This patch fails writes larger than the sub-buffer size and prints a
warning and stack trace when it happens. I chose this over BUG_ON()
or silently failing since while it could probably be considered a bug
for an application to let this happen, it's not fatal and the user
would probably want to know (and change buffer sizes).
Andrew, please apply.
Thanks,
Tom
Signed-off-by: Tom Zanussi <[EMAIL PROTECTED]>
diff -urpN -X dontdiff linux-2.6.12-rc1-mm2/fs/relayfs/relay.c
linux-2.6.12-rc1-mm2-cur/fs/relayfs/relay.c
--- linux-2.6.12-rc1-mm2/fs/relayfs/relay.c 2005-03-20 22:26:47.000000000
-0600
+++ linux-2.6.12-rc1-mm2-cur/fs/relayfs/relay.c 2005-03-20 23:32:50.000000000
-0600
@@ -378,7 +378,10 @@ unsigned relay_switch_subbuf(struct rcha
int new, old, produced = atomic_read(&buf->subbufs_produced);
unsigned padding;
- if (atomic_read(&buf->unfull)) {
+ if (unlikely(length > buf->chan->subbuf_size))
+ goto toobig;
+
+ if (unlikely(atomic_read(&buf->unfull))) {
atomic_set(&buf->unfull, 0);
new = produced % buf->chan->n_subbufs;
old = (produced - 1) % buf->chan->n_subbufs;
@@ -410,7 +413,15 @@ unsigned relay_switch_subbuf(struct rcha
new = (produced + 1) % buf->chan->n_subbufs;
do_switch(buf, new, old);
+ if (unlikely(length + buf->offset > buf->chan->subbuf_size))
+ goto toobig;
+
return length;
+
+toobig:
+ printk(KERN_WARNING "relayfs: event too large (%u)\n", length);
+ WARN_ON(1);
+ return 0;
}
/**
-
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