Merge tag 'powerpc-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...
[linux-2.6-microblaze.git] / kernel / bpf / btf.c
index b1a76fe..0600ed3 100644 (file)
 #define BITS_ROUNDUP_BYTES(bits) \
        (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
 
-#define BTF_INFO_MASK 0x8f00ffff
+#define BTF_INFO_MASK 0x9f00ffff
 #define BTF_INT_MASK 0x0fffffff
 #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE)
 #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET)
@@ -280,9 +280,10 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
        [BTF_KIND_FUNC_PROTO]   = "FUNC_PROTO",
        [BTF_KIND_VAR]          = "VAR",
        [BTF_KIND_DATASEC]      = "DATASEC",
+       [BTF_KIND_FLOAT]        = "FLOAT",
 };
 
-static const char *btf_type_str(const struct btf_type *t)
+const char *btf_type_str(const struct btf_type *t)
 {
        return btf_kind_str[BTF_INFO_KIND(t->info)];
 }
@@ -574,6 +575,7 @@ static bool btf_type_has_size(const struct btf_type *t)
        case BTF_KIND_UNION:
        case BTF_KIND_ENUM:
        case BTF_KIND_DATASEC:
+       case BTF_KIND_FLOAT:
                return true;
        }
 
@@ -787,7 +789,6 @@ static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf,
 
        while (btf_type_is_modifier(t) &&
               BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) {
-               id = t->type;
                t = btf_type_by_id(btf, t->type);
        }
 
@@ -1704,6 +1705,7 @@ __btf_resolve_size(const struct btf *btf, const struct btf_type *type,
                case BTF_KIND_STRUCT:
                case BTF_KIND_UNION:
                case BTF_KIND_ENUM:
+               case BTF_KIND_FLOAT:
                        size = type->size;
                        goto resolved;
 
@@ -1849,7 +1851,7 @@ static int btf_df_check_kflag_member(struct btf_verifier_env *env,
        return -EINVAL;
 }
 
-/* Used for ptr, array and struct/union type members.
+/* Used for ptr, array struct/union and float type members.
  * int, enum and modifier types have their specific callback functions.
  */
 static int btf_generic_check_kflag_member(struct btf_verifier_env *env,
@@ -3675,6 +3677,81 @@ static const struct btf_kind_operations datasec_ops = {
        .show                   = btf_datasec_show,
 };
 
+static s32 btf_float_check_meta(struct btf_verifier_env *env,
+                               const struct btf_type *t,
+                               u32 meta_left)
+{
+       if (btf_type_vlen(t)) {
+               btf_verifier_log_type(env, t, "vlen != 0");
+               return -EINVAL;
+       }
+
+       if (btf_type_kflag(t)) {
+               btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+               return -EINVAL;
+       }
+
+       if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 &&
+           t->size != 16) {
+               btf_verifier_log_type(env, t, "Invalid type_size");
+               return -EINVAL;
+       }
+
+       btf_verifier_log_type(env, t, NULL);
+
+       return 0;
+}
+
+static int btf_float_check_member(struct btf_verifier_env *env,
+                                 const struct btf_type *struct_type,
+                                 const struct btf_member *member,
+                                 const struct btf_type *member_type)
+{
+       u64 start_offset_bytes;
+       u64 end_offset_bytes;
+       u64 misalign_bits;
+       u64 align_bytes;
+       u64 align_bits;
+
+       /* Different architectures have different alignment requirements, so
+        * here we check only for the reasonable minimum. This way we ensure
+        * that types after CO-RE can pass the kernel BTF verifier.
+        */
+       align_bytes = min_t(u64, sizeof(void *), member_type->size);
+       align_bits = align_bytes * BITS_PER_BYTE;
+       div64_u64_rem(member->offset, align_bits, &misalign_bits);
+       if (misalign_bits) {
+               btf_verifier_log_member(env, struct_type, member,
+                                       "Member is not properly aligned");
+               return -EINVAL;
+       }
+
+       start_offset_bytes = member->offset / BITS_PER_BYTE;
+       end_offset_bytes = start_offset_bytes + member_type->size;
+       if (end_offset_bytes > struct_type->size) {
+               btf_verifier_log_member(env, struct_type, member,
+                                       "Member exceeds struct_size");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static void btf_float_log(struct btf_verifier_env *env,
+                         const struct btf_type *t)
+{
+       btf_verifier_log(env, "size=%u", t->size);
+}
+
+static const struct btf_kind_operations float_ops = {
+       .check_meta = btf_float_check_meta,
+       .resolve = btf_df_resolve,
+       .check_member = btf_float_check_member,
+       .check_kflag_member = btf_generic_check_kflag_member,
+       .log_details = btf_float_log,
+       .show = btf_df_show,
+};
+
 static int btf_func_proto_check(struct btf_verifier_env *env,
                                const struct btf_type *t)
 {
@@ -3808,6 +3885,7 @@ static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
        [BTF_KIND_FUNC_PROTO] = &func_proto_ops,
        [BTF_KIND_VAR] = &var_ops,
        [BTF_KIND_DATASEC] = &datasec_ops,
+       [BTF_KIND_FLOAT] = &float_ops,
 };
 
 static s32 btf_check_meta(struct btf_verifier_env *env,
@@ -4298,7 +4376,7 @@ static u8 bpf_ctx_convert_map[] = {
 #undef BPF_LINK_TYPE
 
 static const struct btf_member *
-btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
+btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
                      const struct btf_type *t, enum bpf_prog_type prog_type,
                      int arg)
 {
@@ -4592,8 +4670,10 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
        }
        arg = off / 8;
        args = (const struct btf_param *)(t + 1);
-       /* if (t == NULL) Fall back to default BPF prog with 5 u64 arguments */
-       nr_args = t ? btf_type_vlen(t) : 5;
+       /* if (t == NULL) Fall back to default BPF prog with
+        * MAX_BPF_FUNC_REG_ARGS u64 arguments.
+        */
+       nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS;
        if (prog->aux->attach_btf_trace) {
                /* skip first 'void *__data' argument in btf_trace_##name typedef */
                args++;
@@ -4649,7 +4729,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
                }
        } else {
                if (!t)
-                       /* Default prog with 5 args */
+                       /* Default prog with MAX_BPF_FUNC_REG_ARGS args */
                        return true;
                t = btf_type_by_id(btf, args[arg].type);
        }
@@ -5100,12 +5180,12 @@ int btf_distill_func_proto(struct bpf_verifier_log *log,
 
        if (!func) {
                /* BTF function prototype doesn't match the verifier types.
-                * Fall back to 5 u64 args.
+                * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args.
                 */
-               for (i = 0; i < 5; i++)
+               for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++)
                        m->arg_size[i] = 8;
                m->ret_size = 8;
-               m->nr_args = 5;
+               m->nr_args = MAX_BPF_FUNC_REG_ARGS;
                return 0;
        }
        args = (const struct btf_param *)(func + 1);
@@ -5281,121 +5361,190 @@ int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *pr
        return btf_check_func_type_match(log, btf1, t1, btf2, t2);
 }
 
-/* Compare BTF of a function with given bpf_reg_state.
- * Returns:
- * EFAULT - there is a verifier bug. Abort verification.
- * EINVAL - there is a type mismatch or BTF is not available.
- * 0 - BTF matches with what bpf_reg_state expects.
- * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
- */
-int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
-                            struct bpf_reg_state *regs)
+static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = {
+#ifdef CONFIG_NET
+       [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK],
+       [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
+       [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP],
+#endif
+};
+
+static int btf_check_func_arg_match(struct bpf_verifier_env *env,
+                                   const struct btf *btf, u32 func_id,
+                                   struct bpf_reg_state *regs,
+                                   bool ptr_to_mem_ok)
 {
        struct bpf_verifier_log *log = &env->log;
-       struct bpf_prog *prog = env->prog;
-       struct btf *btf = prog->aux->btf;
-       const struct btf_param *args;
+       const char *func_name, *ref_tname;
        const struct btf_type *t, *ref_t;
-       u32 i, nargs, btf_id, type_size;
-       const char *tname;
-       bool is_global;
-
-       if (!prog->aux->func_info)
-               return -EINVAL;
-
-       btf_id = prog->aux->func_info[subprog].type_id;
-       if (!btf_id)
-               return -EFAULT;
-
-       if (prog->aux->func_info_aux[subprog].unreliable)
-               return -EINVAL;
+       const struct btf_param *args;
+       u32 i, nargs, ref_id;
 
-       t = btf_type_by_id(btf, btf_id);
+       t = btf_type_by_id(btf, func_id);
        if (!t || !btf_type_is_func(t)) {
                /* These checks were already done by the verifier while loading
-                * struct bpf_func_info
+                * struct bpf_func_info or in add_kfunc_call().
                 */
-               bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
-                       subprog);
+               bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n",
+                       func_id);
                return -EFAULT;
        }
-       tname = btf_name_by_offset(btf, t->name_off);
+       func_name = btf_name_by_offset(btf, t->name_off);
 
        t = btf_type_by_id(btf, t->type);
        if (!t || !btf_type_is_func_proto(t)) {
-               bpf_log(log, "Invalid BTF of func %s\n", tname);
+               bpf_log(log, "Invalid BTF of func %s\n", func_name);
                return -EFAULT;
        }
        args = (const struct btf_param *)(t + 1);
        nargs = btf_type_vlen(t);
-       if (nargs > 5) {
-               bpf_log(log, "Function %s has %d > 5 args\n", tname, nargs);
-               goto out;
+       if (nargs > MAX_BPF_FUNC_REG_ARGS) {
+               bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs,
+                       MAX_BPF_FUNC_REG_ARGS);
+               return -EINVAL;
        }
 
-       is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
        /* check that BTF function arguments match actual types that the
         * verifier sees.
         */
        for (i = 0; i < nargs; i++) {
-               struct bpf_reg_state *reg = &regs[i + 1];
+               u32 regno = i + 1;
+               struct bpf_reg_state *reg = &regs[regno];
 
-               t = btf_type_by_id(btf, args[i].type);
-               while (btf_type_is_modifier(t))
-                       t = btf_type_by_id(btf, t->type);
-               if (btf_type_is_int(t) || btf_type_is_enum(t)) {
+               t = btf_type_skip_modifiers(btf, args[i].type, NULL);
+               if (btf_type_is_scalar(t)) {
                        if (reg->type == SCALAR_VALUE)
                                continue;
-                       bpf_log(log, "R%d is not a scalar\n", i + 1);
-                       goto out;
+                       bpf_log(log, "R%d is not a scalar\n", regno);
+                       return -EINVAL;
                }
-               if (btf_type_is_ptr(t)) {
+
+               if (!btf_type_is_ptr(t)) {
+                       bpf_log(log, "Unrecognized arg#%d type %s\n",
+                               i, btf_type_str(t));
+                       return -EINVAL;
+               }
+
+               ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id);
+               ref_tname = btf_name_by_offset(btf, ref_t->name_off);
+               if (btf_is_kernel(btf)) {
+                       const struct btf_type *reg_ref_t;
+                       const struct btf *reg_btf;
+                       const char *reg_ref_tname;
+                       u32 reg_ref_id;
+
+                       if (!btf_type_is_struct(ref_t)) {
+                               bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n",
+                                       func_name, i, btf_type_str(ref_t),
+                                       ref_tname);
+                               return -EINVAL;
+                       }
+
+                       if (reg->type == PTR_TO_BTF_ID) {
+                               reg_btf = reg->btf;
+                               reg_ref_id = reg->btf_id;
+                       } else if (reg2btf_ids[reg->type]) {
+                               reg_btf = btf_vmlinux;
+                               reg_ref_id = *reg2btf_ids[reg->type];
+                       } else {
+                               bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d is not a pointer to btf_id\n",
+                                       func_name, i,
+                                       btf_type_str(ref_t), ref_tname, regno);
+                               return -EINVAL;
+                       }
+
+                       reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id,
+                                                           &reg_ref_id);
+                       reg_ref_tname = btf_name_by_offset(reg_btf,
+                                                          reg_ref_t->name_off);
+                       if (!btf_struct_ids_match(log, reg_btf, reg_ref_id,
+                                                 reg->off, btf, ref_id)) {
+                               bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n",
+                                       func_name, i,
+                                       btf_type_str(ref_t), ref_tname,
+                                       regno, btf_type_str(reg_ref_t),
+                                       reg_ref_tname);
+                               return -EINVAL;
+                       }
+               } else if (btf_get_prog_ctx_type(log, btf, t,
+                                                env->prog->type, i)) {
                        /* If function expects ctx type in BTF check that caller
                         * is passing PTR_TO_CTX.
                         */
-                       if (btf_get_prog_ctx_type(log, btf, t, prog->type, i)) {
-                               if (reg->type != PTR_TO_CTX) {
-                                       bpf_log(log,
-                                               "arg#%d expected pointer to ctx, but got %s\n",
-                                               i, btf_kind_str[BTF_INFO_KIND(t->info)]);
-                                       goto out;
-                               }
-                               if (check_ctx_reg(env, reg, i + 1))
-                                       goto out;
-                               continue;
+                       if (reg->type != PTR_TO_CTX) {
+                               bpf_log(log,
+                                       "arg#%d expected pointer to ctx, but got %s\n",
+                                       i, btf_type_str(t));
+                               return -EINVAL;
                        }
+                       if (check_ctx_reg(env, reg, regno))
+                               return -EINVAL;
+               } else if (ptr_to_mem_ok) {
+                       const struct btf_type *resolve_ret;
+                       u32 type_size;
 
-                       if (!is_global)
-                               goto out;
-
-                       t = btf_type_skip_modifiers(btf, t->type, NULL);
-
-                       ref_t = btf_resolve_size(btf, t, &type_size);
-                       if (IS_ERR(ref_t)) {
+                       resolve_ret = btf_resolve_size(btf, ref_t, &type_size);
+                       if (IS_ERR(resolve_ret)) {
                                bpf_log(log,
-                                   "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
-                                   i, btf_type_str(t), btf_name_by_offset(btf, t->name_off),
-                                       PTR_ERR(ref_t));
-                               goto out;
+                                       "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
+                                       i, btf_type_str(ref_t), ref_tname,
+                                       PTR_ERR(resolve_ret));
+                               return -EINVAL;
                        }
 
-                       if (check_mem_reg(env, reg, i + 1, type_size))
-                               goto out;
-
-                       continue;
+                       if (check_mem_reg(env, reg, regno, type_size))
+                               return -EINVAL;
+               } else {
+                       return -EINVAL;
                }
-               bpf_log(log, "Unrecognized arg#%d type %s\n",
-                       i, btf_kind_str[BTF_INFO_KIND(t->info)]);
-               goto out;
        }
+
        return 0;
-out:
+}
+
+/* Compare BTF of a function with given bpf_reg_state.
+ * Returns:
+ * EFAULT - there is a verifier bug. Abort verification.
+ * EINVAL - there is a type mismatch or BTF is not available.
+ * 0 - BTF matches with what bpf_reg_state expects.
+ * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
+ */
+int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog,
+                               struct bpf_reg_state *regs)
+{
+       struct bpf_prog *prog = env->prog;
+       struct btf *btf = prog->aux->btf;
+       bool is_global;
+       u32 btf_id;
+       int err;
+
+       if (!prog->aux->func_info)
+               return -EINVAL;
+
+       btf_id = prog->aux->func_info[subprog].type_id;
+       if (!btf_id)
+               return -EFAULT;
+
+       if (prog->aux->func_info_aux[subprog].unreliable)
+               return -EINVAL;
+
+       is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
+       err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global);
+
        /* Compiler optimizations can remove arguments from static functions
         * or mismatched type can be passed into a global function.
         * In such cases mark the function as unreliable from BTF point of view.
         */
-       prog->aux->func_info_aux[subprog].unreliable = true;
-       return -EINVAL;
+       if (err)
+               prog->aux->func_info_aux[subprog].unreliable = true;
+       return err;
+}
+
+int btf_check_kfunc_arg_match(struct bpf_verifier_env *env,
+                             const struct btf *btf, u32 func_id,
+                             struct bpf_reg_state *regs)
+{
+       return btf_check_func_arg_match(env, btf, func_id, regs, false);
 }
 
 /* Convert BTF of a function into bpf_reg_state if possible
@@ -5458,9 +5607,9 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
        }
        args = (const struct btf_param *)(t + 1);
        nargs = btf_type_vlen(t);
-       if (nargs > 5) {
-               bpf_log(log, "Global function %s() with %d > 5 args. Buggy compiler.\n",
-                       tname, nargs);
+       if (nargs > MAX_BPF_FUNC_REG_ARGS) {
+               bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n",
+                       tname, nargs, MAX_BPF_FUNC_REG_ARGS);
                return -EINVAL;
        }
        /* check that function returns int */