[PATCH 2/3] powerpc: Fix instruction dumping to use address value correctly

[Aneesh Kumar K.V]

Avoid updating address value in the loop. If in real mode, convert the address
outside the loop. Also, use ___va() to convert the real address that will
skip the input validation. We can get interrupts with IR=0 and with NIP
value > PAGE_OFFSET.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
---
 arch/powerpc/include/asm/processor.h |  9 +++++++++
 arch/powerpc/kernel/process.c        | 18 ++++++++++--------
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 591987da44e2..4e7a5adc04df 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -436,6 +436,15 @@ extern void cvt_fd(float *from, double *to);
 extern void cvt_df(double *from, float *to);
 extern void _nmask_and_or_msr(unsigned long nmask, unsigned long or_val);
 
+static inline unsigned long fixup_real_addr(struct pt_regs *regs,
+					    unsigned long addr)
+{
+	if (!(regs->msr & MSR_IR))
+		return (unsigned long)___va(addr);
+
+	return addr;
+}
+
 #ifdef CONFIG_PPC64
 /*
  * We handle most unaligned accesses in hardware. On the other hand 
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 682deeee421f..36cc03c33d25 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1238,29 +1238,31 @@ struct task_struct *__switch_to(struct task_struct *prev,
 static void show_instructions(struct pt_regs *regs)
 {
 	int i;
+	unsigned long nip = regs->nip;
 	unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
 
 	printk("Instruction dump:");
 
+
+#if !defined(CONFIG_BOOKE)
+	/* If executing with the IMMU off, adjust pc rather
+	 * than print XXXXXXXX.
+	 */
+	pc = fixup_real_addr(regs, pc);
+	nip = fixup_real_addr(regs, nip);
+#endif
 	for (i = 0; i < NR_INSN_TO_PRINT; i++) {
 		int instr;
 
 		if (!(i % 8))
 			pr_cont("\n");
 
-#if !defined(CONFIG_BOOKE)
-		/* If executing with the IMMU off, adjust pc rather
-		 * than print XXXXXXXX.
-		 */
-		if (!(regs->msr & MSR_IR))
-			pc = (unsigned long)phys_to_virt(pc);
-#endif
 
 		if (!__kernel_text_address(pc) ||
 		    probe_kernel_address((const void *)pc, instr)) {
 			pr_cont("XXXXXXXX ");
 		} else {
-			if (regs->nip == pc)
+			if (nip == pc)
 				pr_cont("<%08x> ", instr);
 			else
 				pr_cont("%08x ", instr);
-- 
2.26.2