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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 3B250C433E0 for ; Sun, 21 Feb 2021 01:27:13 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B7B6564EEC for ; Sun, 21 Feb 2021 01:27:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7B6564EEC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codefail.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4DjnjW2jT9z3dgd for ; Sun, 21 Feb 2021 12:27:11 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=codefail.de (client-ip=68.65.122.27; helo=mta-07-4.privateemail.com; envelope-from=cmr@codefail.de; receiver=) Received: from MTA-07-4.privateemail.com (mta-07-4.privateemail.com [68.65.122.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Djnf40jM6z30Pg for ; Sun, 21 Feb 2021 12:24:09 +1100 (AEDT) Received: from MTA-07.privateemail.com (localhost [127.0.0.1]) by MTA-07.privateemail.com (Postfix) with ESMTP id A2EF46004E for ; Sat, 20 Feb 2021 20:24:07 -0500 (EST) Received: from oc8246131445.ibm.com (unknown [10.20.151.213]) by MTA-07.privateemail.com (Postfix) with ESMTPA id 7C69B60049 for ; Sun, 21 Feb 2021 01:24:07 +0000 (UTC) From: "Christopher M. Riedl" To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v6 05/10] powerpc/signal64: Remove TM ifdefery in middle of if/else block Date: Sat, 20 Feb 2021 19:23:56 -0600 Message-Id: <20210221012401.22328-6-cmr@codefail.de> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20210221012401.22328-1-cmr@codefail.de> References: <20210221012401.22328-1-cmr@codefail.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Virus-Scanned: ClamAV using ClamSMTP X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Both rt_sigreturn() and handle_rt_signal_64() contain TM-related ifdefs which break-up an if/else block. Provide stubs for the ifdef-guarded TM functions and remove the need for an ifdef in rt_sigreturn(). Rework the remaining TM ifdef in handle_rt_signal64() similar to commit f1cf4f93de2f ("powerpc/signal32: Remove ifdefery in middle of if/else"). Unlike in the commit for ppc32, the ifdef can't be removed entirely since uc_transact in sigframe depends on CONFIG_PPC_TRANSACTIONAL_MEM. Signed-off-by: Christopher M. Riedl --- arch/powerpc/kernel/process.c | 3 +- arch/powerpc/kernel/signal_64.c | 102 ++++++++++++++++---------------- 2 files changed, 54 insertions(+), 51 deletions(-) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 924d023dad0a..08c3fbe45921 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1117,9 +1117,10 @@ void restore_tm_state(struct pt_regs *regs) regs->msr |= msr_diff; } -#else +#else /* !CONFIG_PPC_TRANSACTIONAL_MEM */ #define tm_recheckpoint_new_task(new) #define __switch_to_tm(prev, new) +void tm_reclaim_current(uint8_t cause) {} #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ static inline void save_sprs(struct thread_struct *t) diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 6ca546192cbf..bd8d210c9115 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -594,6 +594,12 @@ static long restore_tm_sigcontexts(struct task_struct *tsk, return err; } +#else /* !CONFIG_PPC_TRANSACTIONAL_MEM */ +static long restore_tm_sigcontexts(struct task_struct *tsk, struct sigcontext __user *sc, + struct sigcontext __user *tm_sc) +{ + return -EINVAL; +} #endif /* @@ -710,9 +716,7 @@ SYSCALL_DEFINE0(rt_sigreturn) struct pt_regs *regs = current_pt_regs(); struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; sigset_t set; -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM unsigned long msr; -#endif /* Always make any pending restarted system calls return -EINTR */ current->restart_block.fn = do_no_restart_syscall; @@ -724,48 +728,50 @@ SYSCALL_DEFINE0(rt_sigreturn) goto badframe; set_current_blocked(&set); -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM - /* - * If there is a transactional state then throw it away. - * The purpose of a sigreturn is to destroy all traces of the - * signal frame, this includes any transactional state created - * within in. We only check for suspended as we can never be - * active in the kernel, we are active, there is nothing better to - * do than go ahead and Bad Thing later. - * The cause is not important as there will never be a - * recheckpoint so it's not user visible. - */ - if (MSR_TM_SUSPENDED(mfmsr())) - tm_reclaim_current(0); + if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM)) { + /* + * If there is a transactional state then throw it away. + * The purpose of a sigreturn is to destroy all traces of the + * signal frame, this includes any transactional state created + * within in. We only check for suspended as we can never be + * active in the kernel, we are active, there is nothing better to + * do than go ahead and Bad Thing later. + * The cause is not important as there will never be a + * recheckpoint so it's not user visible. + */ + if (MSR_TM_SUSPENDED(mfmsr())) + tm_reclaim_current(0); - /* - * Disable MSR[TS] bit also, so, if there is an exception in the - * code below (as a page fault in copy_ckvsx_to_user()), it does - * not recheckpoint this task if there was a context switch inside - * the exception. - * - * A major page fault can indirectly call schedule(). A reschedule - * process in the middle of an exception can have a side effect - * (Changing the CPU MSR[TS] state), since schedule() is called - * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended - * (switch_to() calls tm_recheckpoint() for the 'new' process). In - * this case, the process continues to be the same in the CPU, but - * the CPU state just changed. - * - * This can cause a TM Bad Thing, since the MSR in the stack will - * have the MSR[TS]=0, and this is what will be used to RFID. - * - * Clearing MSR[TS] state here will avoid a recheckpoint if there - * is any process reschedule in kernel space. The MSR[TS] state - * does not need to be saved also, since it will be replaced with - * the MSR[TS] that came from user context later, at - * restore_tm_sigcontexts. - */ - regs->msr &= ~MSR_TS_MASK; + /* + * Disable MSR[TS] bit also, so, if there is an exception in the + * code below (as a page fault in copy_ckvsx_to_user()), it does + * not recheckpoint this task if there was a context switch inside + * the exception. + * + * A major page fault can indirectly call schedule(). A reschedule + * process in the middle of an exception can have a side effect + * (Changing the CPU MSR[TS] state), since schedule() is called + * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended + * (switch_to() calls tm_recheckpoint() for the 'new' process). In + * this case, the process continues to be the same in the CPU, but + * the CPU state just changed. + * + * This can cause a TM Bad Thing, since the MSR in the stack will + * have the MSR[TS]=0, and this is what will be used to RFID. + * + * Clearing MSR[TS] state here will avoid a recheckpoint if there + * is any process reschedule in kernel space. The MSR[TS] state + * does not need to be saved also, since it will be replaced with + * the MSR[TS] that came from user context later, at + * restore_tm_sigcontexts. + */ + regs->msr &= ~MSR_TS_MASK; - if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) - goto badframe; - if (MSR_TM_ACTIVE(msr)) { + if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) + goto badframe; + } + + if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) && MSR_TM_ACTIVE(msr)) { /* We recheckpoint on return. */ struct ucontext __user *uc_transact; @@ -778,9 +784,7 @@ SYSCALL_DEFINE0(rt_sigreturn) if (restore_tm_sigcontexts(current, &uc->uc_mcontext, &uc_transact->uc_mcontext)) goto badframe; - } else -#endif - { + } else { /* * Fall through, for non-TM restore * @@ -818,10 +822,8 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, unsigned long newsp = 0; long err = 0; struct pt_regs *regs = tsk->thread.regs; -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM /* Save the thread's msr before get_tm_stackpointer() changes it */ unsigned long msr = regs->msr; -#endif frame = get_sigframe(ksig, tsk, sizeof(*frame), 0); if (!access_ok(frame, sizeof(*frame))) @@ -836,8 +838,9 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, /* Create the ucontext. */ err |= __put_user(0, &frame->uc.uc_flags); err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]); -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + if (MSR_TM_ACTIVE(msr)) { +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM /* The ucontext_t passed to userland points to the second * ucontext_t (for transactional state) with its uc_link ptr. */ @@ -847,9 +850,8 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, tsk, ksig->sig, NULL, (unsigned long)ksig->ka.sa.sa_handler, msr); - } else #endif - { + } else { err |= __put_user(0, &frame->uc.uc_link); prepare_setup_sigcontext(tsk); err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig, -- 2.26.1