Oleg Nesterov <oleg@xxxxxxxxxx> writes: > On 07/18, Eric W. Biederman wrote: >> >> - BUG_ON((reason & __SI_MASK) != __SI_POLL); >> + BUG_ON((reason < POLL_IN) || (reason > NSIGPOLL)); > ^^^^^^^^^^^^^^^^^ > looks obviously wrong? Say, POLL_IN is obviously > NSIGPOLL == 6. Strictly speaking that code is wrong until the next patch when I remove __SI_POLL. That is my mistake. When the values are not their messed up internal kernel variants the code works fine and makes sense. #define POLL_IN 1 /* data input available */ #define POLL_OUT 2 /* output buffers available */ #define POLL_MSG 3 /* input message available */ #define POLL_ERR 4 /* i/o error */ #define POLL_PRI 5 /* high priority input available */ #define POLL_HUP 6 /* device disconnected */ #define NSIGPOLL 6 > Probably you meant > > BUG_ON((reason < POLL_IN) || (reason - POLL_IN > NSIGPOLL) > > ? > > but this contradicts with the next line: >> if (reason - POLL_IN >= NSIGPOLL) >> si.si_band = ~0L; > > confused... I am mystified why we test for a condition that we have been bugging on for ages. Eric
