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lib/iov_iter.c
40.9 KB
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// SPDX-License-Identifier: GPL-2.0-only |
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#include <linux/export.h> |
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#include <linux/bvec.h> |
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#include <linux/uio.h> #include <linux/pagemap.h> |
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#include <linux/slab.h> #include <linux/vmalloc.h> |
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#include <linux/splice.h> |
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#include <net/checksum.h> |
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#include <linux/scatterlist.h> |
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#define PIPE_PARANOIA /* for now */ |
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#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; \ } |
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#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; \ } |
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#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) \ |
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continue; \ |
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(void)(STEP); \ |
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} \ |
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} |
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#define iterate_all_kinds(i, n, v, I, B, K) { \ |
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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)) \ |
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} else if (unlikely(i->type & ITER_DISCARD)) { \ |
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} else { \ const struct iovec *iov; \ struct iovec v; \ iterate_iovec(i, n, v, iov, skip, (I)) \ } \ |
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} \ } |
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#define iterate_and_advance(i, n, v, I, B, K) { \ |
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if (unlikely(i->count < n)) \ n = i->count; \ |
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if (i->count) { \ |
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size_t skip = i->iov_offset; \ if (unlikely(i->type & ITER_BVEC)) { \ |
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const struct bio_vec *bvec = i->bvec; \ |
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struct bio_vec v; \ |
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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; \ |
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} 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; \ |
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} else if (unlikely(i->type & ITER_DISCARD)) { \ skip += n; \ |
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} 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; \ |
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} \ |
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i->count -= n; \ i->iov_offset = skip; \ |
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} \ |
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} |
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static int copyout(void __user *to, const void *from, size_t n) { |
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if (access_ok(to, n)) { |
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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) { |
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if (access_ok(from, n)) { |
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kasan_check_write(to, n); n = raw_copy_from_user(to, from, n); } return n; } |
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static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
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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; |
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might_fault(); |
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wanted = bytes; iov = i->iov; skip = i->iov_offset; buf = iov->iov_base + skip; copy = min(bytes, iov->iov_len - skip); |
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if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
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kaddr = kmap_atomic(page); from = kaddr + offset; /* first chunk, usually the only one */ |
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left = copyout(buf, from, copy); |
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copy -= left; skip += copy; from += copy; bytes -= copy; while (unlikely(!left && bytes)) { iov++; buf = iov->iov_base; copy = min(bytes, iov->iov_len); |
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left = copyout(buf, from, copy); |
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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 */ |
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kaddr = kmap(page); from = kaddr + offset; |
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left = copyout(buf, from, copy); |
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copy -= left; skip += copy; from += copy; bytes -= copy; while (unlikely(!left && bytes)) { iov++; buf = iov->iov_base; copy = min(bytes, iov->iov_len); |
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left = copyout(buf, from, copy); |
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copy -= left; skip = copy; from += copy; bytes -= copy; } kunmap(page); |
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done: |
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if (skip == iov->iov_len) { iov++; skip = 0; } |
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i->count -= wanted - bytes; i->nr_segs -= iov - i->iov; i->iov = iov; i->iov_offset = skip; return wanted - bytes; } |
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static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
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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; |
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might_fault(); |
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wanted = bytes; iov = i->iov; skip = i->iov_offset; buf = iov->iov_base + skip; copy = min(bytes, iov->iov_len - skip); |
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if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
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kaddr = kmap_atomic(page); to = kaddr + offset; /* first chunk, usually the only one */ |
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left = copyin(to, buf, copy); |
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copy -= left; skip += copy; to += copy; bytes -= copy; while (unlikely(!left && bytes)) { iov++; buf = iov->iov_base; copy = min(bytes, iov->iov_len); |
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left = copyin(to, buf, copy); |
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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 */ |
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kaddr = kmap(page); to = kaddr + offset; |
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left = copyin(to, buf, copy); |
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copy -= left; skip += copy; to += copy; bytes -= copy; while (unlikely(!left && bytes)) { iov++; buf = iov->iov_base; copy = min(bytes, iov->iov_len); |
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left = copyin(to, buf, copy); |
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copy -= left; skip = copy; to += copy; bytes -= copy; } kunmap(page); |
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done: |
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if (skip == iov->iov_len) { iov++; skip = 0; } |
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i->count -= wanted - bytes; i->nr_segs -= iov - i->iov; i->iov = iov; i->iov_offset = skip; return wanted - bytes; } |
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#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 ", i->idx, i->iov_offset); printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d ", pipe->curbuf, pipe->nrbufs, pipe->buffers); for (idx = 0; idx < pipe->buffers; idx++) printk(KERN_ERR "[%p %p %d %d] ", 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; } |
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/* |
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* 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). */ |
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int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
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{ 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, ({ |
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err = fault_in_pages_readable(v.iov_base, v.iov_len); |
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if (unlikely(err)) return err; 0;})) } return 0; } |
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EXPORT_SYMBOL(iov_iter_fault_in_readable); |
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void iov_iter_init(struct iov_iter *i, unsigned int direction, |
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const struct iovec *iov, unsigned long nr_segs, size_t count) { |
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WARN_ON(direction & ~(READ | WRITE)); direction &= READ | WRITE; |
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/* It will get better. Eventually... */ |
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if (uaccess_kernel()) { |
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i->type = ITER_KVEC | direction; |
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i->kvec = (struct kvec *)iov; } else { |
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i->type = ITER_IOVEC | direction; |
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i->iov = iov; } |
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i->nr_segs = nr_segs; i->iov_offset = 0; i->count = count; } EXPORT_SYMBOL(iov_iter_init); |
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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); } |
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static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
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{ char *to = kmap_atomic(page); memcpy(to + offset, from, len); kunmap_atomic(to); } |
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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); } |
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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; } |
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static __wsum csum_and_memcpy(void *to, const void *from, size_t len, __wsum sum, size_t off) { __wsum next = csum_partial_copy_nocheck(from, to, len, 0); return csum_block_add(sum, next, off); } |
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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; |
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__wsum sum = *csum; |
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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); |
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sum = csum_and_memcpy(p + r, addr, chunk, sum, off); |
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kunmap_atomic(p); i->idx = idx; i->iov_offset = r + chunk; n -= chunk; off += chunk; addr += chunk; } i->count -= bytes; *csum = sum; return bytes; } |
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size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
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{ |
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const char *from = addr; |
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if (unlikely(iov_iter_is_pipe(i))) |
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return copy_pipe_to_iter(addr, bytes, i); |
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if (iter_is_iovec(i)) might_fault(); |
3d4d3e482 iov_iter.c: conve... |
594 |
iterate_and_advance(i, bytes, v, |
09fc68dc6 iov_iter: saner c... |
595 |
copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
3d4d3e482 iov_iter.c: conve... |
596 |
memcpy_to_page(v.bv_page, v.bv_offset, |
a280455fa iov_iter.c: handl... |
597 598 |
(from += v.bv_len) - v.bv_len, v.bv_len), memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) |
3d4d3e482 iov_iter.c: conve... |
599 |
) |
62a8067a7 bio_vec-backed io... |
600 |
|
3d4d3e482 iov_iter.c: conve... |
601 |
return bytes; |
c35e02480 Add copy_to_iter(... |
602 |
} |
aa28de275 iov_iter/hardenin... |
603 |
EXPORT_SYMBOL(_copy_to_iter); |
c35e02480 Add copy_to_iter(... |
604 |
|
8780356ef x86/asm/memcpy_mc... |
605 606 607 |
#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE static int copyout_mcsafe(void __user *to, const void *from, size_t n) { |
96d4f267e Remove 'type' arg... |
608 |
if (access_ok(to, n)) { |
8780356ef x86/asm/memcpy_mc... |
609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 |
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; } |
ca146f6f0 lib/iov_iter: Fix... |
627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 |
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; } |
bf3eeb9b5 lib/iov_iter: Doc... |
657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 |
/** * _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. */ |
8780356ef x86/asm/memcpy_mc... |
683 684 685 686 |
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; |
00e237074 iov_iter: Use acc... |
687 |
if (unlikely(iov_iter_is_pipe(i))) |
ca146f6f0 lib/iov_iter: Fix... |
688 |
return copy_pipe_to_iter_mcsafe(addr, bytes, i); |
8780356ef x86/asm/memcpy_mc... |
689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 |
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 */ |
aa28de275 iov_iter/hardenin... |
717 |
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e02480 Add copy_to_iter(... |
718 |
{ |
0dbca9a4b iov_iter.c: conve... |
719 |
char *to = addr; |
00e237074 iov_iter: Use acc... |
720 |
if (unlikely(iov_iter_is_pipe(i))) { |
241699cd7 new iov_iter flav... |
721 722 723 |
WARN_ON(1); return 0; } |
09fc68dc6 iov_iter: saner c... |
724 725 |
if (iter_is_iovec(i)) might_fault(); |
0dbca9a4b iov_iter.c: conve... |
726 |
iterate_and_advance(i, bytes, v, |
09fc68dc6 iov_iter: saner c... |
727 |
copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4b iov_iter.c: conve... |
728 |
memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455fa iov_iter.c: handl... |
729 730 |
v.bv_offset, v.bv_len), memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) |
0dbca9a4b iov_iter.c: conve... |
731 732 733 |
) return bytes; |
c35e02480 Add copy_to_iter(... |
734 |
} |
aa28de275 iov_iter/hardenin... |
735 |
EXPORT_SYMBOL(_copy_from_iter); |
c35e02480 Add copy_to_iter(... |
736 |
|
aa28de275 iov_iter/hardenin... |
737 |
bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8b [iov_iter] new pr... |
738 739 |
{ char *to = addr; |
00e237074 iov_iter: Use acc... |
740 |
if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8b [iov_iter] new pr... |
741 742 743 |
WARN_ON(1); return false; } |
33844e665 [iov_iter] fix it... |
744 |
if (unlikely(i->count < bytes)) |
cbbd26b8b [iov_iter] new pr... |
745 |
return false; |
09fc68dc6 iov_iter: saner c... |
746 747 |
if (iter_is_iovec(i)) might_fault(); |
cbbd26b8b [iov_iter] new pr... |
748 |
iterate_all_kinds(i, bytes, v, ({ |
09fc68dc6 iov_iter: saner c... |
749 |
if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8b [iov_iter] new pr... |
750 751 752 753 754 755 756 757 758 759 760 |
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; } |
aa28de275 iov_iter/hardenin... |
761 |
EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8b [iov_iter] new pr... |
762 |
|
aa28de275 iov_iter/hardenin... |
763 |
size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096d copy_from_iter_no... |
764 765 |
{ char *to = addr; |
00e237074 iov_iter: Use acc... |
766 |
if (unlikely(iov_iter_is_pipe(i))) { |
241699cd7 new iov_iter flav... |
767 768 769 |
WARN_ON(1); return 0; } |
aa583096d copy_from_iter_no... |
770 |
iterate_and_advance(i, bytes, v, |
3f763453e kill __copy_from_... |
771 |
__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096d copy_from_iter_no... |
772 773 774 775 776 777 778 779 |
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; } |
aa28de275 iov_iter/hardenin... |
780 |
EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096d copy_from_iter_no... |
781 |
|
0aed55af8 x86, uaccess: int... |
782 |
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d2 lib/iov_iter: Doc... |
783 784 785 786 787 788 789 790 791 792 793 794 795 796 |
/** * _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. */ |
6a37e9400 Merge branch 'uac... |
797 |
size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af8 x86, uaccess: int... |
798 799 |
{ char *to = addr; |
00e237074 iov_iter: Use acc... |
800 |
if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af8 x86, uaccess: int... |
801 802 803 804 805 806 807 808 809 810 811 812 813 814 |
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; } |
6a37e9400 Merge branch 'uac... |
815 |
EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af8 x86, uaccess: int... |
816 |
#endif |
aa28de275 iov_iter/hardenin... |
817 |
bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8b [iov_iter] new pr... |
818 819 |
{ char *to = addr; |
00e237074 iov_iter: Use acc... |
820 |
if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8b [iov_iter] new pr... |
821 822 823 |
WARN_ON(1); return false; } |
33844e665 [iov_iter] fix it... |
824 |
if (unlikely(i->count < bytes)) |
cbbd26b8b [iov_iter] new pr... |
825 826 |
return false; iterate_all_kinds(i, bytes, v, ({ |
3f763453e kill __copy_from_... |
827 |
if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8b [iov_iter] new pr... |
828 829 830 831 832 833 834 835 836 837 838 |
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; } |
aa28de275 iov_iter/hardenin... |
839 |
EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8b [iov_iter] new pr... |
840 |
|
72e809ed8 iov_iter: sanity ... |
841 842 |
static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) { |
6daef95b8 iov_iter: optimiz... |
843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 |
struct page *head; size_t v = n + offset; /* * The general case needs to access the page order in order * to compute the page size. * However, we mostly deal with order-0 pages and thus can * avoid a possible cache line miss for requests that fit all * page orders. */ if (n <= v && v <= PAGE_SIZE) return true; head = compound_head(page); v += (page - head) << PAGE_SHIFT; |
a90bcb86a iov_iter: fix pag... |
858 |
|
a50b854e0 mm: introduce pag... |
859 |
if (likely(n <= v && v <= (page_size(head)))) |
72e809ed8 iov_iter: sanity ... |
860 861 862 863 |
return true; WARN_ON(1); return false; } |
cbbd26b8b [iov_iter] new pr... |
864 |
|
62a8067a7 bio_vec-backed io... |
865 866 867 |
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { |
72e809ed8 iov_iter: sanity ... |
868 869 |
if (unlikely(!page_copy_sane(page, offset, bytes))) return 0; |
d271524a3 iov_iter.c: get r... |
870 871 872 873 874 |
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; |
9ea9ce042 iov_iter: Add I/O... |
875 876 877 |
} else if (unlikely(iov_iter_is_discard(i))) return bytes; else if (likely(!iov_iter_is_pipe(i))) |
62a8067a7 bio_vec-backed io... |
878 |
return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd7 new iov_iter flav... |
879 880 |
else return copy_page_to_iter_pipe(page, offset, bytes, i); |
62a8067a7 bio_vec-backed io... |
881 882 883 884 885 886 |
} 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) { |
72e809ed8 iov_iter: sanity ... |
887 888 |
if (unlikely(!page_copy_sane(page, offset, bytes))) return 0; |
9ea9ce042 iov_iter: Add I/O... |
889 |
if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd7 new iov_iter flav... |
890 891 892 |
WARN_ON(1); return 0; } |
a280455fa iov_iter.c: handl... |
893 |
if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a3 iov_iter.c: get r... |
894 |
void *kaddr = kmap_atomic(page); |
aa28de275 iov_iter/hardenin... |
895 |
size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a3 iov_iter.c: get r... |
896 897 898 |
kunmap_atomic(kaddr); return wanted; } else |
62a8067a7 bio_vec-backed io... |
899 900 901 |
return copy_page_from_iter_iovec(page, offset, bytes, i); } EXPORT_SYMBOL(copy_page_from_iter); |
241699cd7 new iov_iter flav... |
902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 |
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; } |
c35e02480 Add copy_to_iter(... |
925 926 |
size_t iov_iter_zero(size_t bytes, struct iov_iter *i) { |
00e237074 iov_iter: Use acc... |
927 |
if (unlikely(iov_iter_is_pipe(i))) |
241699cd7 new iov_iter flav... |
928 |
return pipe_zero(bytes, i); |
8442fa46c iov_iter.c: conve... |
929 |
iterate_and_advance(i, bytes, v, |
09fc68dc6 iov_iter: saner c... |
930 |
clear_user(v.iov_base, v.iov_len), |
a280455fa iov_iter.c: handl... |
931 932 |
memzero_page(v.bv_page, v.bv_offset, v.bv_len), memset(v.iov_base, 0, v.iov_len) |
8442fa46c iov_iter.c: conve... |
933 934 935 |
) return bytes; |
c35e02480 Add copy_to_iter(... |
936 937 |
} EXPORT_SYMBOL(iov_iter_zero); |
62a8067a7 bio_vec-backed io... |
938 939 940 |
size_t iov_iter_copy_from_user_atomic(struct page *page, struct iov_iter *i, unsigned long offset, size_t bytes) { |
04a311655 iov_iter.c: macro... |
941 |
char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed8 iov_iter: sanity ... |
942 943 944 945 |
if (unlikely(!page_copy_sane(page, offset, bytes))) { kunmap_atomic(kaddr); return 0; } |
9ea9ce042 iov_iter: Add I/O... |
946 |
if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd7 new iov_iter flav... |
947 948 949 950 |
kunmap_atomic(kaddr); WARN_ON(1); return 0; } |
04a311655 iov_iter.c: macro... |
951 |
iterate_all_kinds(i, bytes, v, |
09fc68dc6 iov_iter: saner c... |
952 |
copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a311655 iov_iter.c: macro... |
953 |
memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455fa iov_iter.c: handl... |
954 955 |
v.bv_offset, v.bv_len), memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) |
04a311655 iov_iter.c: macro... |
956 957 958 |
) kunmap_atomic(kaddr); return bytes; |
62a8067a7 bio_vec-backed io... |
959 960 |
} EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); |
b9dc6f65b fix a fencepost e... |
961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 |
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--; } } } |
241699cd7 new iov_iter flav... |
980 981 982 |
static void pipe_advance(struct iov_iter *i, size_t size) { struct pipe_inode_info *pipe = i->pipe; |
241699cd7 new iov_iter flav... |
983 984 |
if (unlikely(i->count < size)) size = i->count; |
241699cd7 new iov_iter flav... |
985 |
if (size) { |
b9dc6f65b fix a fencepost e... |
986 987 988 |
struct pipe_buffer *buf; size_t off = i->iov_offset, left = size; int idx = i->idx; |
241699cd7 new iov_iter flav... |
989 |
if (off) /* make it relative to the beginning of buffer */ |
b9dc6f65b fix a fencepost e... |
990 |
left += off - pipe->bufs[idx].offset; |
241699cd7 new iov_iter flav... |
991 992 |
while (1) { buf = &pipe->bufs[idx]; |
b9dc6f65b fix a fencepost e... |
993 |
if (left <= buf->len) |
241699cd7 new iov_iter flav... |
994 |
break; |
b9dc6f65b fix a fencepost e... |
995 |
left -= buf->len; |
241699cd7 new iov_iter flav... |
996 997 |
idx = next_idx(idx, pipe); } |
241699cd7 new iov_iter flav... |
998 |
i->idx = idx; |
b9dc6f65b fix a fencepost e... |
999 |
i->iov_offset = buf->offset + left; |
241699cd7 new iov_iter flav... |
1000 |
} |
b9dc6f65b fix a fencepost e... |
1001 1002 1003 |
i->count -= size; /* ... and discard everything past that point */ pipe_truncate(i); |
241699cd7 new iov_iter flav... |
1004 |
} |
62a8067a7 bio_vec-backed io... |
1005 1006 |
void iov_iter_advance(struct iov_iter *i, size_t size) { |
00e237074 iov_iter: Use acc... |
1007 |
if (unlikely(iov_iter_is_pipe(i))) { |
241699cd7 new iov_iter flav... |
1008 1009 1010 |
pipe_advance(i, size); return; } |
9ea9ce042 iov_iter: Add I/O... |
1011 1012 1013 1014 |
if (unlikely(iov_iter_is_discard(i))) { i->count -= size; return; } |
a280455fa iov_iter.c: handl... |
1015 |
iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a7 bio_vec-backed io... |
1016 1017 |
} EXPORT_SYMBOL(iov_iter_advance); |
27c0e3748 [iov_iter] new pr... |
1018 1019 1020 1021 |
void iov_iter_revert(struct iov_iter *i, size_t unroll) { if (!unroll) return; |
5b47d59af fix braino in gen... |
1022 1023 |
if (WARN_ON(unroll > MAX_RW_COUNT)) return; |
27c0e3748 [iov_iter] new pr... |
1024 |
i->count += unroll; |
00e237074 iov_iter: Use acc... |
1025 |
if (unlikely(iov_iter_is_pipe(i))) { |
27c0e3748 [iov_iter] new pr... |
1026 1027 1028 1029 1030 1031 |
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) { |
4fa55cefe fix a braino in I... |
1032 |
off -= unroll; |
27c0e3748 [iov_iter] new pr... |
1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 |
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; } |
9ea9ce042 iov_iter: Add I/O... |
1049 1050 |
if (unlikely(iov_iter_is_discard(i))) return; |
27c0e3748 [iov_iter] new pr... |
1051 1052 1053 1054 1055 |
if (unroll <= i->iov_offset) { i->iov_offset -= unroll; return; } unroll -= i->iov_offset; |
00e237074 iov_iter: Use acc... |
1056 |
if (iov_iter_is_bvec(i)) { |
27c0e3748 [iov_iter] new pr... |
1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 |
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); |
62a8067a7 bio_vec-backed io... |
1083 1084 1085 1086 1087 |
/* * Return the count of just the current iov_iter segment. */ size_t iov_iter_single_seg_count(const struct iov_iter *i) { |
00e237074 iov_iter: Use acc... |
1088 |
if (unlikely(iov_iter_is_pipe(i))) |
241699cd7 new iov_iter flav... |
1089 |
return i->count; // it is a silly place, anyway |
62a8067a7 bio_vec-backed io... |
1090 1091 |
if (i->nr_segs == 1) return i->count; |
9ea9ce042 iov_iter: Add I/O... |
1092 1093 |
if (unlikely(iov_iter_is_discard(i))) return i->count; |
00e237074 iov_iter: Use acc... |
1094 |
else if (iov_iter_is_bvec(i)) |
62a8067a7 bio_vec-backed io... |
1095 |
return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab929 Fix thinko in iov... |
1096 1097 |
else return min(i->count, i->iov->iov_len - i->iov_offset); |
62a8067a7 bio_vec-backed io... |
1098 1099 |
} EXPORT_SYMBOL(iov_iter_single_seg_count); |
aa563d7bc iov_iter: Separat... |
1100 |
void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77e new helper: iov_i... |
1101 |
const struct kvec *kvec, unsigned long nr_segs, |
abb78f875 new helper: iov_i... |
1102 1103 |
size_t count) { |
aa563d7bc iov_iter: Separat... |
1104 1105 |
WARN_ON(direction & ~(READ | WRITE)); i->type = ITER_KVEC | (direction & (READ | WRITE)); |
05afcb77e new helper: iov_i... |
1106 |
i->kvec = kvec; |
abb78f875 new helper: iov_i... |
1107 1108 1109 1110 1111 |
i->nr_segs = nr_segs; i->iov_offset = 0; i->count = count; } EXPORT_SYMBOL(iov_iter_kvec); |
aa563d7bc iov_iter: Separat... |
1112 |
void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77e new helper: iov_i... |
1113 1114 1115 |
const struct bio_vec *bvec, unsigned long nr_segs, size_t count) { |
aa563d7bc iov_iter: Separat... |
1116 1117 |
WARN_ON(direction & ~(READ | WRITE)); i->type = ITER_BVEC | (direction & (READ | WRITE)); |
05afcb77e new helper: iov_i... |
1118 1119 1120 1121 1122 1123 |
i->bvec = bvec; i->nr_segs = nr_segs; i->iov_offset = 0; i->count = count; } EXPORT_SYMBOL(iov_iter_bvec); |
aa563d7bc iov_iter: Separat... |
1124 |
void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd7 new iov_iter flav... |
1125 1126 1127 |
struct pipe_inode_info *pipe, size_t count) { |
aa563d7bc iov_iter: Separat... |
1128 |
BUG_ON(direction != READ); |
b9dc6f65b fix a fencepost e... |
1129 |
WARN_ON(pipe->nrbufs == pipe->buffers); |
aa563d7bc iov_iter: Separat... |
1130 |
i->type = ITER_PIPE | READ; |
241699cd7 new iov_iter flav... |
1131 1132 1133 1134 |
i->pipe = pipe; i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); i->iov_offset = 0; i->count = count; |
27c0e3748 [iov_iter] new pr... |
1135 |
i->start_idx = i->idx; |
241699cd7 new iov_iter flav... |
1136 1137 |
} EXPORT_SYMBOL(iov_iter_pipe); |
9ea9ce042 iov_iter: Add I/O... |
1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 |
/** * 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); |
62a8067a7 bio_vec-backed io... |
1155 1156 |
unsigned long iov_iter_alignment(const struct iov_iter *i) { |
04a311655 iov_iter.c: macro... |
1157 1158 |
unsigned long res = 0; size_t size = i->count; |
00e237074 iov_iter: Use acc... |
1159 |
if (unlikely(iov_iter_is_pipe(i))) { |
33844e665 [iov_iter] fix it... |
1160 |
if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) |
241699cd7 new iov_iter flav... |
1161 1162 1163 |
return size | i->iov_offset; return size; } |
04a311655 iov_iter.c: macro... |
1164 1165 |
iterate_all_kinds(i, size, v, (res |= (unsigned long)v.iov_base | v.iov_len, 0), |
a280455fa iov_iter.c: handl... |
1166 1167 |
res |= v.bv_offset | v.bv_len, res |= (unsigned long)v.iov_base | v.iov_len |
04a311655 iov_iter.c: macro... |
1168 1169 |
) return res; |
62a8067a7 bio_vec-backed io... |
1170 1171 |
} EXPORT_SYMBOL(iov_iter_alignment); |
357f435d8 fix the copy vs. ... |
1172 1173 |
unsigned long iov_iter_gap_alignment(const struct iov_iter *i) { |
33844e665 [iov_iter] fix it... |
1174 |
unsigned long res = 0; |
357f435d8 fix the copy vs. ... |
1175 |
size_t size = i->count; |
357f435d8 fix the copy vs. ... |
1176 |
|
9ea9ce042 iov_iter: Add I/O... |
1177 |
if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd7 new iov_iter flav... |
1178 1179 1180 |
WARN_ON(1); return ~0U; } |
357f435d8 fix the copy vs. ... |
1181 1182 1183 1184 1185 1186 1187 1188 |
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)) ); |
33844e665 [iov_iter] fix it... |
1189 |
return res; |
357f435d8 fix the copy vs. ... |
1190 1191 |
} EXPORT_SYMBOL(iov_iter_gap_alignment); |
e76b63123 iov_iter: fix ret... |
1192 |
static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd7 new iov_iter flav... |
1193 1194 1195 1196 1197 1198 |
size_t maxsize, struct page **pages, int idx, size_t *start) { struct pipe_inode_info *pipe = i->pipe; |
1689c73a7 Fix off-by-one in... |
1199 |
ssize_t n = push_pipe(i, maxsize, &idx, start); |
241699cd7 new iov_iter flav... |
1200 1201 1202 1203 1204 |
if (!n) return -EFAULT; maxsize = n; n += *start; |
1689c73a7 Fix off-by-one in... |
1205 |
while (n > 0) { |
241699cd7 new iov_iter flav... |
1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 |
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; |
33844e665 [iov_iter] fix it... |
1221 1222 |
if (!maxsize) return 0; |
241699cd7 new iov_iter flav... |
1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 |
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); } |
62a8067a7 bio_vec-backed io... |
1233 |
ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c4 fuse: honour max_... |
1234 |
struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a7 bio_vec-backed io... |
1235 1236 |
size_t *start) { |
e5393fae3 iov_iter.c: conve... |
1237 1238 |
if (maxsize > i->count) maxsize = i->count; |
00e237074 iov_iter: Use acc... |
1239 |
if (unlikely(iov_iter_is_pipe(i))) |
241699cd7 new iov_iter flav... |
1240 |
return pipe_get_pages(i, pages, maxsize, maxpages, start); |
9ea9ce042 iov_iter: Add I/O... |
1241 1242 |
if (unlikely(iov_iter_is_discard(i))) return -EFAULT; |
e5393fae3 iov_iter.c: conve... |
1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 |
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); |
73b0140bf mm/gup: change GU... |
1253 1254 1255 |
res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, pages); |
e5393fae3 iov_iter.c: conve... |
1256 1257 1258 1259 1260 1261 1262 1263 |
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; |
a280455fa iov_iter.c: handl... |
1264 1265 |
}),({ return -EFAULT; |
e5393fae3 iov_iter.c: conve... |
1266 1267 1268 |
}) ) return 0; |
62a8067a7 bio_vec-backed io... |
1269 1270 |
} EXPORT_SYMBOL(iov_iter_get_pages); |
1b17f1f2e iov_iter.c: conve... |
1271 1272 |
static struct page **get_pages_array(size_t n) { |
752ade68c treewide: use kv[... |
1273 |
return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2e iov_iter.c: conve... |
1274 |
} |
241699cd7 new iov_iter flav... |
1275 1276 1277 1278 1279 |
static ssize_t pipe_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start) { struct page **p; |
d7760d638 iov_iter: fix mem... |
1280 |
ssize_t n; |
241699cd7 new iov_iter flav... |
1281 1282 |
int idx; int npages; |
33844e665 [iov_iter] fix it... |
1283 1284 |
if (!maxsize) return 0; |
241699cd7 new iov_iter flav... |
1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 |
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; } |
62a8067a7 bio_vec-backed io... |
1306 1307 1308 1309 |
ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start) { |
1b17f1f2e iov_iter.c: conve... |
1310 1311 1312 1313 |
struct page **p; if (maxsize > i->count) maxsize = i->count; |
00e237074 iov_iter: Use acc... |
1314 |
if (unlikely(iov_iter_is_pipe(i))) |
241699cd7 new iov_iter flav... |
1315 |
return pipe_get_pages_alloc(i, pages, maxsize, start); |
9ea9ce042 iov_iter: Add I/O... |
1316 1317 |
if (unlikely(iov_iter_is_discard(i))) return -EFAULT; |
1b17f1f2e iov_iter.c: conve... |
1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 |
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; |
73b0140bf mm/gup: change GU... |
1329 1330 |
res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); |
1b17f1f2e iov_iter.c: conve... |
1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 |
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; |
a280455fa iov_iter.c: handl... |
1345 1346 |
}),({ return -EFAULT; |
1b17f1f2e iov_iter.c: conve... |
1347 1348 1349 |
}) ) return 0; |
62a8067a7 bio_vec-backed io... |
1350 1351 |
} EXPORT_SYMBOL(iov_iter_get_pages_alloc); |
a604ec7e9 csum_and_copy_...... |
1352 1353 1354 1355 1356 1357 |
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; |
a604ec7e9 csum_and_copy_...... |
1358 |
sum = *csum; |
9ea9ce042 iov_iter: Add I/O... |
1359 |
if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd7 new iov_iter flav... |
1360 1361 1362 |
WARN_ON(1); return 0; } |
a604ec7e9 csum_and_copy_...... |
1363 1364 |
iterate_and_advance(i, bytes, v, ({ int err = 0; |
cbbd26b8b [iov_iter] new pr... |
1365 |
next = csum_and_copy_from_user(v.iov_base, |
a604ec7e9 csum_and_copy_...... |
1366 1367 1368 1369 1370 1371 1372 1373 1374 |
(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); |
f91528955 iov_iter: reduce ... |
1375 1376 1377 |
sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, p + v.bv_offset, v.bv_len, sum, off); |
a604ec7e9 csum_and_copy_...... |
1378 |
kunmap_atomic(p); |
a604ec7e9 csum_and_copy_...... |
1379 1380 |
off += v.bv_len; }),({ |
f91528955 iov_iter: reduce ... |
1381 1382 1383 |
sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len, sum, off); |
a604ec7e9 csum_and_copy_...... |
1384 1385 1386 1387 1388 1389 1390 |
off += v.iov_len; }) ) *csum = sum; return bytes; } EXPORT_SYMBOL(csum_and_copy_from_iter); |
cbbd26b8b [iov_iter] new pr... |
1391 1392 1393 1394 1395 1396 1397 |
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; |
9ea9ce042 iov_iter: Add I/O... |
1398 |
if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
cbbd26b8b [iov_iter] new pr... |
1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 |
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); |
f91528955 iov_iter: reduce ... |
1416 1417 1418 |
sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, p + v.bv_offset, v.bv_len, sum, off); |
cbbd26b8b [iov_iter] new pr... |
1419 |
kunmap_atomic(p); |
cbbd26b8b [iov_iter] new pr... |
1420 1421 |
off += v.bv_len; }),({ |
f91528955 iov_iter: reduce ... |
1422 1423 1424 |
sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len, sum, off); |
cbbd26b8b [iov_iter] new pr... |
1425 1426 1427 1428 1429 1430 1431 1432 |
off += v.iov_len; }) ) *csum = sum; iov_iter_advance(i, bytes); return true; } EXPORT_SYMBOL(csum_and_copy_from_iter_full); |
cb002d074 iov_iter: pass vo... |
1433 |
size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, |
a604ec7e9 csum_and_copy_...... |
1434 1435 |
struct iov_iter *i) { |
36f7a8a4c iov_iter: constif... |
1436 |
const char *from = addr; |
cb002d074 iov_iter: pass vo... |
1437 |
__wsum *csum = csump; |
a604ec7e9 csum_and_copy_...... |
1438 1439 |
__wsum sum, next; size_t off = 0; |
78e1f3861 iov_iter: teach c... |
1440 1441 1442 |
if (unlikely(iov_iter_is_pipe(i))) return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); |
a604ec7e9 csum_and_copy_...... |
1443 |
sum = *csum; |
78e1f3861 iov_iter: teach c... |
1444 |
if (unlikely(iov_iter_is_discard(i))) { |
241699cd7 new iov_iter flav... |
1445 1446 1447 |
WARN_ON(1); /* for now */ return 0; } |
a604ec7e9 csum_and_copy_...... |
1448 1449 1450 |
iterate_and_advance(i, bytes, v, ({ int err = 0; next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, |
cbbd26b8b [iov_iter] new pr... |
1451 |
v.iov_base, |
a604ec7e9 csum_and_copy_...... |
1452 1453 1454 1455 1456 1457 1458 1459 |
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); |
f91528955 iov_iter: reduce ... |
1460 1461 1462 |
sum = csum_and_memcpy(p + v.bv_offset, (from += v.bv_len) - v.bv_len, v.bv_len, sum, off); |
a604ec7e9 csum_and_copy_...... |
1463 |
kunmap_atomic(p); |
a604ec7e9 csum_and_copy_...... |
1464 1465 |
off += v.bv_len; }),({ |
f91528955 iov_iter: reduce ... |
1466 1467 1468 |
sum = csum_and_memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len, sum, off); |
a604ec7e9 csum_and_copy_...... |
1469 1470 1471 1472 1473 1474 1475 |
off += v.iov_len; }) ) *csum = sum; return bytes; } EXPORT_SYMBOL(csum_and_copy_to_iter); |
d05f44355 iov_iter: introdu... |
1476 1477 1478 |
size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, struct iov_iter *i) { |
27fad74a5 iov_iter: Fix bui... |
1479 |
#ifdef CONFIG_CRYPTO |
d05f44355 iov_iter: introdu... |
1480 1481 1482 1483 1484 1485 1486 1487 1488 |
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; |
27fad74a5 iov_iter: Fix bui... |
1489 1490 1491 |
#else return 0; #endif |
d05f44355 iov_iter: introdu... |
1492 1493 |
} EXPORT_SYMBOL(hash_and_copy_to_iter); |
62a8067a7 bio_vec-backed io... |
1494 1495 |
int iov_iter_npages(const struct iov_iter *i, int maxpages) { |
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size_t size = i->count; int npages = 0; if (!size) return 0; |
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if (unlikely(iov_iter_is_discard(i))) return 0; |
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|
00e237074 iov_iter: Use acc... |
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if (unlikely(iov_iter_is_pipe(i))) { |
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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, ({ |
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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; |
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}),({ 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; |
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}) ) return npages; |
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} |
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EXPORT_SYMBOL(iov_iter_npages); |
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const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) { *new = *old; |
00e237074 iov_iter: Use acc... |
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if (unlikely(iov_iter_is_pipe(new))) { |
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WARN_ON(1); return NULL; } |
9ea9ce042 iov_iter: Add I/O... |
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if (unlikely(iov_iter_is_discard(new))) return NULL; |
00e237074 iov_iter: Use acc... |
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if (iov_iter_is_bvec(new)) |
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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); |
bc917be81 saner iov_iter in... |
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|
ffecee4f2 iov_iter: kernel-... |
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/** * 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). * |
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* Return: Negative error code on error, bytes imported on success |
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*/ |
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ssize_t import_iovec(int type, const struct iovec __user * uvector, |
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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; |
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return n; |
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} EXPORT_SYMBOL(import_iovec); #ifdef CONFIG_COMPAT #include <linux/compat.h> |
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ssize_t compat_import_iovec(int type, const struct compat_iovec __user * uvector, unsigned nr_segs, unsigned fast_segs, struct iovec **iov, struct iov_iter *i) |
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{ 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; |
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return n; |
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} #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; |
96d4f267e Remove 'type' arg... |
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if (unlikely(!access_ok(buf, len))) |
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return -EFAULT; iov->iov_base = buf; iov->iov_len = len; iov_iter_init(i, rw, iov, 1, len); return 0; } |
e12675853 iov_iter: export ... |
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EXPORT_SYMBOL(import_single_range); |
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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); |