#include <linux/sched/stat.h>
#include <linux/flex_array.h>
#include <linux/posix-timers.h>
+#include <linux/cpufreq_times.h>
#include <trace/events/oom.h>
#include "internal.h"
#include "fd.h"
unsigned long *entries;
int err;
+ /*
+ * The ability to racily run the kernel stack unwinder on a running task
+ * and then observe the unwinder output is scary; while it is useful for
+ * debugging kernel issues, it can also allow an attacker to leak kernel
+ * stack contents.
+ * Doing this in a manner that is at least safe from races would require
+ * some work to ensure that the remote task can not be scheduled; and
+ * even then, this would still expose the unwinder as local attack
+ * surface.
+ * Therefore, this interface is restricted to root.
+ */
+ if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
+ return -EACCES;
+
entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
GFP_KERNEL);
if (!entries)
#ifdef CONFIG_LIVEPATCH
ONE("patch_state", S_IRUSR, proc_pid_patch_state),
#endif
+#ifdef CONFIG_CPU_FREQ_TIMES
+ ONE("time_in_state", 0444, proc_time_in_state_show),
+#endif
};
static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
#ifdef CONFIG_LIVEPATCH
ONE("patch_state", S_IRUSR, proc_pid_patch_state),
#endif
+#ifdef CONFIG_CPU_FREQ_TIMES
+ ONE("time_in_state", 0444, proc_time_in_state_show),
+#endif
};
static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)