From patchwork Tue Sep 26 12:55:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 13399230 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 2BC6AE7E62E for ; Tue, 26 Sep 2023 12:55:55 +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=u/T2KI/zsCU5BE8H4vMxKis++AV7quTCvObHzn+pJAM=; b=r8u3WvOEsddMFk OX77n3m2gQXbO/CbZMVYwKUTZ8kLa5XkkM9zonTNOMooRzLqseIFQClSjOHaMMKPKao4jUN43pJxk UxIFzyLfSXlXBBY+cdzkHLStDnzInJVWNtsbvytWVWwGG/3dA+dw0W4TGcoeG1VesMIvEntWEuApd U+Kk0TObVxuLLfFdCAZojzU9WhOp/hVlcHoH9s47gEUgd9ftv7AEqLjGZHFgYE8FYx38voaI8mTvm iuxWb2lNSNJ8DhJdRBfUKUBNswUpsydEyfB/cx+CxO7JzIdgZWRZdXbO49/N3lqzNIyKWgnLWSYOO hH4EFmX1NizL+i/yzV4g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1ql7b9-00GPBW-1K; Tue, 26 Sep 2023 12:55:31 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1ql7av-00GP7g-2R for linux-arm-kernel@lists.infradead.org; Tue, 26 Sep 2023 12:55:20 +0000 From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1695732914; 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=bFRH+6ZHyIPY0kdv98ztsysu6Y7ltAnIcqBDY3eIekk=; b=VGhv4Qb/sw+CLrGb2mCdbeotrAv0bFPRb9uOP/HbDKJHOtzaYJfREbrFV4kk1OXBcLlS1f bmEnoaMfCBPOJA1+6SQ/XCZ1yAN7y88SVGW7qEZrQXRsXtKLQ+Ftk6eC0TSCSudOpV8Wgg dyyoomCsLulxKhJtL86842W5G1wj2yNpUQWzoqb8pzGbfN3jmOAn4YbgdSMcxQNIHpa2yC +BPXIIBFis9HaUfNhbueDUr96j3mIi9N1WF5FCymxc13cgkDHsfXTB853Ub7Xx5wHPxuZp g0bd2j3Pzf4XwFXApBsFDFvvL4O5uvccr3X6t63qpoCPLdzdJfjquPOzlXhgSg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1695732914; 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=bFRH+6ZHyIPY0kdv98ztsysu6Y7ltAnIcqBDY3eIekk=; b=n3p6JDU80+ujC85j7Z3Wribim1UYqPyZAEgbr1+2uwMGDQMhjuSnW0bgiTxbT/fSwzv8DX b3DtMmtZK7IjDtCw== To: linux-arm-kernel@lists.infradead.org, linux@armlinux.org.uk Cc: ardb@kernel.org, tglx@linutronix.de, Sebastian Andrzej Siewior Subject: [PATCH v3 4/4] ARM: vfp: Move sending signals outside of vfp_lock()ed section. Date: Tue, 26 Sep 2023 14:55:02 +0200 Message-Id: <20230926125502.1127015-5-bigeasy@linutronix.de> In-Reply-To: <20230926125502.1127015-1-bigeasy@linutronix.de> References: <20230926125502.1127015-1-bigeasy@linutronix.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230926_055518_085626_C1B36F8B 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. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Ard Biesheuvel --- 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 9543f011d0edf..9fde36fcb80c2 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; }