diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/sunrpc/xdr.c | 174 |
1 files changed, 132 insertions, 42 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 5833329c132c..c474339ba9ac 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -266,26 +266,6 @@ _shift_data_left_pages(struct page **pages, size_t pgto_base, } while ((len -= copy) != 0); } -static void -_shift_data_left_tail(struct xdr_buf *buf, unsigned int pgto, size_t len) -{ - struct kvec *tail = buf->tail; - - if (len > tail->iov_len) - len = tail->iov_len; - - _copy_to_pages(buf->pages, - buf->page_base + pgto, - (char *)tail->iov_base, - len); - tail->iov_len -= len; - - if (tail->iov_len > 0) - memmove((char *)tail->iov_base, - tail->iov_base + len, - tail->iov_len); -} - /** * _shift_data_right_pages * @pages: vector of pages containing both the source and dest memory area. @@ -516,6 +496,109 @@ _zero_pages(struct page **pages, size_t pgbase, size_t len) } while ((len -= zero) != 0); } +static void xdr_buf_tail_copy_left(const struct xdr_buf *buf, unsigned int base, + unsigned int len, unsigned int shift) +{ + const struct kvec *tail = buf->tail; + + if (base >= tail->iov_len) + return; + if (len > tail->iov_len - base) + len = tail->iov_len - base; + /* Shift data into head */ + if (shift > buf->page_len + base) { + const struct kvec *head = buf->head; + unsigned int hdto = + head->iov_len + buf->page_len + base - shift; + unsigned int hdlen = len; + + if (WARN_ONCE(shift > head->iov_len + buf->page_len + base, + "SUNRPC: Misaligned data.\n")) + return; + if (hdto + hdlen > head->iov_len) + hdlen = head->iov_len - hdto; + memcpy(head->iov_base + hdto, tail->iov_base + base, hdlen); + base += hdlen; + len -= hdlen; + if (!len) + return; + } + /* Shift data into pages */ + if (shift > base) { + unsigned int pgto = buf->page_len + base - shift; + unsigned int pglen = len; + + if (pgto + pglen > buf->page_len) + pglen = buf->page_len - pgto; + _copy_to_pages(buf->pages, buf->page_base + pgto, + tail->iov_base + base, pglen); + base += pglen; + len -= pglen; + if (!len) + return; + } + memmove(tail->iov_base + base - shift, tail->iov_base + base, len); +} + +static void xdr_buf_pages_copy_left(const struct xdr_buf *buf, + unsigned int base, unsigned int len, + unsigned int shift) +{ + unsigned int pgto; + + if (base >= buf->page_len) + return; + if (len > buf->page_len - base) + len = buf->page_len - base; + /* Shift data into head */ + if (shift > base) { + const struct kvec *head = buf->head; + unsigned int hdto = head->iov_len + base - shift; + unsigned int hdlen = len; + + if (WARN_ONCE(shift > head->iov_len + base, + "SUNRPC: Misaligned data.\n")) + return; + if (hdto + hdlen > head->iov_len) + hdlen = head->iov_len - hdto; + _copy_from_pages(head->iov_base + hdto, buf->pages, + buf->page_base + base, hdlen); + base += hdlen; + len -= hdlen; + if (!len) + return; + } + pgto = base - shift; + _shift_data_left_pages(buf->pages, buf->page_base + pgto, + buf->page_base + base, len); +} + +static void xdr_buf_tail_shift_left(const struct xdr_buf *buf, + unsigned int base, unsigned int len, + unsigned int shift) +{ + if (!shift || !len) + return; + xdr_buf_tail_copy_left(buf, base, len, shift); +} + +static void xdr_buf_pages_shift_left(const struct xdr_buf *buf, + unsigned int base, unsigned int len, + unsigned int shift) +{ + if (!shift || !len) + return; + if (base >= buf->page_len) { + xdr_buf_tail_shift_left(buf, base - buf->page_len, len, shift); + return; + } + xdr_buf_pages_copy_left(buf, base, len, shift); + len += base; + if (len <= buf->page_len) + return; + xdr_buf_tail_copy_left(buf, 0, len - buf->page_len, shift); +} + /** * xdr_shrink_bufhead * @buf: xdr_buf @@ -1261,38 +1344,45 @@ unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) } EXPORT_SYMBOL_GPL(xdr_read_pages); -uint64_t xdr_align_data(struct xdr_stream *xdr, uint64_t offset, uint32_t length) +unsigned int xdr_align_data(struct xdr_stream *xdr, unsigned int offset, + unsigned int length) { struct xdr_buf *buf = xdr->buf; - unsigned int from, bytes; - unsigned int shift = 0; - - if ((offset + length) < offset || - (offset + length) > buf->page_len) - length = buf->page_len - offset; + unsigned int from, bytes, len; + unsigned int shift; xdr_realign_pages(xdr); from = xdr_page_pos(xdr); - bytes = xdr_stream_remaining(xdr); - if (length < bytes) - bytes = length; + + if (from >= buf->page_len + buf->tail->iov_len) + return 0; + if (from + buf->head->iov_len >= buf->len) + return 0; + + len = buf->len - buf->head->iov_len; + + /* We only shift data left! */ + if (WARN_ONCE(from < offset, "SUNRPC: misaligned data src=%u dst=%u\n", + from, offset)) + return 0; + if (WARN_ONCE(offset > buf->page_len, + "SUNRPC: buffer overflow. offset=%u, page_len=%u\n", + offset, buf->page_len)) + return 0; /* Move page data to the left */ - if (from > offset) { - shift = min_t(unsigned int, bytes, buf->page_len - from); - _shift_data_left_pages(buf->pages, - buf->page_base + offset, - buf->page_base + from, - shift); - bytes -= shift; + shift = from - offset; + xdr_buf_pages_shift_left(buf, from, len, shift); + xdr->buf->len -= shift; + xdr->nwords -= XDR_QUADLEN(shift); - /* Move tail data into the pages, if necessary */ - if (bytes > 0) - _shift_data_left_tail(buf, offset + shift, bytes); - } + bytes = xdr_stream_remaining(xdr); + if (length > bytes) + length = bytes; + bytes -= length; xdr->nwords -= XDR_QUADLEN(length); - xdr_set_page(xdr, from + length, xdr_stream_remaining(xdr)); + xdr_set_page(xdr, offset + length, bytes); return length; } EXPORT_SYMBOL_GPL(xdr_align_data); |