Re: [PATCH] powerpc/kprobes: Pass ppc_inst as a pointer to emulate_step() on ppc32

Christophe Leroy wrote:

Le 20/05/2021 à 12:54, Naveen N. Rao a écrit :

quoted

Christophe Leroy wrote:

quoted

Le 20/05/2021 à 09:29, Naveen N. Rao a écrit :

quoted

diff --git a/arch/powerpc/kernel/optprobes.c 

b/arch/powerpc/kernel/optprobes.c
index cdf87086fa33a0..2bc53fa48a1b33 100644

--- a/arch/powerpc/kernel/optprobes.c
+++ b/arch/powerpc/kernel/optprobes.c

@@ -281,8 +281,12 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe 

*p)
      /*
       * 3. load instruction to be emulated into relevant register, and
       */
-    temp = ppc_inst_read((struct ppc_inst *)p->ainsn.insn);
-    patch_imm_load_insns(ppc_inst_as_ulong(temp), 4, buff + TMPL_INSN_IDX);
+    if (IS_ENABLED(CONFIG_PPC64)) {
+        temp = ppc_inst_read((struct ppc_inst *)p->ainsn.insn);
+        patch_imm_load_insns(ppc_inst_as_ulong(temp), 4, buff + TMPL_INSN_IDX);
+    } else {
+        patch_imm_load_insns((unsigned long)p->ainsn.insn, 4, buff + TMPL_INSN_IDX);
+    }

It means commit https://github.com/linuxppc/linux/commit/693557ebf407a85ea400a0b501bb97687d8f4856 
was not necessary and may be reverted.

Indeed, I will send a revert for it.

I'm not completely sure it is worth reverting, on an other hand it is pointless anyway to have 
something to convert to a u64 something that cannot be more than 32 bits on a PPC32, so now that we 
have ppc_inst_as_ulong() it is as good I think.

Sure. If necessary, the revert can go in separately as part of your 
other cleanup series.

- Naveen