| #include <linux/export.h> |
| #include <linux/bvec.h> |
| #include <linux/uio.h> |
| #include <linux/pagemap.h> |
| #include <linux/slab.h> |
| #include <linux/vmalloc.h> |
| #include <linux/splice.h> |
| #include <net/checksum.h> |
| #include <linux/scatterlist.h> |
| |
| #define PIPE_PARANOIA /* for now */ |
| |
| #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, __bi, skip, STEP) { \ |
| struct bvec_iter __start; \ |
| __start.bi_size = n; \ |
| __start.bi_bvec_done = skip; \ |
| __start.bi_idx = 0; \ |
| for_each_bvec(__v, i->bvec, __bi, __start) { \ |
| if (!__v.bv_len) \ |
| continue; \ |
| (void)(STEP); \ |
| } \ |
| } |
| |
| #define iterate_all_kinds(i, n, v, I, B, K) { \ |
| if (likely(n)) { \ |
| size_t skip = i->iov_offset; \ |
| if (unlikely(i->type & ITER_BVEC)) { \ |
| struct bio_vec v; \ |
| struct bvec_iter __bi; \ |
| iterate_bvec(i, n, v, __bi, 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 if (unlikely(i->type & ITER_DISCARD)) { \ |
| } 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) { \ |
| if (unlikely(i->count < n)) \ |
| n = i->count; \ |
| if (i->count) { \ |
| size_t skip = i->iov_offset; \ |
| if (unlikely(i->type & ITER_BVEC)) { \ |
| const struct bio_vec *bvec = i->bvec; \ |
| struct bio_vec v; \ |
| struct bvec_iter __bi; \ |
| iterate_bvec(i, n, v, __bi, skip, (B)) \ |
| i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ |
| i->nr_segs -= i->bvec - bvec; \ |
| skip = __bi.bi_bvec_done; \ |
| } 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 if (unlikely(i->type & ITER_DISCARD)) { \ |
| skip += n; \ |
| } 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 int copyout(void __user *to, const void *from, size_t n) |
| { |
| if (access_ok(to, n)) { |
| kasan_check_read(from, n); |
| n = raw_copy_to_user(to, from, n); |
| } |
| return n; |
| } |
| |
| static int copyin(void *to, const void __user *from, size_t n) |
| { |
| if (access_ok(from, n)) { |
| kasan_check_write(to, n); |
| n = raw_copy_from_user(to, from, n); |
| } |
| return n; |
| } |
| |
| 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; |
| |
| might_fault(); |
| wanted = bytes; |
| iov = i->iov; |
| skip = i->iov_offset; |
| buf = iov->iov_base + skip; |
| copy = min(bytes, iov->iov_len - skip); |
| |
| if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
| kaddr = kmap_atomic(page); |
| from = kaddr + offset; |
| |
| /* first chunk, usually the only one */ |
| left = copyout(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 = copyout(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 = copyout(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 = copyout(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; |
| |
| might_fault(); |
| wanted = bytes; |
| iov = i->iov; |
| skip = i->iov_offset; |
| buf = iov->iov_base + skip; |
| copy = min(bytes, iov->iov_len - skip); |
| |
| if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
| kaddr = kmap_atomic(page); |
| to = kaddr + offset; |
| |
| /* first chunk, usually the only one */ |
| left = copyin(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 = copyin(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 = copyin(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 = copyin(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; |
| } |
| |
| #ifdef PIPE_PARANOIA |
| static bool sanity(const struct iov_iter *i) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| int idx = i->idx; |
| int next = pipe->curbuf + pipe->nrbufs; |
| if (i->iov_offset) { |
| struct pipe_buffer *p; |
| if (unlikely(!pipe->nrbufs)) |
| goto Bad; // pipe must be non-empty |
| if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) |
| goto Bad; // must be at the last buffer... |
| |
| p = &pipe->bufs[idx]; |
| if (unlikely(p->offset + p->len != i->iov_offset)) |
| goto Bad; // ... at the end of segment |
| } else { |
| if (idx != (next & (pipe->buffers - 1))) |
| goto Bad; // must be right after the last buffer |
| } |
| return true; |
| Bad: |
| printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); |
| printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", |
| pipe->curbuf, pipe->nrbufs, pipe->buffers); |
| for (idx = 0; idx < pipe->buffers; idx++) |
| printk(KERN_ERR "[%p %p %d %d]\n", |
| pipe->bufs[idx].ops, |
| pipe->bufs[idx].page, |
| pipe->bufs[idx].offset, |
| pipe->bufs[idx].len); |
| WARN_ON(1); |
| return false; |
| } |
| #else |
| #define sanity(i) true |
| #endif |
| |
| static inline int next_idx(int idx, struct pipe_inode_info *pipe) |
| { |
| return (idx + 1) & (pipe->buffers - 1); |
| } |
| |
| static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, |
| struct iov_iter *i) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| struct pipe_buffer *buf; |
| size_t off; |
| int idx; |
| |
| if (unlikely(bytes > i->count)) |
| bytes = i->count; |
| |
| if (unlikely(!bytes)) |
| return 0; |
| |
| if (!sanity(i)) |
| return 0; |
| |
| off = i->iov_offset; |
| idx = i->idx; |
| buf = &pipe->bufs[idx]; |
| if (off) { |
| if (offset == off && buf->page == page) { |
| /* merge with the last one */ |
| buf->len += bytes; |
| i->iov_offset += bytes; |
| goto out; |
| } |
| idx = next_idx(idx, pipe); |
| buf = &pipe->bufs[idx]; |
| } |
| if (idx == pipe->curbuf && pipe->nrbufs) |
| return 0; |
| pipe->nrbufs++; |
| buf->ops = &page_cache_pipe_buf_ops; |
| get_page(buf->page = page); |
| buf->offset = offset; |
| buf->len = bytes; |
| i->iov_offset = offset + bytes; |
| i->idx = idx; |
| out: |
| i->count -= bytes; |
| return bytes; |
| } |
| |
| /* |
| * Fault in one or more iovecs of the given iov_iter, to a maximum length of |
| * bytes. For each iovec, fault in each page that constitutes the iovec. |
| * |
| * Return 0 on success, or non-zero if the memory could not be accessed (i.e. |
| * because it is an invalid address). |
| */ |
| int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
| { |
| size_t skip = i->iov_offset; |
| const struct iovec *iov; |
| int err; |
| struct iovec v; |
| |
| if (!(i->type & (ITER_BVEC|ITER_KVEC))) { |
| iterate_iovec(i, bytes, v, iov, skip, ({ |
| err = fault_in_pages_readable(v.iov_base, v.iov_len); |
| if (unlikely(err)) |
| return err; |
| 0;})) |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL(iov_iter_fault_in_readable); |
| |
| void iov_iter_init(struct iov_iter *i, unsigned int direction, |
| const struct iovec *iov, unsigned long nr_segs, |
| size_t count) |
| { |
| WARN_ON(direction & ~(READ | WRITE)); |
| direction &= READ | WRITE; |
| |
| /* It will get better. Eventually... */ |
| if (uaccess_kernel()) { |
| i->type = ITER_KVEC | direction; |
| i->kvec = (struct kvec *)iov; |
| } else { |
| i->type = ITER_IOVEC | 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, const 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); |
| } |
| |
| static inline bool allocated(struct pipe_buffer *buf) |
| { |
| return buf->ops == &default_pipe_buf_ops; |
| } |
| |
| static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) |
| { |
| size_t off = i->iov_offset; |
| int idx = i->idx; |
| if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { |
| idx = next_idx(idx, i->pipe); |
| off = 0; |
| } |
| *idxp = idx; |
| *offp = off; |
| } |
| |
| static size_t push_pipe(struct iov_iter *i, size_t size, |
| int *idxp, size_t *offp) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| size_t off; |
| int idx; |
| ssize_t left; |
| |
| if (unlikely(size > i->count)) |
| size = i->count; |
| if (unlikely(!size)) |
| return 0; |
| |
| left = size; |
| data_start(i, &idx, &off); |
| *idxp = idx; |
| *offp = off; |
| if (off) { |
| left -= PAGE_SIZE - off; |
| if (left <= 0) { |
| pipe->bufs[idx].len += size; |
| return size; |
| } |
| pipe->bufs[idx].len = PAGE_SIZE; |
| idx = next_idx(idx, pipe); |
| } |
| while (idx != pipe->curbuf || !pipe->nrbufs) { |
| struct page *page = alloc_page(GFP_USER); |
| if (!page) |
| break; |
| pipe->nrbufs++; |
| pipe->bufs[idx].ops = &default_pipe_buf_ops; |
| pipe->bufs[idx].page = page; |
| pipe->bufs[idx].offset = 0; |
| if (left <= PAGE_SIZE) { |
| pipe->bufs[idx].len = left; |
| return size; |
| } |
| pipe->bufs[idx].len = PAGE_SIZE; |
| left -= PAGE_SIZE; |
| idx = next_idx(idx, pipe); |
| } |
| return size - left; |
| } |
| |
| static size_t copy_pipe_to_iter(const void *addr, size_t bytes, |
| struct iov_iter *i) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| size_t n, off; |
| int idx; |
| |
| if (!sanity(i)) |
| return 0; |
| |
| bytes = n = push_pipe(i, bytes, &idx, &off); |
| if (unlikely(!n)) |
| return 0; |
| for ( ; n; idx = next_idx(idx, pipe), off = 0) { |
| size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
| memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); |
| i->idx = idx; |
| i->iov_offset = off + chunk; |
| n -= chunk; |
| addr += chunk; |
| } |
| i->count -= bytes; |
| return bytes; |
| } |
| |
| static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, |
| __wsum *csum, struct iov_iter *i) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| size_t n, r; |
| size_t off = 0; |
| __wsum sum = *csum, next; |
| int idx; |
| |
| if (!sanity(i)) |
| return 0; |
| |
| bytes = n = push_pipe(i, bytes, &idx, &r); |
| if (unlikely(!n)) |
| return 0; |
| for ( ; n; idx = next_idx(idx, pipe), r = 0) { |
| size_t chunk = min_t(size_t, n, PAGE_SIZE - r); |
| char *p = kmap_atomic(pipe->bufs[idx].page); |
| next = csum_partial_copy_nocheck(addr, p + r, chunk, 0); |
| sum = csum_block_add(sum, next, off); |
| kunmap_atomic(p); |
| i->idx = idx; |
| i->iov_offset = r + chunk; |
| n -= chunk; |
| off += chunk; |
| addr += chunk; |
| } |
| i->count -= bytes; |
| *csum = sum; |
| return bytes; |
| } |
| |
| size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
| { |
| const char *from = addr; |
| if (unlikely(iov_iter_is_pipe(i))) |
| return copy_pipe_to_iter(addr, bytes, i); |
| if (iter_is_iovec(i)) |
| might_fault(); |
| iterate_and_advance(i, bytes, v, |
| copyout(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); |
| |
| #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE |
| static int copyout_mcsafe(void __user *to, const void *from, size_t n) |
| { |
| if (access_ok(to, n)) { |
| kasan_check_read(from, n); |
| n = copy_to_user_mcsafe((__force void *) to, from, n); |
| } |
| return n; |
| } |
| |
| static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, |
| const char *from, size_t len) |
| { |
| unsigned long ret; |
| char *to; |
| |
| to = kmap_atomic(page); |
| ret = memcpy_mcsafe(to + offset, from, len); |
| kunmap_atomic(to); |
| |
| return ret; |
| } |
| |
| static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, |
| struct iov_iter *i) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| size_t n, off, xfer = 0; |
| int idx; |
| |
| if (!sanity(i)) |
| return 0; |
| |
| bytes = n = push_pipe(i, bytes, &idx, &off); |
| if (unlikely(!n)) |
| return 0; |
| for ( ; n; idx = next_idx(idx, pipe), off = 0) { |
| size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
| unsigned long rem; |
| |
| rem = memcpy_mcsafe_to_page(pipe->bufs[idx].page, off, addr, |
| chunk); |
| i->idx = idx; |
| i->iov_offset = off + chunk - rem; |
| xfer += chunk - rem; |
| if (rem) |
| break; |
| n -= chunk; |
| addr += chunk; |
| } |
| i->count -= xfer; |
| return xfer; |
| } |
| |
| /** |
| * _copy_to_iter_mcsafe - copy to user with source-read error exception handling |
| * @addr: source kernel address |
| * @bytes: total transfer length |
| * @iter: destination iterator |
| * |
| * The pmem driver arranges for filesystem-dax to use this facility via |
| * dax_copy_to_iter() for protecting read/write to persistent memory. |
| * Unless / until an architecture can guarantee identical performance |
| * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a |
| * performance regression to switch more users to the mcsafe version. |
| * |
| * Otherwise, the main differences between this and typical _copy_to_iter(). |
| * |
| * * Typical tail/residue handling after a fault retries the copy |
| * byte-by-byte until the fault happens again. Re-triggering machine |
| * checks is potentially fatal so the implementation uses source |
| * alignment and poison alignment assumptions to avoid re-triggering |
| * hardware exceptions. |
| * |
| * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. |
| * Compare to copy_to_iter() where only ITER_IOVEC attempts might return |
| * a short copy. |
| * |
| * See MCSAFE_TEST for self-test. |
| */ |
| size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) |
| { |
| const char *from = addr; |
| unsigned long rem, curr_addr, s_addr = (unsigned long) addr; |
| |
| if (unlikely(iov_iter_is_pipe(i))) |
| return copy_pipe_to_iter_mcsafe(addr, bytes, i); |
| if (iter_is_iovec(i)) |
| might_fault(); |
| iterate_and_advance(i, bytes, v, |
| copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
| ({ |
| rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, |
| (from += v.bv_len) - v.bv_len, v.bv_len); |
| if (rem) { |
| curr_addr = (unsigned long) from; |
| bytes = curr_addr - s_addr - rem; |
| return bytes; |
| } |
| }), |
| ({ |
| rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, |
| v.iov_len); |
| if (rem) { |
| curr_addr = (unsigned long) from; |
| bytes = curr_addr - s_addr - rem; |
| return bytes; |
| } |
| }) |
| ) |
| |
| return bytes; |
| } |
| EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); |
| #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ |
| |
| size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
| { |
| char *to = addr; |
| if (unlikely(iov_iter_is_pipe(i))) { |
| WARN_ON(1); |
| return 0; |
| } |
| if (iter_is_iovec(i)) |
| might_fault(); |
| iterate_and_advance(i, bytes, v, |
| copyin((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); |
| |
| bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
| { |
| char *to = addr; |
| if (unlikely(iov_iter_is_pipe(i))) { |
| WARN_ON(1); |
| return false; |
| } |
| if (unlikely(i->count < bytes)) |
| return false; |
| |
| if (iter_is_iovec(i)) |
| might_fault(); |
| iterate_all_kinds(i, bytes, v, ({ |
| if (copyin((to += v.iov_len) - v.iov_len, |
| v.iov_base, v.iov_len)) |
| return false; |
| 0;}), |
| 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) |
| ) |
| |
| iov_iter_advance(i, bytes); |
| return true; |
| } |
| EXPORT_SYMBOL(_copy_from_iter_full); |
| |
| size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
| { |
| char *to = addr; |
| if (unlikely(iov_iter_is_pipe(i))) { |
| WARN_ON(1); |
| return 0; |
| } |
| iterate_and_advance(i, bytes, v, |
| __copy_from_user_inatomic_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); |
| |
| #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
| /** |
| * _copy_from_iter_flushcache - write destination through cpu cache |
| * @addr: destination kernel address |
| * @bytes: total transfer length |
| * @iter: source iterator |
| * |
| * The pmem driver arranges for filesystem-dax to use this facility via |
| * dax_copy_from_iter() for ensuring that writes to persistent memory |
| * are flushed through the CPU cache. It is differentiated from |
| * _copy_from_iter_nocache() in that guarantees all data is flushed for |
| * all iterator types. The _copy_from_iter_nocache() only attempts to |
| * bypass the cache for the ITER_IOVEC case, and on some archs may use |
| * instructions that strand dirty-data in the cache. |
| */ |
| size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
| { |
| char *to = addr; |
| if (unlikely(iov_iter_is_pipe(i))) { |
| WARN_ON(1); |
| return 0; |
| } |
| iterate_and_advance(i, bytes, v, |
| __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, |
| v.iov_base, v.iov_len), |
| memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, |
| v.bv_offset, v.bv_len), |
| memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, |
| v.iov_len) |
| ) |
| |
| return bytes; |
| } |
| EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
| #endif |
| |
| bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
| { |
| char *to = addr; |
| if (unlikely(iov_iter_is_pipe(i))) { |
| WARN_ON(1); |
| return false; |
| } |
| if (unlikely(i->count < bytes)) |
| return false; |
| iterate_all_kinds(i, bytes, v, ({ |
| if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
| v.iov_base, v.iov_len)) |
| return false; |
| 0;}), |
| 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) |
| ) |
| |
| iov_iter_advance(i, bytes); |
| return true; |
| } |
| EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
| |
| static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
| { |
| struct page *head = compound_head(page); |
| size_t v = n + offset + page_address(page) - page_address(head); |
| |
| if (likely(n <= v && v <= (PAGE_SIZE << compound_order(head)))) |
| return true; |
| WARN_ON(1); |
| return false; |
| } |
| |
| size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
| struct iov_iter *i) |
| { |
| if (unlikely(!page_copy_sane(page, offset, bytes))) |
| return 0; |
| 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 if (unlikely(iov_iter_is_discard(i))) |
| return bytes; |
| else if (likely(!iov_iter_is_pipe(i))) |
| return copy_page_to_iter_iovec(page, offset, bytes, i); |
| else |
| return copy_page_to_iter_pipe(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 (unlikely(!page_copy_sane(page, offset, bytes))) |
| return 0; |
| if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
| WARN_ON(1); |
| return 0; |
| } |
| 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); |
| |
| static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| size_t n, off; |
| int idx; |
| |
| if (!sanity(i)) |
| return 0; |
| |
| bytes = n = push_pipe(i, bytes, &idx, &off); |
| if (unlikely(!n)) |
| return 0; |
| |
| for ( ; n; idx = next_idx(idx, pipe), off = 0) { |
| size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
| memzero_page(pipe->bufs[idx].page, off, chunk); |
| i->idx = idx; |
| i->iov_offset = off + chunk; |
| n -= chunk; |
| } |
| i->count -= bytes; |
| return bytes; |
| } |
| |
| size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
| { |
| if (unlikely(iov_iter_is_pipe(i))) |
| return pipe_zero(bytes, i); |
| 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; |
| if (unlikely(!page_copy_sane(page, offset, bytes))) { |
| kunmap_atomic(kaddr); |
| return 0; |
| } |
| if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
| kunmap_atomic(kaddr); |
| WARN_ON(1); |
| return 0; |
| } |
| iterate_all_kinds(i, bytes, v, |
| copyin((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); |
| |
| static inline void pipe_truncate(struct iov_iter *i) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| if (pipe->nrbufs) { |
| size_t off = i->iov_offset; |
| int idx = i->idx; |
| int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); |
| if (off) { |
| pipe->bufs[idx].len = off - pipe->bufs[idx].offset; |
| idx = next_idx(idx, pipe); |
| nrbufs++; |
| } |
| while (pipe->nrbufs > nrbufs) { |
| pipe_buf_release(pipe, &pipe->bufs[idx]); |
| idx = next_idx(idx, pipe); |
| pipe->nrbufs--; |
| } |
| } |
| } |
| |
| static void pipe_advance(struct iov_iter *i, size_t size) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| if (unlikely(i->count < size)) |
| size = i->count; |
| if (size) { |
| struct pipe_buffer *buf; |
| size_t off = i->iov_offset, left = size; |
| int idx = i->idx; |
| if (off) /* make it relative to the beginning of buffer */ |
| left += off - pipe->bufs[idx].offset; |
| while (1) { |
| buf = &pipe->bufs[idx]; |
| if (left <= buf->len) |
| break; |
| left -= buf->len; |
| idx = next_idx(idx, pipe); |
| } |
| i->idx = idx; |
| i->iov_offset = buf->offset + left; |
| } |
| i->count -= size; |
| /* ... and discard everything past that point */ |
| pipe_truncate(i); |
| } |
| |
| void iov_iter_advance(struct iov_iter *i, size_t size) |
| { |
| if (unlikely(iov_iter_is_pipe(i))) { |
| pipe_advance(i, size); |
| return; |
| } |
| if (unlikely(iov_iter_is_discard(i))) { |
| i->count -= size; |
| return; |
| } |
| iterate_and_advance(i, size, v, 0, 0, 0) |
| } |
| EXPORT_SYMBOL(iov_iter_advance); |
| |
| void iov_iter_revert(struct iov_iter *i, size_t unroll) |
| { |
| if (!unroll) |
| return; |
| if (WARN_ON(unroll > MAX_RW_COUNT)) |
| return; |
| i->count += unroll; |
| if (unlikely(iov_iter_is_pipe(i))) { |
| struct pipe_inode_info *pipe = i->pipe; |
| int idx = i->idx; |
| size_t off = i->iov_offset; |
| while (1) { |
| size_t n = off - pipe->bufs[idx].offset; |
| if (unroll < n) { |
| off -= unroll; |
| break; |
| } |
| unroll -= n; |
| if (!unroll && idx == i->start_idx) { |
| off = 0; |
| break; |
| } |
| if (!idx--) |
| idx = pipe->buffers - 1; |
| off = pipe->bufs[idx].offset + pipe->bufs[idx].len; |
| } |
| i->iov_offset = off; |
| i->idx = idx; |
| pipe_truncate(i); |
| return; |
| } |
| if (unlikely(iov_iter_is_discard(i))) |
| return; |
| if (unroll <= i->iov_offset) { |
| i->iov_offset -= unroll; |
| return; |
| } |
| unroll -= i->iov_offset; |
| if (iov_iter_is_bvec(i)) { |
| const struct bio_vec *bvec = i->bvec; |
| while (1) { |
| size_t n = (--bvec)->bv_len; |
| i->nr_segs++; |
| if (unroll <= n) { |
| i->bvec = bvec; |
| i->iov_offset = n - unroll; |
| return; |
| } |
| unroll -= n; |
| } |
| } else { /* same logics for iovec and kvec */ |
| const struct iovec *iov = i->iov; |
| while (1) { |
| size_t n = (--iov)->iov_len; |
| i->nr_segs++; |
| if (unroll <= n) { |
| i->iov = iov; |
| i->iov_offset = n - unroll; |
| return; |
| } |
| unroll -= n; |
| } |
| } |
| } |
| EXPORT_SYMBOL(iov_iter_revert); |
| |
| /* |
| * Return the count of just the current iov_iter segment. |
| */ |
| size_t iov_iter_single_seg_count(const struct iov_iter *i) |
| { |
| if (unlikely(iov_iter_is_pipe(i))) |
| return i->count; // it is a silly place, anyway |
| if (i->nr_segs == 1) |
| return i->count; |
| if (unlikely(iov_iter_is_discard(i))) |
| return i->count; |
| else if (iov_iter_is_bvec(i)) |
| 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, unsigned int direction, |
| const struct kvec *kvec, unsigned long nr_segs, |
| size_t count) |
| { |
| WARN_ON(direction & ~(READ | WRITE)); |
| i->type = ITER_KVEC | (direction & (READ | WRITE)); |
| 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, unsigned int direction, |
| const struct bio_vec *bvec, unsigned long nr_segs, |
| size_t count) |
| { |
| WARN_ON(direction & ~(READ | WRITE)); |
| i->type = ITER_BVEC | (direction & (READ | WRITE)); |
| i->bvec = bvec; |
| i->nr_segs = nr_segs; |
| i->iov_offset = 0; |
| i->count = count; |
| } |
| EXPORT_SYMBOL(iov_iter_bvec); |
| |
| void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
| struct pipe_inode_info *pipe, |
| size_t count) |
| { |
| BUG_ON(direction != READ); |
| WARN_ON(pipe->nrbufs == pipe->buffers); |
| i->type = ITER_PIPE | READ; |
| i->pipe = pipe; |
| i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); |
| i->iov_offset = 0; |
| i->count = count; |
| i->start_idx = i->idx; |
| } |
| EXPORT_SYMBOL(iov_iter_pipe); |
| |
| /** |
| * iov_iter_discard - Initialise an I/O iterator that discards data |
| * @i: The iterator to initialise. |
| * @direction: The direction of the transfer. |
| * @count: The size of the I/O buffer in bytes. |
| * |
| * Set up an I/O iterator that just discards everything that's written to it. |
| * It's only available as a READ iterator. |
| */ |
| void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) |
| { |
| BUG_ON(direction != READ); |
| i->type = ITER_DISCARD | READ; |
| i->count = count; |
| i->iov_offset = 0; |
| } |
| EXPORT_SYMBOL(iov_iter_discard); |
| |
| unsigned long iov_iter_alignment(const struct iov_iter *i) |
| { |
| unsigned long res = 0; |
| size_t size = i->count; |
| |
| if (unlikely(iov_iter_is_pipe(i))) { |
| if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) |
| return size | i->iov_offset; |
| return size; |
| } |
| 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); |
| |
| unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
| { |
| unsigned long res = 0; |
| size_t size = i->count; |
| |
| if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
| WARN_ON(1); |
| return ~0U; |
| } |
| |
| iterate_all_kinds(i, size, v, |
| (res |= (!res ? 0 : (unsigned long)v.iov_base) | |
| (size != v.iov_len ? size : 0), 0), |
| (res |= (!res ? 0 : (unsigned long)v.bv_offset) | |
| (size != v.bv_len ? size : 0)), |
| (res |= (!res ? 0 : (unsigned long)v.iov_base) | |
| (size != v.iov_len ? size : 0)) |
| ); |
| return res; |
| } |
| EXPORT_SYMBOL(iov_iter_gap_alignment); |
| |
| static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
| size_t maxsize, |
| struct page **pages, |
| int idx, |
| size_t *start) |
| { |
| struct pipe_inode_info *pipe = i->pipe; |
| ssize_t n = push_pipe(i, maxsize, &idx, start); |
| if (!n) |
| return -EFAULT; |
| |
| maxsize = n; |
| n += *start; |
| while (n > 0) { |
| get_page(*pages++ = pipe->bufs[idx].page); |
| idx = next_idx(idx, pipe); |
| n -= PAGE_SIZE; |
| } |
| |
| return maxsize; |
| } |
| |
| static ssize_t pipe_get_pages(struct iov_iter *i, |
| struct page **pages, size_t maxsize, unsigned maxpages, |
| size_t *start) |
| { |
| unsigned npages; |
| size_t capacity; |
| int idx; |
| |
| if (!maxsize) |
| return 0; |
| |
| if (!sanity(i)) |
| return -EFAULT; |
| |
| data_start(i, &idx, start); |
| /* some of this one + all after this one */ |
| npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; |
| capacity = min(npages,maxpages) * PAGE_SIZE - *start; |
| |
| return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); |
| } |
| |
| 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 (unlikely(iov_iter_is_pipe(i))) |
| return pipe_get_pages(i, pages, maxsize, maxpages, start); |
| if (unlikely(iov_iter_is_discard(i))) |
| return -EFAULT; |
| |
| 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, iov_iter_rw(i) != 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) |
| { |
| return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
| } |
| |
| static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
| struct page ***pages, size_t maxsize, |
| size_t *start) |
| { |
| struct page **p; |
| ssize_t n; |
| int idx; |
| int npages; |
| |
| if (!maxsize) |
| return 0; |
| |
| if (!sanity(i)) |
| return -EFAULT; |
| |
| data_start(i, &idx, start); |
| /* some of this one + all after this one */ |
| npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; |
| n = npages * PAGE_SIZE - *start; |
| if (maxsize > n) |
| maxsize = n; |
| else |
| npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); |
| p = get_pages_array(npages); |
| if (!p) |
| return -ENOMEM; |
| n = __pipe_get_pages(i, maxsize, p, idx, start); |
| if (n > 0) |
| *pages = p; |
| else |
| kvfree(p); |
| return n; |
| } |
| |
| 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 (unlikely(iov_iter_is_pipe(i))) |
| return pipe_get_pages_alloc(i, pages, maxsize, start); |
| if (unlikely(iov_iter_is_discard(i))) |
| return -EFAULT; |
| |
| 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, iov_iter_rw(i) != 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; |
| sum = *csum; |
| if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
| WARN_ON(1); |
| return 0; |
| } |
| 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); |
| |
| bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
| struct iov_iter *i) |
| { |
| char *to = addr; |
| __wsum sum, next; |
| size_t off = 0; |
| sum = *csum; |
| if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
| WARN_ON(1); |
| return false; |
| } |
| if (unlikely(i->count < bytes)) |
| return false; |
| iterate_all_kinds(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) |
| return false; |
| sum = csum_block_add(sum, next, off); |
| off += 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; |
| iov_iter_advance(i, bytes); |
| return true; |
| } |
| EXPORT_SYMBOL(csum_and_copy_from_iter_full); |
| |
| size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, |
| struct iov_iter *i) |
| { |
| const char *from = addr; |
| __wsum *csum = csump; |
| __wsum sum, next; |
| size_t off = 0; |
| |
| if (unlikely(iov_iter_is_pipe(i))) |
| return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); |
| |
| sum = *csum; |
| if (unlikely(iov_iter_is_discard(i))) { |
| WARN_ON(1); /* for now */ |
| return 0; |
| } |
| 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); |
| |
| size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
| struct iov_iter *i) |
| { |
| struct ahash_request *hash = hashp; |
| struct scatterlist sg; |
| size_t copied; |
| |
| copied = copy_to_iter(addr, bytes, i); |
| sg_init_one(&sg, addr, copied); |
| ahash_request_set_crypt(hash, &sg, NULL, copied); |
| crypto_ahash_update(hash); |
| return copied; |
| } |
| EXPORT_SYMBOL(hash_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; |
| if (unlikely(iov_iter_is_discard(i))) |
| return 0; |
| |
| if (unlikely(iov_iter_is_pipe(i))) { |
| struct pipe_inode_info *pipe = i->pipe; |
| size_t off; |
| int idx; |
| |
| if (!sanity(i)) |
| return 0; |
| |
| data_start(i, &idx, &off); |
| /* some of this one + all after this one */ |
| npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; |
| if (npages >= maxpages) |
| return maxpages; |
| } else 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); |
| |
| const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) |
| { |
| *new = *old; |
| if (unlikely(iov_iter_is_pipe(new))) { |
| WARN_ON(1); |
| return NULL; |
| } |
| if (unlikely(iov_iter_is_discard(new))) |
| return NULL; |
| if (iov_iter_is_bvec(new)) |
| return new->bvec = kmemdup(new->bvec, |
| new->nr_segs * sizeof(struct bio_vec), |
| flags); |
| else |
| /* iovec and kvec have identical layout */ |
| return new->iov = kmemdup(new->iov, |
| new->nr_segs * sizeof(struct iovec), |
| flags); |
| } |
| EXPORT_SYMBOL(dup_iter); |
| |
| /** |
| * import_iovec() - Copy an array of &struct iovec from userspace |
| * into the kernel, check that it is valid, and initialize a new |
| * &struct iov_iter iterator to access it. |
| * |
| * @type: One of %READ or %WRITE. |
| * @uvector: Pointer to the userspace array. |
| * @nr_segs: Number of elements in userspace array. |
| * @fast_segs: Number of elements in @iov. |
| * @iov: (input and output parameter) Pointer to pointer to (usually small |
| * on-stack) kernel array. |
| * @i: Pointer to iterator that will be initialized on success. |
| * |
| * If the array pointed to by *@iov is large enough to hold all @nr_segs, |
| * then this function places %NULL in *@iov on return. Otherwise, a new |
| * array will be allocated and the result placed in *@iov. This means that |
| * the caller may call kfree() on *@iov regardless of whether the small |
| * on-stack array was used or not (and regardless of whether this function |
| * returns an error or not). |
| * |
| * Return: 0 on success or negative error code on error. |
| */ |
| int import_iovec(int type, const struct iovec __user * uvector, |
| unsigned nr_segs, unsigned fast_segs, |
| struct iovec **iov, struct iov_iter *i) |
| { |
| ssize_t n; |
| struct iovec *p; |
| n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, |
| *iov, &p); |
| if (n < 0) { |
| if (p != *iov) |
| kfree(p); |
| *iov = NULL; |
| return n; |
| } |
| iov_iter_init(i, type, p, nr_segs, n); |
| *iov = p == *iov ? NULL : p; |
| return 0; |
| } |
| EXPORT_SYMBOL(import_iovec); |
| |
| #ifdef CONFIG_COMPAT |
| #include <linux/compat.h> |
| |
| int compat_import_iovec(int type, const struct compat_iovec __user * uvector, |
| unsigned nr_segs, unsigned fast_segs, |
| struct iovec **iov, struct iov_iter *i) |
| { |
| ssize_t n; |
| struct iovec *p; |
| n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, |
| *iov, &p); |
| if (n < 0) { |
| if (p != *iov) |
| kfree(p); |
| *iov = NULL; |
| return n; |
| } |
| iov_iter_init(i, type, p, nr_segs, n); |
| *iov = p == *iov ? NULL : p; |
| return 0; |
| } |
| #endif |
| |
| int import_single_range(int rw, void __user *buf, size_t len, |
| struct iovec *iov, struct iov_iter *i) |
| { |
| if (len > MAX_RW_COUNT) |
| len = MAX_RW_COUNT; |
| if (unlikely(!access_ok(buf, len))) |
| return -EFAULT; |
| |
| iov->iov_base = buf; |
| iov->iov_len = len; |
| iov_iter_init(i, rw, iov, 1, len); |
| return 0; |
| } |
| EXPORT_SYMBOL(import_single_range); |
| |
| int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, |
| int (*f)(struct kvec *vec, void *context), |
| void *context) |
| { |
| struct kvec w; |
| int err = -EINVAL; |
| if (!bytes) |
| return 0; |
| |
| iterate_all_kinds(i, bytes, v, -EINVAL, ({ |
| w.iov_base = kmap(v.bv_page) + v.bv_offset; |
| w.iov_len = v.bv_len; |
| err = f(&w, context); |
| kunmap(v.bv_page); |
| err;}), ({ |
| w = v; |
| err = f(&w, context);}) |
| ) |
| return err; |
| } |
| EXPORT_SYMBOL(iov_iter_for_each_range); |