* [PATCH] returning errors from copy_xxx_user in generic_serial.c (2417p4)
@ 2001-12-07 13:11 Rasmus Andersen
0 siblings, 0 replies; only message in thread
From: Rasmus Andersen @ 2001-12-07 13:11 UTC (permalink / raw)
To: marcelo; +Cc: R.E.Wolff, linux-kernel
Hi Marcelo.
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,
compiles and survives test loads. It applies against 2417p4
with tiny fuzz.
--- linux-2414-kbuild-clean/drivers/char/generic_serial.c Thu Oct 11 20:52:37 2001
+++ linux-2414/drivers/char/generic_serial.c Thu Dec 6 14:40:02 2001
@@ -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 -aur linux-2414-kbuild-clean/drivers/char/rio/rio_linux.c linux-2414/drivers/char/rio/rio_linux.c
--- linux-2414-kbuild-clean/drivers/char/rio/rio_linux.c Tue Nov 6 20:16:57 2001
+++ linux-2414/drivers/char/rio/rio_linux.c Fri Nov 16 20:52:00 2001
@@ -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 -aur linux-2414-kbuild-clean/drivers/char/serial_tx3912.c linux-2414/drivers/char/serial_tx3912.c
--- linux-2414-kbuild-clean/drivers/char/serial_tx3912.c Wed Oct 31 21:04:43 2001
+++ linux-2414/drivers/char/serial_tx3912.c Fri Nov 16 20:52:00 2001
@@ -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 -aur linux-2414-kbuild-clean/drivers/char/sh-sci.c linux-2414/drivers/char/sh-sci.c
--- linux-2414-kbuild-clean/drivers/char/sh-sci.c Wed Oct 31 21:08:37 2001
+++ linux-2414/drivers/char/sh-sci.c Fri Nov 16 20:52:00 2001
@@ -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 -aur linux-2414-kbuild-clean/drivers/char/sx.c linux-2414/drivers/char/sx.c
--- linux-2414-kbuild-clean/drivers/char/sx.c Thu Oct 11 20:52:39 2001
+++ linux-2414/drivers/char/sx.c Fri Nov 16 20:52:00 2001
@@ -1810,7 +1810,7 @@
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 -aur linux-2414-kbuild-clean/include/linux/generic_serial.h linux-2414/include/linux/generic_serial.h
--- linux-2414-kbuild-clean/include/linux/generic_serial.h Thu Oct 11 20:53:04 2001
+++ linux-2414/include/linux/generic_serial.h Fri Nov 16 20:54:49 2001
@@ -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;
--
Rasmus(rasmus@jaquet.dk)
Cutler Webster's Law: There are two sides to every argument, unless a
person is personally involved, in which case there is only one.
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