From 58fa879e1e640a1856f736b418984ebeccee1c95 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 21 Sep 2009 17:03:31 -0700 Subject: mm: FOLL flags for GUP flags __get_user_pages() has been taking its own GUP flags, then processing them into FOLL flags for follow_page(). Though oddly named, the FOLL flags are more widely used, so pass them to __get_user_pages() now. Sorry, VM flags, VM_FAULT flags and FAULT_FLAGs are still distinct. (The patch to __get_user_pages() looks peculiar, with both gup_flags and foll_flags: the gup_flags remain constant; but as before there's an exceptional case, out of scope of the patch, in which foll_flags per page have FOLL_WRITE masked off.) Signed-off-by: Hugh Dickins Cc: Rik van Riel Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Mel Gorman Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 1 + mm/internal.h | 6 +----- mm/memory.c | 44 +++++++++++++++++++------------------------- mm/mlock.c | 4 ++-- mm/nommu.c | 16 ++++++++-------- 5 files changed, 31 insertions(+), 40 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 45ee5b5a343d..5409eced7aae 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1232,6 +1232,7 @@ struct page *follow_page(struct vm_area_struct *, unsigned long address, #define FOLL_TOUCH 0x02 /* mark page accessed */ #define FOLL_GET 0x04 /* do get_page on page */ #define FOLL_DUMP 0x08 /* give error on hole if it would be zero */ +#define FOLL_FORCE 0x10 /* get_user_pages read/write w/o permission */ typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, void *data); diff --git a/mm/internal.h b/mm/internal.h index d41475078b20..75596574911e 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -250,12 +250,8 @@ static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, } #endif /* CONFIG_SPARSEMEM */ -#define GUP_FLAGS_WRITE 0x01 -#define GUP_FLAGS_FORCE 0x02 -#define GUP_FLAGS_DUMP 0x04 - int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, int len, int flags, + unsigned long start, int len, unsigned int foll_flags, struct page **pages, struct vm_area_struct **vmas); #define ZONE_RECLAIM_NOSCAN -2 diff --git a/mm/memory.c b/mm/memory.c index c8b5b9435a92..5c694f2b9c12 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1209,27 +1209,29 @@ no_page_table: } int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, int nr_pages, int flags, + unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages, struct vm_area_struct **vmas) { int i; - unsigned int vm_flags = 0; - int write = !!(flags & GUP_FLAGS_WRITE); - int force = !!(flags & GUP_FLAGS_FORCE); + unsigned long vm_flags; if (nr_pages <= 0) return 0; + + VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET)); + /* * Require read or write permissions. - * If 'force' is set, we only require the "MAY" flags. + * If FOLL_FORCE is set, we only require the "MAY" flags. */ - vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); - vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); + vm_flags = (gup_flags & FOLL_WRITE) ? + (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); + vm_flags &= (gup_flags & FOLL_FORCE) ? + (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); i = 0; do { struct vm_area_struct *vma; - unsigned int foll_flags; vma = find_extend_vma(mm, start); if (!vma && in_gate_area(tsk, start)) { @@ -1241,7 +1243,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, pte_t *pte; /* user gate pages are read-only */ - if (write) + if (gup_flags & FOLL_WRITE) return i ? : -EFAULT; if (pg > TASK_SIZE) pgd = pgd_offset_k(pg); @@ -1278,22 +1280,15 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, !(vm_flags & vma->vm_flags)) return i ? : -EFAULT; - foll_flags = FOLL_TOUCH; - if (pages) - foll_flags |= FOLL_GET; - if (flags & GUP_FLAGS_DUMP) - foll_flags |= FOLL_DUMP; - if (write) - foll_flags |= FOLL_WRITE; - if (is_vm_hugetlb_page(vma)) { i = follow_hugetlb_page(mm, vma, pages, vmas, - &start, &nr_pages, i, foll_flags); + &start, &nr_pages, i, gup_flags); continue; } do { struct page *page; + unsigned int foll_flags = gup_flags; /* * If we have a pending SIGKILL, don't keep faulting @@ -1302,9 +1297,6 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, if (unlikely(fatal_signal_pending(current))) return i ? i : -ERESTARTSYS; - if (write) - foll_flags |= FOLL_WRITE; - cond_resched(); while (!(page = follow_page(vma, start, foll_flags))) { int ret; @@ -1415,12 +1407,14 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int nr_pages, int write, int force, struct page **pages, struct vm_area_struct **vmas) { - int flags = 0; + int flags = FOLL_TOUCH; + if (pages) + flags |= FOLL_GET; if (write) - flags |= GUP_FLAGS_WRITE; + flags |= FOLL_WRITE; if (force) - flags |= GUP_FLAGS_FORCE; + flags |= FOLL_FORCE; return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas); } @@ -1447,7 +1441,7 @@ struct page *get_dump_page(unsigned long addr) struct page *page; if (__get_user_pages(current, current->mm, addr, 1, - GUP_FLAGS_FORCE | GUP_FLAGS_DUMP, &page, &vma) < 1) + FOLL_FORCE | FOLL_DUMP | FOLL_GET, &page, &vma) < 1) return NULL; if (page == ZERO_PAGE(0)) { page_cache_release(page); diff --git a/mm/mlock.c b/mm/mlock.c index e13918d4fc4f..22041aa9f5c1 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -166,9 +166,9 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma, VM_BUG_ON(end > vma->vm_end); VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem)); - gup_flags = 0; + gup_flags = FOLL_TOUCH | FOLL_GET; if (vma->vm_flags & VM_WRITE) - gup_flags = GUP_FLAGS_WRITE; + gup_flags |= FOLL_WRITE; while (nr_pages > 0) { int i; diff --git a/mm/nommu.c b/mm/nommu.c index 386443e9d2c6..2d02ca17ce18 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -168,20 +168,20 @@ unsigned int kobjsize(const void *objp) } int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, int nr_pages, int flags, + unsigned long start, int nr_pages, int foll_flags, struct page **pages, struct vm_area_struct **vmas) { struct vm_area_struct *vma; unsigned long vm_flags; int i; - int write = !!(flags & GUP_FLAGS_WRITE); - int force = !!(flags & GUP_FLAGS_FORCE); /* calculate required read or write permissions. - * - if 'force' is set, we only require the "MAY" flags. + * If FOLL_FORCE is set, we only require the "MAY" flags. */ - vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); - vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); + vm_flags = (foll_flags & FOLL_WRITE) ? + (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); + vm_flags &= (foll_flags & FOLL_FORCE) ? + (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); for (i = 0; i < nr_pages; i++) { vma = find_vma(mm, start); @@ -223,9 +223,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, int flags = 0; if (write) - flags |= GUP_FLAGS_WRITE; + flags |= FOLL_WRITE; if (force) - flags |= GUP_FLAGS_FORCE; + flags |= FOLL_FORCE; return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas); } -- cgit v1.2.2