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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 EDAA5C4338F for ; Mon, 23 Aug 2021 15:35:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D636061214 for ; Mon, 23 Aug 2021 15:35:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231626AbhHWPgl (ORCPT ); Mon, 23 Aug 2021 11:36:41 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:60915 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229550AbhHWPgi (ORCPT ); Mon, 23 Aug 2021 11:36:38 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4GtbtK5qwBz9sWs; Mon, 23 Aug 2021 17:35:53 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Ext5xMQIZ3Nl; Mon, 23 Aug 2021 17:35:53 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4GtbtJ4ndxz9sT5; Mon, 23 Aug 2021 17:35:52 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 8481F8B7AF; Mon, 23 Aug 2021 17:35:52 +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 C87AxL4hLxiq; Mon, 23 Aug 2021 17:35:52 +0200 (CEST) Received: from po18078vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.100]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 5BCD18B7AD; Mon, 23 Aug 2021 17:35:52 +0200 (CEST) Received: by po18078vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 54CA96BC7C; Mon, 23 Aug 2021 15:35:52 +0000 (UTC) Message-Id: <1e1b76f778c28e2e79a7ec303fd36bcd64bf639d.1629732940.git.christophe.leroy@csgroup.eu> In-Reply-To: References: From: Christophe Leroy Subject: [PATCH v2 2/5] powerpc/signal: Include the new stack frame inside the user access block To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Mon, 23 Aug 2021 15:35:52 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 0608581967f0..ff101e2b3bab 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -726,7 +726,7 @@ 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 */ @@ -734,6 +734,7 @@ 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; @@ -743,7 +744,7 @@ 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 */ @@ -779,6 +780,9 @@ 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)) @@ -790,13 +794,8 @@ 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; @@ -826,7 +825,7 @@ 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 */ @@ -834,6 +833,7 @@ 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; @@ -843,7 +843,7 @@ 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; @@ -873,6 +873,8 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, unsafe_put_user(PPC_RAW_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; @@ -881,12 +883,7 @@ 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_set_return_ip(regs, (unsigned long) ksig->ka.sa.sa_handler); diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 790c450c2de8..2cca6c8febe1 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_set_return_ip(regs, (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; @@ -952,7 +952,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, /* enter the signal handler in native-endian mode */ regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (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) { -- 2.25.0