On Mon, Feb 06, 2012 at 07:47:26PM +0200, Kalle Valo wrote: > > Are you not making sure that the > > length of the data is not more than the requested one which is > > passed to copy_to_user() so that read() is always called with > > *ppos=0?. The following code seems to do that > > But the function is called multiple times with increasing values of > *ppos as more data is returned to user space: > > [ 100.303747] ath6kl_fwlog_block_read(): *ppos 0 > [ 100.305252] ath6kl_fwlog_block_read(): *ppos 30116 > [ 101.768947] ath6kl_fwlog_block_read(): *ppos 31624 > [ 117.027469] ath6kl_fwlog_block_read(): *ppos 33124 > [ 117.090146] ath6kl_fwlog_block_read(): *ppos 34628 > [ 117.172338] ath6kl_fwlog_block_read(): *ppos 36128 > > So I can't assume that *ppos = 0. Right, unless we say we have no more data to pass (when read() returns 0), *ppos would be keep on increasing by the number of bytes copied to user space. Updating *ppos just looks like a formality here though. But I'm also not sure about doing it cleanly. Vasanth -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
