diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/Makefile | 2 | ||||
| -rw-r--r-- | mm/iov_iter.c | 753 |
2 files changed, 1 insertions, 754 deletions
diff --git a/mm/Makefile b/mm/Makefile index 3c1caa2693bd..15dbe9903c27 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -21,7 +21,7 @@ obj-y := filemap.o mempool.o oom_kill.o \ mm_init.o mmu_context.o percpu.o slab_common.o \ compaction.o vmacache.o \ interval_tree.o list_lru.o workingset.o \ - iov_iter.o debug.o $(mmu-y) + debug.o $(mmu-y) obj-y += init-mm.o diff --git a/mm/iov_iter.c b/mm/iov_iter.c deleted file mode 100644 index 827732047da1..000000000000 --- a/mm/iov_iter.c +++ /dev/null @@ -1,753 +0,0 @@ -#include <linux/export.h> -#include <linux/uio.h> -#include <linux/pagemap.h> -#include <linux/slab.h> -#include <linux/vmalloc.h> -#include <net/checksum.h> - -#define iterate_iovec(i, n, __v, __p, skip, STEP) { \ - size_t left; \ - size_t wanted = n; \ - __p = i->iov; \ - __v.iov_len = min(n, __p->iov_len - skip); \ - if (likely(__v.iov_len)) { \ - __v.iov_base = __p->iov_base + skip; \ - left = (STEP); \ - __v.iov_len -= left; \ - skip += __v.iov_len; \ - n -= __v.iov_len; \ - } else { \ - left = 0; \ - } \ - while (unlikely(!left && n)) { \ - __p++; \ - __v.iov_len = min(n, __p->iov_len); \ - if (unlikely(!__v.iov_len)) \ - continue; \ - __v.iov_base = __p->iov_base; \ - left = (STEP); \ - __v.iov_len -= left; \ - skip = __v.iov_len; \ - n -= __v.iov_len; \ - } \ - n = wanted - n; \ -} - -#define iterate_kvec(i, n, __v, __p, skip, STEP) { \ - size_t wanted = n; \ - __p = i->kvec; \ - __v.iov_len = min(n, __p->iov_len - skip); \ - if (likely(__v.iov_len)) { \ - __v.iov_base = __p->iov_base + skip; \ - (void)(STEP); \ - skip += __v.iov_len; \ - n -= __v.iov_len; \ - } \ - while (unlikely(n)) { \ - __p++; \ - __v.iov_len = min(n, __p->iov_len); \ - if (unlikely(!__v.iov_len)) \ - continue; \ - __v.iov_base = __p->iov_base; \ - (void)(STEP); \ - skip = __v.iov_len; \ - n -= __v.iov_len; \ - } \ - n = wanted; \ -} - -#define iterate_bvec(i, n, __v, __p, skip, STEP) { \ - size_t wanted = n; \ - __p = i->bvec; \ - __v.bv_len = min_t(size_t, n, __p->bv_len - skip); \ - if (likely(__v.bv_len)) { \ - __v.bv_page = __p->bv_page; \ - __v.bv_offset = __p->bv_offset + skip; \ - (void)(STEP); \ - skip += __v.bv_len; \ - n -= __v.bv_len; \ - } \ - while (unlikely(n)) { \ - __p++; \ - __v.bv_len = min_t(size_t, n, __p->bv_len); \ - if (unlikely(!__v.bv_len)) \ - continue; \ - __v.bv_page = __p->bv_page; \ - __v.bv_offset = __p->bv_offset; \ - (void)(STEP); \ - skip = __v.bv_len; \ - n -= __v.bv_len; \ - } \ - n = wanted; \ -} - -#define iterate_all_kinds(i, n, v, I, B, K) { \ - size_t skip = i->iov_offset; \ - if (unlikely(i->type & ITER_BVEC)) { \ - const struct bio_vec *bvec; \ - struct bio_vec v; \ - iterate_bvec(i, n, v, bvec, skip, (B)) \ - } else if (unlikely(i->type & ITER_KVEC)) { \ - const struct kvec *kvec; \ - struct kvec v; \ - iterate_kvec(i, n, v, kvec, skip, (K)) \ - } else { \ - const struct iovec *iov; \ - struct iovec v; \ - iterate_iovec(i, n, v, iov, skip, (I)) \ - } \ -} - -#define iterate_and_advance(i, n, v, I, B, K) { \ - size_t skip = i->iov_offset; \ - if (unlikely(i->type & ITER_BVEC)) { \ - const struct bio_vec *bvec; \ - struct bio_vec v; \ - iterate_bvec(i, n, v, bvec, skip, (B)) \ - if (skip == bvec->bv_len) { \ - bvec++; \ - skip = 0; \ - } \ - i->nr_segs -= bvec - i->bvec; \ - i->bvec = bvec; \ - } else if (unlikely(i->type & ITER_KVEC)) { \ - const struct kvec *kvec; \ - struct kvec v; \ - iterate_kvec(i, n, v, kvec, skip, (K)) \ - if (skip == kvec->iov_len) { \ - kvec++; \ - skip = 0; \ - } \ - i->nr_segs -= kvec - i->kvec; \ - i->kvec = kvec; \ - } else { \ - const struct iovec *iov; \ - struct iovec v; \ - iterate_iovec(i, n, v, iov, skip, (I)) \ - if (skip == iov->iov_len) { \ - iov++; \ - skip = 0; \ - } \ - i->nr_segs -= iov - i->iov; \ - i->iov = iov; \ - } \ - i->count -= n; \ - i->iov_offset = skip; \ -} - -static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, - struct iov_iter *i) -{ - size_t skip, copy, left, wanted; - const struct iovec *iov; - char __user *buf; - void *kaddr, *from; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - iov = i->iov; - skip = i->iov_offset; - buf = iov->iov_base + skip; - copy = min(bytes, iov->iov_len - skip); - - if (!fault_in_pages_writeable(buf, copy)) { - kaddr = kmap_atomic(page); - from = kaddr + offset; - - /* first chunk, usually the only one */ - left = __copy_to_user_inatomic(buf, from, copy); - copy -= left; - skip += copy; - from += copy; - bytes -= copy; - - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __copy_to_user_inatomic(buf, from, copy); - copy -= left; - skip = copy; - from += copy; - bytes -= copy; - } - if (likely(!bytes)) { - kunmap_atomic(kaddr); - goto done; - } - offset = from - kaddr; - buf += copy; - kunmap_atomic(kaddr); - copy = min(bytes, iov->iov_len - skip); - } - /* Too bad - revert to non-atomic kmap */ - kaddr = kmap(page); - from = kaddr + offset; - left = __copy_to_user(buf, from, copy); - copy -= left; - skip += copy; - from += copy; - bytes -= copy; - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __copy_to_user(buf, from, copy); - copy -= left; - skip = copy; - from += copy; - bytes -= copy; - } - kunmap(page); -done: - if (skip == iov->iov_len) { - iov++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= iov - i->iov; - i->iov = iov; - i->iov_offset = skip; - return wanted - bytes; -} - -static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, - struct iov_iter *i) -{ - size_t skip, copy, left, wanted; - const struct iovec *iov; - char __user *buf; - void *kaddr, *to; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - iov = i->iov; - skip = i->iov_offset; - buf = iov->iov_base + skip; - copy = min(bytes, iov->iov_len - skip); - - if (!fault_in_pages_readable(buf, copy)) { - kaddr = kmap_atomic(page); - to = kaddr + offset; - - /* first chunk, usually the only one */ - left = __copy_from_user_inatomic(to, buf, copy); - copy -= left; - skip += copy; - to += copy; - bytes -= copy; - - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __copy_from_user_inatomic(to, buf, copy); - copy -= left; - skip = copy; - to += copy; - bytes -= copy; - } - if (likely(!bytes)) { - kunmap_atomic(kaddr); - goto done; - } - offset = to - kaddr; - buf += copy; - kunmap_atomic(kaddr); - copy = min(bytes, iov->iov_len - skip); - } - /* Too bad - revert to non-atomic kmap */ - kaddr = kmap(page); - to = kaddr + offset; - left = __copy_from_user(to, buf, copy); - copy -= left; - skip += copy; - to += copy; - bytes -= copy; - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __copy_from_user(to, buf, copy); - copy -= left; - skip = copy; - to += copy; - bytes -= copy; - } - kunmap(page); -done: - if (skip == iov->iov_len) { - iov++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= iov - i->iov; - i->iov = iov; - i->iov_offset = skip; - return wanted - bytes; -} - -/* - * Fault in the first iovec of the given iov_iter, to a maximum length - * of bytes. Returns 0 on success, or non-zero if the memory could not be - * accessed (ie. because it is an invalid address). - * - * writev-intensive code may want this to prefault several iovecs -- that - * would be possible (callers must not rely on the fact that _only_ the - * first iovec will be faulted with the current implementation). - */ -int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) -{ - if (!(i->type & (ITER_BVEC|ITER_KVEC))) { - char __user *buf = i->iov->iov_base + i->iov_offset; - bytes = min(bytes, i->iov->iov_len - i->iov_offset); - return fault_in_pages_readable(buf, bytes); - } - return 0; -} -EXPORT_SYMBOL(iov_iter_fault_in_readable); - -void iov_iter_init(struct iov_iter *i, int direction, - const struct iovec *iov, unsigned long nr_segs, - size_t count) -{ - /* It will get better. Eventually... */ - if (segment_eq(get_fs(), KERNEL_DS)) { - direction |= ITER_KVEC; - i->type = direction; - i->kvec = (struct kvec *)iov; - } else { - i->type = direction; - i->iov = iov; - } - i->nr_segs = nr_segs; - i->iov_offset = 0; - i->count = count; -} -EXPORT_SYMBOL(iov_iter_init); - -static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) -{ - char *from = kmap_atomic(page); - memcpy(to, from + offset, len); - kunmap_atomic(from); -} - -static void memcpy_to_page(struct page *page, size_t offset, char *from, size_t len) -{ - char *to = kmap_atomic(page); - memcpy(to + offset, from, len); - kunmap_atomic(to); -} - -static void memzero_page(struct page *page, size_t offset, size_t len) -{ - char *addr = kmap_atomic(page); - memset(addr + offset, 0, len); - kunmap_atomic(addr); -} - -size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i) -{ - char *from = addr; - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - iterate_and_advance(i, bytes, v, - __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, - v.iov_len), - memcpy_to_page(v.bv_page, v.bv_offset, - (from += v.bv_len) - v.bv_len, v.bv_len), - memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) - ) - - return bytes; -} -EXPORT_SYMBOL(copy_to_iter); - -size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) -{ - char *to = addr; - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - iterate_and_advance(i, bytes, v, - __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, - v.iov_len), - memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, - v.bv_offset, v.bv_len), - memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) - ) - - return bytes; -} -EXPORT_SYMBOL(copy_from_iter); - -size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) -{ - char *to = addr; - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - iterate_and_advance(i, bytes, v, - __copy_from_user_nocache((to += v.iov_len) - v.iov_len, - v.iov_base, v.iov_len), - memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, - v.bv_offset, v.bv_len), - memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) - ) - - return bytes; -} -EXPORT_SYMBOL(copy_from_iter_nocache); - -size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, - struct iov_iter *i) -{ - if (i->type & (ITER_BVEC|ITER_KVEC)) { - void *kaddr = kmap_atomic(page); - size_t wanted = copy_to_iter(kaddr + offset, bytes, i); - kunmap_atomic(kaddr); - return wanted; - } else - return copy_page_to_iter_iovec(page, offset, bytes, i); -} -EXPORT_SYMBOL(copy_page_to_iter); - -size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, - struct iov_iter *i) -{ - if (i->type & (ITER_BVEC|ITER_KVEC)) { - void *kaddr = kmap_atomic(page); - size_t wanted = copy_from_iter(kaddr + offset, bytes, i); - kunmap_atomic(kaddr); - return wanted; - } else - return copy_page_from_iter_iovec(page, offset, bytes, i); -} -EXPORT_SYMBOL(copy_page_from_iter); - -size_t iov_iter_zero(size_t bytes, struct iov_iter *i) -{ - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - iterate_and_advance(i, bytes, v, - __clear_user(v.iov_base, v.iov_len), - memzero_page(v.bv_page, v.bv_offset, v.bv_len), - memset(v.iov_base, 0, v.iov_len) - ) - - return bytes; -} -EXPORT_SYMBOL(iov_iter_zero); - -size_t iov_iter_copy_from_user_atomic(struct page *page, - struct iov_iter *i, unsigned long offset, size_t bytes) -{ - char *kaddr = kmap_atomic(page), *p = kaddr + offset; - iterate_all_kinds(i, bytes, v, - __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, - v.iov_base, v.iov_len), - memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, - v.bv_offset, v.bv_len), - memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) - ) - kunmap_atomic(kaddr); - return bytes; -} -EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); - -void iov_iter_advance(struct iov_iter *i, size_t size) -{ - iterate_and_advance(i, size, v, 0, 0, 0) -} -EXPORT_SYMBOL(iov_iter_advance); - -/* - * Return the count of just the current iov_iter segment. - */ -size_t iov_iter_single_seg_count(const struct iov_iter *i) -{ - if (i->nr_segs == 1) - return i->count; - else if (i->type & ITER_BVEC) - return min(i->count, i->bvec->bv_len - i->iov_offset); - else - return min(i->count, i->iov->iov_len - i->iov_offset); -} -EXPORT_SYMBOL(iov_iter_single_seg_count); - -void iov_iter_kvec(struct iov_iter *i, int direction, - const struct kvec *kvec, unsigned long nr_segs, - size_t count) -{ - BUG_ON(!(direction & ITER_KVEC)); - i->type = direction; - i->kvec = kvec; - i->nr_segs = nr_segs; - i->iov_offset = 0; - i->count = count; -} -EXPORT_SYMBOL(iov_iter_kvec); - -void iov_iter_bvec(struct iov_iter *i, int direction, - const struct bio_vec *bvec, unsigned long nr_segs, - size_t count) -{ - BUG_ON(!(direction & ITER_BVEC)); - i->type = direction; - i->bvec = bvec; - i->nr_segs = nr_segs; - i->iov_offset = 0; - i->count = count; -} -EXPORT_SYMBOL(iov_iter_bvec); - -unsigned long iov_iter_alignment(const struct iov_iter *i) -{ - unsigned long res = 0; - size_t size = i->count; - - if (!size) - return 0; - - iterate_all_kinds(i, size, v, - (res |= (unsigned long)v.iov_base | v.iov_len, 0), - res |= v.bv_offset | v.bv_len, - res |= (unsigned long)v.iov_base | v.iov_len - ) - return res; -} -EXPORT_SYMBOL(iov_iter_alignment); - -ssize_t iov_iter_get_pages(struct iov_iter *i, - struct page **pages, size_t maxsize, unsigned maxpages, - size_t *start) -{ - if (maxsize > i->count) - maxsize = i->count; - - if (!maxsize) - return 0; - - iterate_all_kinds(i, maxsize, v, ({ - unsigned long addr = (unsigned long)v.iov_base; - size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); - int n; - int res; - - if (len > maxpages * PAGE_SIZE) - len = maxpages * PAGE_SIZE; - addr &= ~(PAGE_SIZE - 1); - n = DIV_ROUND_UP(len, PAGE_SIZE); - res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); - if (unlikely(res < 0)) - return res; - return (res == n ? len : res * PAGE_SIZE) - *start; - 0;}),({ - /* can't be more than PAGE_SIZE */ - *start = v.bv_offset; - get_page(*pages = v.bv_page); - return v.bv_len; - }),({ - return -EFAULT; - }) - ) - return 0; -} -EXPORT_SYMBOL(iov_iter_get_pages); - -static struct page **get_pages_array(size_t n) -{ - struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); - if (!p) - p = vmalloc(n * sizeof(struct page *)); - return p; -} - -ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, - struct page ***pages, size_t maxsize, - size_t *start) -{ - struct page **p; - - if (maxsize > i->count) - maxsize = i->count; - - if (!maxsize) - return 0; - - iterate_all_kinds(i, maxsize, v, ({ - unsigned long addr = (unsigned long)v.iov_base; - size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); - int n; - int res; - - addr &= ~(PAGE_SIZE - 1); - n = DIV_ROUND_UP(len, PAGE_SIZE); - p = get_pages_array(n); - if (!p) - return -ENOMEM; - res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); - if (unlikely(res < 0)) { - kvfree(p); - return res; - } - *pages = p; - return (res == n ? len : res * PAGE_SIZE) - *start; - 0;}),({ - /* can't be more than PAGE_SIZE */ - *start = v.bv_offset; - *pages = p = get_pages_array(1); - if (!p) - return -ENOMEM; - get_page(*p = v.bv_page); - return v.bv_len; - }),({ - return -EFAULT; - }) - ) - return 0; -} -EXPORT_SYMBOL(iov_iter_get_pages_alloc); - -size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, - struct iov_iter *i) -{ - char *to = addr; - __wsum sum, next; - size_t off = 0; - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - sum = *csum; - iterate_and_advance(i, bytes, v, ({ - int err = 0; - next = csum_and_copy_from_user(v.iov_base, - (to += v.iov_len) - v.iov_len, - v.iov_len, 0, &err); - if (!err) { - sum = csum_block_add(sum, next, off); - off += v.iov_len; - } - err ? v.iov_len : 0; - }), ({ - char *p = kmap_atomic(v.bv_page); - next = csum_partial_copy_nocheck(p + v.bv_offset, - (to += v.bv_len) - v.bv_len, - v.bv_len, 0); - kunmap_atomic(p); - sum = csum_block_add(sum, next, off); - off += v.bv_len; - }),({ - next = csum_partial_copy_nocheck(v.iov_base, - (to += v.iov_len) - v.iov_len, - v.iov_len, 0); - sum = csum_block_add(sum, next, off); - off += v.iov_len; - }) - ) - *csum = sum; - return bytes; -} -EXPORT_SYMBOL(csum_and_copy_from_iter); - -size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum, - struct iov_iter *i) -{ - char *from = addr; - __wsum sum, next; - size_t off = 0; - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - sum = *csum; - iterate_and_advance(i, bytes, v, ({ - int err = 0; - next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, - v.iov_base, - v.iov_len, 0, &err); - if (!err) { - sum = csum_block_add(sum, next, off); - off += v.iov_len; - } - err ? v.iov_len : 0; - }), ({ - char *p = kmap_atomic(v.bv_page); - next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, - p + v.bv_offset, - v.bv_len, 0); - kunmap_atomic(p); - sum = csum_block_add(sum, next, off); - off += v.bv_len; - }),({ - next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, - v.iov_base, - v.iov_len, 0); - sum = csum_block_add(sum, next, off); - off += v.iov_len; - }) - ) - *csum = sum; - return bytes; -} -EXPORT_SYMBOL(csum_and_copy_to_iter); - -int iov_iter_npages(const struct iov_iter *i, int maxpages) -{ - size_t size = i->count; - int npages = 0; - - if (!size) - return 0; - - iterate_all_kinds(i, size, v, ({ - unsigned long p = (unsigned long)v.iov_base; - npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) - - p / PAGE_SIZE; - if (npages >= maxpages) - return maxpages; - 0;}),({ - npages++; - if (npages >= maxpages) - return maxpages; - }),({ - unsigned long p = (unsigned long)v.iov_base; - npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) - - p / PAGE_SIZE; - if (npages >= maxpages) - return maxpages; - }) - ) - return npages; -} -EXPORT_SYMBOL(iov_iter_npages); |