Re: [PATCH v2 12/39] x86/ibt,ftrace: Search for __fentry__ location

[Steven Rostedt]

On Fri, 25 Feb 2022 10:34:49 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> > > > +	if (!rec) {
> > > > +		if (!kallsyms_lookup_size_offset(ip, &size, &offset))
> > > > +			goto out;
> > > > +
> > > > +		if (!offset)    
> > > 
> > > Isn't this 'if (offset)' ?  
> > 
> > No, the point to only look for the fentry location if the ip passed in
> > points to the start of the function. IOW, +0 offset.  
> 
> OK, so this means ftrace_location() will be same as
> ftrace_location_range(sym, sym_end) ?

No. It only acts like ftrace_location_range(sym, sym_end) if the passed
in argument is the ip of the function (kallsyms returns offset = 0)

-- Steve