Merge branch 'fixes' into next

Merge our fixes branch. It has a few important fixes that are needed for
futher testing and also some commits that will conflict with content in
next.

3 files changed, 28 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 301a6a86a20f..b9239dbf6d59 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1344,9 +1344,7 @@ EXC_REAL_BEGIN(denorm_exception_hv, 0x1500, 0x100)
 
 #ifdef CONFIG_PPC_DENORMALISATION
 	mfspr	r10,SPRN_HSRR1
-	mfspr	r11,SPRN_HSRR0		/* save HSRR0 */
 	andis.	r10,r10,(HSRR1_DENORM)@h /* denorm? */
-	addi	r11,r11,-4		/* HSRR0 is next instruction */
 	bne+	denorm_assist
 #endif
 
@@ -1412,6 +1410,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
  */
 	XVCPSGNDP32(32)
 denorm_done:
+	mfspr	r11,SPRN_HSRR0
+	subi	r11,r11,4
 	mtspr	SPRN_HSRR0,r11
 	mtcrf	0x80,r9
 	ld	r9,PACA_EXGEN+EX_R9(r13)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ec264a6f0eb3..d9d4eb2ea6c9 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1303,6 +1303,16 @@ void show_user_instructions(struct pt_regs *regs)
 
 	pc = regs->nip - (instructions_to_print * 3 / 4 * sizeof(int));
 
+	/*
+	 * Make sure the NIP points at userspace, not kernel text/data or
+	 * elsewhere.
+	 */
+	if (!__access_ok(pc, instructions_to_print * sizeof(int), USER_DS)) {
+		pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",
+			current->comm, current->pid);
+		return;
+	}
+
 	pr_info("%s[%d]: code: ", current->comm, current->pid);
 
 	for (i = 0; i < instructions_to_print; i++) {
diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S
index e6b527e5c90c..9fabdce255cd 100644
--- a/arch/powerpc/kernel/tm.S
+++ b/arch/powerpc/kernel/tm.S
@@ -180,6 +180,20 @@ _GLOBAL(tm_reclaim)
 
 	std	r11, GPR11(r1)			/* Temporary stash */
 
+	/*
+	 * Move the saved user r1 to the kernel stack in case PACATMSCRATCH is
+	 * clobbered by an exception once we turn on MSR_RI below.
+	 */
+	ld	r11, PACATMSCRATCH(r13)
+	std	r11, GPR1(r1)
+
+	/*
+	 * Store r13 away so we can free up the scratch SPR for the SLB fault
+	 * handler (needed once we start accessing the thread_struct).
+	 */
+	GET_SCRATCH0(r11)
+	std	r11, GPR13(r1)
+
 	/* Reset MSR RI so we can take SLB faults again */
 	li	r11, MSR_RI
 	mtmsrd	r11, 1
@@ -210,11 +224,11 @@ _GLOBAL(tm_reclaim)
 	SAVE_GPR(8, r7)				/* user r8 */
 	SAVE_GPR(9, r7)				/* user r9 */
 	SAVE_GPR(10, r7)			/* user r10 */
-	ld	r3, PACATMSCRATCH(r13)		/* user r1 */
+	ld	r3, GPR1(r1)			/* user r1 */
 	ld	r4, GPR7(r1)			/* user r7 */
 	ld	r5, GPR11(r1)			/* user r11 */
 	ld	r6, GPR12(r1)			/* user r12 */
-	GET_SCRATCH0(8)				/* user r13 */
+	ld	r8, GPR13(r1)			/* user r13 */
 	std	r3, GPR1(r7)
 	std	r4, GPR7(r7)
 	std	r5, GPR11(r7)