Re: Linux 2.4.18-pre7

Rasmus Andersen (rasmus@jaquet.dk)
Thu, 24 Jan 2002 23:49:44 +0100


On Wed, Jan 23, 2002 at 07:55:46PM -0200, Marcelo Tosatti wrote:
>
> Hi,
>
> So here goes pre7.

Hi Marcelo.

This is a resend of a patch I sent you earlier, rediffed. Explanation
below. If you would prefer Rogier Wolff to send it, please let me
know.

---
The following patch makes drivers/char/generic_serial.c check the
return code of copy_{from,to}_user, coverts a cli/sti to
save_flags/cli/restore_flags and does some minor cleanup. It
also makes the rio_linux, serial_tx3912, sh-sci and sx drivers
propagate the copy_xxx_user return codes upwards.
 
The patch has been blessed by Rogier Wolff, the maintainer.
---

diff -uar linux-2418p7-clean/drivers/char/generic_serial.c linux-2418p7/drivers/char/generic_serial.c --- linux-2418p7-clean/drivers/char/generic_serial.c Fri Sep 14 00:21:32 2001 +++ linux-2418p7/drivers/char/generic_serial.c Thu Jan 24 23:45:14 2002 @@ -143,7 +143,12 @@ /* Can't copy more? break out! */ if (c <= 0) break; if (from_user) - copy_from_user (port->xmit_buf + port->xmit_head, buf, c); + if (copy_from_user (port->xmit_buf + port->xmit_head, + buf, c)) { + up (& port->port_write_sem); + return -EFAULT; + } + else memcpy (port->xmit_buf + port->xmit_head, buf, c); @@ -214,8 +219,13 @@ while (1) { c = count; - /* This is safe because we "OWN" the "head". Noone else can - change the "head": we own the port_write_sem. */ + /* Note: This part can be done without + * interrupt routine protection since + * the interrupt routines may only modify + * shared variables in safe ways, in the worst + * case causing us to loop twice in the code + * below. See comments below. */ + /* Don't overrun the end of the buffer */ t = SERIAL_XMIT_SIZE - port->xmit_head; if (t < c) c = t; @@ -506,7 +516,7 @@ void gs_shutdown_port (struct gs_port *port) { - long flags; + unsigned long flags; func_enter(); @@ -589,6 +599,7 @@ int do_clocal = 0; int CD; struct tty_struct *tty; + unsigned long flags; func_enter (); @@ -604,7 +615,7 @@ * until it's done, and then try again. */ if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) { - interruptible_sleep_on(&port->close_wait); + interruptible_sleep_on(&port->close_wait); if (port->flags & ASYNC_HUP_NOTIFY) return -EAGAIN; else @@ -668,10 +679,11 @@ add_wait_queue(&port->open_wait, &wait); gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n"); + save_flags(flags); cli(); if (!tty_hung_up_p(filp)) port->count--; - sti(); + restore_flags(flags); port->blocked_open++; while (1) { CD = port->rd->get_CD (port); @@ -1003,7 +1015,8 @@ { struct serial_struct sio; - copy_from_user(&sio, sp, sizeof(struct serial_struct)); + if (copy_from_user(&sio, sp, sizeof(struct serial_struct))) + return(-EFAULT); if (!capable(CAP_SYS_ADMIN)) { if ((sio.baud_base != port->baud_base) || @@ -1033,7 +1046,7 @@ * Generate the serial struct info. */ -void gs_getserial(struct gs_port *port, struct serial_struct *sp) +int gs_getserial(struct gs_port *port, struct serial_struct *sp) { struct serial_struct sio; @@ -1055,7 +1068,10 @@ if (port->rd->getserial) port->rd->getserial (port, &sio); - copy_to_user(sp, &sio, sizeof(struct serial_struct)); + if (copy_to_user(sp, &sio, sizeof(struct serial_struct))) + return -EFAULT; + return 0; + } diff -uar linux-2418p7-clean/drivers/char/rio/rio_linux.c linux-2418p7/drivers/char/rio/rio_linux.c --- linux-2418p7-clean/drivers/char/rio/rio_linux.c Thu Oct 25 22:53:47 2001 +++ linux-2418p7/drivers/char/rio/rio_linux.c Thu Jan 24 23:45:14 2002 @@ -742,7 +742,7 @@ case TIOCGSERIAL: if ((rc = verify_area(VERIFY_WRITE, (void *) arg, sizeof(struct serial_struct))) == 0) - gs_getserial(&PortP->gs, (struct serial_struct *) arg); + rc = gs_getserial(&PortP->gs, (struct serial_struct *) arg); break; case TCSBRK: if ( PortP->State & RIO_DELETED ) { diff -uar linux-2418p7-clean/drivers/char/serial_tx3912.c linux-2418p7/drivers/char/serial_tx3912.c --- linux-2418p7-clean/drivers/char/serial_tx3912.c Fri Nov 9 23:01:21 2001 +++ linux-2418p7/drivers/char/serial_tx3912.c Thu Jan 24 23:45:14 2002 @@ -673,7 +673,7 @@ case TIOCGSERIAL: if ((rc = verify_area(VERIFY_WRITE, (void *) arg, sizeof(struct serial_struct))) == 0) - gs_getserial(&port->gs, (struct serial_struct *) arg); + rc = gs_getserial(&port->gs, (struct serial_struct *) arg); break; case TIOCSSERIAL: if ((rc = verify_area(VERIFY_READ, (void *) arg, diff -uar linux-2418p7-clean/drivers/char/sh-sci.c linux-2418p7/drivers/char/sh-sci.c --- linux-2418p7-clean/drivers/char/sh-sci.c Mon Oct 15 22:36:48 2001 +++ linux-2418p7/drivers/char/sh-sci.c Thu Jan 24 23:45:14 2002 @@ -919,7 +919,7 @@ case TIOCGSERIAL: if ((rc = verify_area(VERIFY_WRITE, (void *) arg, sizeof(struct serial_struct))) == 0) - gs_getserial(&port->gs, (struct serial_struct *) arg); + rc = gs_getserial(&port->gs, (struct serial_struct *) arg); break; case TIOCSSERIAL: if ((rc = verify_area(VERIFY_READ, (void *) arg, diff -uar linux-2418p7-clean/drivers/char/sx.c linux-2418p7/drivers/char/sx.c --- linux-2418p7-clean/drivers/char/sx.c Thu Jan 24 23:37:09 2002 +++ linux-2418p7/drivers/char/sx.c Thu Jan 24 23:45:14 2002 @@ -1817,7 +1817,7 @@ case TIOCGSERIAL: if ((rc = verify_area(VERIFY_WRITE, (void *) arg, sizeof(struct serial_struct))) == 0) - gs_getserial(&port->gs, (struct serial_struct *) arg); + rc = gs_getserial(&port->gs, (struct serial_struct *) arg); break; case TIOCSSERIAL: if ((rc = verify_area(VERIFY_READ, (void *) arg, diff -uar linux-2418p7-clean/include/linux/generic_serial.h linux-2418p7/include/linux/generic_serial.h --- linux-2418p7-clean/include/linux/generic_serial.h Fri Sep 7 18:28:38 2001 +++ linux-2418p7/include/linux/generic_serial.h Thu Jan 24 23:45:14 2002 @@ -12,9 +12,6 @@ #ifndef GENERIC_SERIAL_H #define GENERIC_SERIAL_H - - - struct real_driver { void (*disable_tx_interrupts) (void *); void (*enable_tx_interrupts) (void *); @@ -98,7 +95,7 @@ struct termios * old_termios); int gs_init_port(struct gs_port *port); int gs_setserial(struct gs_port *port, struct serial_struct *sp); -void gs_getserial(struct gs_port *port, struct serial_struct *sp); +int gs_getserial(struct gs_port *port, struct serial_struct *sp); void gs_got_break(struct gs_port *port); extern int gs_debug;

-- 
Regards,
        Rasmus(rasmus@jaquet.dk)
-
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