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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B86D7C433EF for ; Fri, 15 Oct 2021 01:16:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E5AF611EE for ; Fri, 15 Oct 2021 01:16:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232735AbhJOBSH (ORCPT ); Thu, 14 Oct 2021 21:18:07 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:46316 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232107AbhJOBSD (ORCPT ); Thu, 14 Oct 2021 21:18:03 -0400 Message-ID: <20211015011538.493570236@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1634260556; 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: references:references; bh=820daWr24eERPD7yq1vPcOq80bu7Gqh2gnJkboAilY8=; b=z53ZadhVh8vsDDvHU5A/i/6fuZtxC7hf31elMkx2NVRaAhIjJw2q67Mnhzs6olSug/YRL5 FQ3+cIofFgLm9hx4FcEDAjX6kD+ECW4cf2tdyw1osGpw8QIjBy5PNCYmf0xaC3gP9K2K0Q S7C3xhtlf4DQeBCO35jEu/WGLIBqAqgan+aOzSh75BsdIBrITAN8KMFPSgK5HO7vHAXfPu /L4TzBHDG4lI9v0ek22wdfekcT+iAFa9okU7GzA4iyK7Cyk/UUQhbndl1kXaU6qTv+g+x6 atf13KrdqHRIrO3FoB7GKfBtbZHwW05oTqUsEGcE00jB8kVT+ixPfabl+XxkOg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1634260556; 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: references:references; bh=820daWr24eERPD7yq1vPcOq80bu7Gqh2gnJkboAilY8=; b=AEPRVCARSRQzAN3pwy/nwh0mp2LFcKPazkvR5+9t3z2g5d5RMpUPFY2HmCOwHNyh2retB9 bJFuvfjZ0pq4AtCg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, "Chang S. Bae" , Dave Hansen , Arjan van de Ven , kvm@vger.kernel.org, Paolo Bonzini , "Liu, Jing2" , Sean Christopherson , Xiaoyao Li Subject: [patch V2 02/30] x86/fpu: Update stale comments References: <20211015011411.304289784@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Fri, 15 Oct 2021 03:15:56 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org copy_fpstate_to_sigframe() does not have a slow path anymore. Neither does the !ia32 restore in __fpu_restore_sig(). Update the comments accordingly. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/fpu/signal.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) --- diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 37dbfed29d75..64f0d4eda0b0 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -155,10 +155,8 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf) * buf == buf_fx for 64-bit frames and 32-bit fsave frame. * buf != buf_fx for 32-bit frames with fxstate. * - * Try to save it directly to the user frame with disabled page fault handler. - * If this fails then do the slow path where the FPU state is first saved to - * task's fpu->state and then copy it to the user frame pointed to by the - * aligned pointer 'buf_fx'. + * Save it directly to the user frame with disabled page fault handler. If + * that faults, try to clear the frame which handles the page fault. * * If this is a 32-bit frame with fxstate, put a fsave header before * the aligned state at 'buf_fx'. @@ -334,12 +332,7 @@ static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx, } if (likely(!ia32_fxstate)) { - /* - * Attempt to restore the FPU registers directly from user - * memory. For that to succeed, the user access cannot cause page - * faults. If it does, fall back to the slow path below, going - * through the kernel buffer with the enabled pagefault handler. - */ + /* Restore the FPU registers directly from user memory. */ return restore_fpregs_from_user(buf_fx, user_xfeatures, fx_only, state_size); }