On Mon, Aug 15, 2022 at 12:13:39PM +0200, Peter Zijlstra wrote: > On Thu, Aug 11, 2022 at 11:15:22AM +0200, Jiri Olsa wrote: > > Keeping the resolved 'addr' in kallsyms_callback, instead of taking > > ftrace_location value, because we depend on symbol address in the > > cookie related code. > > > > With CONFIG_X86_KERNEL_IBT option the ftrace_location value differs > > from symbol address, which screwes the symbol address cookies matching. > > > > There are 2 users of this function: > > - bpf_kprobe_multi_link_attach > > for which this fix is for > > Except you fail to explain what the problem is and how this helps > anything. we search this array of resolved addresses later in cookie code (bpf_kprobe_multi_cookie) for address returned by fprobe, which is not 'ftrace_location' address so we want ftrace_lookup_symbols to return 'only' resolved address at this point, not 'ftrace_location' address jirka
