From patchwork Tue Jun 15 06:41:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 1492001 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4G3zJX38X6z9sT6 for ; Tue, 15 Jun 2021 16:42:20 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4G3zJY0NZxz3cDm for ; Tue, 15 Jun 2021 16:42:21 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4G3zHJ6x6Cz3btC for ; Tue, 15 Jun 2021 16:41:16 +1000 (AEST) Received: from localhost (mailhub3.si.c-s.fr [192.168.12.233]) by localhost (Postfix) with ESMTP id 4G3zH10g96zB9C7; Tue, 15 Jun 2021 08:41:01 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8xzz5YnCJCSc; Tue, 15 Jun 2021 08:41:01 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4G3zH06pKfzB9BM; Tue, 15 Jun 2021 08:41:00 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id E03DD8B7A4; Tue, 15 Jun 2021 08:41:00 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id 90MrqGNBmaWg; Tue, 15 Jun 2021 08:41:00 +0200 (CEST) Received: from po9473vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 881FA8B7A2; Tue, 15 Jun 2021 08:41:00 +0200 (CEST) Received: by po9473vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 60BFD6627B; Tue, 15 Jun 2021 06:41:00 +0000 (UTC) Message-Id: <6fc18af6d3caf1de0afc476cbebb9de5ad8b54d1.1623739212.git.christophe.leroy@csgroup.eu> In-Reply-To: References: From: Christophe Leroy Subject: [PATCH 4/7] powerpc/signal: Include the new stack frame inside the user access block To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Date: Tue, 15 Jun 2021 06:41:00 +0000 (UTC) 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: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Include the new stack frame inside the user access block and set it up using unsafe_put_user(). On an mpc 8321 (book3s/32) the improvment is about 4% on a process sending a signal to itself. Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/signal_32.c | 29 +++++++++++++---------------- arch/powerpc/kernel/signal_64.c | 14 +++++++------- 2 files changed, 20 insertions(+), 23 deletions(-) diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 8f05ed0da292..621de6e457b3 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -781,7 +781,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, struct rt_sigframe __user *frame; struct mcontext __user *mctx; struct mcontext __user *tm_mctx = NULL; - unsigned long newsp = 0; + unsigned long __user *newsp; unsigned long tramp; struct pt_regs *regs = tsk->thread.regs; /* Save the thread's msr before get_tm_stackpointer() changes it */ @@ -789,6 +789,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, /* Set up Signal Frame */ frame = get_sigframe(ksig, tsk, sizeof(*frame), 1); + newsp = (unsigned long __user *)((unsigned long)frame - (__SIGNAL_FRAMESIZE + 16)); mctx = &frame->uc.uc_mcontext; #ifdef CONFIG_PPC_TRANSACTIONAL_MEM tm_mctx = &frame->uc_transact.uc_mcontext; @@ -798,7 +799,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, else prepare_save_user_regs(1); - if (!user_access_begin(frame, sizeof(*frame))) + if (!user_access_begin(newsp, __SIGNAL_FRAMESIZE + 16 + sizeof(*frame))) goto badframe; /* Put the siginfo & fill in most of the ucontext */ @@ -836,6 +837,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, } unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, failed); + /* create a stack frame for the caller of the handler */ + unsafe_put_user(regs->gpr[1], newsp, failed); + user_access_end(); if (copy_siginfo_to_user(&frame->info, &ksig->info)) @@ -847,13 +851,8 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ #endif - /* create a stack frame for the caller of the handler */ - newsp = ((unsigned long)frame) - (__SIGNAL_FRAMESIZE + 16); - if (put_user(regs->gpr[1], (u32 __user *)newsp)) - goto badframe; - /* Fill registers for signal handler */ - regs->gpr[1] = newsp; + regs->gpr[1] = (unsigned long)newsp; regs->gpr[3] = ksig->sig; regs->gpr[4] = (unsigned long)&frame->info; regs->gpr[5] = (unsigned long)&frame->uc; @@ -883,7 +882,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct sigframe __user *frame; struct mcontext __user *mctx; struct mcontext __user *tm_mctx = NULL; - unsigned long newsp = 0; + unsigned long __user *newsp; unsigned long tramp; struct pt_regs *regs = tsk->thread.regs; /* Save the thread's msr before get_tm_stackpointer() changes it */ @@ -891,6 +890,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, /* Set up Signal Frame */ frame = get_sigframe(ksig, tsk, sizeof(*frame), 1); + newsp = (unsigned long __user *)((unsigned long)frame - __SIGNAL_FRAMESIZE); mctx = &frame->mctx; #ifdef CONFIG_PPC_TRANSACTIONAL_MEM tm_mctx = &frame->mctx_transact; @@ -900,7 +900,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, else prepare_save_user_regs(1); - if (!user_access_begin(frame, sizeof(*frame))) + if (!user_access_begin(newsp, __SIGNAL_FRAMESIZE + sizeof(*frame))) goto badframe; sc = (struct sigcontext __user *) &frame->sctx; @@ -931,6 +931,8 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed); asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0])); } + /* create a stack frame for the caller of the handler */ + unsafe_put_user(regs->gpr[1], newsp, failed); user_access_end(); regs->link = tramp; @@ -939,12 +941,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ #endif - /* create a stack frame for the caller of the handler */ - newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; - if (put_user(regs->gpr[1], (u32 __user *)newsp)) - goto badframe; - - regs->gpr[1] = newsp; + regs->gpr[1] = (unsigned long)newsp; regs->gpr[3] = ksig->sig; regs->gpr[4] = (unsigned long) sc; regs->nip = (unsigned long)ksig->ka.sa.sa_handler; diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 9ca97b4366df..35c301457fbf 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -847,13 +847,14 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct task_struct *tsk) { struct rt_sigframe __user *frame; - unsigned long newsp = 0; + unsigned long __user *newsp; long err = 0; struct pt_regs *regs = tsk->thread.regs; /* Save the thread's msr before get_tm_stackpointer() changes it */ unsigned long msr = regs->msr; frame = get_sigframe(ksig, tsk, sizeof(*frame), 0); + newsp = (unsigned long __user *)((unsigned long)frame - __SIGNAL_FRAMESIZE); /* * This only applies when calling unsafe_setup_sigcontext() and must be @@ -862,7 +863,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, if (!MSR_TM_ACTIVE(msr)) prepare_setup_sigcontext(tsk); - if (!user_write_access_begin(frame, sizeof(*frame))) + if (!user_write_access_begin(newsp, __SIGNAL_FRAMESIZE + sizeof(*frame))) goto badframe; unsafe_put_user(&frame->info, &frame->pinfo, badframe_block); @@ -900,6 +901,9 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, } unsafe_copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set), badframe_block); + /* Allocate a dummy caller frame for the signal handler. */ + unsafe_put_user(regs->gpr[1], newsp, badframe_block); + user_write_access_end(); /* Save the siginfo outside of the unsafe block. */ @@ -919,10 +923,6 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, regs->nip = (unsigned long) &frame->tramp[0]; } - /* Allocate a dummy caller frame for the signal handler. */ - newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; - err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); - /* Set up "regs" so we "return" to the signal handler. */ if (is_elf2_task()) { regs->ctr = (unsigned long) ksig->ka.sa.sa_handler; @@ -953,7 +953,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, /* enter the signal handler in native-endian mode */ regs->msr &= ~MSR_LE; regs->msr |= (MSR_KERNEL & MSR_LE); - regs->gpr[1] = newsp; + regs->gpr[1] = (unsigned long)newsp; regs->gpr[3] = ksig->sig; regs->result = 0; if (ksig->ka.sa.sa_flags & SA_SIGINFO) {