On Fri, Feb 06, 2015 at 04:09:02PM +0000, John Baldwin wrote: > Author: jhb > Date: Fri Feb 6 16:09:01 2015 > New Revision: 278320 > URL: https://svnweb.freebsd.org/changeset/base/278320 > > Log: > Add a new device control utility for new-bus devices called devctl. This > allows the user to request administrative changes to individual devices [..] > +static int > +devctl2_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag, > + struct thread *td) > +{ > + struct devreq *req; > + device_t dev; > + int error, old; > + > + /* Locate the device to control. */ > + mtx_lock(&Giant); > + req = (struct devreq *)data; [..] > + switch (cmd) { [..] > + case DEV_SET_DRIVER: { > + devclass_t dc; > + char driver[128]; > + > + error = copyinstr(req->dr_data, driver, sizeof(driver), NULL); [..] > + if (!driver_exists(dev->parent, driver)) { > + error = ENOENT; > + break; > + } [..] > + } > + mtx_unlock(&Giant); > + return (error); > +}
I only skimmed thourgh this, will not a page fault drop + reacquire Giant lock? iow, would not it be better to copy prior to taking the lock? -- Mateusz Guzik <mjguzik gmail.com> _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
