Petkov , Peter Zijlstra , Kan Liang Subject: [patch V3 21/66] x86/fpu/regset: Move fpu__read_begin() into regset References: <20210618141823.161158090@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The function can only be used from the regset get() callbacks safely. So there is no reason to have it globaly exposed. Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/fpu/internal.h | 1 - arch/x86/kernel/fpu/core.c | 20 -------------------- arch/x86/kernel/fpu/regset.c | 22 +++++++++++++++++++--- 3 files changed, 19 insertions(+), 24 deletions(-) --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -26,7 +26,6 @@ /* * High level FPU state handling functions: */ -extern void fpu__prepare_read(struct fpu *fpu); extern void fpu__prepare_write(struct fpu *fpu); extern void fpu__save(struct fpu *fpu); extern int fpu__restore_sig(void __user *buf, int ia32_frame); --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -282,26 +282,6 @@ static void fpu__initialize(struct fpu * } /* - * This function must be called before we read a task's fpstate. - * - * There's two cases where this gets called: - * - * - for the current task (when coredumping), in which case we have - * to save the latest FPU registers into the fpstate, - * - * - or it's called for stopped tasks (ptrace), in which case the - * registers were already saved by the context-switch code when - * the task scheduled out. - * - * If the task has used the FPU before then save it. - */ -void fpu__prepare_read(struct fpu *fpu) -{ - if (fpu == ¤t->thread.fpu) - fpu__save(fpu); -} - -/* * This function must be called before we write a task's fpstate. * * Invalidate any cached FPU registers. --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -28,6 +28,22 @@ int regset_xregset_fpregs_active(struct return 0; } +/* + * The regset get() functions are invoked from: + * + * - coredump to dump the current task's fpstate. If the current task + * owns the FPU then the memory state has to be synchronized and the + * FPU register state preserved. Otherwise fpstate is already in sync. + * + * - ptrace to dump fpstate of a stopped task, in which case the register + * have already been saved to fpstate on context switch. + */ +static void sync_fpstate(struct fpu *fpu) +{ + if (fpu == ¤t->thread.fpu) + fpu__save(fpu); +} + int xfpregs_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) { @@ -36,7 +52,7 @@ int xfpregs_get(struct task_struct *targ if (!cpu_feature_enabled(X86_FEATURE_FXSR)) return -ENODEV; - fpu__prepare_read(fpu); + sync_fpstate(fpu); if (!use_xsave()) { return membuf_write(&to, &fpu->state.fxsave, @@ -97,7 +113,7 @@ int xstateregs_get(struct task_struct *t if (!cpu_feature_enabled(X86_FEATURE_XSAVE)) return -ENODEV; - fpu__prepare_read(fpu); + sync_fpstate(fpu); copy_xstate_to_uabi_buf(to, &fpu->state.xsave, XSTATE_COPY_XSAVE); return 0; @@ -288,7 +304,7 @@ int fpregs_get(struct task_struct *targe struct user_i387_ia32_struct env; struct fxregs_state fxsave, *fx; - fpu__prepare_read(fpu); + sync_fpstate(fpu); if (!cpu_feature_enabled(X86_FEATURE_FPU)) return fpregs_soft_get(target, regset, to);