From patchwork Fri Mar 15 14:51:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 13593580 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 11C95C54E67 for ; Fri, 15 Mar 2024 14:52:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=61Apcs7eeffXPO0absXGGZKVd2PRmW0Ismo2PgPpdC4=; b=Hy/8S8N8NVTgPV bnaXA4GYo0A9pAwqNwI76K1FmT0+QmgLuXoBg/ceChYzySzszUXR+84UMuzA53pdwEZmLgVVYq3MQ LPW4wTMNJbzewjxEYccMFWpHT7EYgdjJKlNt/fc6CZLB06t7YnehqQwAVi5Dh1aCWnspvVBX7w3KU ewx5OCowQVHHzw/HFKr9unnVjbn8xSitCtpHAboCCITXVK9L/m4ZaT/WcVSqPchVhvj9FwBIx1zZ9 SNY+9Vv/PyvUE4feyA1f7h21CV4BC1HCV0s8RveTSMEikRHQ5XBimKCUroj7HDyxeQKcMf8Y09thL k+XRVU9LbucMC9K2xVuQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rl8vJ-00000000Z4X-40mm; Fri, 15 Mar 2024 14:52:41 +0000 Received: from galois.linutronix.de ([2a0a:51c0:0:12e:550::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rl8v0-00000000YxI-3DPs for linux-arm-kernel@lists.infradead.org; Fri, 15 Mar 2024 14:52:35 +0000 From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1710514339; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BYTJDrcJfpdw8gLVlmoUe+wlBs78jjIV619RBA//dvI=; b=lCz82WgCb+GWkryDjnkBApvzBJ0IQAJWbYD5MRRX2bjfsk/odLvWmLnX8GTQkYMcs7bXMG XQbOkfoNewuBjCthw9bnzsQMDz27rzFBNoLnAJMxr83PabqsXQa2Tw3x+EMTXPZRQMdrhs vSw1OTVqk9l6+Xw8VNjSTKFcu9+7bICkEU5CHSlrU+/9QvOnGr3xFqTCrxBYnazKOuKfc3 bOgi2vILlucw/BDNZ8RC8s4ox3l1xkluiBHGqO0C/y0y3Irxv0/IuloDghCitxHzTjDLjC Zpfdr6fhmYjqUsYgl1T3VR5FQrKHh1EMspk29j4ub+QkLxLvMKB1P4lywLq2MQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1710514339; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BYTJDrcJfpdw8gLVlmoUe+wlBs78jjIV619RBA//dvI=; b=BM//5S3qV1rw1sSo8QpmktAIpse23InaLIeTHJBFgdsDtCDTfZLBYrhQ51nrZ+/7xOkjjr 0PC3okwhCuuSMfBg== To: linux-arm-kernel@lists.infradead.org, linux@armlinux.org.uk Cc: ardb@kernel.org, tglx@linutronix.de, Sebastian Andrzej Siewior Subject: [PATCH v4 4/4] ARM: vfp: Move sending signals outside of vfp_lock()ed section. Date: Fri, 15 Mar 2024 15:51:03 +0100 Message-ID: <20240315145208.3598288-5-bigeasy@linutronix.de> In-Reply-To: <20240315145208.3598288-1-bigeasy@linutronix.de> References: <20240315145208.3598288-1-bigeasy@linutronix.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240315_075223_132827_5C6731DC X-CRM114-Status: GOOD ( 13.08 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org VFP_bounce() is invoked from within vfp_support_entry() and may send a signal. Sending a signal uses spinlock_t which becomes a sleeping lock on PREEMPT_RT and must not be acquired within a preempt-disabled section. Move the vfp_raise_sigfpe() block outside of the vfp_lock() section. Reviewed-by: Ard Biesheuvel Signed-off-by: Sebastian Andrzej Siewior --- arch/arm/vfp/vfpmodule.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 6ebd5d4b8fa29..48745a3c52618 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -268,7 +268,7 @@ static void vfp_panic(char *reason, u32 inst) /* * Process bitmask of exception conditions. */ -static void vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr, struct pt_regs *regs) +static int vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr) { int si_code = 0; @@ -276,8 +276,7 @@ static void vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr, struct pt_ if (exceptions == VFP_EXCEPTION_ERROR) { vfp_panic("unhandled bounce", inst); - vfp_raise_sigfpe(FPE_FLTINV, regs); - return; + return FPE_FLTINV; } /* @@ -305,8 +304,7 @@ static void vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr, struct pt_ RAISE(FPSCR_OFC, FPSCR_OFE, FPE_FLTOVF); RAISE(FPSCR_IOC, FPSCR_IOE, FPE_FLTINV); - if (si_code) - vfp_raise_sigfpe(si_code, regs); + return si_code; } /* @@ -352,6 +350,8 @@ static u32 vfp_emulate_instruction(u32 inst, u32 fpscr, struct pt_regs *regs) static void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) { u32 fpscr, orig_fpscr, fpsid, exceptions; + int si_code2 = 0; + int si_code = 0; pr_debug("VFP: bounce: trigger %08x fpexc %08x\n", trigger, fpexc); @@ -397,8 +397,8 @@ static void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) * unallocated VFP instruction but with FPSCR.IXE set and not * on VFP subarch 1. */ - vfp_raise_exceptions(VFP_EXCEPTION_ERROR, trigger, fpscr, regs); - return; + si_code = vfp_raise_exceptions(VFP_EXCEPTION_ERROR, trigger, fpscr); + goto exit; } /* @@ -422,14 +422,14 @@ static void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) */ exceptions = vfp_emulate_instruction(trigger, fpscr, regs); if (exceptions) - vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs); + si_code2 = vfp_raise_exceptions(exceptions, trigger, orig_fpscr); /* * If there isn't a second FP instruction, exit now. Note that * the FPEXC.FP2V bit is valid only if FPEXC.EX is 1. */ if ((fpexc & (FPEXC_EX | FPEXC_FP2V)) != (FPEXC_EX | FPEXC_FP2V)) - return; + goto exit; /* * The barrier() here prevents fpinst2 being read @@ -441,7 +441,13 @@ static void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) emulate: exceptions = vfp_emulate_instruction(trigger, orig_fpscr, regs); if (exceptions) - vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs); + si_code = vfp_raise_exceptions(exceptions, trigger, orig_fpscr); +exit: + vfp_unlock(); + if (si_code2) + vfp_raise_sigfpe(si_code2, regs); + if (si_code) + vfp_raise_sigfpe(si_code, regs); } static void vfp_enable(void *unused) @@ -773,6 +779,7 @@ static int vfp_support_entry(struct pt_regs *regs, u32 trigger) * replay the instruction that trapped. */ fmxr(FPEXC, fpexc); + vfp_unlock(); } else { /* Check for synchronous or asynchronous exceptions */ if (!(fpexc & (FPEXC_EX | FPEXC_DEX))) { @@ -794,10 +801,10 @@ static int vfp_support_entry(struct pt_regs *regs, u32 trigger) } } bounce: regs->ARM_pc += 4; + /* VFP_bounce() will invoke vfp_unlock() */ VFP_bounce(trigger, fpexc, regs); } - vfp_unlock(); return 0; }