[RFC] ppc64le: Enable emulation support for simple Load/Store instructions

[Ravi Bangoria]

emulate_step() uses a number of underlying kernel functions that were
initially not enabled for LE. This has been rectified since. So, fix
emulate_step() for LE for the corresponding instructions.

Reported-by: Anton Blanchard <an...@samba.org>
Signed-off-by: Ravi Bangoria <ravi.bango...@linux.vnet.ibm.com>
---
Note: This patch only enables LOAD, STORE, LARX and STCX instructions.
      I'll send a subsequent patch for other types like LOAD_FP,
      LOAD_VMX etc.

 arch/powerpc/lib/sstep.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 3362299..82323ef 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1807,8 +1807,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned 
int instr)
                goto instr_done;
 
        case LARX:
-               if (regs->msr & MSR_LE)
-                       return 0;
                if (op.ea & (size - 1))
                        break;          /* can't handle misaligned */
                err = -EFAULT;
@@ -1832,8 +1830,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned 
int instr)
                goto ldst_done;
 
        case STCX:
-               if (regs->msr & MSR_LE)
-                       return 0;
                if (op.ea & (size - 1))
                        break;          /* can't handle misaligned */
                err = -EFAULT;
@@ -1859,8 +1855,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned 
int instr)
                goto ldst_done;
 
        case LOAD:
-               if (regs->msr & MSR_LE)
-                       return 0;
                err = read_mem(&regs->gpr[op.reg], op.ea, size, regs);
                if (!err) {
                        if (op.type & SIGNEXT)
@@ -1913,8 +1907,6 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned 
int instr)
                goto instr_done;
 
        case STORE:
-               if (regs->msr & MSR_LE)
-                       return 0;
                if ((op.type & UPDATE) && size == sizeof(long) &&
                    op.reg == 1 && op.update_reg == 1 &&
                    !(regs->msr & MSR_PR) &&
-- 
1.8.3.1