From 5b56d49fc31dbb0487e14ead790fc81ca9fb2c99 Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Wed, 14 Dec 2016 15:06:52 -0800 Subject: [PATCH] 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 Acked-by: Michal Hocko Cc: Jan Kara Cc: Hugh Dickins Cc: Dave Hansen Cc: Rik van Riel Cc: Mel Gorman Cc: Paolo Bonzini Cc: Radim Krcmar Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpu/drm/etnaviv/etnaviv_gem.c | 2 +- drivers/gpu/drm/i915/i915_gem_userptr.c | 2 +- drivers/infiniband/core/umem_odp.c | 2 +- drivers/vfio/vfio_iommu_type1.c | 2 +- fs/exec.c | 2 +- include/linux/mm.h | 2 +- kernel/events/uprobes.c | 4 ++-- mm/gup.c | 12 ++++++++---- mm/memory.c | 2 +- security/tomoyo/domain.c | 2 +- 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]; -- 2.39.5