add an in-kernel /dev/xf86 aperture driver. the 'machdep.allowaperture'

sysctl controls whether it is permitted to access it. This sysctl can only
be manipulated when securelevel=0, hence in sysctl.conf

4 files changed, 61 insertions, 7 deletions

diff --git a/sys/arch/i386/conf/GENERIC b/sys/arch/i386/conf/GENERIC
index 3cb01c4d356..50b4226818c 100644
--- a/sys/arch/i386/conf/GENERIC
+++ b/sys/arch/i386/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.60 1998/01/06 02:35:18 deraadt Exp $
+#	$OpenBSD: GENERIC,v 1.61 1998/02/17 23:49:28 matthieu Exp $
 #	$NetBSD: GENERIC,v 1.48 1996/05/20 18:17:23 mrg Exp $
 #
 #	GENERIC -- everything that's currently supported
@@ -17,6 +17,7 @@ option		GPL_MATH_EMULATE	# floating point emulation
 #option		VM86		# Virtual 8086 emulation
 #option		USER_LDT	# user-settable LDT; used by WINE
 option		XSERVER
+option		APERTURE	# in-kernel aperture driver for XFree86
 
 # Some BIOSes don't get the size of extended memory right.  If you
 # have a broken BIOS, uncomment the following and set the value
diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index 90c45de024f..dbae8873a20 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.77 1998/01/22 02:30:46 niklas Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.78 1998/02/17 23:49:29 matthieu Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -230,6 +230,14 @@ int	bus_mem_add_mapping __P((bus_addr_t, bus_size_t,
 extern u_int cnvmem;	/* BIOS's conventional memory size */
 extern u_int extmem;	/* BIOS's extended memory size */
 
+#ifdef APERTURE
+#ifdef INSECURE
+int allowaperture = 1;
+#else
+int allowaperture = 0;
+#endif
+#endif
+
 void	cyrix6x86_cpu_setup __P((const char *));
 void	intel586_cpu_setup __P((const char *));
 
@@ -1871,6 +1879,15 @@ cpu_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
 			return (ENOTDIR);		/* overloaded */
 		dev = chrtoblk((dev_t)name[1]);
 		return sysctl_rdstruct(oldp, oldlenp, newp, &dev, sizeof(dev));
+#ifdef APERTURE
+	case  CPU_ALLOWAPERTURE:
+		if (securelevel > 0) 
+			return (sysctl_rdint(oldp, oldlenp, newp, 
+					     allowaperture));
+		else
+			return (sysctl_int(oldp, oldlenp, newp, newlen, 
+					   &allowaperture));
+#endif
 	default:
 		return EOPNOTSUPP;
 	}
diff --git a/sys/arch/i386/i386/mem.c b/sys/arch/i386/i386/mem.c
index 175b016f334..4b1ec10f896 100644
--- a/sys/arch/i386/i386/mem.c
+++ b/sys/arch/i386/i386/mem.c
@@ -60,6 +60,13 @@
 extern char *vmmap;            /* poor name! */
 caddr_t zeropage;
 
+/* open counter for aperture */
+static int ap_open_count = 0;
+extern int allowaperture;
+
+#define VGA_START 0xA0000
+#define VGA_END   0xBFFFF
+
 /*ARGSUSED*/
 int
 mmopen(dev, flag, mode, p)
@@ -79,7 +86,21 @@ mmopen(dev, flag, mode, p)
 		}
 		break;
 #endif
-
+#ifdef APERTURE
+	case 4:
+	        if (suser(p->p_ucred, &p->p_acflag) != 0) {
+			return(EPERM);
+		}
+		if (!allowaperture) {
+			return(EPERM);
+		}
+		/* authorize only one simultaneous open() */
+		if (ap_open_count > 0) {
+			return(EPERM);
+		}
+		ap_open_count++;
+		break;
+#endif
 	default:
 		break;
 	}
@@ -93,7 +114,11 @@ mmclose(dev, flag, mode, p)
 	int flag, mode;
 	struct proc *p;
 {
-
+#ifdef APERTURE
+	if (minor(dev) == 4) {
+		ap_open_count--;
+	}
+#endif
 	return (0);
 }
 
@@ -215,7 +240,16 @@ mmmmap(dev, off, prot)
 		if (!kernacc((caddr_t)off, NBPG, B_READ))
 			return -1;
 		return i386_btop(vtophys(off));
-
+#ifdef APERTURE
+/* minor device 4 is aperture driver */
+	case 4:
+		if (allowaperture 
+		    && (((off >= VGA_START && off <= VGA_END )
+			 || (unsigned)off > (unsigned)ctob(physmem)))) 
+			return i386_btop(off);
+		else 
+			return -1;
+#endif
 	default:
 		return -1;
 	}
diff --git a/sys/arch/i386/include/cpu.h b/sys/arch/i386/include/cpu.h
index 33527023919..fed648fadf4 100644
--- a/sys/arch/i386/include/cpu.h
+++ b/sys/arch/i386/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.19 1997/12/17 08:54:51 downsj Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.20 1998/02/17 23:49:31 matthieu Exp $	*/
 /*	$NetBSD: cpu.h,v 1.35 1996/05/05 19:29:26 christos Exp $	*/
 
 /*-
@@ -234,7 +234,8 @@ void	setconf __P((void));
 #define	CPU_BIOS		2	/* BIOS variables */
 #define	CPU_BLK2CHR		3	/* convert blk maj into chr one */
 #define	CPU_CHR2BLK		4	/* convert chr maj into blk one */
-#define	CPU_MAXID		5	/* number of valid machdep ids */
+#define CPU_ALLOWAPERTURE	5	/* allow mmap of /dev/xf86 */
+#define	CPU_MAXID		6	/* number of valid machdep ids */
 
 #define	CTL_MACHDEP_NAMES { \
 	{ 0, 0 }, \
@@ -242,6 +243,7 @@ void	setconf __P((void));
 	{ "bios", CTLTYPE_INT }, \
 	{ "blk2chr", CTLTYPE_STRUCT }, \
 	{ "chr2blk", CTLTYPE_STRUCT }, \
+	{ "allowaperture", CTLTYPE_INT }, \
 }
 
 #endif /* !_I386_CPU_H_ */