[PATCH 13/21] kgr: x86: refuse to build without fentry support

From: Jiri Kosina The only reliable way for function redirection through ftrace_ops (when modifying pt_regs->rip in the handler) is fentry. The alternative -- mcount -- is problematic in several ways. Namely the caller's function prologue (that has already been executed by the time mcount

[PATCH 13/21] kgr: x86: refuse to build without fentry support

From: Jiri Kosina jkos...@suse.cz The only reliable way for function redirection through ftrace_ops (when modifying pt_regs-rip in the handler) is fentry. The alternative -- mcount -- is problematic in several ways. Namely the caller's function prologue (that has already been executed by the