Add retguard macros to cpu_switchto, setjmp, longjmp.

ok kettenis@

3 files changed, 31 insertions, 9 deletions

diff --git a/sys/arch/arm64/arm64/cpuswitch.S b/sys/arch/arm64/arm64/cpuswitch.S
index 4cdda217f4c..0eaa6d583e3 100644
--- a/sys/arch/arm64/arm64/cpuswitch.S
+++ b/sys/arch/arm64/arm64/cpuswitch.S
@@ -1,4 +1,4 @@
-/* $OpenBSD: cpuswitch.S,v 1.3 2018/03/29 19:25:39 patrick Exp $ */
+/* $OpenBSD: cpuswitch.S,v 1.4 2018/09/07 01:32:01 mortimer Exp $ */
 /*
  * Copyright (c) 2015 Dale Rahn <drahn@dalerahn.com>
  *
@@ -59,6 +59,8 @@ ENTRY(cpu_switchto)
 
 	mov	x1, x19
 1:
+	RETGUARD_SYMBOL(cpu_switchto)
+	RETGUARD_LOAD_RANDOM(cpu_switchto, x20)
 
 	mrs	x2, tpidr_el1			// load curcpu
 	mov	w5, #SONPROC
@@ -75,6 +77,7 @@ ENTRY(cpu_switchto)
 	mov	x0, x1
 	bl	pmap_setttb
 	mov	x3, x19
+	mov	x15, x20
 
 	mov	sp, x3
 
@@ -84,7 +87,9 @@ ENTRY(cpu_switchto)
 	ldp	x25, x26,  [x3, #(SF_X25)]
 	ldp	x27, x28,  [x3, #(SF_X27)]
 	ldp	x29, x30,  [x3, #(SF_X29)]
+	RETGUARD_CALC_COOKIE(x15)
 	add	sp, sp, #(SWITCHFRAME_SZ)
+	RETGUARD_CHECK(cpu_switchto, x15)
 	ret
 
 ENTRY(proc_trampoline)
diff --git a/sys/arch/arm64/arm64/support.S b/sys/arch/arm64/arm64/support.S
index 765327627ba..da4dbb74583 100644
--- a/sys/arch/arm64/arm64/support.S
+++ b/sys/arch/arm64/arm64/support.S
@@ -1,4 +1,4 @@
-/* $OpenBSD: support.S,v 1.7 2018/08/12 17:15:10 mortimer Exp $ */
+/* $OpenBSD: support.S,v 1.8 2018/09/07 01:32:01 mortimer Exp $ */
 /*-
  * Copyright (c) 2014 Andrew Turner
  * Copyright (c) 2014-2015 The FreeBSD Foundation
@@ -43,6 +43,7 @@ __FBSDID("$FreeBSD: head/sys/arm64/arm64/support.S 297615 2016-04-06 14:08:10Z a
 
 #ifdef DDB
 ENTRY(setjmp)
+	RETGUARD_SETUP(setjmp, x15)
 	/* Store the stack pointer */
 	mov	x8, sp
 	str	x8, [x0], #8
@@ -57,10 +58,13 @@ ENTRY(setjmp)
 
 	/* Return zero */
 	mov	x0, #0
+	RETGUARD_CHECK(setjmp, x15)
 	ret
 END(setjmp)
 
 ENTRY(longjmp)
+	RETGUARD_SYMBOL(longjmp)
+	RETGUARD_LOAD_RANDOM(longjmp, x15)
 	/* Restore the stack pointer */
 	ldr	x8, [x0], #8
 	mov	sp, x8
@@ -72,9 +76,11 @@ ENTRY(longjmp)
 	ldp	x25, x26, [x0], #16
 	ldp	x27, x28, [x0], #16
 	ldp	x29, lr, [x0], #16
+	RETGUARD_CALC_COOKIE(x15)
 
 	/* Return nonzero */
 	mov	x0, #1
+	RETGUARD_CHECK(longjmp, x15)
 	ret
 END(longjmp)
 #endif
diff --git a/sys/arch/arm64/include/asm.h b/sys/arch/arm64/include/asm.h
index f31386ea4d1..874625d4430 100644
--- a/sys/arch/arm64/include/asm.h
+++ b/sys/arch/arm64/include/asm.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: asm.h,v 1.4 2018/08/12 17:15:10 mortimer Exp $	*/
+/*	$OpenBSD: asm.h,v 1.5 2018/09/07 01:32:01 mortimer Exp $	*/
 /*	$NetBSD: asm.h,v 1.4 2001/07/16 05:43:32 matt Exp $	*/
 
 /*
@@ -83,23 +83,32 @@
 #endif
 
 #if defined(_RET_PROTECTOR)
+# define RETGUARD_CALC_COOKIE(reg) \
+	eor     reg, reg, x30
+
+# define RETGUARD_LOAD_RANDOM(x, reg) \
+	adrp    reg, __CONCAT(__retguard_, x); \
+	ldr     reg, [reg, :lo12:__CONCAT(__retguard_, x)]
+
 # define RETGUARD_SETUP(x, reg) \
 	RETGUARD_SYMBOL(x); \
-	adrp    reg, __CONCAT(__retguard_, x); \
-	ldr     reg, [reg, :lo12:__CONCAT(__retguard_, x)]; \
-	eor     reg, reg, x30
+	RETGUARD_LOAD_RANDOM(x, reg); \
+	RETGUARD_CALC_COOKIE(reg)
+
 # define RETGUARD_CHECK(x, reg) \
-	eor     reg, reg, x30; \
-	adrp    x9, __CONCAT(__retguard_, x); \
-	ldr     x9, [x9, :lo12:__CONCAT(__retguard_, x)]; \
+	RETGUARD_CALC_COOKIE(reg); \
+	RETGUARD_LOAD_RANDOM(x, x9); \
 	subs    reg, reg, x9; \
 	cbz     reg, 66f; \
 	brk     #0x1; \
 66:
+
 # define RETGUARD_PUSH(reg) \
 	str     reg, [sp, #-16]!
+
 # define RETGUARD_POP(reg) \
 	ldr     reg, [sp, #16]!
+
 # define RETGUARD_SYMBOL(x) \
 	.ifndef __CONCAT(__retguard_, x); \
 	.hidden __CONCAT(__retguard_, x); \
@@ -113,6 +122,8 @@
 	.popsection; \
 	.endif
 #else
+# define RETGUARD_CALC_COOKIE(reg)
+# define RETGUARD_LOAD_RANDOM(x, reg)
 # define RETGUARD_SETUP(x, reg)
 # define RETGUARD_CHECK(x, reg)
 # define RETGUARD_PUSH(reg)