1 files changed, 58 insertions, 8 deletions

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 40db0f9188b6..99411fa91350 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -48,8 +48,7 @@
 	.macro	alignment_trap, rtmp1, rtmp2, label
 #ifdef CONFIG_ALIGNMENT_TRAP
 	mrc	p15, 0, \rtmp2, c1, c0, 0
-	ldr	\rtmp1, \label
-	ldr	\rtmp1, [\rtmp1]
+	ldr_va	\rtmp1, \label
 	teq	\rtmp1, \rtmp2
 	mcrne	p15, 0, \rtmp1, c1, c0, 0
 #endif
@@ -292,6 +291,20 @@
 
 
 	.macro	restore_user_regs, fast = 0, offset = 0
+#if defined(CONFIG_CPU_32v6K) && \
+    (!defined(CONFIG_CPU_V6) || defined(CONFIG_SMP))
+#ifdef CONFIG_CPU_V6
+ALT_SMP(nop)
+ALT_UP_B(.L1_\@)
+#endif
+	@ The TLS register update is deferred until return to user space so we
+	@ can use it for other things while running in the kernel
+	mrc	p15, 0, r1, c13, c0, 3		@ get current_thread_info pointer
+	ldr	r1, [r1, #TI_TP_VALUE]
+	mcr	p15, 0, r1, c13, c0, 3		@ set TLS register
+.L1_\@:
+#endif
+
 	uaccess_enable r1, isb=0
 #ifndef CONFIG_THUMB2_KERNEL
 	@ ARM mode restore
@@ -353,25 +366,25 @@
  * between user and kernel mode.
  */
 	.macro ct_user_exit, save = 1
-#ifdef CONFIG_CONTEXT_TRACKING
+#ifdef CONFIG_CONTEXT_TRACKING_USER
 	.if	\save
 	stmdb   sp!, {r0-r3, ip, lr}
-	bl	context_tracking_user_exit
+	bl	user_exit_callable
 	ldmia	sp!, {r0-r3, ip, lr}
 	.else
-	bl	context_tracking_user_exit
+	bl	user_exit_callable
 	.endif
 #endif
 	.endm
 
 	.macro ct_user_enter, save = 1
-#ifdef CONFIG_CONTEXT_TRACKING
+#ifdef CONFIG_CONTEXT_TRACKING_USER
 	.if	\save
 	stmdb   sp!, {r0-r3, ip, lr}
-	bl	context_tracking_user_enter
+	bl	user_enter_callable
 	ldmia	sp!, {r0-r3, ip, lr}
 	.else
-	bl	context_tracking_user_enter
+	bl	user_enter_callable
 	.endif
 #endif
 	.endm
@@ -415,3 +428,40 @@ scno	.req	r7		@ syscall number
 tbl	.req	r8		@ syscall table pointer
 why	.req	r8		@ Linux syscall (!= 0)
 tsk	.req	r9		@ current thread_info
+
+	.macro	do_overflow_check, frame_size:req
+#ifdef CONFIG_VMAP_STACK
+	@
+	@ Test whether the SP has overflowed. Task and IRQ stacks are aligned
+	@ so that SP & BIT(THREAD_SIZE_ORDER + PAGE_SHIFT) should always be
+	@ zero.
+	@
+ARM(	tst	sp, #1 << (THREAD_SIZE_ORDER + PAGE_SHIFT)	)
+THUMB(	tst	r1, #1 << (THREAD_SIZE_ORDER + PAGE_SHIFT)	)
+THUMB(	it	ne						)
+	bne	.Lstack_overflow_check\@
+
+	.pushsection	.text
+.Lstack_overflow_check\@:
+	@
+	@ The stack pointer is not pointing to a valid vmap'ed stack, but it
+	@ may be pointing into the linear map instead, which may happen if we
+	@ are already running from the overflow stack. We cannot detect overflow
+	@ in such cases so just carry on.
+	@
+	str	ip, [r0, #12]			@ Stash IP on the mode stack
+	ldr_va	ip, high_memory			@ Start of VMALLOC space
+ARM(	cmp	sp, ip			)	@ SP in vmalloc space?
+THUMB(	cmp	r1, ip			)
+THUMB(	itt	lo			)
+	ldrlo	ip, [r0, #12]			@ Restore IP
+	blo	.Lout\@				@ Carry on
+
+THUMB(	sub	r1, sp, r1		)	@ Restore original R1
+THUMB(	sub	sp, r1			)	@ Restore original SP
+	add	sp, sp, #\frame_size		@ Undo svc_entry's SP change
+	b	__bad_stack			@ Handle VMAP stack overflow
+	.popsection
+.Lout\@:
+#endif
+	.endm