Re: [PATCH v8 3/6] powerpc/code-patching: Verify instruction patch succeeded

On Mon, 2022-10-24 at 14:20 +1100, Russell Currey wrote:

On Fri, 2022-10-21 at 16:22 +1100, Benjamin Gray wrote:

quoted

diff --git a/arch/powerpc/lib/code-patching.c

b/arch/powerpc/lib/code-patching.c
index 34fc7ac34d91..9b9eba574d7e 100644

--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c

@@ -186,6 +186,8 @@ static int do_patch_instruction(u32 *addr,

ppc_inst_t instr)
        err = __do_patch_instruction(addr, instr);
        local_irq_restore(flags);
 
+       WARN_ON(!err && !ppc_inst_equal(instr,
ppc_inst_read(addr)));
+

As a side note, I had a look at test-code-patching.c and it doesn't
look like we don't have a test for ppc_inst_equal() with prefixed
instructions.  We should fix that.

Yeah, for a different series though I assume. And I think it would be
better suited in a suite dedicated to testing asm/inst.h functions.