From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) (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 D65891CBEB9 for ; Tue, 1 Apr 2025 06:58:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.60.130.6 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743490727; cv=none; b=hXwSGq2TPzZ/MtbsVcLqMHZpDVmX8tGJ0OEWiRxc2nDgi8S1mr2fq9PLORbr9AptHOrRYbg4EZC/lFH0lBQ/Yz1PfWie6VVVjnADGEuxW4kHPVNMbNEjyCYjp0//NQ3RzFVEEwF09CU8xT5dkikkGyvUIFQp8eeR3eVNbqk8TYE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743490727; c=relaxed/simple; bh=linBA49Xq+6OE5t6rLpAMQ2es3izbbcVz4iwGmmuDrY=; h=Mime-Version:Content-Type:Date:Message-Id:Cc:Subject:From:To: References:In-Reply-To; b=D96GuF6E3ZHhydGdNA7ccah2DoMXofa2+zznLaz+cAnYWa00arJd+5EYD+u+AC2/xZH0HbPPVLsCeaj1uFV09iaAQnLta+R7TKyg1t9TP00oK7o6Elq506rAcq4XX0sGgjXKjlHliJDEyduME7sfvAV0ddePPtxXR3Hk1CUJafE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=JCqji5+M; arc=none smtp.client-ip=178.60.130.6 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="JCqji5+M" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=In-Reply-To:References:To:From:Subject:Cc:Message-Id:Date: Content-Type:Content-Transfer-Encoding:Mime-Version:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=BfpXQZwCXbJzhjggqSYZGkJOxoJNUGWrPnGQqBunZoA=; b=JCqji5+Mrkx5vb6yVqSHhFKzta pvmane6DfwlzDs/pTEDz5Elqy32nPUy20jV/aQFUQMY56XHPQaQOH0JN9kfCAFJcoaUE0me6AnRcq QHKPUMB0kYEOZlgug42Fdn6zPhsY7FwjBU6kJklVo2A8qf0tNMDY1JocmGMS4TW8jKjhJ14k0msAM fzjI3HgLOtAATT8odEeZ2hN6PD62jNYzsqmA69fGuZJbx0jX6k1SdxSxrP64mDtFBO0RiFYVuMqQ8 YYe4BFaIcSEl1UNfIJnKAdD+uZQ/gO+VuctwuzqLfbL7Zl/Nr5bUkYIkFkTmquIqyRKlGcR/wNkAF UCOvqKxg==; Received: from i59f7adb8.versanet.de ([89.247.173.184] helo=localhost) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1tzVZz-009XOO-4i; Tue, 01 Apr 2025 08:58:35 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Tue, 01 Apr 2025 08:58:33 +0200 Message-Id: Cc: , , , Subject: Re: [PATCH] arm64: Don't call NULL in do_compat_alignment_fixup From: "Angelos Oikonomopoulos" To: "Anshuman Khandual" , X-Mailer: aerc 0.20.1 References: <20250331085415.122409-1-angelos@igalia.com> <17de4426-8263-4ccb-8420-f6913d478ae9@arm.com> In-Reply-To: <17de4426-8263-4ccb-8420-f6913d478ae9@arm.com> On Tue Apr 1, 2025 at 8:05 AM CEST, Anshuman Khandual wrote: > On 3/31/25 14:24, Angelos Oikonomopoulos wrote: >> do_alignment_t32_to_handler only fixes up alignment faults for specific >> instructions; it returns NULL otherwise. When that's the case, signal to >> the caller that it needs to proceed with the regular alignment fault >> handling (i.e. SIGBUS). >>=20 >> Signed-off-by: Angelos Oikonomopoulos >> --- >> arch/arm64/kernel/compat_alignment.c | 2 ++ >> 1 file changed, 2 insertions(+) >>=20 >> diff --git a/arch/arm64/kernel/compat_alignment.c b/arch/arm64/kernel/co= mpat_alignment.c >> index deff21bfa680..b68e1d328d4c 100644 >> --- a/arch/arm64/kernel/compat_alignment.c >> +++ b/arch/arm64/kernel/compat_alignment.c >> @@ -368,6 +368,8 @@ int do_compat_alignment_fixup(unsigned long addr, st= ruct pt_regs *regs) >> return 1; >> } >> =20 >> + if (!handler) >> + return 1; > > do_alignment_t32_to_handler() could return NULL, returning 1 seems to be > the right thing to do here and consistent. Otherwise does this cause a > kernel crash during subsequent call into handler() ? Yes. We call a NULL pointer so we Oops. Angelos