Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm

Pull ARM fixes from Russell King:
 "This fixes various issues found during July"

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7479/1: mm: avoid NULL dereference when flushing gate_vma with VIVT caches
  ARM: Fix undefined instruction exception handling
  ARM: 7480/1: only call smp_send_stop() on SMP
  ARM: 7478/1: errata: extend workaround for erratum #720789
  ARM: 7477/1: vfp: Always save VFP state in vfp_pm_suspend on UP
  ARM: 7476/1: vfp: only clear vfp state for current cpu in vfp_pm_suspend
  ARM: 7468/1: ftrace: Trace function entry before updating index
  ARM: 7467/1: mutex: use generic xchg-based implementation for ARMv6+
  ARM: 7466/1: disable interrupt before spinning endlessly
  ARM: 7465/1: Handle >4GB memory sizes in device tree and mem=size@start option

6 files changed, 88 insertions, 59 deletions

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 0d1851ca6eb9..0f82098c9bfe 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -244,6 +244,19 @@ svc_preempt:
 	b	1b
 #endif
 
+__und_fault:
+	@ Correct the PC such that it is pointing at the instruction
+	@ which caused the fault.  If the faulting instruction was ARM
+	@ the PC will be pointing at the next instruction, and have to
+	@ subtract 4.  Otherwise, it is Thumb, and the PC will be
+	@ pointing at the second half of the Thumb instruction.  We
+	@ have to subtract 2.
+	ldr	r2, [r0, #S_PC]
+	sub	r2, r2, r1
+	str	r2, [r0, #S_PC]
+	b	do_undefinstr
+ENDPROC(__und_fault)
+
 	.align	5
 __und_svc:
 #ifdef CONFIG_KPROBES
@@ -261,25 +274,32 @@ __und_svc:
 	@
 	@  r0 - instruction
 	@
-#ifndef	CONFIG_THUMB2_KERNEL
+#ifndef CONFIG_THUMB2_KERNEL
 	ldr	r0, [r4, #-4]
 #else
+	mov	r1, #2
 	ldrh	r0, [r4, #-2]			@ Thumb instruction at LR - 2
 	cmp	r0, #0xe800			@ 32-bit instruction if xx >= 0
-	ldrhhs	r9, [r4]			@ bottom 16 bits
-	orrhs	r0, r9, r0, lsl #16
+	blo	__und_svc_fault
+	ldrh	r9, [r4]			@ bottom 16 bits
+	add	r4, r4, #2
+	str	r4, [sp, #S_PC]
+	orr	r0, r9, r0, lsl #16
 #endif
-	adr	r9, BSYM(1f)
+	adr	r9, BSYM(__und_svc_finish)
 	mov	r2, r4
 	bl	call_fpe
 
+	mov	r1, #4				@ PC correction to apply
+__und_svc_fault:
 	mov	r0, sp				@ struct pt_regs *regs
-	bl	do_undefinstr
+	bl	__und_fault
 
 	@
 	@ IRQs off again before pulling preserved data off the stack
 	@
-1:	disable_irq_notrace
+__und_svc_finish:
+	disable_irq_notrace
 
 	@
 	@ restore SPSR and restart the instruction
@@ -423,25 +443,33 @@ __und_usr:
 	mov	r2, r4
 	mov	r3, r5
 
+	@ r2 = regs->ARM_pc, which is either 2 or 4 bytes ahead of the
+	@      faulting instruction depending on Thumb mode.
+	@ r3 = regs->ARM_cpsr
 	@
-	@ fall through to the emulation code, which returns using r9 if
-	@ it has emulated the instruction, or the more conventional lr
-	@ if we are to treat this as a real undefined instruction
-	@
-	@  r0 - instruction
+	@ The emulation code returns using r9 if it has emulated the
+	@ instruction, or the more conventional lr if we are to treat
+	@ this as a real undefined instruction
 	@
 	adr	r9, BSYM(ret_from_exception)
-	adr	lr, BSYM(__und_usr_unknown)
+
 	tst	r3, #PSR_T_BIT			@ Thumb mode?
-	itet	eq				@ explicit IT needed for the 1f label
-	subeq	r4, r2, #4			@ ARM instr at LR - 4
-	subne	r4, r2, #2			@ Thumb instr at LR - 2
-1:	ldreqt	r0, [r4]
+	bne	__und_usr_thumb
+	sub	r4, r2, #4			@ ARM instr at LR - 4
+1:	ldrt	r0, [r4]
 #ifdef CONFIG_CPU_ENDIAN_BE8
-	reveq	r0, r0				@ little endian instruction
+	rev	r0, r0				@ little endian instruction
 #endif
-	beq	call_fpe
+	@ r0 = 32-bit ARM instruction which caused the exception
+	@ r2 = PC value for the following instruction (:= regs->ARM_pc)
+	@ r4 = PC value for the faulting instruction
+	@ lr = 32-bit undefined instruction function
+	adr	lr, BSYM(__und_usr_fault_32)
+	b	call_fpe
+
+__und_usr_thumb:
 	@ Thumb instruction
+	sub	r4, r2, #2			@ First half of thumb instr at LR - 2
 #if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
 /*
  * Thumb-2 instruction handling.  Note that because pre-v6 and >= v6 platforms
@@ -455,7 +483,7 @@ __und_usr:
 	ldr	r5, .LCcpu_architecture
 	ldr	r5, [r5]
 	cmp	r5, #CPU_ARCH_ARMv7
-	blo	__und_usr_unknown
+	blo	__und_usr_fault_16		@ 16bit undefined instruction
 /*
  * The following code won't get run unless the running CPU really is v7, so
  * coding round the lack of ldrht on older arches is pointless.  Temporarily
@@ -463,15 +491,18 @@ __und_usr:
  */
 	.arch	armv6t2
 #endif
-2:
- ARM(	ldrht	r5, [r4], #2	)
- THUMB(	ldrht	r5, [r4]	)
- THUMB(	add	r4, r4, #2	)
+2:	ldrht	r5, [r4]
 	cmp	r5, #0xe800			@ 32bit instruction if xx != 0
-	blo	__und_usr_unknown
-3:	ldrht	r0, [r4]
+	blo	__und_usr_fault_16		@ 16bit undefined instruction
+3:	ldrht	r0, [r2]
 	add	r2, r2, #2			@ r2 is PC + 2, make it PC + 4
+	str	r2, [sp, #S_PC]			@ it's a 2x16bit instr, update
 	orr	r0, r0, r5, lsl #16
+	adr	lr, BSYM(__und_usr_fault_32)
+	@ r0 = the two 16-bit Thumb instructions which caused the exception
+	@ r2 = PC value for the following Thumb instruction (:= regs->ARM_pc)
+	@ r4 = PC value for the first 16-bit Thumb instruction
+	@ lr = 32bit undefined instruction function
 
 #if __LINUX_ARM_ARCH__ < 7
 /* If the target arch was overridden, change it back: */
@@ -482,17 +513,13 @@ __und_usr:
 #endif
 #endif /* __LINUX_ARM_ARCH__ < 7 */
 #else /* !(CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7) */
-	b	__und_usr_unknown
+	b	__und_usr_fault_16
 #endif
- UNWIND(.fnend		)
+ UNWIND(.fnend)
 ENDPROC(__und_usr)
 
-	@
-	@ fallthrough to call_fpe
-	@
-
 /*
- * The out of line fixup for the ldrt above.
+ * The out of line fixup for the ldrt instructions above.
  */
 	.pushsection .fixup, "ax"
 	.align	2
@@ -524,11 +551,12 @@ ENDPROC(__und_usr)
  * NEON handler code.
  *
  * Emulators may wish to make use of the following registers:
- *  r0  = instruction opcode.
- *  r2  = PC+4
+ *  r0  = instruction opcode (32-bit ARM or two 16-bit Thumb)
+ *  r2  = PC value to resume execution after successful emulation
  *  r9  = normal "successful" return address
- *  r10 = this threads thread_info structure.
+ *  r10 = this threads thread_info structure
  *  lr  = unrecognised instruction return address
+ * IRQs disabled, FIQs enabled.
  */
 	@
 	@ Fall-through from Thumb-2 __und_usr
@@ -659,12 +687,17 @@ ENTRY(no_fp)
 	mov	pc, lr
 ENDPROC(no_fp)
 
-__und_usr_unknown:
-	enable_irq
+__und_usr_fault_32:
+	mov	r1, #4
+	b	1f
+__und_usr_fault_16:
+	mov	r1, #2
+1:	enable_irq
 	mov	r0, sp
 	adr	lr, BSYM(ret_from_exception)
-	b	do_undefinstr
-ENDPROC(__und_usr_unknown)
+	b	__und_fault
+ENDPROC(__und_usr_fault_32)
+ENDPROC(__und_usr_fault_16)
 
 	.align	5
 __pabt_usr:
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index df0bf0c8cb79..34e56647dcee 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -179,19 +179,20 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 	old = *parent;
 	*parent = return_hooker;
 
-	err = ftrace_push_return_trace(old, self_addr, &trace.depth,
-				       frame_pointer);
-	if (err == -EBUSY) {
-		*parent = old;
-		return;
-	}
-
 	trace.func = self_addr;
+	trace.depth = current->curr_ret_stack + 1;
 
 	/* Only trace if the calling function expects to */
 	if (!ftrace_graph_entry(&trace)) {
-		current->curr_ret_stack--;
 		*parent = old;
+		return;
+	}
+
+	err = ftrace_push_return_trace(old, self_addr, &trace.depth,
+				       frame_pointer);
+	if (err == -EBUSY) {
+		*parent = old;
+		return;
 	}
 }
 
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 19c95ea65b2f..693b744fd572 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -247,6 +247,7 @@ void machine_shutdown(void)
 void machine_halt(void)
 {
 	machine_shutdown();
+	local_irq_disable();
 	while (1);
 }
 
@@ -268,6 +269,7 @@ void machine_restart(char *cmd)
 
 	/* Whoops - the platform was unable to reboot. Tell the user! */
 	printk("Reboot failed -- System halted\n");
+	local_irq_disable();
 	while (1);
 }
 
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index e15d83bb4ea3..a81dcecc7343 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -508,7 +508,7 @@ void __init dump_machine_table(void)
 		/* can't use cpu_relax() here as it may require MMU setup */;
 }
 
-int __init arm_add_memory(phys_addr_t start, unsigned long size)
+int __init arm_add_memory(phys_addr_t start, phys_addr_t size)
 {
 	struct membank *bank = &meminfo.bank[meminfo.nr_banks];
 
@@ -538,7 +538,7 @@ int __init arm_add_memory(phys_addr_t start, unsigned long size)
 	}
 #endif
 
-	bank->size = size & PAGE_MASK;
+	bank->size = size & ~(phys_addr_t)(PAGE_SIZE - 1);
 
 	/*
 	 * Check whether this memory region has non-zero size or
@@ -558,7 +558,7 @@ int __init arm_add_memory(phys_addr_t start, unsigned long size)
 static int __init early_mem(char *p)
 {
 	static int usermem __initdata = 0;
-	unsigned long size;
+	phys_addr_t size;
 	phys_addr_t start;
 	char *endp;
 
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index aea74f5bc34a..ebd8ad274d76 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -563,7 +563,8 @@ void smp_send_stop(void)
 
 	cpumask_copy(&mask, cpu_online_mask);
 	cpumask_clear_cpu(smp_processor_id(), &mask);
-	smp_cross_call(&mask, IPI_CPU_STOP);
+	if (!cpumask_empty(&mask))
+		smp_cross_call(&mask, IPI_CPU_STOP);
 
 	/* Wait up to one second for other CPUs to stop */
 	timeout = USEC_PER_SEC;
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 8b97d739b17b..7978d4f0f3ae 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -402,18 +402,10 @@ static int call_undef_hook(struct pt_regs *regs, unsigned int instr)
 
 asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
 {
-	unsigned int correction = thumb_mode(regs) ? 2 : 4;
 	unsigned int instr;
 	siginfo_t info;
 	void __user *pc;
 
-	/*
-	 * According to the ARM ARM, PC is 2 or 4 bytes ahead,
-	 * depending whether we're in Thumb mode or not.
-	 * Correct this offset.
-	 */
-	regs->ARM_pc -= correction;
-
 	pc = (void __user *)instruction_pointer(regs);
 
 	if (processor_mode(regs) == SVC_MODE) {