[PATCH] drivers/char/ppdev.c: returning copy_to_user result

From: Arnaldo Carvalho de Melo (acme@conectiva.com.br)
Date: Fri Aug 25 2000 - 06:22:29 EST

Hi,

     Please take a look and consider applying. Feedback about why it would
be wrong would be greatly appreciated. 8)

                        - Arnaldo

--- linux-2.4.0-test7/drivers/char/ppdev.c Thu Jul 13 01:58:42 2000
+++ linux-2.4.0-test7.acme/drivers/char/ppdev.c Fri Aug 25 08:13:32 2000
@@ -39,7 +39,13 @@
  * read/write read or write in current IEEE 1284 protocol
  * select wait for interrupt (in readfds)
  *
+ * Changes:
  * Added SETTIME/GETTIME ioctl, Fred Barnes 1999.
+ *
+ * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
+ * - don't return directly copy_*_user return, on failure it returns
+ * a greater than zero number, the number of bytes successfully
+ * copied, and not -EFAULT, which is the correct return for failure
  */
 
 #include <linux/module.h>
@@ -369,19 +375,19 @@
 
         case PPRSTATUS:
                 reg = parport_read_status (port);
- return copy_to_user ((unsigned char *) arg, &reg,
- sizeof (reg));
-
+ if (copy_to_user ((unsigned char *) arg, &reg, sizeof (reg)))
+ return -EFAULT;
+ return 0;
         case PPRDATA:
                 reg = parport_read_data (port);
- return copy_to_user ((unsigned char *) arg, &reg,
- sizeof (reg));
-
+ if (copy_to_user ((unsigned char *) arg, &reg, sizeof (reg)))
+ return -EFAULT;
+ return 0;
         case PPRCONTROL:
                 reg = parport_read_control (port);
- return copy_to_user ((unsigned char *) arg, &reg,
- sizeof (reg));
-
+ if (copy_to_user ((unsigned char *) arg, &reg, sizeof (reg)))
+ return -EFAULT;
+ return 0;
         case PPYIELD:
                 parport_yield_blocking (pp->pdev);
                 return 0;
-
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This archive was generated by hypermail 2b29 : Thu Aug 31 2000 - 21:00:16 EST