From nobody Sun Feb 8 18:15:36 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB4ADC433EF for ; Tue, 17 May 2022 10:46:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344604AbiEQKqd (ORCPT ); Tue, 17 May 2022 06:46:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344616AbiEQKpL (ORCPT ); Tue, 17 May 2022 06:45:11 -0400 Received: from mail-wm1-x335.google.com (mail-wm1-x335.google.com [IPv6:2a00:1450:4864:20::335]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDDA8326D8 for ; Tue, 17 May 2022 03:45:10 -0700 (PDT) Received: by mail-wm1-x335.google.com with SMTP id v191-20020a1cacc8000000b00397001398c0so1120708wme.5 for ; Tue, 17 May 2022 03:45:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=LbqWA0ma3Gj0jvWCSxtRNJBD3Bf6tu8RmToQD/S/1tA=; b=DbFwuJQo294/gbHi6rpEOZU7Bz8G1bkjIMoiFErEualQSecRSwmKf1I2+jZW9Z2kpu zBVu9cWLVGg/qgCYtp5WtCi23R9+i/eukUmUrAjhKuuHzpuiVzKj67SBAKNQTmStarsG cji3nj6EAMJWiT1Zh/7be54brEwpGjD5HPbEz2Wd3onKo0e8XxXp9IqAmVwqCb3Vq6+e CgAYJ4j1MuC+KdFWv3ABusFIBQ0l1g39ZCx6YtNXwVH0Sa5wvaC3V/2UUGF6Rj9e0A5b L/nnlvt5EB0IhTt3AJWuQqGZL9frRl1iSdijBdq9iBvdtf6BmnTUPndhbOw2PJom5nr3 UlzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=LbqWA0ma3Gj0jvWCSxtRNJBD3Bf6tu8RmToQD/S/1tA=; b=S2BPn2H3k54+UZmqHwAzYhqMOFW6mvbo3GtrONZKUR7/yl2VXjfTkYcU/30k2HtexJ fMwJZuv+DfUrVZjY1Y970LLQCWiB2J7eq07/AzK0SqdWGju/J6hU8U/J0Bwdk5WgIl2R sPLgNwspJbrkdf5/gBjozFr1zQ9OnIal2WCW/Hex9+s6QCwQxgCQxVmC/Sg4fXPjUXkm jLllTljIQhfq5VBVv9+XguUPG1KNr/u0F3mRRWALzeW760j3lwuyLccndMI0TGe7WtMA oEK4ve/6ULPGmlUq4X4FLYFKICDGzlmcio+zk00Ji6a/+lIhzagHjZwTCtNM+OI0xE7O XQMQ== X-Gm-Message-State: AOAM530EEBL77oKBuFKKTGjhhPXg/cZKoEfgSKXJOGsg0qM7QGOTHMe+ nOrO3fa+h9tdx8WGzGDZH4pyKwwADIg= X-Google-Smtp-Source: ABdhPJyrKgC4/kWiVatQEZYepXXoDCRN9um/5NtYnhfJ1Yi7jh8UaBOqub6l8zKFfl2CnzbkDj3Nag== X-Received: by 2002:a1c:f710:0:b0:394:1960:e8a1 with SMTP id v16-20020a1cf710000000b003941960e8a1mr20749622wmh.154.1652784309472; Tue, 17 May 2022 03:45:09 -0700 (PDT) Received: from octofox.metropolis ([178.134.210.144]) by smtp.gmail.com with ESMTPSA id r5-20020adfbb05000000b0020d00174eabsm8612218wrg.94.2022.05.17.03.45.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 May 2022 03:45:09 -0700 (PDT) From: Max Filippov To: linux-xtensa@linux-xtensa.org Cc: Chris Zankel , linux-kernel@vger.kernel.org, Max Filippov Subject: [PATCH v3 1/3] xtensa: add trap handler for division by zero Date: Tue, 17 May 2022 03:44:56 -0700 Message-Id: <20220517104458.257799-2-jcmvbkbc@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220517104458.257799-1-jcmvbkbc@gmail.com> References: <20220517104458.257799-1-jcmvbkbc@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add c-level handler for the division by zero exception and kill the task if it was thrown from the kernel space or send SIGFPE otherwise. Signed-off-by: Max Filippov --- arch/xtensa/kernel/traps.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c index 138a86fbe9d7..24d11b44fa57 100644 --- a/arch/xtensa/kernel/traps.c +++ b/arch/xtensa/kernel/traps.c @@ -49,6 +49,7 @@ */ =20 static void do_illegal_instruction(struct pt_regs *regs); +static void do_div0(struct pt_regs *regs); static void do_interrupt(struct pt_regs *regs); #if XTENSA_FAKE_NMI static void do_nmi(struct pt_regs *regs); @@ -95,7 +96,7 @@ static dispatch_init_table_t __initdata dispatch_init_tab= le[] =3D { #ifdef SUPPORT_WINDOWED { EXCCAUSE_ALLOCA, USER|KRNL, fast_alloca }, #endif -/* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */ +{ EXCCAUSE_INTEGER_DIVIDE_BY_ZERO, 0, do_div0 }, /* EXCCAUSE_PRIVILEGED unhandled */ #if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION #ifdef CONFIG_XTENSA_UNALIGNED_USER @@ -307,6 +308,11 @@ static void do_illegal_instruction(struct pt_regs *reg= s) force_sig(SIGILL); } =20 +static void do_div0(struct pt_regs *regs) +{ + __die_if_kernel("Unhandled division by 0 in kernel", regs, SIGKILL); + force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->pc); +} =20 /* * Handle unaligned memory accesses from user space. Kill task. --=20 2.30.2