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authorLorenzo Stoakes <lstoakes@gmail.com>2016-12-14 15:06:52 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 16:04:08 -0800
commit5b56d49fc31dbb0487e14ead790fc81ca9fb2c99 (patch)
treee9170cf8e9e0c2820d97c9ed9a418189a1bdf9c3
parent370b262c896e5565b271a3ea3abee4d0914ba443 (diff)
downloadlinux-5b56d49fc31dbb0487e14ead790fc81ca9fb2c99.tar.bz2
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>
-rw-r--r--drivers/gpu/drm/etnaviv/etnaviv_gem.c2
-rw-r--r--drivers/gpu/drm/i915/i915_gem_userptr.c2
-rw-r--r--drivers/infiniband/core/umem_odp.c2
-rw-r--r--drivers/vfio/vfio_iommu_type1.c2
-rw-r--r--fs/exec.c2
-rw-r--r--include/linux/mm.h2
-rw-r--r--kernel/events/uprobes.c4
-rw-r--r--mm/gup.c12
-rw-r--r--mm/memory.c2
-rw-r--r--security/tomoyo/domain.c2
10 files changed, 18 insertions, 14 deletions
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index 7d066a91d778..6f5dfabb3096 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -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;
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 107ddf51065e..d068af2ec3a3 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -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;
diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
index 1f0fe3217f23..6b079a31dced 100644
--- a/drivers/infiniband/core/umem_odp.c
+++ b/drivers/infiniband/core/umem_odp.c
@@ -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)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 9815e45c23c4..f3726ba12aa6 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -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);
}
diff --git a/fs/exec.c b/fs/exec.c
index 923c57d96899..eac60886b0ab 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -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;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a92c8d73aeaf..cc154454675a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1274,7 +1274,7 @@ extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
- struct vm_area_struct **vmas);
+ struct vm_area_struct **vmas, int *locked);
long get_user_pages(unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
struct vm_area_struct **vmas);
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index f9ec9add2164..215871bda3a2 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -301,7 +301,7 @@ int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr,
retry:
/* Read the page with vaddr into memory */
ret = get_user_pages_remote(NULL, mm, vaddr, 1, FOLL_FORCE, &old_page,
- &vma);
+ &vma, NULL);
if (ret <= 0)
return ret;
@@ -1712,7 +1712,7 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
* essentially a kernel access to the memory.
*/
result = get_user_pages_remote(NULL, mm, vaddr, 1, FOLL_FORCE, &page,
- NULL);
+ NULL, NULL);
if (result < 0)
return result;
diff --git a/mm/gup.c b/mm/gup.c
index e50178c58b97..b64c907aa4f0 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -917,6 +917,9 @@ EXPORT_SYMBOL(get_user_pages_unlocked);
* only intends to ensure the pages are faulted in.
* @vmas: array of pointers to vmas corresponding to each page.
* Or NULL if the caller does not require them.
+ * @locked: pointer to lock flag indicating whether lock is held and
+ * subsequently whether VM_FAULT_RETRY functionality can be
+ * utilised. Lock must initially be held.
*
* Returns number of pages pinned. This may be fewer than the number
* requested. If nr_pages is 0 or negative, returns 0. If no pages
@@ -960,10 +963,10 @@ EXPORT_SYMBOL(get_user_pages_unlocked);
long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
- struct vm_area_struct **vmas)
+ struct vm_area_struct **vmas, int *locked)
{
return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas,
- NULL, false,
+ locked, true,
gup_flags | FOLL_TOUCH | FOLL_REMOTE);
}
EXPORT_SYMBOL(get_user_pages_remote);
@@ -971,8 +974,9 @@ EXPORT_SYMBOL(get_user_pages_remote);
/*
* This is the same as get_user_pages_remote(), just with a
* less-flexible calling convention where we assume that the task
- * and mm being operated on are the current task's. We also
- * obviously don't pass FOLL_REMOTE in here.
+ * and mm being operated on are the current task's and don't allow
+ * passing of a locked parameter. We also obviously don't pass
+ * FOLL_REMOTE in here.
*/
long get_user_pages(unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
diff --git a/mm/memory.c b/mm/memory.c
index c264f7cd3e47..3a6a1239c42b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3919,7 +3919,7 @@ static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
struct page *page = NULL;
ret = get_user_pages_remote(tsk, mm, addr, 1,
- gup_flags, &page, &vma);
+ gup_flags, &page, &vma, NULL);
if (ret <= 0) {
#ifndef CONFIG_HAVE_IOREMAP_PROT
break;
diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index 682b73af7766..838ffa78cfda 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -881,7 +881,7 @@ bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
* the execve().
*/
if (get_user_pages_remote(current, bprm->mm, pos, 1,
- FOLL_FORCE, &page, NULL) <= 0)
+ FOLL_FORCE, &page, NULL, NULL) <= 0)
return false;
#else
page = bprm->page[pos / PAGE_SIZE];