diff options
Diffstat (limited to 'kernel/ksyms_common.c')
-rw-r--r-- | kernel/ksyms_common.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/kernel/ksyms_common.c b/kernel/ksyms_common.c new file mode 100644 index 000000000000..3840fa1c9c86 --- /dev/null +++ b/kernel/ksyms_common.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ksyms_common.c: A split of kernel/kallsyms.c + * Contains a few generic function definations independent of config KALLSYMS. + */ +#include <linux/kallsyms.h> +#include <linux/security.h> + +#ifdef CONFIG_KALLSYMS +static inline int kallsyms_for_perf(void) +{ +#ifdef CONFIG_PERF_EVENTS + extern int sysctl_perf_event_paranoid; + + if (sysctl_perf_event_paranoid <= 1) + return 1; +#endif + return 0; +} + +/* + * We show kallsyms information even to normal users if we've enabled + * kernel profiling and are explicitly not paranoid (so kptr_restrict + * is clear, and sysctl_perf_event_paranoid isn't set). + * + * Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to + * block even that). + */ +bool kallsyms_show_value(const struct cred *cred) +{ + switch (kptr_restrict) { + case 0: + if (kallsyms_for_perf()) + return true; + fallthrough; + case 1: + if (security_capable(cred, &init_user_ns, CAP_SYSLOG, + CAP_OPT_NOAUDIT) == 0) + return true; + fallthrough; + default: + return false; + } +} +#endif |