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[23.128.96.18]) by mx.google.com with ESMTP id w18si1697549ejy.196.2021.03.11.05.48.53; Thu, 11 Mar 2021 05:49:16 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@ellerman.id.au header.s=201909 header.b=LqPgtXO3; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233708AbhCKNq6 (ORCPT + 99 others); Thu, 11 Mar 2021 08:46:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233241AbhCKNqo (ORCPT ); Thu, 11 Mar 2021 08:46:44 -0500 Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 032DEC061574 for ; Thu, 11 Mar 2021 05:46:43 -0800 (PST) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4Dx9GR2Cmcz9sWW; Fri, 12 Mar 2021 00:46:38 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1615470399; bh=iZZn561Pa2Y3vO+gJp8nHF4i8Co1/FqjhNLC6ZpDGho=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=LqPgtXO3e6V4LubRzK/fX4PXhI+W0hYK9LIksz+qJsNJ96M5akc9+swSpQEUI5QdB IkwUG2aqYmylB34Nc09+dtxBsJW7Cms819k7JxYqdObB3LJ2jkDjhbAxjjHQf+3v3q j3XNpGXmrKQ+AD0lSMtPrf7yAuiTYBzEE8wnWnbye0lT1BAlswMcMp3SVPXOX5Dse+ aqg0g/ETJsYJIzRTYIQNcOVV8ZyH4j77XfocRtVRXEnW3HeAKcPG9yl6frCWLlAt+J j79DFutgCunfzaWUIf01Zwm1NqdEBlHiZWxH/6GBt3Gq9Lb8A4HGXWZpL62BWebsSv tIjCGKp27rHNA== From: Michael Ellerman To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , npiggin@gmail.com Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v2 25/43] powerpc/32: Replace ASM exception exit by C exception exit from ppc64 In-Reply-To: References: Date: Fri, 12 Mar 2021 00:46:36 +1100 Message-ID: <87tuphkdkz.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christophe Leroy writes: > This patch replaces the PPC32 ASM exception exit by C exception exit. > > Signed-off-by: Christophe Leroy > --- > arch/powerpc/kernel/entry_32.S | 481 +++++++++----------------------- > arch/powerpc/kernel/interrupt.c | 4 + > 2 files changed, 132 insertions(+), 353 deletions(-) Bisect points to this breaking qemu mac99 for me, with pmac32_defconfig. I haven't had time to dig any deeper sorry. cheers Freeing unused kernel memory: 1132K This architecture does not have kernel memory protection. Run /init as init process init[1]: User access of kernel address (fffffd20) - exploit attempt? (uid: 0) init[1]: segfault (11) at fffffd20 nip b7e78638 lr b7e845e4 code 1 in ld-2.27.so[b7e6b000+22000] init[1]: code: 92010080 92210084 92410088 92810090 92a10094 92c10098 930100a0 932100a4 init[1]: code: 934100a8 936100ac 93a100b4 91810074 <7d41496e> 39400000 3b810017 579c0036 Kernel panic - not syncing: Attempted to kill init! exitcode=0x00ERROR: Error: saw oops/warning etc. while expecting 00000b CPU: 0 PID: 1 Comm: init Not tainted 5.12.0-rc2+ #1 Call Trace: [f1019d80] [c004f1ec] panic+0x138/0x328 (unreliable) [f1019de0] [c0051c8c] do_exit+0x880/0x8f4 [f1019e30] [c0052bdc] do_group_exit+0x40/0xa4 [f1019e50] [c0060d04] get_signal+0x1e8/0x834 [f1019eb0] [c000b624] do_notify_resume+0xc8/0x314 [f1019f10] [c0010da8] interrupt_exit_user_prepare+0xa4/0xdc [f1019f30] [c0018228] interrupt_return+0x14/0x14c --- interrupt: 300 at 0xb7e78638 NIP: b7e78638 LR: b7e845e4 CTR: c01ea2d8 REGS: f1019f40 TRAP: 0300 Not tainted (5.12.0-rc2+) MSR: 0000d032 CR: 28004422 XER: 20000000 DAR: fffffd20 DSISR: 42000000 GPR00: b7e845e4 bf951440 00000000 bf951460 00000000 bf951718 fefefeff 7f7f7f7f GPR08: bf9516b0 406ae8e0 b7eac1d4 00000000 0a12247b 00000000 b7e8a0d0 b7e78554 GPR16: bf951730 bf9516f0 b7eaaf40 bf9516f0 00000001 b7eaa688 10002178 bf951460 GPR24: 00000000 00000000 b7eac200 100cff38 bf9516f0 10002179 b7e845e4 bf951440 NIP [b7e78638] 0xb7e78638 LR [b7e845e4] 0xb7e845e4 --- interrupt: 300 Rebooting in 180 seconds..