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由 Jann Horn 提交于
To be safe against concurrent changes to the VMA tree, we must take the mmap lock around GUP operations (excluding the GUP-fast family of operations, which will take the mmap lock by themselves if necessary). This code is only for testing, and it's only reachable by root through debugfs, so this doesn't really have any impact; however, if we want to add lockdep asserts into the GUP path, we need to have clean locking here. Signed-off-by: NJann Horn <jannh@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Reviewed-by: NJason Gunthorpe <jgg@nvidia.com> Reviewed-by: NJohn Hubbard <jhubbard@nvidia.com> Acked-by: NMichel Lespinasse <walken@google.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Link: https://lkml.kernel.org/r/CAG48ez3SG6ngZLtasxJ6LABpOnqCz5-QHqb0B4k44TQ8F9n6+w@mail.gmail.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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