Commit 5b56d49f authored Dec 14, 2016 by Lorenzo Stoakes Committed by Linus Torvalds Dec 14, 2016

mm: add locked parameter to get_user_pages_remote()

Patch series "mm: unexport __get_user_pages_unlocked()".

This patch series continues the cleanup of get_user_pages*() functions
taking advantage of the fact we can now pass gup_flags as we please.

It firstly adds an additional 'locked' parameter to
get_user_pages_remote() to allow for its callers to utilise
VM_FAULT_RETRY functionality.  This is necessary as the invocation of
__get_user_pages_unlocked() in process_vm_rw_single_vec() makes use of
this and no other existing higher level function would allow it to do
so.

Secondly existing callers of __get_user_pages_unlocked() are replaced
with the appropriate higher-level replacement -
get_user_pages_unlocked() if the current task and memory descriptor are
referenced, or get_user_pages_remote() if other task/memory descriptors
are referenced (having acquiring mmap_sem.)

This patch (of 2):

Add a int *locked parameter to get_user_pages_remote() to allow
VM_FAULT_RETRY faulting behaviour similar to get_user_pages_[un]locked().

Taking into account the previous adjustments to get_user_pages*()
functions allowing for the passing of gup_flags, we are now in a
position where __get_user_pages_unlocked() need only be exported for his
ability to allow VM_FAULT_RETRY behaviour, this adjustment allows us to
subsequently unexport __get_user_pages_unlocked() as well as allowing
for future flexibility in the use of get_user_pages_remote().

[sfr@canb.auug.org.au: merge fix for get_user_pages_remote API change]
  Link: http://lkml.kernel.org/r/20161122210511.024ec341@canb.auug.org.au
Link: http://lkml.kernel.org/r/20161027095141.2569-2-lstoakes@gmail.com


Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 370b262c

drivers/gpu/drm/etnaviv/etnaviv_gem.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -759,7 +759,7 @@ static struct page **etnaviv_gem_userptr_do_get_pages(
		down_read(&mm->mmap_sem);
		while (pinned < npages) {
		ret = get_user_pages_remote(task, mm, ptr, npages - pinned,
		flags, pvec + pinned, NULL);
		flags, pvec + pinned, NULL, NULL);
		if (ret < 0)
		break;

drivers/gpu/drm/i915/i915_gem_userptr.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -515,7 +515,7 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work)
		obj->userptr.ptr + pinned * PAGE_SIZE,
		npages - pinned,
		flags,
		pvec + pinned, NULL);
		pvec + pinned, NULL, NULL);
		if (ret < 0)
		break;

drivers/infiniband/core/umem_odp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -578,7 +578,7 @@ int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 user_virt, u64 bcnt,
		*/
		npages = get_user_pages_remote(owning_process, owning_mm,
		user_virt, gup_num_pages,
		flags, local_page_list, NULL);
		flags, local_page_list, NULL, NULL);
		up_read(&owning_mm->mmap_sem);

		if (npages < 0)

drivers/vfio/vfio_iommu_type1.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -362,7 +362,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,

		down_read(&mm->mmap_sem);
		ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags, page,
		NULL);
		NULL, NULL);
		up_read(&mm->mmap_sem);
		}

fs/exec.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -209,7 +209,7 @@ static struct page get_arg_page(struct linux_binprm bprm, unsigned long pos,
		* doing the exec and bprm->mm is the new process's mm.
		*/
		ret = get_user_pages_remote(current, bprm->mm, pos, 1, gup_flags,
		&page, NULL);
		&page, NULL, NULL);
		if (ret <= 0)
		return NULL;

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