Messages in this thread | | | Date | Tue, 27 Oct 2020 00:09:20 +0000 | From | Al Viro <> | Subject | Re: [PATCH] Fix compat regression in process_vm_rw() |
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On Mon, Oct 26, 2020 at 06:03:18PM -0600, Jens Axboe wrote: > The removal of compat_process_vm_{readv,writev} didn't change > process_vm_rw(), which always assumes it's not doing a compat syscall. > Instead of passing in 'false' unconditionally for 'compat', make it > conditional on in_compat_syscall(). > > Fixes: c3973b401ef2 ("mm: remove compat_process_vm_{readv,writev}") > Reported-by: Kyle Huey <me@kylehuey.com> > Signed-off-by: Jens Axboe <axboe@kernel.dk>
ACK with some reservations - I suspect that we want an explicit flag for process_vm_{read,write}v() that would force the 64bit layout for the vector refering to the foreign process. It's not relevant for regression fix; however, as it is these syscalls are not usable for 32bit process trying to access memory of 64bit one - there's no way to specify the addresses past 4G.
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