> On Nov 24, 2019, at 8:38 PM, Jackie Liu <jackieliu@xxxxxxxxxxxxxx> wrote: > > > >> 2019年11月25日 10:38，Jens Axboe <axboe@xxxxxxxxx> 写道： >> >>> On 11/24/19 5:43 PM, Jackie Liu wrote: >>> >>> >>>> 2019年11月25日 01:52，Pavel Begunkov <asml.silence@xxxxxxxxx> 写道： >>>> >>>> On 24/11/2019 20:10, Jens Axboe wrote: >>>>> On 11/24/19 1:58 AM, Pavel Begunkov wrote: >>>>>> Read/write requests to devices without implemented read/write_iter >>>>>> using fixed buffers causes general protection fault, which totally >>>>>> hangs a machine. >>>>>> >>>>>> io_import_fixed() initialises iov_iter with bvec, but loop_rw_iter() >>>>>> accesses it as iovec, so dereferencing random address. >>>>>> >>>>>> kmap() page by page in this case >>>>> >>>>> This looks good to me, much cleaner/simpler. I've added a few pipe fixed >>>>> buffer tests to liburing as well. Didn't crash for me, but obvious >>>>> garbage coming out. I've flagged this for stable as well. >>>>> >>>> The problem I have is that __user pointer is meant to be checked >>>> for not being a kernel address. I suspect, it could fail in some >>>> device, which double checks the pointer after vfs (e.g. using access_ok()). >>>> Am I wrong? Not a fault at least... >>>> >>>> #define access_ok(...) __range_not_ok(addr, user_addr_max()); >>>> >>>> BTW, is there anybody testing it for non x86-64 arch? >>>> >>> >>> I have some aarch64 platform, What test do you want me to do? >> >> A basic one to try would be: >> >> axboe@x1:/home/axboe/git/liburing $ test/stdout >> This is a pipe test >> This is a fixed pipe test >> >> But in general I'd just run make runtests in the liburing directory >> and go through all of them. >> > > For test/stdout is PASS. Tested-by: Jackie Liu <liuyun01@xxxxxxxxxx> Thanks! > But test/accept-link and test/fixed-link failed in for-5.5/io_uring-post branch. > that is expect? Yes, the fix for that is in 5.4, didn’t merge it into the 5.5 branch. It’ll pass once Linus pulls the 5.5 bits and the branches merge. — Jens Axboe
