Oleg Nesterov [off-list ref] writes:

Christophe, et al,

So what?

Are you going to push your change or should I re-send 1-2 without
whitespace cleanups?

I'll take your 1 & 2 and fixup the whitespace issues when applying.

cheers

On 11/19, Oleg Nesterov wrote:

quoted

On 11/19, Christophe Leroy wrote:

quoted

I think the following should work, and not require the first patch (compile
tested only).

--- a/arch/powerpc/kernel/ptrace/ptrace-view.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-view.c

@@ -234,9 +234,21 @@ static int gpr_get(struct task_struct *target, const

struct user_regset *regset,
 	BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
 		     offsetof(struct pt_regs, msr) + sizeof(long));

+#ifdef CONFIG_PPC64
+	membuf_write(&to, &target->thread.regs->orig_gpr3,
+		     offsetof(struct pt_regs, softe) - offsetof(struct pt_regs,
orig_gpr3));
+	membuf_store(&to, 1UL);
+
+	BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
+		     offsetof(struct pt_regs, softe) + sizeof(long));
+
+	membuf_write(&to, &target->thread.regs->trap,
+		     sizeof(struct user_pt_regs) - offsetof(struct pt_regs, trap));
+#else
 	membuf_write(&to, &target->thread.regs->orig_gpr3,
 			sizeof(struct user_pt_regs) -
 			offsetof(struct pt_regs, orig_gpr3));
+#endif
 	return membuf_zero(&to, ELF_NGREG * sizeof(unsigned long) -
 				 sizeof(struct user_pt_regs));
 }

Probably yes.

This mirrors the previous patch I sent (https://lore.kernel.org/lkml/20190917143753.GA12300@redhat.com/ (local))
and this is exactly what I tried to avoid, we can make a simpler fix now.

But let me repeat, I agree with any fix even if imp my version simplifies the code, just
commit this change and lets forget this problem.

Oleg.