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([2001:df0:0:200c:c0e7:435e:1bae:e7d]) by smtp.gmail.com with ESMTPSA id b3sm16963139pfi.179.2021.07.12.12.12.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 Jul 2021 12:12:50 -0700 (PDT) Subject: Re: RFC: remove set_fs for m68k To: Andreas Schwab Cc: Christoph Hellwig , Geert Uytterhoeven , Greg Ungerer , linux-m68k@lists.linux-m68k.org References: <20210709070132.3387689-1-hch@lst.de> <039e2f42-b9bc-d8ce-393a-c0896439f784@gmail.com> <87fswjomtm.fsf@igel.home> From: Michael Schmitz Message-ID: <969718aa-92d4-e77b-0630-f9da6c809178@gmail.com> Date: Tue, 13 Jul 2021 07:12:45 +1200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <87fswjomtm.fsf@igel.home> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org Hi Andreas, On 12/07/21 10:20 pm, Andreas Schwab wrote: > On Jul 11 2021, Michael Schmitz wrote: > >> Testing your series, I've got this in the console log: >> >> [16534.130000] *** FORMAT ERROR *** FORMAT=0 >> [16534.150000] Current process id is 1347 >> [16534.160000] BAD KERNEL TRAP: 00000000 >> [16534.180000] Modules linked in: atari_scsi ne 8390p >> [16534.210000] PC: [<00002a8c>] resume_userspace+0x14/0x16 >> [16534.230000] SR: 2200 SP: d1b6e0e8 a2: 00000000 >> [16534.240000] d0: 0000001e d1: 00000003 d2: 00000578 d3: 00000000 >> [16534.270000] d4: ffffffff d5: 00000001 a0: 00000578 a1: 00000080 >> [16534.300000] Process savelog (pid: 1347, task=e3955528) >> [16534.310000] Frame format=0 >> [16534.330000] Stack from 005e9fa4: >> [16534.330000] 02108005 0d06b008 1eeeb649 007e0001 00aea040 >> 003ec318 005e9e68 000279a2 >> [16534.330000] 000b0000 00000000 00000000 030dfffb 0044fffa >> 0e000000 fffa1a00 fffa1c00 >> [16534.330000] fffa1e00 fffb0e40 fffb0e80 00049e02 00000040 >> 0085a800 00000001 >> [16534.430000] Call Trace: [<000279a2>] warn_slowpath_fmt+0x0/0x62 >> [16534.460000] [<000b0000>] vm_map_ram+0x144/0x5ae >> [16534.490000] [<00049e02>] __handle_irq_event_percpu+0x38/0xce >> [16534.520000] >> [16534.540000] Code: 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 <9f38> 9f38 >> 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 > That looks like something overwrote the kernel code. 0x9f38 isn't an > insn that you would ever see in the kernel. That confirms my guess - can we rely on the call trace in that case? And how does overwriting kernel code at that address tee up with the kernel still happily chugging along? Cheers,     Michael > > Andreas. >