From 876e80cf83d10585df6ee1e353cfbf562f9a930e Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Wed, 18 Dec 2024 14:04:53 -0800 Subject: [PATCH] perf tools: Fixup end address of modules In machine__create_module(), it reads /proc/modules to get a list of modules in the system. The file shows the start address (of text) and the size of the module so it uses the info to reconstruct system memory maps for symbol resolution. But module memory consists of multiple segments and they can be scaterred. Currently perf tools assume they are contiguous and see some overlaps. This can confuse the tool when it finds a map containing a given address. As we mostly care about the function symbols in the text segment, it can fixup the size or end address of modules when there's an overlap. We can use maps__fixup_end() which updates the end address using the start address of the next map. Ideally it should be able to track other segments (like data/rodata), but that would require some changes in /proc/modules IMHO. Reported-by: Blake Jones Signed-off-by: Namhyung Kim Acked-by: Ian Rogers Cc: Adrian Hunter Cc: Daniel Gomez Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Luis Chamberlain Cc: Peter Zijlstra Cc: Petr Pavlu Cc: Sami Tolvanen Link: https://lore.kernel.org/r/20241218220453.203069-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/machine.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 9be2f4479f52..2d51badfbf2e 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1468,6 +1468,8 @@ static int machine__create_modules(struct machine *machine) if (modules__parse(modules, machine, machine__create_module)) return -1; + maps__fixup_end(machine__kernel_maps(machine)); + if (!machine__set_modules_path(machine)) return 0;