RE: [PATCH 2/2] perf tools: Fix find_perf_probe_point_from_map() which incorrectly returns success

Date: Fri Nov 06 2015 - 01:29:08 EST

From: acme@xxxxxxxxxx [mailto:acme@xxxxxxxxxx]
>Em Thu, Nov 05, 2015 at 02:08:48PM +0000, åæéå / HIRAMATUïMASAMI escreveu:
>> From: Wang Nan [mailto:wangnan0@xxxxxxxxxx]
>> >
>> >It is possible that find_perf_probe_point_from_map() fails to find
>> >symbol but still returns 0 because of an small error when coding:
>> >find_perf_probe_point_from_map() set 'ret' to error code at first,
>> >but also use it to hold return value of
>> >kernel_get_symbol_address_by_name().
>> OK, I didn't expect that there is a symbol which can be found by
>> kernel_get_symbol_address_by_name() but not by __find_kernel_function()...
>> Would you have any example of the error?
>> >
>> >This patch resets 'ret' to error even kernel_get_symbol_address_by_name()
>> >success, so if !sym, the whole function returns error correctly.
>> Hmm, that sounds tricky. I'd rather like to add *psym to kernel_get_symbol_address_by_name()
>> to save symbol and don't use __find_kernel_function() instead.
>Tricky? I don't think so, suboptimal? possibly, but it fixes an error,
>so should be processed quickly, right? I'm applying his patch and then
>whatever improvement can be done on top.

OK, then I'll send an improvement patch.


>- Arnaldo