Re: [PATCH V2] perf tools: Fix maps__find_symbol_by_name()

From: Jiri Olsa
Date: Fri Sep 07 2018 - 05:58:47 EST


On Fri, Sep 07, 2018 at 11:51:16AM +0300, Adrian Hunter wrote:
> Commit 1c5aae7710bb ("perf machine: Create maps for x86 PTI entry
> trampolines") revealed a problem with maps__find_symbol_by_name() that
> resulted in probes not being found e.g.
>
> $ sudo perf probe xsk_mmap
> xsk_mmap is out of .text, skip it.
> Probe point 'xsk_mmap' not found.
> Error: Failed to add events.
>
> maps__find_symbol_by_name() can optionally return the map of the found
> symbol. It can get the map wrong because, in fact, the symbol is found
> on the map's dso, not allowing for the possibility that the dso has more
> than one map. Fix by always checking the map contains the symbol.
>
> Reported-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
> Tested-by: Björn Töpel <bjorn.topel@xxxxxxxxx>

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka