Commit 61f82e3f authored May 12, 2020 by Adrian Hunter Committed by Arnaldo Carvalho de Melo May 28, 2020

perf kcore_copy: Fix module map when there are no modules loaded

In the absence of any modules, no "modules" map is created, but there
are other executable pages to map, due to eBPF JIT, kprobe or ftrace.
Map them by recognizing that the first "module" symbol is not
necessarily from a module, and adjust the map accordingly.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20200512121922.8997-10-adrian.hunter@intel.com

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

parent 0bdf3181

tools/perf/util/symbol-elf.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1458,6 +1458,7 @@ struct kcore_copy_info {
		u64 first_symbol;
		u64 last_symbol;
		u64 first_module;
		u64 first_module_symbol;
		u64 last_module_symbol;
		size_t phnum;
		struct list_head phdrs;
		@@ -1534,6 +1535,8 @@ static int kcore_copy__process_kallsyms(void arg, const char name, char type,
		return 0;

		if (strchr(name, '[')) {
		if (!kci->first_module_symbol \|\| start < kci->first_module_symbol)
		kci->first_module_symbol = start;
		if (start > kci->last_module_symbol)
		kci->last_module_symbol = start;
		return 0;
		@@ -1731,6 +1734,10 @@ static int kcore_copy__calc_maps(struct kcore_copy_info kci, const char dir,
		kci->etext += page_size;
		}

		if (kci->first_module_symbol &&
		(!kci->first_module \|\| kci->first_module_symbol < kci->first_module))
		kci->first_module = kci->first_module_symbol;

		kci->first_module = round_down(kci->first_module, page_size);

		if (kci->last_module_symbol) {

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