bpf: Dynptr support for ring buffers

[linux-2.6-microblaze.git] / include / linux / bpf_verifier.h

diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 3a9d2d7..e8439f6 100644 (file)
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -72,6 +72,18 @@ struct bpf_reg_state {
 
                u32 mem_size; /* for PTR_TO_MEM | PTR_TO_MEM_OR_NULL */
 
+               /* For dynptr stack slots */
+               struct {
+                       enum bpf_dynptr_type type;
+                       /* A dynptr is 16 bytes so it takes up 2 stack slots.
+                        * We need to track which slot is the first slot
+                        * to protect against cases where the user may try to
+                        * pass in an address starting at the second slot of the
+                        * dynptr.
+                        */
+                       bool first_slot;
+               } dynptr;
+
                /* Max size from any of the above. */
                struct {
                        unsigned long raw1;
@@ -88,6 +100,8 @@ struct bpf_reg_state {
         * for the purpose of tracking that it's freed.
         * For PTR_TO_SOCKET this is used to share which pointers retain the
         * same reference to the socket, to determine proper reference freeing.
+        * For stack slots that are dynptrs, this is used to track references to
+        * the dynptr to determine proper reference freeing.
         */
        u32 id;
        /* PTR_TO_SOCKET and PTR_TO_TCP_SOCK could be a ptr returned
@@ -174,9 +188,15 @@ enum bpf_stack_slot_type {
        STACK_SPILL,      /* register spilled into stack */
        STACK_MISC,       /* BPF program wrote some data into this slot */
        STACK_ZERO,       /* BPF program wrote constant zero */
+       /* A dynptr is stored in this stack slot. The type of dynptr
+        * is stored in bpf_stack_state->spilled_ptr.dynptr.type
+        */
+       STACK_DYNPTR,
 };
 
 #define BPF_REG_SIZE 8 /* size of eBPF register in bytes */
+#define BPF_DYNPTR_SIZE                sizeof(struct bpf_dynptr_kern)
+#define BPF_DYNPTR_NR_SLOTS            (BPF_DYNPTR_SIZE / BPF_REG_SIZE)
 
 struct bpf_stack_state {
        struct bpf_reg_state spilled_ptr;
@@ -523,8 +543,7 @@ int check_ptr_off_reg(struct bpf_verifier_env *env,
                      const struct bpf_reg_state *reg, int regno);
 int check_func_arg_reg_off(struct bpf_verifier_env *env,
                           const struct bpf_reg_state *reg, int regno,
-                          enum bpf_arg_type arg_type,
-                          bool is_release_func);
+                          enum bpf_arg_type arg_type);
 int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
                             u32 regno);
 int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg,