diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 375ed160d936..472f62790022 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -80,6 +80,7 @@ static bool use_tui, use_stdio; static int default_interval = 0; +static bool kptr_restrict_warned; static bool inherit = false; static int realtime_prio = 0; static bool group = false; @@ -738,6 +739,20 @@ static void perf_event__process_sample(const union perf_event *event, al.filtered) return; + if (!kptr_restrict_warned && + symbol_conf.kptr_restrict && + al.cpumode == PERF_RECORD_MISC_KERNEL) { + ui__warning( +"Kernel address maps (/proc/{kallsyms,modules}) are restricted.\n\n" +"Check /proc/sys/kernel/kptr_restrict.\n\n" +"Kernel%s samples will not be resolved.\n", + !RB_EMPTY_ROOT(&al.map->dso->symbols[MAP__FUNCTION]) ? + " modules" : ""); + if (use_browser <= 0) + sleep(5); + kptr_restrict_warned = true; + } + if (al.sym == NULL) { /* * As we do lazy loading of symtabs we only will know if the