diff options
| -rw-r--r-- | mm/internal.h | 3 | ||||
| -rw-r--r-- | mm/memory.c | 23 | ||||
| -rw-r--r-- | mm/mlock.c | 40 | ||||
| -rw-r--r-- | mm/nommu.c | 6 |
4 files changed, 47 insertions, 25 deletions
diff --git a/mm/internal.h b/mm/internal.h index dedb0af..bd4f581 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -243,7 +243,8 @@ static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int len, unsigned int foll_flags, - struct page **pages, struct vm_area_struct **vmas); + struct page **pages, struct vm_area_struct **vmas, + int *nonblocking); #define ZONE_RECLAIM_NOSCAN -2 #define ZONE_RECLAIM_FULL -1 diff --git a/mm/memory.c b/mm/memory.c index 15e1f19..1bbe9a2 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1363,7 +1363,8 @@ no_page_table: int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int nr_pages, unsigned int gup_flags, - struct page **pages, struct vm_area_struct **vmas) + struct page **pages, struct vm_area_struct **vmas, + int *nonblocking) { int i; unsigned long vm_flags; @@ -1463,10 +1464,15 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, cond_resched(); while (!(page = follow_page(vma, start, foll_flags))) { int ret; + unsigned int fault_flags = 0; + + if (foll_flags & FOLL_WRITE) + fault_flags |= FAULT_FLAG_WRITE; + if (nonblocking) + fault_flags |= FAULT_FLAG_ALLOW_RETRY; ret = handle_mm_fault(mm, vma, start, - (foll_flags & FOLL_WRITE) ? - FAULT_FLAG_WRITE : 0); + fault_flags); if (ret & VM_FAULT_ERROR) { if (ret & VM_FAULT_OOM) @@ -1482,6 +1488,11 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, else tsk->min_flt++; + if (ret & VM_FAULT_RETRY) { + *nonblocking = 0; + return i; + } + /* * The VM_FAULT_WRITE bit tells us that * do_wp_page has broken COW when necessary, @@ -1581,7 +1592,8 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, if (force) flags |= FOLL_FORCE; - return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas); + return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas, + NULL); } EXPORT_SYMBOL(get_user_pages); @@ -1606,7 +1618,8 @@ struct page *get_dump_page(unsigned long addr) struct page *page; if (__get_user_pages(current, current->mm, addr, 1, - FOLL_FORCE | FOLL_DUMP | FOLL_GET, &page, &vma) < 1) + FOLL_FORCE | FOLL_DUMP | FOLL_GET, &page, &vma, + NULL) < 1) return NULL; flush_cache_page(vma, addr, page_to_pfn(page)); return page; @@ -155,13 +155,13 @@ static inline int stack_guard_page(struct vm_area_struct *vma, unsigned long add * vma->vm_mm->mmap_sem must be held for at least read. */ static long __mlock_vma_pages_range(struct vm_area_struct *vma, - unsigned long start, unsigned long end) + unsigned long start, unsigned long end, + int *nonblocking) { struct mm_struct *mm = vma->vm_mm; unsigned long addr = start; int nr_pages = (end - start) / PAGE_SIZE; int gup_flags; - int ret; VM_BUG_ON(start & ~PAGE_MASK); VM_BUG_ON(end & ~PAGE_MASK); @@ -187,9 +187,8 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma, nr_pages--; } - ret = __get_user_pages(current, mm, addr, nr_pages, gup_flags, - NULL, NULL); - return max(ret, 0); /* 0 or negative error code */ + return __get_user_pages(current, mm, addr, nr_pages, gup_flags, + NULL, NULL, nonblocking); } /* @@ -233,7 +232,7 @@ long mlock_vma_pages_range(struct vm_area_struct *vma, is_vm_hugetlb_page(vma) || vma == get_gate_vma(current))) { - __mlock_vma_pages_range(vma, start, end); + __mlock_vma_pages_range(vma, start, end, NULL); /* Hide errors from mmap() and other callers */ return 0; @@ -429,21 +428,23 @@ static int do_mlock_pages(unsigned long start, size_t len, int ignore_errors) struct mm_struct *mm = current->mm; unsigned long end, nstart, nend; struct vm_area_struct *vma = NULL; + int locked = 0; int ret = 0; VM_BUG_ON(start & ~PAGE_MASK); VM_BUG_ON(len != PAGE_ALIGN(len)); end = start + len; - down_read(&mm->mmap_sem); for (nstart = start; nstart < end; nstart = nend) { /* * We want to fault in pages for [nstart; end) address range. * Find first corresponding VMA. */ - if (!vma) + if (!locked) { + locked = 1; + down_read(&mm->mmap_sem); vma = find_vma(mm, nstart); - else + } else if (nstart >= vma->vm_end) vma = vma->vm_next; if (!vma || vma->vm_start >= end) break; @@ -457,19 +458,24 @@ static int do_mlock_pages(unsigned long start, size_t len, int ignore_errors) if (nstart < vma->vm_start) nstart = vma->vm_start; /* - * Now fault in a range of pages within the first VMA. + * Now fault in a range of pages. __mlock_vma_pages_range() + * double checks the vma flags, so that it won't mlock pages + * if the vma was already munlocked. */ - ret = __mlock_vma_pages_range(vma, nstart, nend); - if (ret < 0 && ignore_errors) { - ret = 0; - continue; /* continue at next VMA */ - } - if (ret) { + ret = __mlock_vma_pages_range(vma, nstart, nend, &locked); + if (ret < 0) { + if (ignore_errors) { + ret = 0; + continue; /* continue at next VMA */ + } ret = __mlock_posix_error_return(ret); break; } + nend = nstart + ret * PAGE_SIZE; + ret = 0; } - up_read(&mm->mmap_sem); + if (locked) + up_read(&mm->mmap_sem); return ret; /* 0 or negative error code */ } @@ -127,7 +127,8 @@ unsigned int kobjsize(const void *objp) int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int nr_pages, unsigned int foll_flags, - struct page **pages, struct vm_area_struct **vmas) + struct page **pages, struct vm_area_struct **vmas, + int *retry) { struct vm_area_struct *vma; unsigned long vm_flags; @@ -185,7 +186,8 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, if (force) flags |= FOLL_FORCE; - return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas); + return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas, + NULL); } EXPORT_SYMBOL(get_user_pages); |
