1 files changed, 13 insertions, 0 deletions

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 0974f957b8fa..2ca107f3efdf 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -823,6 +823,19 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
 
         symbol__init();
 
+        if (symbol_conf.kptr_restrict)
+                pr_warning("WARNING: Kernel address maps "
+                           "(/proc/{kallsyms,modules}) are restricted, "
+                           "check /proc/sys/kernel/kptr_restrict.\n\n"
+                           "Samples in kernel functions may not be resolved "
+                           "if a suitable vmlinux file is not found in the "
+                           "buildid cache or in the vmlinux path.\n\n"
+                           "Samples in kernel modules won't be resolved "
+                           "at all.\n\n"
+                           "If some relocation was applied (e.g. kexec) "
+                           "symbols may be misresolved even with a suitable "
+                           "vmlinux or kallsyms file.\n\n");
+
         if (no_buildid_cache || no_buildid)
                 disable_buildid_cache();