From: Tom Zanussi Date: Thu, 12 Jul 2007 06:12:04 +0000 (+0200) Subject: relay: fix bogus cast in subbuf_splice_actor() X-Git-Tag: v2.6.23-rc1~1078^2~3 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=24da24de2eae0c277b85836e2b4b09cfafeea995;p=linux-2.6-omap-h63xx.git relay: fix bogus cast in subbuf_splice_actor() The current code that sets the read position in subbuf_splice_actor may give erroneous results if the buffer size isn't a power of 2. This patch fixes the problem. Signed-off-by: Tom Zanussi Signed-off-by: Jens Axboe --- diff --git a/kernel/relay.c b/kernel/relay.c index 3b299fb3855..780269765f2 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -1074,7 +1074,9 @@ static int subbuf_splice_actor(struct file *in, unsigned int pidx, poff, total_len, subbuf_pages, ret; struct rchan_buf *rbuf = in->private_data; unsigned int subbuf_size = rbuf->chan->subbuf_size; - size_t read_start = ((size_t)*ppos) % rbuf->chan->alloc_size; + uint64_t pos = (uint64_t) *ppos; + uint32_t alloc_size = (uint32_t) rbuf->chan->alloc_size; + size_t read_start = (size_t) do_div(pos, alloc_size); size_t read_subbuf = read_start / subbuf_size; size_t padding = rbuf->padding[read_subbuf]; size_t nonpad_end = read_subbuf * subbuf_size + subbuf_size - padding;