Le lundi 11 juin 2007 à 16:26 -0500, Nelson Castillo a écrit : > Hi. > > I just added support for user space buffers in kfifo. I found useful > __kfifo_get_user to copy data to a user buffer in a read call. I didn't > like the idea of having an extra buffer. > > * Is it ok to add this support?
I suppose it is, however: > + spin_lock_irqsave(fifo->lock, flags); > + > + ret = __kfifo_put_user(fifo, buffer, len); > + > + spin_unlock_irqrestore(fifo->lock, flags); [...] > +int __kfifo_put_user(struct kfifo *fifo, const unsigned char __user *buffer, > + unsigned int len) [...] > + if(copy_from_user(fifo->buffer + (fifo->in & (fifo->size - 1)), > + buffer, l)) > + return -EFAULT; [...] accessing userspace memory with a spinlock taken (moreover an irqsave() one) is bad bad bad. Stelian. -- Stelian Pop <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
