Introduce KERNEL_RING

	* i386/i386/seg.h (KERNEL_RING): New macro, set to 0.
        (ACC_PL_K, SEL_PL_K): Use KERNEL_RING instead of assuming 0.
        * i386/i386/gdt.h (KERNEL_CS, KERNEL_DS): Likewise.
        * i386/i386/db_interface.c (kdb_trap, kdb_kentry): Likewise.
        * i386/i386/kttd_interface.c (kttd_trap, kttd_netentry): Likewise.
	* i386/i386/i386asm.sym: Add KERNEL_RING expression.

5 files changed, 16 insertions, 12 deletions

diff --git a/i386/i386/db_interface.c b/i386/i386/db_interface.c
index 29f03c9..252ad7e 100644
--- a/i386/i386/db_interface.c
+++ b/i386/i386/db_interface.c
@@ -134,7 +134,7 @@ kdb_trap(
 	    /* XXX Should switch to ddb`s own stack here. */
 
 	    ddb_regs = *regs;
-	    if ((regs->cs & 0x3) == 0) {
+	    if ((regs->cs & 0x3) == KERNEL_RING) {
 		/*
 		 * Kernel mode - esp and ss not saved
 		 */
@@ -152,7 +152,7 @@ kdb_trap(
 	    regs->ecx    = ddb_regs.ecx;
 	    regs->edx    = ddb_regs.edx;
 	    regs->ebx    = ddb_regs.ebx;
-	    if (regs->cs & 0x3) {
+	    if ((regs->cs & 0x3) != KERNEL_RING) {
 		/*
 		 * user mode - saved esp and ss valid
 		 */
@@ -205,7 +205,7 @@ kdb_kentry(
 	if (db_enter())
 #endif	/* NCPUS > 1 */
 	{
-	    if (is->cs & 0x3) {
+	    if ((is->cs & 0x3) != KERNEL_RING) {
 		ddb_regs.uesp = ((int *)(is+1))[0];
 		ddb_regs.ss   = ((int *)(is+1))[1];
 	    }
@@ -232,7 +232,7 @@ kdb_kentry(
 	    db_task_trap(-1, 0, (ddb_regs.cs & 0x3) != 0);
 	    cnpollc(FALSE);
 
-	    if (ddb_regs.cs & 0x3) {
+	    if ((ddb_regs.cs & 0x3) != KERNEL_RING) {
 		((int *)(is+1))[0] = ddb_regs.uesp;
 		((int *)(is+1))[1] = ddb_regs.ss & 0xffff;
 	    }
diff --git a/i386/i386/gdt.h b/i386/i386/gdt.h
index 9b58427..50e01e6 100644
--- a/i386/i386/gdt.h
+++ b/i386/i386/gdt.h
@@ -38,8 +38,8 @@
 /*
  * Kernel descriptors for Mach - 32-bit flat address space.
  */
-#define	KERNEL_CS	0x08		/* kernel code */
-#define	KERNEL_DS	0x10		/* kernel data */
+#define	KERNEL_CS	(0x08 | KERNEL_RING)		/* kernel code */
+#define	KERNEL_DS	(0x10 | KERNEL_RING)		/* kernel data */
 #define	KERNEL_LDT	0x18		/* master LDT */
 #define	KERNEL_TSS	0x20		/* master TSS (uniprocessor) */
 #define	USER_LDT	0x28		/* place for per-thread LDT */
diff --git a/i386/i386/i386asm.sym b/i386/i386/i386asm.sym
index 45f210e..868bf09 100644
--- a/i386/i386/i386asm.sym
+++ b/i386/i386/i386asm.sym
@@ -112,6 +112,8 @@ expr	IDTSZ
 expr	GDTSZ
 expr	LDTSZ
 
+expr	KERNEL_RING
+
 expr	KERNEL_CS
 expr	KERNEL_DS
 expr	KERNEL_TSS
diff --git a/i386/i386/kttd_interface.c b/i386/i386/kttd_interface.c
index 9097061..b9e0624 100644
--- a/i386/i386/kttd_interface.c
+++ b/i386/i386/kttd_interface.c
@@ -395,7 +395,7 @@ boolean_t kttd_trap(int	type, int code, struct i386_saved_state *regs)
 
 	kttd_regs = *regs;
 
-	if ((regs->cs & 0x3) == 0) {
+	if ((regs->cs & 0x3) == KERNEL_RING) {
 	    /*
 	     * Kernel mode - esp and ss not saved
 	     */
@@ -442,7 +442,7 @@ boolean_t kttd_trap(int	type, int code, struct i386_saved_state *regs)
 	regs->ecx    = kttd_regs.ecx;
 	regs->edx    = kttd_regs.edx;
 	regs->ebx    = kttd_regs.ebx;
-	if (regs->cs & 0x3) {
+	if ((regs->cs & 0x3) != KERNEL_RING) {
 	    /*
 	     * user mode - saved esp and ss valid
 	     */
@@ -513,7 +513,7 @@ kttd_netentry(int_regs)
 	if (kttd_debug)
 		printf("kttd_NETENTRY after slphigh()\n");
 
-	if (is->cs & 0x3) {
+	if ((is->cs & 0x3) != KERNEL_RING) {
 	    /*
 	     * Interrupted from User Space
 	     */
@@ -546,7 +546,7 @@ kttd_netentry(int_regs)
 	kttd_task_trap(-1, 0, (kttd_regs.cs & 0x3) != 0);
 	kttd_active--;
 
-	if (kttd_regs.cs & 0x3) {
+	if ((kttd_regs.cs & 0x3) != KERNEL_RING) {
 	    ((int *)(is+1))[0] = kttd_regs.uesp;
 	    ((int *)(is+1))[1] = kttd_regs.ss & 0xffff;
 	}
diff --git a/i386/i386/seg.h b/i386/i386/seg.h
index ad7a0f5..9a09af5 100644
--- a/i386/i386/seg.h
+++ b/i386/i386/seg.h
@@ -37,6 +37,8 @@
  * i386 segmentation.
  */
 
+#define	KERNEL_RING	0
+
 #ifndef __ASSEMBLER__
 
 /*
@@ -95,7 +97,7 @@ struct real_gate {
 #define	ACC_CODE_CR	0x1e			    /* code, conforming,
 						       readable */
 #define	ACC_PL		0x60			/* access rights: */
-#define	ACC_PL_K	0x00			/* kernel access only */
+#define	ACC_PL_K	(KERNEL_RING << 5)	/* kernel access only */
 #define	ACC_PL_U	0x60			/* user access */
 #define	ACC_P		0x80			/* segment present */
 
@@ -104,7 +106,7 @@ struct real_gate {
  */
 #define	SEL_LDT		0x04			/* local selector */
 #define	SEL_PL		0x03			/* privilege level: */
-#define	SEL_PL_K	0x00			    /* kernel selector */
+#define	SEL_PL_K	KERNEL_RING		    /* kernel selector */
 #define	SEL_PL_U	0x03			    /* user selector */
 
 /*