Function profiler shows the hit count of each function using its symbol
name. However, there are some same-name local symbols, which we can not
distinguish.
To solve this issue, this introduces an option to show the symbols
in "_text+OFFSET" format. This can avoid exposing the random shift of
KASLR. The functions in modules are shown as "MODNAME+OFFSET" where the
offset is from ".text".
E.g. for the kernel text symbols, specify vmlinux and the output to
addr2line, you can find the actual function and source info;
$ addr2line -fie vmlinux _text+3078208
__balance_callbacks
kernel/sched/core.c:5064
for modules, specify the module file and .text+OFFSET;
$ addr2line -fie samples/trace_events/trace-events-sample.ko .text+8224
do_simple_thread_func
samples/trace_events/trace-events-sample.c:23
Link: https://lore.kernel.org/all/176187878064.994619.8878296550240416558.stgit@devnote2/
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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