From mboxrd@z Thu Jan 1 00:00:00 1970 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 AF52ECDE00A for ; Thu, 25 Jun 2026 12:08:35 +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:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=rnC19SJIB8IwjPpZjyOW9vAFG81ZtsEUSHRdP82RYv4=; b=WQS4yZNcXFzoSneVUghD0QqvLd GPK50KrAAVaY+NMxI8zf78PW9I8bX4z4IsUDQir2cPUJ0BlsNAPkqriKkR5oDOl7wJw/tKXvCdvta 4wolR8Z2m0Ok8+jy0SzD1eVeFdctNukSk4aMVBlAP7L88OerQ1+/jdIpXa78Lpogf9MJuuIDELPMw Q5XM/vivmOdBYdFhAFMkSCAw68Opz8Btb373GFCtLRsmCfHtTdwW4ozuiz/g37lAT7igT4YQsv58l MuJXuFdszLJ5j25Cyh4fIvhZJMYZwQJxmNaZqTd2g3LMu5OSEFOpfOFGXXu1iDUD82pdEeLyKX6pb /WvNsQww==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wcisd-000000099kN-1WCB; Thu, 25 Jun 2026 12:08:27 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wcisa-000000099jg-2IQh for linux-arm-kernel@lists.infradead.org; Thu, 25 Jun 2026 12:08:25 +0000 Date: Thu, 25 Jun 2026 14:08:19 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1782389301; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rnC19SJIB8IwjPpZjyOW9vAFG81ZtsEUSHRdP82RYv4=; b=hZWj1sxvXAx2kbIij7hPOANuGEApe9ROSVloikyhvbWue0ENgZXJP0wx9pYQCc7L3CWPL2 azZsEGY8Kq4xT+YfwPi6Uj7b18Z0+b9F4uy/tjceDqTgKW2Sbj1EtzxEhPDU6N9M+Qan7R 95Xq89RMt1ksBDn8S0FrBlGRHj1tsbl0G0q0kXlBofs0wzzwZHwx5nT4kK8ee1oj55LMb4 bZYvX3RfnrjhMJsttIQ8i+4ZGo4GdUGB49YAb6dEEAKTUpU8bmKGKqzVe41cGgKXzmw1ec YxKTCLcV9k9wHDF++loCqt5YMfACC48XySlqNiYUtAPuAI2tffl2sz5y2TlJCQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1782389301; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rnC19SJIB8IwjPpZjyOW9vAFG81ZtsEUSHRdP82RYv4=; b=NNthX3RLO/2AwrFk7DPc9eyAGWhbPpJ8XQgDtdhk4wHM9jdyiePonsiFcXkG/66zDdTtDk sPSHQv6K0tRz8RBg== From: Sebastian Andrzej Siewior To: Russell King Cc: Xie Yuanbin , clrkwllms@kernel.org, rostedt@goodmis.org, linusw@kernel.org, arnd@arndb.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, liaohua4@huawei.com, lilinjie8@huawei.com Subject: Re: [PATCH] ARM: enable interrupts when arm_notify_die() is handling user mode errors Message-ID: <20260625120819.K5e1OVeG@linutronix.de> References: <20260625073522.182503-1-xieyuanbin1@huawei.com> <20260625085034.tvyGSmaP@linutronix.de> <20260625093008.e5I4bh-_@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260625_050824_729200_07E01E2B X-CRM114-Status: GOOD ( 13.37 ) 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 On 2026-06-25 11:20:13 [+0100], Russell King wrote: > > is not worth doing it? With this I can my little testcase working. >=20 > No, it isn't, because if you enable PERF_EVENTS then BKPT breaks. > hw_breakpoint.c claims this vector. I see. =E2=80=A6 > BKPT is a total mess. Understood. > > it does cond_local_irq_enable() which enables the interrupts if they > > were enabled by the "caller", sends the signal (SIGTRAP). >=20 > I'm happy with that approach as far as interrupts go, but we can't > change the behaviour for FSR=3D2 again, beyond fixing LinusW's > commit (which has recently been reported as a regression.) >=20 > Note that the change which makes this raise a SIGTRAP rather than > SIGBUS when PERF_EVENTS=3Dy could _also_ be reported as a regression > that we would have to fix, and making FSR=3D2 raise a SIGTRAP now > could very well invite that regression to be reported. >=20 > Essentially, I don't think we can "fix" BKPT to always raise SIGTRAP. > The BKPT instruction is something the kernel has never _officially_ > supported. It looked like an easy fix. You explained that it is a bigger mess with "other features" and so on. Given that and the fact that it was never supported, I would appreciate just to enable interrupts before the (SIGBUS) signal is sent. Sebastian