Messages in this thread | | | Date | Wed, 23 Feb 2022 07:41:39 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH 04/29] x86/livepatch: Validate __fentry__ location |
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On Wed, 23 Feb 2022 11:57:26 +0100 Peter Zijlstra <peterz@infradead.org> wrote:
> --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -1578,7 +1578,23 @@ unsigned long ftrace_location_range(unsi > */ > unsigned long ftrace_location(unsigned long ip) > { > - return ftrace_location_range(ip, ip); > + struct dyn_ftrace *rec; > + unsigned long offset; > + unsigned long size; > + > + rec = lookup_rec(ip, ip); > + if (!rec) { > + if (!kallsyms_lookup_size_offset(ip, &size, &offset)) > + goto out; > + > + rec = lookup_rec(ip - offset, (ip - offset) + size); > + } > +
Please create a new function for this. Perhaps find_ftrace_location().
ftrace_location() is used to see if the address given is a ftrace nop or not. This change will make it always return true.
-- Steve
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