perf symbols: Figure out start address of kernel map from kallsyms (d214afbd) · Commits · 戴 / test

On ARM, module symbol start address is ahead of kernel symbol start address, so we can't suppose that the start address of kernel map always is zero, otherwise may cause incorrect .start and .end of kernel map (caused by fixup) when there are modules loaded, then map_groups__find may return incorrect map for symbol query. This patch always figures out the start address of kernel map from /proc/kallsyms if the file is available, so fix the issues on ARM for module loaded case. This patch fixes the following issues on ARM when modules are loaded: - vmlinux symbol can't be found by kallsyms maps doing 'perf test' - module symbols are parsed mistakenlly when doing 'perf top'/'perf report' Cc: Ian Munsie <imunsie@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <20101125192725.62d31b42@tom-lei> Signed-off-by:

Ming Lei <tom.leiming@gmail.com> Signed-off-by:

Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/symbol.c

+42 −1

Original line number	Diff line number	Diff line
		@@ -2131,14 +2131,55 @@ static struct dso machine__create_kernel(struct machine self)
		return kernel;
		}

		struct process_args {
		u64 start;
		};

		static int symbol__in_kernel(void arg, const char name,
		char type __used, u64 start)
		{
		struct process_args *args = arg;

		if (strchr(name, '['))
		return 0;

		args->start = start;
		return 1;
		}

		/* Figure out the start address of kernel map from /proc/kallsyms */
		static u64 machine__get_kernel_start_addr(struct machine *machine)
		{
		const char *filename;
		char path[PATH_MAX];
		struct process_args args;

		if (machine__is_host(machine)) {
		filename = "/proc/kallsyms";
		} else {
		if (machine__is_default_guest(machine))
		filename = (char *)symbol_conf.default_guest_kallsyms;
		else {
		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
		filename = path;
		}
		}

		if (kallsyms__parse(filename, &args, symbol__in_kernel) <= 0)
		return 0;

		return args.start;
		}

		int __machine__create_kernel_maps(struct machine self, struct dso kernel)
		{
		enum map_type type;
		u64 start = machine__get_kernel_start_addr(self);

		for (type = 0; type < MAP__NR_TYPES; ++type) {
		struct kmap *kmap;

		self->vmlinux_maps[type] = map__new2(0, kernel, type);
		self->vmlinux_maps[type] = map__new2(start, kernel, type);
		if (self->vmlinux_maps[type] == NULL)
		return -1;

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