bpf: introduce current->pid, tgid, uid, gid, comm accessors

[deliverable/linux.git] / kernel / bpf / helpers.c

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 7ad5d8842d5b28e2fcdfeba7b14061bb65d1c30e..1447ec09421ebc4905c922f4f4fa2b65b52b474a 100644 (file)
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -14,6 +14,8 @@
 #include <linux/random.h>
 #include <linux/smp.h>
 #include <linux/ktime.h>
+#include <linux/sched.h>
+#include <linux/uidgid.h>
 
 /* If kernel subsystem is allowing eBPF programs to call this function,
  * inside its own verifier_ops->get_func_proto() callback it should return
@@ -124,3 +126,59 @@ const struct bpf_func_proto bpf_ktime_get_ns_proto = {
        .gpl_only       = true,
        .ret_type       = RET_INTEGER,
 };
+
+static u64 bpf_get_current_pid_tgid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+       struct task_struct *task = current;
+
+       if (!task)
+               return -EINVAL;
+
+       return (u64) task->tgid << 32 | task->pid;
+}
+
+const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
+       .func           = bpf_get_current_pid_tgid,
+       .gpl_only       = false,
+       .ret_type       = RET_INTEGER,
+};
+
+static u64 bpf_get_current_uid_gid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+       struct task_struct *task = current;
+       kuid_t uid;
+       kgid_t gid;
+
+       if (!task)
+               return -EINVAL;
+
+       current_uid_gid(&uid, &gid);
+       return (u64) from_kgid(&init_user_ns, gid) << 32 |
+               from_kuid(&init_user_ns, uid);
+}
+
+const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
+       .func           = bpf_get_current_uid_gid,
+       .gpl_only       = false,
+       .ret_type       = RET_INTEGER,
+};
+
+static u64 bpf_get_current_comm(u64 r1, u64 size, u64 r3, u64 r4, u64 r5)
+{
+       struct task_struct *task = current;
+       char *buf = (char *) (long) r1;
+
+       if (!task)
+               return -EINVAL;
+
+       memcpy(buf, task->comm, min_t(size_t, size, sizeof(task->comm)));
+       return 0;
+}
+
+const struct bpf_func_proto bpf_get_current_comm_proto = {
+       .func           = bpf_get_current_comm,
+       .gpl_only       = false,
+       .ret_type       = RET_INTEGER,
+       .arg1_type      = ARG_PTR_TO_STACK,
+       .arg2_type      = ARG_CONST_STACK_SIZE,
+};