diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/gup.c | 190 | ||||
| -rw-r--r-- | mm/gup_benchmark.c | 5 |
2 files changed, 120 insertions, 75 deletions
@@ -1018,6 +1018,15 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, int *locked) { + /* + * FIXME: Current FOLL_LONGTERM behavior is incompatible with + * FAULT_FLAG_ALLOW_RETRY because of the FS DAX check requirement on + * vmas. As there are no users of this flag in this call we simply + * disallow this option for now. + */ + if (WARN_ON_ONCE(gup_flags & FOLL_LONGTERM)) + return -EINVAL; + return __get_user_pages_locked(current, current->mm, start, nr_pages, pages, NULL, locked, gup_flags | FOLL_TOUCH); @@ -1046,6 +1055,15 @@ long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, int locked = 1; long ret; + /* + * FIXME: Current FOLL_LONGTERM behavior is incompatible with + * FAULT_FLAG_ALLOW_RETRY because of the FS DAX check requirement on + * vmas. As there are no users of this flag in this call we simply + * disallow this option for now. + */ + if (WARN_ON_ONCE(gup_flags & FOLL_LONGTERM)) + return -EINVAL; + down_read(&mm->mmap_sem); ret = __get_user_pages_locked(current, mm, start, nr_pages, pages, NULL, &locked, gup_flags | FOLL_TOUCH); @@ -1116,32 +1134,22 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, unsigned int gup_flags, struct page **pages, struct vm_area_struct **vmas, int *locked) { + /* + * FIXME: Current FOLL_LONGTERM behavior is incompatible with + * FAULT_FLAG_ALLOW_RETRY because of the FS DAX check requirement on + * vmas. As there are no users of this flag in this call we simply + * disallow this option for now. + */ + if (WARN_ON_ONCE(gup_flags & FOLL_LONGTERM)) + return -EINVAL; + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, locked, gup_flags | FOLL_TOUCH | FOLL_REMOTE); } 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 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, - struct vm_area_struct **vmas) -{ - return __get_user_pages_locked(current, current->mm, start, nr_pages, - pages, vmas, NULL, - gup_flags | FOLL_TOUCH); -} -EXPORT_SYMBOL(get_user_pages); - #if defined(CONFIG_FS_DAX) || defined (CONFIG_CMA) - -#ifdef CONFIG_FS_DAX static bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages) { long i; @@ -1160,12 +1168,6 @@ static bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages) } return false; } -#else -static inline bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages) -{ - return false; -} -#endif #ifdef CONFIG_CMA static struct page *new_non_cma_page(struct page *page, unsigned long private) @@ -1219,10 +1221,13 @@ static struct page *new_non_cma_page(struct page *page, unsigned long private) return __alloc_pages_node(nid, gfp_mask, 0); } -static long check_and_migrate_cma_pages(unsigned long start, long nr_pages, - unsigned int gup_flags, +static long check_and_migrate_cma_pages(struct task_struct *tsk, + struct mm_struct *mm, + unsigned long start, + unsigned long nr_pages, struct page **pages, - struct vm_area_struct **vmas) + struct vm_area_struct **vmas, + unsigned int gup_flags) { long i; bool drain_allow = true; @@ -1278,10 +1283,14 @@ check_again: putback_movable_pages(&cma_page_list); } /* - * We did migrate all the pages, Try to get the page references again - * migrating any new CMA pages which we failed to isolate earlier. + * We did migrate all the pages, Try to get the page references + * again migrating any new CMA pages which we failed to isolate + * earlier. */ - nr_pages = get_user_pages(start, nr_pages, gup_flags, pages, vmas); + nr_pages = __get_user_pages_locked(tsk, mm, start, nr_pages, + pages, vmas, NULL, + gup_flags); + if ((nr_pages > 0) && migrate_allow) { drain_allow = true; goto check_again; @@ -1291,66 +1300,101 @@ check_again: return nr_pages; } #else -static inline long check_and_migrate_cma_pages(unsigned long start, long nr_pages, - unsigned int gup_flags, - struct page **pages, - struct vm_area_struct **vmas) +static long check_and_migrate_cma_pages(struct task_struct *tsk, + struct mm_struct *mm, + unsigned long start, + unsigned long nr_pages, + struct page **pages, + struct vm_area_struct **vmas, + unsigned int gup_flags) { return nr_pages; } #endif /* - * This is the same as get_user_pages() in that it assumes we are - * operating on the current task's mm, but it goes further to validate - * that the vmas associated with the address range are suitable for - * longterm elevated page reference counts. For example, filesystem-dax - * mappings are subject to the lifetime enforced by the filesystem and - * we need guarantees that longterm users like RDMA and V4L2 only - * establish mappings that have a kernel enforced revocation mechanism. - * - * "longterm" == userspace controlled elevated page count lifetime. - * Contrast this to iov_iter_get_pages() usages which are transient. + * __gup_longterm_locked() is a wrapper for __get_user_pages_locked which + * allows us to process the FOLL_LONGTERM flag. */ -long get_user_pages_longterm(unsigned long start, unsigned long nr_pages, - unsigned int gup_flags, struct page **pages, - struct vm_area_struct **vmas_arg) +static long __gup_longterm_locked(struct task_struct *tsk, + struct mm_struct *mm, + unsigned long start, + unsigned long nr_pages, + struct page **pages, + struct vm_area_struct **vmas, + unsigned int gup_flags) { - struct vm_area_struct **vmas = vmas_arg; - unsigned long flags; + struct vm_area_struct **vmas_tmp = vmas; + unsigned long flags = 0; long rc, i; - if (!pages) - return -EINVAL; - - if (!vmas) { - vmas = kcalloc(nr_pages, sizeof(struct vm_area_struct *), - GFP_KERNEL); - if (!vmas) - return -ENOMEM; + if (gup_flags & FOLL_LONGTERM) { + if (!pages) + return -EINVAL; + + if (!vmas_tmp) { + vmas_tmp = kcalloc(nr_pages, + sizeof(struct vm_area_struct *), + GFP_KERNEL); + if (!vmas_tmp) + return -ENOMEM; + } + flags = memalloc_nocma_save(); } - flags = memalloc_nocma_save(); - rc = get_user_pages(start, nr_pages, gup_flags, pages, vmas); - memalloc_nocma_restore(flags); - if (rc < 0) - goto out; + rc = __get_user_pages_locked(tsk, mm, start, nr_pages, pages, + vmas_tmp, NULL, gup_flags); - if (check_dax_vmas(vmas, rc)) { - for (i = 0; i < rc; i++) - put_page(pages[i]); - rc = -EOPNOTSUPP; - goto out; + if (gup_flags & FOLL_LONGTERM) { + memalloc_nocma_restore(flags); + if (rc < 0) + goto out; + + if (check_dax_vmas(vmas_tmp, rc)) { + for (i = 0; i < rc; i++) + put_page(pages[i]); + rc = -EOPNOTSUPP; + goto out; + } + + rc = check_and_migrate_cma_pages(tsk, mm, start, rc, pages, + vmas_tmp, gup_flags); } - rc = check_and_migrate_cma_pages(start, rc, gup_flags, pages, vmas); out: - if (vmas != vmas_arg) - kfree(vmas); + if (vmas_tmp != vmas) + kfree(vmas_tmp); return rc; } -EXPORT_SYMBOL(get_user_pages_longterm); -#endif /* CONFIG_FS_DAX */ +#else /* !CONFIG_FS_DAX && !CONFIG_CMA */ +static __always_inline long __gup_longterm_locked(struct task_struct *tsk, + struct mm_struct *mm, + unsigned long start, + unsigned long nr_pages, + struct page **pages, + struct vm_area_struct **vmas, + unsigned int flags) +{ + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, + NULL, flags); +} +#endif /* CONFIG_FS_DAX || CONFIG_CMA */ + +/* + * 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 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, + struct vm_area_struct **vmas) +{ + return __gup_longterm_locked(current, current->mm, start, nr_pages, + pages, vmas, gup_flags | FOLL_TOUCH); +} +EXPORT_SYMBOL(get_user_pages); /** * populate_vma_page_range() - populate a range of pages in the vma. diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c index 6c0279e70cc4..7dd602d7f8db 100644 --- a/mm/gup_benchmark.c +++ b/mm/gup_benchmark.c @@ -54,8 +54,9 @@ static int __gup_benchmark_ioctl(unsigned int cmd, pages + i); break; case GUP_LONGTERM_BENCHMARK: - nr = get_user_pages_longterm(addr, nr, gup->flags & 1, - pages + i, NULL); + nr = get_user_pages(addr, nr, + (gup->flags & 1) | FOLL_LONGTERM, + pages + i, NULL); break; case GUP_BENCHMARK: nr = get_user_pages(addr, nr, gup->flags & 1, pages + i, |