* [PATCH v2 0/2] mm: unexport __get_user_pages_unlocked() @ 2016-10-27 20:34 ` Lorenzo Stoakes 0 siblings, 0 replies; 6+ messages in thread From: Lorenzo Stoakes @ 2016-10-27 20:34 UTC (permalink / raw) To: linux-mm Cc: Michal Hocko, Linus Torvalds, Jan Kara, Hugh Dickins, Dave Hansen, Rik van Riel, Mel Gorman, Andrew Morton, Paolo Bonzini, Radim Krčmář, kvm, linux-kernel, linux-security-module, linux-rdma, dri-devel, linux-fsdevel 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.) Lorenzo Stoakes (2): mm: add locked parameter to get_user_pages_remote() mm: unexport __get_user_pages_unlocked() drivers/gpu/drm/etnaviv/etnaviv_gem.c | 2 +- drivers/gpu/drm/i915/i915_gem_userptr.c | 2 +- drivers/infiniband/core/umem_odp.c | 2 +- fs/exec.c | 2 +- include/linux/mm.h | 5 +---- kernel/events/uprobes.c | 4 ++-- mm/gup.c | 20 ++++++++++++-------- mm/memory.c | 2 +- mm/nommu.c | 7 +++---- mm/process_vm_access.c | 12 ++++++++---- security/tomoyo/domain.c | 2 +- virt/kvm/async_pf.c | 10 +++++++--- virt/kvm/kvm_main.c | 5 ++--- 13 files changed, 41 insertions(+), 34 deletions(-) ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 0/2] mm: unexport __get_user_pages_unlocked() @ 2016-10-27 20:34 ` Lorenzo Stoakes 0 siblings, 0 replies; 6+ messages in thread From: Lorenzo Stoakes @ 2016-10-27 20:34 UTC (permalink / raw) To: linux-mm Cc: Michal Hocko, Linus Torvalds, Jan Kara, Hugh Dickins, Dave Hansen, Rik van Riel, Mel Gorman, Andrew Morton, Paolo Bonzini, Radim Krčmář, kvm, linux-kernel, linux-security-module, linux-rdma, dri-devel, linux-fsdevel 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.) Lorenzo Stoakes (2): mm: add locked parameter to get_user_pages_remote() mm: unexport __get_user_pages_unlocked() drivers/gpu/drm/etnaviv/etnaviv_gem.c | 2 +- drivers/gpu/drm/i915/i915_gem_userptr.c | 2 +- drivers/infiniband/core/umem_odp.c | 2 +- fs/exec.c | 2 +- include/linux/mm.h | 5 +---- kernel/events/uprobes.c | 4 ++-- mm/gup.c | 20 ++++++++++++-------- mm/memory.c | 2 +- mm/nommu.c | 7 +++---- mm/process_vm_access.c | 12 ++++++++---- security/tomoyo/domain.c | 2 +- virt/kvm/async_pf.c | 10 +++++++--- virt/kvm/kvm_main.c | 5 ++--- 13 files changed, 41 insertions(+), 34 deletions(-) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 1/2] mm: add locked parameter to get_user_pages_remote() 2016-10-27 20:34 ` Lorenzo Stoakes @ 2016-10-27 20:34 ` Lorenzo Stoakes -1 siblings, 0 replies; 6+ messages in thread From: Lorenzo Stoakes @ 2016-10-27 20:34 UTC (permalink / raw) To: linux-mm Cc: Michal Hocko, Linus Torvalds, Jan Kara, Hugh Dickins, Dave Hansen, Rik van Riel, Mel Gorman, Andrew Morton, Paolo Bonzini, Radim Krčmář, kvm, linux-kernel, linux-security-module, linux-rdma, dri-devel, linux-fsdevel, Lorenzo Stoakes This patch adds an int *locked parameter to get_user_pages_remote() to allow VM_FAULT_RETRY faulting behaviour similar to get_user_pages_[un]locked(). It additionally clears the way for __get_user_pages_unlocked() to be unexported as its sole remaining useful characteristic was to allow for VM_FAULT_RETRY behaviour when faulting in pages. It should not introduce any functional changes, however it does allow for subsequent changes to get_user_pages_remote() callers to take advantage of VM_FAULT_RETRY. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> --- v2: updated description drivers/gpu/drm/etnaviv/etnaviv_gem.c | 2 +- drivers/gpu/drm/i915/i915_gem_userptr.c | 2 +- drivers/infiniband/core/umem_odp.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 +- 9 files changed, 17 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c index 0370b84..0c69a97f 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c @@ -763,7 +763,7 @@ 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 c6f780f..836b525 100644 --- a/drivers/gpu/drm/i915/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/i915_gem_userptr.c @@ -522,7 +522,7 @@ __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 1f0fe32..6b079a3 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/fs/exec.c b/fs/exec.c index 4e497b9..2cf049d 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 a92c8d7..cc15445 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 f9ec9ad..215871b 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 ec4f827..0567851 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -920,6 +920,9 @@ 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 @@ -963,10 +966,10 @@ 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); @@ -974,8 +977,9 @@ 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 e18c57b..2f3949b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3883,7 +3883,7 @@ 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 682b73a..838ffa7 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]; -- 2.10.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 1/2] mm: add locked parameter to get_user_pages_remote() @ 2016-10-27 20:34 ` Lorenzo Stoakes 0 siblings, 0 replies; 6+ messages in thread From: Lorenzo Stoakes @ 2016-10-27 20:34 UTC (permalink / raw) To: linux-mm Cc: Michal Hocko, Linus Torvalds, Jan Kara, Hugh Dickins, Dave Hansen, Rik van Riel, Mel Gorman, Andrew Morton, Paolo Bonzini, Radim Krčmář, kvm, linux-kernel, linux-security-module, linux-rdma, dri-devel, linux-fsdevel, Lorenzo Stoakes This patch adds an int *locked parameter to get_user_pages_remote() to allow VM_FAULT_RETRY faulting behaviour similar to get_user_pages_[un]locked(). It additionally clears the way for __get_user_pages_unlocked() to be unexported as its sole remaining useful characteristic was to allow for VM_FAULT_RETRY behaviour when faulting in pages. It should not introduce any functional changes, however it does allow for subsequent changes to get_user_pages_remote() callers to take advantage of VM_FAULT_RETRY. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> --- v2: updated description drivers/gpu/drm/etnaviv/etnaviv_gem.c | 2 +- drivers/gpu/drm/i915/i915_gem_userptr.c | 2 +- drivers/infiniband/core/umem_odp.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 +- 9 files changed, 17 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c index 0370b84..0c69a97f 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c @@ -763,7 +763,7 @@ 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 c6f780f..836b525 100644 --- a/drivers/gpu/drm/i915/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/i915_gem_userptr.c @@ -522,7 +522,7 @@ __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 1f0fe32..6b079a3 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/fs/exec.c b/fs/exec.c index 4e497b9..2cf049d 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 a92c8d7..cc15445 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 f9ec9ad..215871b 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 ec4f827..0567851 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -920,6 +920,9 @@ 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 @@ -963,10 +966,10 @@ 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); @@ -974,8 +977,9 @@ 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 e18c57b..2f3949b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3883,7 +3883,7 @@ 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 682b73a..838ffa7 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]; -- 2.10.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 2/2] mm: unexport __get_user_pages_unlocked() 2016-10-27 20:34 ` Lorenzo Stoakes @ 2016-10-27 20:34 ` Lorenzo Stoakes -1 siblings, 0 replies; 6+ messages in thread From: Lorenzo Stoakes @ 2016-10-27 20:34 UTC (permalink / raw) To: linux-mm Cc: Michal Hocko, Linus Torvalds, Jan Kara, Hugh Dickins, Dave Hansen, Rik van Riel, Mel Gorman, Andrew Morton, Paolo Bonzini, Radim Krčmář, kvm, linux-kernel, linux-security-module, linux-rdma, dri-devel, linux-fsdevel, Lorenzo Stoakes This patch unexports the low-level __get_user_pages_unlocked() function and replaces invocations with calls to more appropriate higher-level functions. In hva_to_pfn_slow() we are able to replace __get_user_pages_unlocked() with get_user_pages_unlocked() since we can now pass gup_flags. In async_pf_execute() and process_vm_rw_single_vec() we need to pass different tsk, mm arguments so get_user_pages_remote() is the sane replacement in these cases (having added manual acquisition and release of mmap_sem.) Additionally get_user_pages_remote() reintroduces use of the FOLL_TOUCH flag. However, this flag was originally silently dropped by 1e9877902dc7e ("mm/gup: Introduce get_user_pages_remote()"), so this appears to have been unintentional and reintroducing it is therefore not an issue. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> --- v2: updated patch to apply against mainline rather than -mmots include/linux/mm.h | 3 --- mm/gup.c | 8 ++++---- mm/nommu.c | 7 +++---- mm/process_vm_access.c | 12 ++++++++---- virt/kvm/async_pf.c | 10 +++++++--- virt/kvm/kvm_main.c | 5 ++--- 6 files changed, 24 insertions(+), 21 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index cc15445..7b2d14e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1280,9 +1280,6 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, struct vm_area_struct **vmas); long get_user_pages_locked(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, int *locked); -long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, unsigned long nr_pages, - struct page **pages, unsigned int gup_flags); long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags); int get_user_pages_fast(unsigned long start, int nr_pages, int write, diff --git a/mm/gup.c b/mm/gup.c index 0567851..8028af1 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -866,9 +866,10 @@ EXPORT_SYMBOL(get_user_pages_locked); * according to the parameters "pages", "write", "force" * respectively. */ -__always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, unsigned long nr_pages, - struct page **pages, unsigned int gup_flags) +static __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, + struct mm_struct *mm, unsigned long start, + unsigned long nr_pages, struct page **pages, + unsigned int gup_flags) { long ret; int locked = 1; @@ -880,7 +881,6 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m up_read(&mm->mmap_sem); return ret; } -EXPORT_SYMBOL(__get_user_pages_unlocked); /* * get_user_pages_unlocked() is suitable to replace the form: diff --git a/mm/nommu.c b/mm/nommu.c index 8b8faaf..669437b 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -176,9 +176,9 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, } EXPORT_SYMBOL(get_user_pages_locked); -long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, unsigned long nr_pages, - struct page **pages, unsigned int gup_flags) +static long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, unsigned long nr_pages, + struct page **pages, unsigned int gup_flags) { long ret; down_read(&mm->mmap_sem); @@ -187,7 +187,6 @@ long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, up_read(&mm->mmap_sem); return ret; } -EXPORT_SYMBOL(__get_user_pages_unlocked); long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags) diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index be8dc8d..84d0c7e 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -88,7 +88,7 @@ static int process_vm_rw_single_vec(unsigned long addr, ssize_t rc = 0; unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES / sizeof(struct pages *); - unsigned int flags = FOLL_REMOTE; + unsigned int flags = 0; /* Work out address and page range required */ if (len == 0) @@ -100,15 +100,19 @@ static int process_vm_rw_single_vec(unsigned long addr, while (!rc && nr_pages && iov_iter_count(iter)) { int pages = min(nr_pages, max_pages_per_loop); + int locked = 1; size_t bytes; /* * Get the pages we're interested in. We must - * add FOLL_REMOTE because task/mm might not + * access remotely because task/mm might not * current/current->mm */ - pages = __get_user_pages_unlocked(task, mm, pa, pages, - process_pages, flags); + down_read(&mm->mmap_sem); + pages = get_user_pages_remote(task, mm, pa, pages, flags, + process_pages, NULL, &locked); + if (locked) + up_read(&mm->mmap_sem); if (pages <= 0) return -EFAULT; diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index 8035cc1..dab8b19 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -76,16 +76,20 @@ static void async_pf_execute(struct work_struct *work) struct kvm_vcpu *vcpu = apf->vcpu; unsigned long addr = apf->addr; gva_t gva = apf->gva; + int locked = 1; might_sleep(); /* * This work is run asynchromously to the task which owns * mm and might be done in another context, so we must - * use FOLL_REMOTE. + * access remotely. */ - __get_user_pages_unlocked(NULL, mm, addr, 1, NULL, - FOLL_WRITE | FOLL_REMOTE); + down_read(&mm->mmap_sem); + get_user_pages_remote(NULL, mm, addr, 1, FOLL_WRITE, NULL, NULL, + &locked); + if (locked) + up_read(&mm->mmap_sem); kvm_async_page_present_sync(vcpu, apf); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2907b7b..c45d951 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1415,13 +1415,12 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, npages = get_user_page_nowait(addr, write_fault, page); up_read(¤t->mm->mmap_sem); } else { - unsigned int flags = FOLL_TOUCH | FOLL_HWPOISON; + unsigned int flags = FOLL_HWPOISON; if (write_fault) flags |= FOLL_WRITE; - npages = __get_user_pages_unlocked(current, current->mm, addr, 1, - page, flags); + npages = get_user_pages_unlocked(addr, 1, page, flags); } if (npages != 1) return npages; -- 2.10.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 2/2] mm: unexport __get_user_pages_unlocked() @ 2016-10-27 20:34 ` Lorenzo Stoakes 0 siblings, 0 replies; 6+ messages in thread From: Lorenzo Stoakes @ 2016-10-27 20:34 UTC (permalink / raw) To: linux-mm Cc: Michal Hocko, Linus Torvalds, Jan Kara, Hugh Dickins, Dave Hansen, Rik van Riel, Mel Gorman, Andrew Morton, Paolo Bonzini, Radim Krčmář, kvm, linux-kernel, linux-security-module, linux-rdma, dri-devel, linux-fsdevel, Lorenzo Stoakes This patch unexports the low-level __get_user_pages_unlocked() function and replaces invocations with calls to more appropriate higher-level functions. In hva_to_pfn_slow() we are able to replace __get_user_pages_unlocked() with get_user_pages_unlocked() since we can now pass gup_flags. In async_pf_execute() and process_vm_rw_single_vec() we need to pass different tsk, mm arguments so get_user_pages_remote() is the sane replacement in these cases (having added manual acquisition and release of mmap_sem.) Additionally get_user_pages_remote() reintroduces use of the FOLL_TOUCH flag. However, this flag was originally silently dropped by 1e9877902dc7e ("mm/gup: Introduce get_user_pages_remote()"), so this appears to have been unintentional and reintroducing it is therefore not an issue. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> --- v2: updated patch to apply against mainline rather than -mmots include/linux/mm.h | 3 --- mm/gup.c | 8 ++++---- mm/nommu.c | 7 +++---- mm/process_vm_access.c | 12 ++++++++---- virt/kvm/async_pf.c | 10 +++++++--- virt/kvm/kvm_main.c | 5 ++--- 6 files changed, 24 insertions(+), 21 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index cc15445..7b2d14e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1280,9 +1280,6 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, struct vm_area_struct **vmas); long get_user_pages_locked(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, int *locked); -long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, unsigned long nr_pages, - struct page **pages, unsigned int gup_flags); long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags); int get_user_pages_fast(unsigned long start, int nr_pages, int write, diff --git a/mm/gup.c b/mm/gup.c index 0567851..8028af1 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -866,9 +866,10 @@ EXPORT_SYMBOL(get_user_pages_locked); * according to the parameters "pages", "write", "force" * respectively. */ -__always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, unsigned long nr_pages, - struct page **pages, unsigned int gup_flags) +static __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, + struct mm_struct *mm, unsigned long start, + unsigned long nr_pages, struct page **pages, + unsigned int gup_flags) { long ret; int locked = 1; @@ -880,7 +881,6 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m up_read(&mm->mmap_sem); return ret; } -EXPORT_SYMBOL(__get_user_pages_unlocked); /* * get_user_pages_unlocked() is suitable to replace the form: diff --git a/mm/nommu.c b/mm/nommu.c index 8b8faaf..669437b 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -176,9 +176,9 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, } EXPORT_SYMBOL(get_user_pages_locked); -long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, unsigned long nr_pages, - struct page **pages, unsigned int gup_flags) +static long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, unsigned long nr_pages, + struct page **pages, unsigned int gup_flags) { long ret; down_read(&mm->mmap_sem); @@ -187,7 +187,6 @@ long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, up_read(&mm->mmap_sem); return ret; } -EXPORT_SYMBOL(__get_user_pages_unlocked); long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags) diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index be8dc8d..84d0c7e 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -88,7 +88,7 @@ static int process_vm_rw_single_vec(unsigned long addr, ssize_t rc = 0; unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES / sizeof(struct pages *); - unsigned int flags = FOLL_REMOTE; + unsigned int flags = 0; /* Work out address and page range required */ if (len == 0) @@ -100,15 +100,19 @@ static int process_vm_rw_single_vec(unsigned long addr, while (!rc && nr_pages && iov_iter_count(iter)) { int pages = min(nr_pages, max_pages_per_loop); + int locked = 1; size_t bytes; /* * Get the pages we're interested in. We must - * add FOLL_REMOTE because task/mm might not + * access remotely because task/mm might not * current/current->mm */ - pages = __get_user_pages_unlocked(task, mm, pa, pages, - process_pages, flags); + down_read(&mm->mmap_sem); + pages = get_user_pages_remote(task, mm, pa, pages, flags, + process_pages, NULL, &locked); + if (locked) + up_read(&mm->mmap_sem); if (pages <= 0) return -EFAULT; diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index 8035cc1..dab8b19 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -76,16 +76,20 @@ static void async_pf_execute(struct work_struct *work) struct kvm_vcpu *vcpu = apf->vcpu; unsigned long addr = apf->addr; gva_t gva = apf->gva; + int locked = 1; might_sleep(); /* * This work is run asynchromously to the task which owns * mm and might be done in another context, so we must - * use FOLL_REMOTE. + * access remotely. */ - __get_user_pages_unlocked(NULL, mm, addr, 1, NULL, - FOLL_WRITE | FOLL_REMOTE); + down_read(&mm->mmap_sem); + get_user_pages_remote(NULL, mm, addr, 1, FOLL_WRITE, NULL, NULL, + &locked); + if (locked) + up_read(&mm->mmap_sem); kvm_async_page_present_sync(vcpu, apf); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2907b7b..c45d951 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1415,13 +1415,12 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, npages = get_user_page_nowait(addr, write_fault, page); up_read(¤t->mm->mmap_sem); } else { - unsigned int flags = FOLL_TOUCH | FOLL_HWPOISON; + unsigned int flags = FOLL_HWPOISON; if (write_fault) flags |= FOLL_WRITE; - npages = __get_user_pages_unlocked(current, current->mm, addr, 1, - page, flags); + npages = get_user_pages_unlocked(addr, 1, page, flags); } if (npages != 1) return npages; -- 2.10.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-10-27 20:34 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2016-10-27 20:34 [PATCH v2 0/2] mm: unexport __get_user_pages_unlocked() Lorenzo Stoakes 2016-10-27 20:34 ` Lorenzo Stoakes 2016-10-27 20:34 ` [PATCH v2 1/2] mm: add locked parameter to get_user_pages_remote() Lorenzo Stoakes 2016-10-27 20:34 ` Lorenzo Stoakes 2016-10-27 20:34 ` [PATCH v2 2/2] mm: unexport __get_user_pages_unlocked() Lorenzo Stoakes 2016-10-27 20:34 ` Lorenzo Stoakes
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