> 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> But test/accept-link and test/fixed-link failed in for-5.5/io_uring-post branch. that is expect? -- Jackie Liu
