From d214afbd81405d4da2c5745fe867e6b313fd4178 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Nov 2010 19:27:25 +0800 Subject: [PATCH] perf symbols: Figure out start address of kernel map from kallsyms 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 Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tom Zanussi LKML-Reference: <20101125192725.62d31b42@tom-lei> Signed-off-by: Ming Lei Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol.c | 43 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 2af4d7d22373..d628c8d1cf5e 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -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; -- 2.20.1