From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1684311-1523561586-2-2423238537708612371 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, MAILING_LIST_MULTI -1, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-api-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1523561585; b=pQav1fwn/rO75wEIrCR4IB9YkUB46IzpQO3gMvxOGh9DGeuWwW /mSC0bMsm/SWfH3K2nwFDC9ZwQAEYdNrC1EXHKqstchJGw1VZ+B/6+MPgiYbykVk om3/ZsxJXbHrx7pu+GLSvG5t7W2YpzHARulffMV73839lcBg/bucWZCYZahw+lOA E2PCoe02EcNeyqSyedsvHtzgLOU0+EYxm6IbWvaR/Y+Ns8Lz2aoUXSLpadjC186N PYkuUBLnaVPMkFtnBInannLz6LOvZ6fJ7kHfCxlYoSvjMdaX+BArsCSs3GxQhklQ dk2UKz9XIPt7PWhp7LDTmtKTwCFqA3BokreQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:sender:list-id; s=fm2; t=1523561585; bh= k9cog7jnkJZ42hQv4bReVhNxtPiZ4b3/mEdi9beWqQk=; b=XZRd3U2+WRsps1yb a3qbzL0nb+3n7v8+5Jp7mSur42qFKx5GGkSX4rM+hn+J5jkTtLSdPqV+aTRi+0Fj XpacAdzJVum7saWGOhN5McBaoJZRtzCSrJfeEHSBOkBQwEu9coyLV1AEhrDXJLsb cpjXiz2AogLnVuOuDf0rMrWKeet6inNjHLRuzCn1YEXVKsFhZa3X+pTxAbl57G/+ UQRvi3HjrXozeU6oOUS1+mazjvw1XAlDygewv8sk+NYd3CDFdj5e1PnI0Gyj9obh c1kHU195/r8YlZ0DkN5ZBdBiBL5H+tggj1MxznGXYOC3ERITGkbMCk9TU3eJtZY1 /LdqKg== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=efficios.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=efficios.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=efficios.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=efficios.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfFGcib+tOq6iX2yJntpZ3CxDMVFgNcTeeJ54tk16ks5Ff67u3qfyfaQ9tCg24v7EaO1nugJ+DU04ReiR0L7In3Dc3nCUus+WDStyHQKU3zzTyCSNgSX2 5zgu/ReTzoE9tFFuGQBsw8J4vynpzT7cu05rHDC7R5bnSn1ackbHh4uMWh4NKjN2xVbMxl5C9fbIoayK6XKW9cJvcA9zXCf9MqTAzmgaWV5HdERfp3ug4HCA X-CM-Analysis: v=2.3 cv=WaUilXpX c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=Kd1tUaAdevIA:10 a=7d_E57ReAAAA:8 a=drOt6m5kAAAA:8 a=7CQSdrXTAAAA:8 a=1XWaLZrsAAAA:8 a=JfrnYn6hAAAA:8 a=SOq6UgPBAAAA:8 a=WfulkdPnAAAA:8 a=FOH2dFAWAAAA:8 a=NufY4J3AAAAA:8 a=20KFwNOVAAAA:8 a=oGMlB6cnAAAA:8 a=meVymXHHAAAA:8 a=VnNF1IyMAAAA:8 a=UPm3pfgAAAAA:8 a=Z4Rwk6OoAAAA:8 a=pGLkceISAAAA:8 a=VwQbUJbxAAAA:8 a=d79AQB8eE-0OSRNI08kA:9 a=ETx1mNwkyILpblSV:21 a=v2IWsg-P_ydaLAOV:21 a=x8gzFH9gYPwA:10 a=jhqOcbufqs7Y1TYCrUUU:22 a=RMMjzBEyIzXRtoq5n5K6:22 a=a-qgeE7W1pNrGK8U0ZQC:22 a=1CNFftbPRP8L7MoqJWF3:22 a=3hv5r9HjGAh9o5iR9qwG:22 a=56QPVbyS4OZCpcuOg7Z9:22 a=i3VuKzQdj-NEYjvDI-p3:22 a=TPcZfFuj8SYsoCJAFAiX:22 a=NdAtdrkLVvyUPsUoGJp4:22 a=2JgSa4NbpEOStq-L5dxp:22 a=uD9XBtlS4o1URY3aiGdj:22 a=HkZW87K1Qel5hWWM3VKY:22 a=AjGcO6oz07-iQ99wixmX:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753149AbeDLTdC (ORCPT ); Thu, 12 Apr 2018 15:33:02 -0400 Received: from mail.efficios.com ([167.114.142.138]:45580 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753058AbeDLT2W (ORCPT ); Thu, 12 Apr 2018 15:28:22 -0400 From: Mathieu Desnoyers To: Peter Zijlstra , "Paul E . McKenney" , Boqun Feng , Andy Lutomirski , Dave Watson Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Paul Turner , Andrew Morton , Russell King , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andrew Hunter , Andi Kleen , Chris Lameter , Ben Maurer , Steven Rostedt , Josh Triplett , Linus Torvalds , Catalin Marinas , Will Deacon , Michael Kerrisk , Mathieu Desnoyers Subject: [RFC PATCH for 4.18 05/23] x86: Add support for restartable sequences (v2) Date: Thu, 12 Apr 2018 15:27:42 -0400 Message-Id: <20180412192800.15708-6-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180412192800.15708-1-mathieu.desnoyers@efficios.com> References: <20180412192800.15708-1-mathieu.desnoyers@efficios.com> Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Call the rseq_handle_notify_resume() function on return to userspace if TIF_NOTIFY_RESUME thread flag is set. Perform fixup on the pre-signal frame when a signal is delivered on top of a restartable sequence critical section. Check that system calls are not invoked from within rseq critical sections by invoking rseq_signal() from syscall_return_slowpath(). With CONFIG_DEBUG_RSEQ, such behavior results in termination of the process with SIGSEGV. Signed-off-by: Mathieu Desnoyers Reviewed-by: Thomas Gleixner CC: Russell King CC: Catalin Marinas CC: Will Deacon CC: Paul Turner CC: Andrew Hunter CC: Peter Zijlstra CC: Andy Lutomirski CC: Andi Kleen CC: Dave Watson CC: Chris Lameter CC: Ingo Molnar CC: "H. Peter Anvin" CC: Ben Maurer CC: Steven Rostedt CC: "Paul E. McKenney" CC: Josh Triplett CC: Linus Torvalds CC: Andrew Morton CC: Boqun Feng CC: linux-api@vger.kernel.org --- Changes since v1: - Call rseq_signal() when returning from a system call. --- arch/x86/Kconfig | 1 + arch/x86/entry/common.c | 3 +++ arch/x86/kernel/signal.c | 6 ++++++ 3 files changed, 10 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0fa71a78ec99..47a2b14fcc7d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -178,6 +178,7 @@ config X86 select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION select HAVE_STACK_VALIDATION if X86_64 + select HAVE_RSEQ select HAVE_SYSCALL_TRACEPOINTS select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_USER_RETURN_NOTIFIER diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 74f6eee15179..5bc9c9fe49c4 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -164,6 +164,7 @@ static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags) if (cached_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + rseq_handle_notify_resume(regs); } if (cached_flags & _TIF_USER_RETURN_NOTIFY) @@ -254,6 +255,8 @@ __visible inline void syscall_return_slowpath(struct pt_regs *regs) WARN(irqs_disabled(), "syscall %ld left IRQs disabled", regs->orig_ax)) local_irq_enable(); + rseq_syscall(regs); + /* * First do one-time work. If these work items are enabled, we * want to run them exactly once per syscall exit with IRQs on. diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 4cdc0b27ec82..0f549cbd8b46 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -687,6 +687,12 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) sigset_t *set = sigmask_to_save(); compat_sigset_t *cset = (compat_sigset_t *) set; + /* + * Increment event counter and perform fixup for the pre-signal + * frame. + */ + rseq_signal_deliver(regs); + /* Set up the stack frame */ if (is_ia32_frame(ksig)) { if (ksig->ka.sa.sa_flags & SA_SIGINFO) -- 2.11.0