+ kernel_map = session->host_machine.vmlinux_maps[MAP__FUNCTION];
+ kernel_kmap = map__kmap(kernel_map);
+ if (kernel_map == NULL ||
+ (kernel_map->dso->hit &&
+ (kernel_kmap->ref_reloc_sym == NULL ||
+ kernel_kmap->ref_reloc_sym->addr == 0))) {
+ const struct dso *kdso = kernel_map->dso;
+
+ ui__warning(
+"Kernel address maps (/proc/{kallsyms,modules}) were restricted.\n\n"
+"Check /proc/sys/kernel/kptr_restrict before running 'perf record'.\n\n%s\n\n"
+"Samples in kernel modules can't be resolved as well.\n\n",
+ RB_EMPTY_ROOT(&kdso->symbols[MAP__FUNCTION]) ?
+"As no suitable kallsyms nor vmlinux was found, kernel samples\n"
+"can't be resolved." :
+"If some relocation was applied (e.g. kexec) symbols may be misresolved.");
+ }
+