Messages in this thread | | | Date | Mon, 19 Dec 2022 13:57:18 -0700 | From | Ross Zwisler <> | Subject | Re: [PATCH 1/2] tracing: Add a way to filter function addresses to function names |
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On Mon, Dec 19, 2022 at 01:31:07PM -0500, Steven Rostedt wrote: > From: "Steven Rostedt (Google)" <rostedt@goodmis.org> > > There's been several times where an event records a function address in > its field and I needed to filter on that address for a specific function > name. It required looking up the function in kallsyms, finding its size, > and doing a compare of "field >= function_start && field < function_end". > > But this would change from boot to boot and is unreliable in scripts. > Also, it is useful to have this at boot up, where the addresses will not > be known. For example, on the boot command line: > > trace_trigger="initcall_finish.traceoff if func.function == acpi_init" > > To implement this, add a ".function" prefix, that will check that the > field is of size long, and the only operations allowed (so far) are "==" > and "!=". > > Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Ross Zwisler <zwisler@google.com>
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