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[2003:d8:2f45:d000:62f2:4df0:704a:e859]) by smtp.gmail.com with ESMTPSA id w16-20020adfec50000000b003143867d2ebsm11776170wrn.63.2023.07.23.23.23.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 23 Jul 2023 23:23:56 -0700 (PDT) Message-ID: <86fd0ccb-f460-651f-8048-1026d905a2d6@redhat.com> Date: Mon, 24 Jul 2023 08:23:55 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH v8 1/4] fs/proc/kcore: avoid bounce buffer for ktext data To: Baoquan He , Jiri Olsa Cc: Lorenzo Stoakes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Uladzislau Rezki , Matthew Wilcox , Liu Shixin , Jens Axboe , Alexander Viro References: From: David Hildenbrand Organization: Red Hat In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: A4333140010 X-Stat-Signature: 51nwbsmpb37rqkgqz81z51kfcoyjaqtu X-Rspam-User: X-HE-Tag: 1690179840-909102 X-HE-Meta: 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 Kzy2Z2z0 vbDaQeKWhBf2694bvEDLCRYfyhTEgF/B/Md8JRog/z8MWduFqxYDmlhOR5eVfBXFVJDZ9vo8ayLehArKgqJj3yYnOSG4zMrRs3O2eb65ckQ6E2vyjIyTKpu4hkCbrtNn1fv1ncQcOucmpB+bbzOTlVFVR0udYX64TZYOdgA1GrvP3MmiyhiigFQfxPyeuJ2hwI4ZhHT7BibbvgvFla6nu4IY32UolhaZrdXzeymbuC8t8mFqFyJBWWXWlAqT2TZJPFca7OuPRygpUghJ+/snfIS+1vA8ITX08+c8pHMpbijGqaT0wsyQESUs77hkzWCeY3lhftLVeRt3F4cdfwXqyLbh2HE5t5Z9Wj+LsRi1+oyf8HDqpZnl4HVZE+eJNZvavssE4 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi, > > I met this too when I executed below command to trigger a kcore reading. > I wanted to do a simple testing during system running and got this. > > makedumpfile --mem-usage /proc/kcore > > Later I tried your above objdump testing, it corrupted system too. > What do you mean with "corrupted system too" -- did it not only fail to dump the system, but also actually harmed the system? @Lorenzo do you plan on reproduce + fix, or should we consider reverting that change? -- Cheers, David / dhildenb