[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.ku...@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