From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E8BA03C6A38 for ; Fri, 22 May 2026 09:56:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779443813; cv=none; b=hT/kf/GTWT+G6d5e6TTa59jSPPVNKpn3N1pTH8x6Sjyaf00uTBT0kcDW6D+56qIUNIVRZQRxHd5B/meI0lYNXZGCpq/VkwIBKsvts+QMVQPw/kyRrsgP2hVXS4CmviJtTzKpmhp+gq3Ax7+47rjSEoAy73bkqHM6WyKDOPy6ZuI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779443813; c=relaxed/simple; bh=Sv4X8VTWrdN2udw9liQNQS0v17NX1w7EdMh1y0n3YiI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=daalSzy0gYY1PlM1Ml448qjHk9guxTpXH5xsG5n1AnqE3l4vstImelDY0bFyC1d1n3lrv4Jt8kikeV8VO39Hl7QJRz5zWYcAEblvaZzOmI7AJH7gI0q2wmCp6lv1MXo5pJdS59GOwmPpC2Zg0y82agTaSbNMigPu8gRmhMl7/lQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=juefcFJ4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="juefcFJ4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DFDAA1F00A3E; Fri, 22 May 2026 09:56:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779443811; bh=CdobDuTOgoolQVkszSDKLRqhHkRLaU01XRBQ3D9Mjb0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=juefcFJ4bFlo8QZ7FNxJNiejm93GsvrXCg1TNQD1hAuE+y1FKJpAQoMvvxCRivbEG hdgPB4fbp5jD7aenObJW8g7Hk+q55Ur/xHf24c2vAl4LhJq8+qeVfp81zXe1QzzhSK JdnOjTgzZDwIc2pvghim70C9WDU9ICY/LTLFSfyRVZK1NiIzhURdJ7ee9SDyZxaO3C fkDyLRgGC7zIItQ5e9NJRQt4Ol2xbslmqx4LGVBIYKaUm0NyzRmKuvbNlBj63T8G3N Ly82hDjNWwgL3Y6hBB90HHxgsRJJRa/YlcKG38vk2bkkYSu46DnGHTF6GdjCSuT3ZD Jex2zxw4BgBZg== From: "Christophe Leroy (CS GROUP)" To: Michael Ellerman , Nicholas Piggin , Madhavan Srinivasan Cc: "Christophe Leroy (CS GROUP)" , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v1 5/8] powerpc/signal: Include the new stack frame inside the user access block Date: Fri, 22 May 2026 11:56:05 +0200 Message-ID: <287fc000d2f51fde862db0db643801c0ff22cfb7.1779441786.git.chleroy@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=6733; i=chleroy@kernel.org; h=from:subject:message-id; bh=Sv4X8VTWrdN2udw9liQNQS0v17NX1w7EdMh1y0n3YiI=; b=owGbwMvMwCV2d0KB2p7V54MZT6slMWQJaNj9kHp1pe6KY2VMntFlFxFx3eub/nzT/rW4dvqp/ WHvLtcv6ChlYRDjYpAVU2Q5/p9714yuL6n5U3fpw8xhZQIZwsDFKQATsRFj+O964lSV4bMTdoI+ jY/bF//vuXW1huOF7KI2tSSJ81/9InoZ/vDvW5fR8OWMsX5NWGbW8315kqzMgfb3P65a7eyX1MZ 4jRUA X-Developer-Key: i=chleroy@kernel.org; a=openpgp; fpr=10FFE6F8B390DE17ACC2632368A92FEB01B8DD78 Content-Transfer-Encoding: 8bit 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 (CS GROUP) --- arch/powerpc/kernel/signal_32.c | 28 ++++++++++++---------------- arch/powerpc/kernel/signal_64.c | 13 ++++++------- 2 files changed, 18 insertions(+), 23 deletions(-) diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index f5d5139a1426..6b1fbd95b07d 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -730,7 +730,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, struct task_struct *tsk) { struct rt_sigframe __user *frame; - 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 */ @@ -738,12 +738,13 @@ 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)); if (MSR_TM_ACTIVE(msr)) prepare_save_tm_user_regs(); else prepare_save_user_regs(1); - scoped_user_rw_access(frame, badframe) { + scoped_user_rw_access_size(newsp, __SIGNAL_FRAMESIZE + 16 + sizeof(*frame), badframe) { struct mcontext __user *mctx; struct mcontext __user *tm_mctx = NULL; @@ -784,6 +785,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0])); } unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, badframe); + + /* create a stack frame for the caller of the handler */ + unsafe_put_user(regs->gpr[1], newsp, badframe); } if (copy_siginfo_to_user(&frame->info, &ksig->info)) @@ -795,13 +799,8 @@ 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 sigcontext __user *sc; struct sigframe __user *frame; - 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 */ @@ -834,12 +833,13 @@ 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); if (MSR_TM_ACTIVE(msr)) prepare_save_tm_user_regs(); else prepare_save_user_regs(1); - scoped_user_rw_access(frame, badframe) { + scoped_user_rw_access_size(newsp, __SIGNAL_FRAMESIZE + sizeof(*frame), badframe) { struct mcontext __user *mctx; struct mcontext __user *tm_mctx = NULL; @@ -876,6 +876,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, unsafe_put_user(PPC_RAW_SC(), &mctx->mc_pad[1], badframe); asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0])); } + unsafe_put_user(regs->gpr[1], newsp, badframe); } regs->link = tramp; @@ -884,12 +885,7 @@ 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 bf7fc579d572..67de29cf581a 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -846,13 +846,14 @@ 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 @@ -870,7 +871,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, msr); #endif - scoped_user_write_access(frame, badframe) { + scoped_user_write_access_size(newsp, __SIGNAL_FRAMESIZE + sizeof(*frame), badframe) { unsafe_put_user(&frame->info, &frame->pinfo, badframe); unsafe_put_user(&frame->uc, &frame->puc, badframe); @@ -892,6 +893,8 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, } unsafe_copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set), badframe); + /* Allocate a dummy caller frame for the signal handler. */ + unsafe_put_user(regs->gpr[1], newsp, badframe); } /* Save the siginfo outside of the unsafe block. */ @@ -911,10 +914,6 @@ 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; @@ -936,7 +935,7 @@ 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) { -- 2.54.0