From patchwork Fri Jun 28 13:46:19 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: 13716170 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 1FBA0C3064D for ; Fri, 28 Jun 2024 13:47:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=sM38sOmfIdCFFYyDvNpvpUuwmvEwtYEx5FxOYUTWG5U=; b=SPFYBbItgoubac/hQqXx63EIRC wEoU0Fe3k3bAOGfzBbGUGwao87PakFzp2oiJgBSzwA7FA0ilcthOw/uyyEr3+Z54gFp9Zj2DCfov/ hV6lHJg9D/0KRAl2486pjFRnFDCnkm7WsmPfpB+Qhg8LVA9cnleL/iouuXPVZc+nJzQJ221Yvutln aCdCES12UGKQ+uO25EB/T6DmttfinGAYR1mYJnU+wuz5lorYDedzvC0vsIfQsVoZ0NcjHTpdm3UiB OpjAZI6FubotZLifPRuloSp4t9bticuLhnK0lYZqhLd2RKi7OEjc0bqbciiT1OP5XLQko1k1Nj1WO YZsFih7w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sNBwt-0000000DrcJ-40Od; Fri, 28 Jun 2024 13:47:35 +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 1sNBwG-0000000DrNo-3i2K for linux-arm-kernel@lists.infradead.org; Fri, 28 Jun 2024 13:47:03 +0000 From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1719582415; 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=sM38sOmfIdCFFYyDvNpvpUuwmvEwtYEx5FxOYUTWG5U=; b=Teqlhws+geRqJFQ0r3DKmZEiLAB8JVi7eFHX90lyuLf8xwlBzgAtuM4Ac/4U7lKgts/su5 unbKOPebFa7YdBvuf6M2gg0SS8DKjS04GiZAuMyp9rhQYFpOSfI4uOJJ5PHUQ4qtmE95W6 QHI1p69Kka++spLZvHn3rziaMaqn6/9cXDU94n4rJxsrYYkVsdxp95AXFJbLMSbd7Zi5v4 q6/71nnp5uMnTmIEjicAWSN7DhEufcWAiFOunvvL4iVu3bjd5+ulRozrk/4ANlZipXb3I3 pThBY1vggt274rqUIKVgprGYRU4AbE2q4GhntkTqi1Q0Xf1y0YcdRvp2++222A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1719582415; 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=sM38sOmfIdCFFYyDvNpvpUuwmvEwtYEx5FxOYUTWG5U=; b=UDah1GXViFyq6V5mimxXluqkpKKS5ZPf3cavzIUGvOBQtAkcFzyROfH5zoVBjHletetDY+ acQv1mo5GzUBZDCA== To: linux-arm-kernel@lists.infradead.org Cc: Arnd Bergmann , Russell King , Thomas Gleixner , Sebastian Andrzej Siewior , Ard Biesheuvel Subject: [PATCH v5 4/4] ARM: vfp: Move sending signals outside of vfp_lock()ed section. Date: Fri, 28 Jun 2024 15:46:19 +0200 Message-ID: <20240628134648.1852041-5-bigeasy@linutronix.de> In-Reply-To: <20240628134648.1852041-1-bigeasy@linutronix.de> References: <20240628134648.1852041-1-bigeasy@linutronix.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240628_064657_483506_B6168FB7 X-CRM114-Status: GOOD ( 14.00 ) 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; }