[PATCH v5 1/5] trace/kprobes: fix check for kretprobe offset within function entry

perf specifies an offset from _text and since this offset is fed directly into the arch-specific helper, kprobes tracer rejects installation of kretprobes through perf. Fix this by looking up the actual offset from a function for the specified sym+offset. Refactor and reuse existing routines to

[PATCH v5 1/5] trace/kprobes: fix check for kretprobe offset within function entry

perf specifies an offset from _text and since this offset is fed directly into the arch-specific helper, kprobes tracer rejects installation of kretprobes through perf. Fix this by looking up the actual offset from a function for the specified sym+offset. Refactor and reuse existing routines to