[PATCH v2 1/3] powerpc: sstep: Fix load and update emulation

[Sandipan Das]

On 03/02/21 3:19 pm, Naveen N. Rao wrote:
> [...]
> 
> Wouldn't it be easier to just do the below at the end? Or, am I missing something?
> 
> diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
> index ede093e9623472..a2d726d2a5e9d1 100644
> --- a/arch/powerpc/lib/sstep.c
> +++ b/arch/powerpc/lib/sstep.c
> @@ -2980,6 +2980,10 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
>         }
>  #endif /* CONFIG_VSX */
> 
> +       if (GETTYPE(op->type) == LOAD && (op->type & UPDATE) &&
> +                       (ra == 0 || ra == rd))
> +               goto unknown_opcode;
> +
>         return 0;
> 
>   logical_done:
> 

This looks good?

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index e96cff845ef7..a9c149bfd2f5 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -3017,6 +3017,21 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
        }
 
+       if (op->type & UPDATE) {
+               if (ra == rd && GETTYPE(op->type) == LOAD)
+                       goto unknown_opcode;
+               else if (ra == 0)
+                       switch(GETTYPE(op->type)) {
+                       case LOAD:
+                       case STORE:
+#ifdef CONFIG_PPC_FPU
+                       case LOAD_FP:
+                       case STORE_FP:
+#endif
+                               goto unknown_opcode;
+                       }
+       }
+
 #ifdef CONFIG_VSX
        if ((GETTYPE(op->type) == LOAD_VSX ||
             GETTYPE(op->type) == STORE_VSX) &&


- Sandipan