Re: Linux 2.4.18-pre2

Rasmus Andersen
2002-01-08T21:21:06Z

Hi Marcelo.

This is a resend of a patch I sent you earlier, rediffed. Explanation
below.

---
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-2418p2-clean/drivers/char/generic_serial.c linux-2418p2/drivers/char/generic_serial.c
--- linux-2418p2-clean/drivers/char/generic_serial.c Fri Sep 14 00:21:32 2001
+++ linux-2418p2/drivers/char/generic_serial.c Tue Jan 8 22:10:22 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-2418p2-clean/drivers/char/rio/rio_linux.c linux-2418p2/drivers/char/rio/rio_linux.c
--- linux-2418p2-clean/drivers/char/rio/rio_linux.c Thu Oct 25 22:53:47 2001
+++ linux-2418p2/drivers/char/rio/rio_linux.c Tue Jan 8 22:10:22 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-2418p2-clean/drivers/char/serial_tx3912.c linux-2418p2/drivers/char/serial_tx3912.c
--- linux-2418p2-clean/drivers/char/serial_tx3912.c Fri Nov 9 23:01:21 2001
+++ linux-2418p2/drivers/char/serial_tx3912.c Tue Jan 8 22:10:22 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-2418p2-clean/drivers/char/sh-sci.c linux-2418p2/drivers/char/sh-sci.c
--- linux-2418p2-clean/drivers/char/sh-sci.c Mon Oct 15 22:36:48 2001
+++ linux-2418p2/drivers/char/sh-sci.c Tue Jan 8 22:10:22 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-2418p2-clean/drivers/char/sx.c linux-2418p2/drivers/char/sx.c
--- linux-2418p2-clean/drivers/char/sx.c Tue Jan 8 22:09:24 2002
+++ linux-2418p2/drivers/char/sx.c Tue Jan 8 22:10:22 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,
Only in linux-2418p2/drivers/char: sx.c~
diff -uar linux-2418p2-clean/include/linux/generic_serial.h linux-2418p2/include/linux/generic_serial.h
--- linux-2418p2-clean/include/linux/generic_serial.h Fri Sep 7 18:28:38 2001
+++ linux-2418p2/include/linux/generic_serial.h Tue Jan 8 22:10:22 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