Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc64: Fix hardirq tracing in trap return path.
  sparc64: Use correct pt_regs in decode_access_size() error paths.
  sparc64: Fix PREEMPT_ACTIVE value.
  sparc64: Run NMIs on the hardirq stack.
  sparc64: Allocate sufficient stack space in ftrace stubs.
  sparc: Fix forgotten kmemleak headers inclusion

arch/sparc/include/asm/thread_info_64.h

@@ -111,7 +111,7 @@ struct thread_info {
 #define THREAD_SHIFT PAGE_SHIFT
 #endif /* PAGE_SHIFT == 13 */
 
-#define PREEMPT_ACTIVE		0x4000000
+#define PREEMPT_ACTIVE		0x10000000
 
 /*
  * macros/functions for gaining access to the thread information structure

arch/sparc/kernel/irq_64.c

@@ -22,6 +22,7 @@
 #include <linux/seq_file.h>
 #include <linux/ftrace.h>
 #include <linux/irq.h>
+#include <linux/kmemleak.h>
 
 #include <asm/ptrace.h>
 #include <asm/processor.h>
@@ -46,6 +47,7 @@
 
 #include "entry.h"
 #include "cpumap.h"
+#include "kstack.h"
 
 #define NUM_IVECS	(IMAP_INR + 1)
 
@@ -712,24 +714,6 @@ void ack_bad_irq(unsigned int virt_irq)
 void *hardirq_stack[NR_CPUS];
 void *softirq_stack[NR_CPUS];
 
-static __attribute__((always_inline)) void *set_hardirq_stack(void)
-{
-	void *orig_sp, *sp = hardirq_stack[smp_processor_id()];
-
-	__asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));
-	if (orig_sp < sp ||
-	    orig_sp > (sp + THREAD_SIZE)) {
-		sp += THREAD_SIZE - 192 - STACK_BIAS;
-		__asm__ __volatile__("mov %0, %%sp" : : "r" (sp));
-	}
-
-	return orig_sp;
-}
-static __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)
-{
-	__asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));
-}
-
 void __irq_entry handler_irq(int irq, struct pt_regs *regs)
 {
 	unsigned long pstate, bucket_pa;

arch/sparc/kernel/kstack.h

@@ -61,4 +61,23 @@ static inline bool kstack_is_trap_frame(struct thread_info *tp, struct pt_regs *
 
 }
 
+static inline __attribute__((always_inline)) void *set_hardirq_stack(void)
+{
+	void *orig_sp, *sp = hardirq_stack[smp_processor_id()];
+
+	__asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));
+	if (orig_sp < sp ||
+	    orig_sp > (sp + THREAD_SIZE)) {
+		sp += THREAD_SIZE - 192 - STACK_BIAS;
+		__asm__ __volatile__("mov %0, %%sp" : : "r" (sp));
+	}
+
+	return orig_sp;
+}
+
+static inline __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)
+{
+	__asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));
+}
+
 #endif /* _KSTACK_H */

arch/sparc/kernel/nmi.c

@@ -23,6 +23,8 @@
 #include <asm/ptrace.h>
 #include <asm/pcr.h>
 
+#include "kstack.h"
+
 /* We don't have a real NMI on sparc64, but we can fake one
  * up using profiling counter overflow interrupts and interrupt
  * levels.
@@ -92,13 +94,16 @@ static void die_nmi(const char *str, struct pt_regs *regs, int do_panic)
 notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs)
 {
 	unsigned int sum, touched = 0;
+	void *orig_sp;
 
 	clear_softint(1 << irq);
 
 	local_cpu_data().__nmi_count++;
 
 	nmi_enter();
 
+	orig_sp = set_hardirq_stack();
+
 	if (notify_die(DIE_NMI, "nmi", regs, 0,
 		       pt_regs_trap_type(regs), SIGINT) == NOTIFY_STOP)
 		touched = 1;
@@ -124,6 +129,8 @@ notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs)
 		pcr_ops->write(pcr_enable);
 	}
 
+	restore_hardirq_stack(orig_sp);
+
 	nmi_exit();
 }
 

arch/sparc/kernel/rtrap_64.S

@@ -130,7 +130,17 @@ rtrap_xcall:
 		 nop
 		call			trace_hardirqs_on
 		 nop
-		wrpr			%l4, %pil
+		/* Do not actually set the %pil here.  We will do that
+		 * below after we clear PSTATE_IE in the %pstate register.
+		 * If we re-enable interrupts here, we can recurse down
+		 * the hardirq stack potentially endlessly, causing a
+		 * stack overflow.
+		 *
+		 * It is tempting to put this test and trace_hardirqs_on
+		 * call at the 'rt_continue' label, but that will not work
+		 * as that path hits unconditionally and we do not want to
+		 * execute this in NMI return paths, for example.
+		 */
 #endif
 rtrap_no_irq_enable:
 		andcc			%l1, TSTATE_PRIV, %l3

arch/sparc/kernel/unaligned_64.c

@@ -50,7 +50,7 @@ static inline enum direction decode_direction(unsigned int insn)
 }
 
 /* 16 = double-word, 8 = extra-word, 4 = word, 2 = half-word */
-static inline int decode_access_size(unsigned int insn)
+static inline int decode_access_size(struct pt_regs *regs, unsigned int insn)
 {
 	unsigned int tmp;
 
@@ -66,7 +66,7 @@ static inline int decode_access_size(unsigned int insn)
 		return 2;
 	else {
 		printk("Impossible unaligned trap. insn=%08x\n", insn);
-		die_if_kernel("Byte sized unaligned access?!?!", current_thread_info()->kregs);
+		die_if_kernel("Byte sized unaligned access?!?!", regs);
 
 		/* GCC should never warn that control reaches the end
 		 * of this function without returning a value because
@@ -286,7 +286,7 @@ static void log_unaligned(struct pt_regs *regs)
 asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
 {
 	enum direction dir = decode_direction(insn);
-	int size = decode_access_size(insn);
+	int size = decode_access_size(regs, insn);
 	int orig_asi, asi;
 
 	current_thread_info()->kern_una_regs = regs;

arch/sparc/lib/mcount.S

@@ -34,7 +34,7 @@ mcount:
 	cmp		%g1, %g2
 	be,pn		%icc, 1f
 	 mov		%i7, %g3
-	save		%sp, -128, %sp
+	save		%sp, -176, %sp
 	mov		%g3, %o1
 	jmpl		%g1, %o7
 	 mov		%i7, %o0
@@ -56,7 +56,7 @@ mcount:
 	 nop
 5:	mov		%i7, %g2
 	mov		%fp, %g3
-	save		%sp, -128, %sp
+	save		%sp, -176, %sp
 	mov		%g2, %l0
 	ba,pt		%xcc, ftrace_graph_caller
 	 mov		%g3, %l1
@@ -85,7 +85,7 @@ ftrace_caller:
 	lduw		[%g1 + %lo(function_trace_stop)], %g1
 	brnz,pn		%g1, ftrace_stub
 	 mov		%fp, %g3
-	save		%sp, -128, %sp
+	save		%sp, -176, %sp
 	mov		%g2, %o1
 	mov		%g2, %l0
 	mov		%g3, %l1
@@ -120,7 +120,7 @@ ENTRY(ftrace_graph_caller)
 END(ftrace_graph_caller)
 
 ENTRY(return_to_handler)
-	save		%sp, -128, %sp
+	save		%sp, -176, %sp
 	call		ftrace_return_to_handler
 	 mov		%fp, %o0
 	jmpl		%o0 + 8, %g0