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Howlett" , Michael Keyes , Tad , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rick.p.edgecombe@intel.com References: <90777046-a420-b19f-1847-d353b9938131@vigovproductions.net> <20230502140828.hilf3myxj6kpiunz@revolver> <20230502140907.o7fznev4jthtgp4i@revolver> Content-Language: en-US From: Juhyung Park In-Reply-To: <20230502140907.o7fznev4jthtgp4i@revolver> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Liam, It's a bit hard to follow this particular issue on v6.1 as there are many email threads related to this. I just wanted to ask if whether this is fixed on mainline and v6.1 stable yet. If there's a new thread tackling this issue, I'd appreciate it if you can link it here. Thanks, regards On 5/2/23 23:09, Liam R. Howlett wrote: > ...Adding Rick to the Cc this time. > > * Liam R. Howlett [230502 10:08]: >> * Michael Keyes [230430 18:41]: >>> On 29.04.23 15:32, Tad wrote: >>>> This reintroduces the issue described in >>>> https://lore.kernel.org/linux-mm/cb8dc31a-fef2-1d09-f133-e9f7b9f9e77a@sony.com/ >>> Yes, I also ran into this (even though I'd somehow missed it the >>> previous time). >> >> Rick Edgecombe reported something similar [1]. >> >> This is probably to do with my stack guard checks I recently added. >> >>> >>> Apparently the issue arises at mm/mmap.c:1582, where low_limit is set to >>> vm_end_gap(tmp). Occasionally, this returns a 64-bit address (e.g. >>> 0x7fedea581000), which is obviously greater than high_limit for a 32-bit >>> mmap, and causes the next call to mas_empty_area() to fail. >>> >>> I'm not sure why vm_end_gap(tmp) occasionally returns a 64-bit address, >>> or if the best solution is to just check for this and skip the retry if >>> it occurs… >>> >> >> Thanks for the debugging. I will look into it. >> >> I am currently trying to revise how the iterators, prev/next deal with >> shifting outside the requested limits. I suspect it's something to do >> with hitting the limit and what someone would assume the next operation >> means. >> >> [1] https://lore.kernel.org/linux-mm/32f156ba80010fd97dbaf0a0cdfc84366608624d.camel@intel.com/ > >