Re: [PATCH] uprobes/x86: emulate push insns for uprobe on x86

On 11/09, Yonghong Song wrote:

+	if (insn_class == UPROBE_PUSH_INSN) {
+		src_ptr = get_push_reg_ptr(auprobe, regs);
+		reg_width = sizeof_long();
+		sp = regs->sp;
+		if (copy_to_user((void __user *)(sp - reg_width), src_ptr, reg_width))
+			return false;
+
+		regs->sp = sp - reg_width;
+		regs->ip += 1 + (auprobe->push.rex_prefix != 0);
+		return true;

Another nit... You can rename push_ret_address() and use it here

		src_ptr = ...;
		if (push_ret_address(regs, *src_ptr))
			return false;

		regs->ip += ...;
		return true;

and I think get_push_reg_ptr() should just return "unsigned long", not the
pointer.

And again, please make a separate method for this code. Let me repeat, the
main reason for branch_xol_ops/etc is that we simply can not execute these
insns out-of-line, we have to emulate them. "push" differs, the only reason
why we may want to emulate it is optimization.

Oleg.