Commit 03db8b58 authored Sep 07, 2018 by Adrian Hunter Committed by Arnaldo Carvalho de Melo Sep 11, 2018

perf tools: Fix maps__find_symbol_by_name()



Commit 1c5aae77 ("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@intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Björn Töpel <bjorn.topel@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 1c5aae77 ("perf machine: Create maps for x86 PTI entry trampolines")
Link: http://lkml.kernel.org/r/20180907085116.25782-1-adrian.hunter@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 5db48a8d

tools/perf/util/map.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -576,6 +576,13 @@ struct symbol map_groups__find_symbol(struct map_groups mg,
		return NULL;
		}

		static bool map__contains_symbol(struct map map, struct symbol sym)
		{
		u64 ip = map->unmap_ip(map, sym->start);

		return ip >= map->start && ip < map->end;
		}

		struct symbol maps__find_symbol_by_name(struct maps maps, const char *name,
		struct map **mapp)
		{
		@@ -591,6 +598,10 @@ struct symbol maps__find_symbol_by_name(struct maps maps, const char *name,

		if (sym == NULL)
		continue;
		if (!map__contains_symbol(pos, sym)) {
		sym = NULL;
		continue;
		}
		if (mapp != NULL)
		*mapp = pos;
		goto out;