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-rw-r--r--kernel/bpf/btf.c504
1 files changed, 426 insertions, 78 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index ed2075884724..b7c1660fb594 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -180,11 +180,6 @@
*/
#define BTF_MAX_SIZE (16 * 1024 * 1024)
-#define for_each_member(i, struct_type, member) \
- for (i = 0, member = btf_type_member(struct_type); \
- i < btf_type_vlen(struct_type); \
- i++, member++)
-
#define for_each_member_from(i, from, struct_type, member) \
for (i = from, member = btf_type_member(struct_type) + from; \
i < btf_type_vlen(struct_type); \
@@ -281,6 +276,11 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
[BTF_KIND_DATASEC] = "DATASEC",
};
+static const char *btf_type_str(const struct btf_type *t)
+{
+ return btf_kind_str[BTF_INFO_KIND(t->info)];
+}
+
struct btf_kind_operations {
s32 (*check_meta)(struct btf_verifier_env *env,
const struct btf_type *t,
@@ -382,6 +382,65 @@ static bool btf_type_is_datasec(const struct btf_type *t)
return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
}
+s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
+{
+ const struct btf_type *t;
+ const char *tname;
+ u32 i;
+
+ for (i = 1; i <= btf->nr_types; i++) {
+ t = btf->types[i];
+ if (BTF_INFO_KIND(t->info) != kind)
+ continue;
+
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (!strcmp(tname, name))
+ return i;
+ }
+
+ return -ENOENT;
+}
+
+const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
+ u32 id, u32 *res_id)
+{
+ const struct btf_type *t = btf_type_by_id(btf, id);
+
+ while (btf_type_is_modifier(t)) {
+ id = t->type;
+ t = btf_type_by_id(btf, t->type);
+ }
+
+ if (res_id)
+ *res_id = id;
+
+ return t;
+}
+
+const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
+ u32 id, u32 *res_id)
+{
+ const struct btf_type *t;
+
+ t = btf_type_skip_modifiers(btf, id, NULL);
+ if (!btf_type_is_ptr(t))
+ return NULL;
+
+ return btf_type_skip_modifiers(btf, t->type, res_id);
+}
+
+const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
+ u32 id, u32 *res_id)
+{
+ const struct btf_type *ptype;
+
+ ptype = btf_type_resolve_ptr(btf, id, res_id);
+ if (ptype && btf_type_is_func_proto(ptype))
+ return ptype;
+
+ return NULL;
+}
+
/* Types that act only as a source, not sink or intermediate
* type when resolving.
*/
@@ -446,30 +505,6 @@ static const char *btf_int_encoding_str(u8 encoding)
return "UNKN";
}
-static u16 btf_type_vlen(const struct btf_type *t)
-{
- return BTF_INFO_VLEN(t->info);
-}
-
-static bool btf_type_kflag(const struct btf_type *t)
-{
- return BTF_INFO_KFLAG(t->info);
-}
-
-static u32 btf_member_bit_offset(const struct btf_type *struct_type,
- const struct btf_member *member)
-{
- return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
- : member->offset;
-}
-
-static u32 btf_member_bitfield_size(const struct btf_type *struct_type,
- const struct btf_member *member)
-{
- return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
- : 0;
-}
-
static u32 btf_type_int(const struct btf_type *t)
{
return *(u32 *)(t + 1);
@@ -480,11 +515,6 @@ static const struct btf_array *btf_type_array(const struct btf_type *t)
return (const struct btf_array *)(t + 1);
}
-static const struct btf_member *btf_type_member(const struct btf_type *t)
-{
- return (const struct btf_member *)(t + 1);
-}
-
static const struct btf_enum *btf_type_enum(const struct btf_type *t)
{
return (const struct btf_enum *)(t + 1);
@@ -1057,7 +1087,7 @@ static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
* *elem_type: same as return type ("struct X")
* *total_nelems: 1
*/
-static const struct btf_type *
+const struct btf_type *
btf_resolve_size(const struct btf *btf, const struct btf_type *type,
u32 *type_size, const struct btf_type **elem_type,
u32 *total_nelems)
@@ -1111,8 +1141,10 @@ resolved:
return ERR_PTR(-EINVAL);
*type_size = nelems * size;
- *total_nelems = nelems;
- *elem_type = type;
+ if (total_nelems)
+ *total_nelems = nelems;
+ if (elem_type)
+ *elem_type = type;
return array_type ? : type;
}
@@ -1826,7 +1858,10 @@ static void btf_modifier_seq_show(const struct btf *btf,
u32 type_id, void *data,
u8 bits_offset, struct seq_file *m)
{
- t = btf_type_id_resolve(btf, &type_id);
+ if (btf->resolved_ids)
+ t = btf_type_id_resolve(btf, &type_id);
+ else
+ t = btf_type_skip_modifiers(btf, type_id, NULL);
btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m);
}
@@ -2621,8 +2656,8 @@ static s32 btf_func_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
+ if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
+ btf_verifier_log_type(env, t, "Invalid func linkage");
return -EINVAL;
}
@@ -3476,7 +3511,8 @@ static u8 bpf_ctx_convert_map[] = {
static const struct btf_member *
btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
- const struct btf_type *t, enum bpf_prog_type prog_type)
+ const struct btf_type *t, enum bpf_prog_type prog_type,
+ int arg)
{
const struct btf_type *conv_struct;
const struct btf_type *ctx_struct;
@@ -3497,12 +3533,13 @@ btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
* is not supported yet.
* BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
*/
- bpf_log(log, "BPF program ctx type is not a struct\n");
+ if (log->level & BPF_LOG_LEVEL)
+ bpf_log(log, "arg#%d type is not a struct\n", arg);
return NULL;
}
tname = btf_name_by_offset(btf, t->name_off);
if (!tname) {
- bpf_log(log, "BPF program ctx struct doesn't have a name\n");
+ bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
return NULL;
}
/* prog_type is valid bpf program type. No need for bounds check. */
@@ -3535,11 +3572,12 @@ btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
struct btf *btf,
const struct btf_type *t,
- enum bpf_prog_type prog_type)
+ enum bpf_prog_type prog_type,
+ int arg)
{
const struct btf_member *prog_ctx_type, *kern_ctx_type;
- prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type);
+ prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
if (!prog_ctx_type)
return -ENOENT;
kern_ctx_type = prog_ctx_type + 1;
@@ -3605,6 +3643,8 @@ struct btf *btf_parse_vmlinux(void)
goto errout;
}
+ bpf_struct_ops_init(btf);
+
btf_verifier_env_free(env);
refcount_set(&btf->refcnt, 1);
return btf;
@@ -3629,6 +3669,19 @@ struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
}
}
+static bool is_string_ptr(struct btf *btf, const struct btf_type *t)
+{
+ /* t comes in already as a pointer */
+ t = btf_type_by_id(btf, t->type);
+
+ /* allow const */
+ if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST)
+ t = btf_type_by_id(btf, t->type);
+
+ /* char, signed char, unsigned char */
+ return btf_type_is_int(t) && t->size == 1;
+}
+
bool btf_ctx_access(int off, int size, enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
@@ -3677,7 +3730,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
/* skip modifiers */
while (btf_type_is_modifier(t))
t = btf_type_by_id(btf, t->type);
- if (btf_type_is_int(t))
+ if (btf_type_is_int(t) || btf_type_is_enum(t))
/* accessing a scalar */
return true;
if (!btf_type_is_ptr(t)) {
@@ -3695,12 +3748,14 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
*/
return true;
+ if (is_string_ptr(btf, t))
+ return true;
+
/* this is a pointer to another type */
info->reg_type = PTR_TO_BTF_ID;
- info->btf_id = t->type;
if (tgt_prog) {
- ret = btf_translate_to_vmlinux(log, btf, t, tgt_prog->type);
+ ret = btf_translate_to_vmlinux(log, btf, t, tgt_prog->type, arg);
if (ret > 0) {
info->btf_id = ret;
return true;
@@ -3708,10 +3763,14 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
return false;
}
}
+
+ info->btf_id = t->type;
t = btf_type_by_id(btf, t->type);
/* skip modifiers */
- while (btf_type_is_modifier(t))
+ while (btf_type_is_modifier(t)) {
+ info->btf_id = t->type;
t = btf_type_by_id(btf, t->type);
+ }
if (!btf_type_is_struct(t)) {
bpf_log(log,
"func '%s' arg%d type %s is not a struct\n",
@@ -3737,23 +3796,57 @@ int btf_struct_access(struct bpf_verifier_log *log,
again:
tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
if (!btf_type_is_struct(t)) {
- bpf_log(log, "Type '%s' is not a struct", tname);
+ bpf_log(log, "Type '%s' is not a struct\n", tname);
return -EINVAL;
}
- for_each_member(i, t, member) {
- if (btf_member_bitfield_size(t, member))
- /* bitfields are not supported yet */
- continue;
+ if (off + size > t->size) {
+ bpf_log(log, "access beyond struct %s at off %u size %u\n",
+ tname, off, size);
+ return -EACCES;
+ }
+ for_each_member(i, t, member) {
/* offset of the field in bytes */
moff = btf_member_bit_offset(t, member) / 8;
if (off + size <= moff)
/* won't find anything, field is already too far */
break;
+
+ if (btf_member_bitfield_size(t, member)) {
+ u32 end_bit = btf_member_bit_offset(t, member) +
+ btf_member_bitfield_size(t, member);
+
+ /* off <= moff instead of off == moff because clang
+ * does not generate a BTF member for anonymous
+ * bitfield like the ":16" here:
+ * struct {
+ * int :16;
+ * int x:8;
+ * };
+ */
+ if (off <= moff &&
+ BITS_ROUNDUP_BYTES(end_bit) <= off + size)
+ return SCALAR_VALUE;
+
+ /* off may be accessing a following member
+ *
+ * or
+ *
+ * Doing partial access at either end of this
+ * bitfield. Continue on this case also to
+ * treat it as not accessing this bitfield
+ * and eventually error out as field not
+ * found to keep it simple.
+ * It could be relaxed if there was a legit
+ * partial access case later.
+ */
+ continue;
+ }
+
/* In case of "off" is pointing to holes of a struct */
if (off < moff)
- continue;
+ break;
/* type of the field */
mtype = btf_type_by_id(btf_vmlinux, member->type);
@@ -4043,11 +4136,158 @@ int btf_distill_func_proto(struct bpf_verifier_log *log,
return 0;
}
-int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog)
+/* Compare BTFs of two functions assuming only scalars and pointers to context.
+ * t1 points to BTF_KIND_FUNC in btf1
+ * t2 points to BTF_KIND_FUNC in btf2
+ * Returns:
+ * EINVAL - function prototype mismatch
+ * EFAULT - verifier bug
+ * 0 - 99% match. The last 1% is validated by the verifier.
+ */
+int btf_check_func_type_match(struct bpf_verifier_log *log,
+ struct btf *btf1, const struct btf_type *t1,
+ struct btf *btf2, const struct btf_type *t2)
+{
+ const struct btf_param *args1, *args2;
+ const char *fn1, *fn2, *s1, *s2;
+ u32 nargs1, nargs2, i;
+
+ fn1 = btf_name_by_offset(btf1, t1->name_off);
+ fn2 = btf_name_by_offset(btf2, t2->name_off);
+
+ if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) {
+ bpf_log(log, "%s() is not a global function\n", fn1);
+ return -EINVAL;
+ }
+ if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) {
+ bpf_log(log, "%s() is not a global function\n", fn2);
+ return -EINVAL;
+ }
+
+ t1 = btf_type_by_id(btf1, t1->type);
+ if (!t1 || !btf_type_is_func_proto(t1))
+ return -EFAULT;
+ t2 = btf_type_by_id(btf2, t2->type);
+ if (!t2 || !btf_type_is_func_proto(t2))
+ return -EFAULT;
+
+ args1 = (const struct btf_param *)(t1 + 1);
+ nargs1 = btf_type_vlen(t1);
+ args2 = (const struct btf_param *)(t2 + 1);
+ nargs2 = btf_type_vlen(t2);
+
+ if (nargs1 != nargs2) {
+ bpf_log(log, "%s() has %d args while %s() has %d args\n",
+ fn1, nargs1, fn2, nargs2);
+ return -EINVAL;
+ }
+
+ t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
+ t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
+ if (t1->info != t2->info) {
+ bpf_log(log,
+ "Return type %s of %s() doesn't match type %s of %s()\n",
+ btf_type_str(t1), fn1,
+ btf_type_str(t2), fn2);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < nargs1; i++) {
+ t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL);
+ t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL);
+
+ if (t1->info != t2->info) {
+ bpf_log(log, "arg%d in %s() is %s while %s() has %s\n",
+ i, fn1, btf_type_str(t1),
+ fn2, btf_type_str(t2));
+ return -EINVAL;
+ }
+ if (btf_type_has_size(t1) && t1->size != t2->size) {
+ bpf_log(log,
+ "arg%d in %s() has size %d while %s() has %d\n",
+ i, fn1, t1->size,
+ fn2, t2->size);
+ return -EINVAL;
+ }
+
+ /* global functions are validated with scalars and pointers
+ * to context only. And only global functions can be replaced.
+ * Hence type check only those types.
+ */
+ if (btf_type_is_int(t1) || btf_type_is_enum(t1))
+ continue;
+ if (!btf_type_is_ptr(t1)) {
+ bpf_log(log,
+ "arg%d in %s() has unrecognized type\n",
+ i, fn1);
+ return -EINVAL;
+ }
+ t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
+ t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
+ if (!btf_type_is_struct(t1)) {
+ bpf_log(log,
+ "arg%d in %s() is not a pointer to context\n",
+ i, fn1);
+ return -EINVAL;
+ }
+ if (!btf_type_is_struct(t2)) {
+ bpf_log(log,
+ "arg%d in %s() is not a pointer to context\n",
+ i, fn2);
+ return -EINVAL;
+ }
+ /* This is an optional check to make program writing easier.
+ * Compare names of structs and report an error to the user.
+ * btf_prepare_func_args() already checked that t2 struct
+ * is a context type. btf_prepare_func_args() will check
+ * later that t1 struct is a context type as well.
+ */
+ s1 = btf_name_by_offset(btf1, t1->name_off);
+ s2 = btf_name_by_offset(btf2, t2->name_off);
+ if (strcmp(s1, s2)) {
+ bpf_log(log,
+ "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n",
+ i, fn1, s1, fn2, s2);
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+/* Compare BTFs of given program with BTF of target program */
+int btf_check_type_match(struct bpf_verifier_env *env, struct bpf_prog *prog,
+ struct btf *btf2, const struct btf_type *t2)
+{
+ struct btf *btf1 = prog->aux->btf;
+ const struct btf_type *t1;
+ u32 btf_id = 0;
+
+ if (!prog->aux->func_info) {
+ bpf_log(&env->log, "Program extension requires BTF\n");
+ return -EINVAL;
+ }
+
+ btf_id = prog->aux->func_info[0].type_id;
+ if (!btf_id)
+ return -EFAULT;
+
+ t1 = btf_type_by_id(btf1, btf_id);
+ if (!t1 || !btf_type_is_func(t1))
+ return -EFAULT;
+
+ return btf_check_func_type_match(&env->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 *reg)
{
- struct bpf_verifier_state *st = env->cur_state;
- struct bpf_func_state *func = st->frame[st->curframe];
- struct bpf_reg_state *reg = func->regs;
struct bpf_verifier_log *log = &env->log;
struct bpf_prog *prog = env->prog;
struct btf *btf = prog->aux->btf;
@@ -4057,27 +4297,30 @@ int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog)
const char *tname;
if (!prog->aux->func_info)
- return 0;
+ return -EINVAL;
btf_id = prog->aux->func_info[subprog].type_id;
if (!btf_id)
- return 0;
+ return -EFAULT;
if (prog->aux->func_info_aux[subprog].unreliable)
- return 0;
+ return -EINVAL;
t = btf_type_by_id(btf, btf_id);
if (!t || !btf_type_is_func(t)) {
- bpf_log(log, "BTF of subprog %d doesn't point to KIND_FUNC\n",
+ /* These checks were already done by the verifier while loading
+ * struct bpf_func_info
+ */
+ bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
subprog);
- return -EINVAL;
+ return -EFAULT;
}
tname = 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 type of func %s\n", tname);
- return -EINVAL;
+ bpf_log(log, "Invalid BTF of func %s\n", tname);
+ return -EFAULT;
}
args = (const struct btf_param *)(t + 1);
nargs = btf_type_vlen(t);
@@ -4103,25 +4346,130 @@ int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog)
bpf_log(log, "R%d is not a pointer\n", i + 1);
goto out;
}
- /* If program is passing PTR_TO_CTX into subprogram
- * check that BTF type matches.
+ /* If function expects ctx type in BTF check that caller
+ * is passing PTR_TO_CTX.
*/
- if (reg[i + 1].type == PTR_TO_CTX &&
- !btf_get_prog_ctx_type(log, btf, t, prog->type))
- goto out;
- /* All other pointers are ok */
- continue;
+ if (btf_get_prog_ctx_type(log, btf, t, prog->type, i)) {
+ if (reg[i + 1].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], i + 1))
+ goto out;
+ continue;
+ }
}
- bpf_log(log, "Unrecognized argument type %s\n",
- btf_kind_str[BTF_INFO_KIND(t->info)]);
+ bpf_log(log, "Unrecognized arg#%d type %s\n",
+ i, btf_kind_str[BTF_INFO_KIND(t->info)]);
goto out;
}
return 0;
out:
- /* LLVM optimizations can remove arguments from static functions. */
- bpf_log(log,
- "Type info disagrees with actual arguments due to compiler optimizations\n");
+ /* 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;
+}
+
+/* Convert BTF of a function into bpf_reg_state if possible
+ * Returns:
+ * EFAULT - there is a verifier bug. Abort verification.
+ * EINVAL - cannot convert BTF.
+ * 0 - Successfully converted BTF into bpf_reg_state
+ * (either PTR_TO_CTX or SCALAR_VALUE).
+ */
+int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
+ struct bpf_reg_state *reg)
+{
+ struct bpf_verifier_log *log = &env->log;
+ struct bpf_prog *prog = env->prog;
+ enum bpf_prog_type prog_type = prog->type;
+ struct btf *btf = prog->aux->btf;
+ const struct btf_param *args;
+ const struct btf_type *t;
+ u32 i, nargs, btf_id;
+ const char *tname;
+
+ if (!prog->aux->func_info ||
+ prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) {
+ bpf_log(log, "Verifier bug\n");
+ return -EFAULT;
+ }
+
+ btf_id = prog->aux->func_info[subprog].type_id;
+ if (!btf_id) {
+ bpf_log(log, "Global functions need valid BTF\n");
+ return -EFAULT;
+ }
+
+ t = btf_type_by_id(btf, btf_id);
+ if (!t || !btf_type_is_func(t)) {
+ /* These checks were already done by the verifier while loading
+ * struct bpf_func_info
+ */
+ bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
+ subprog);
+ return -EFAULT;
+ }
+ tname = btf_name_by_offset(btf, t->name_off);
+
+ if (log->level & BPF_LOG_LEVEL)
+ bpf_log(log, "Validating %s() func#%d...\n",
+ tname, subprog);
+
+ if (prog->aux->func_info_aux[subprog].unreliable) {
+ bpf_log(log, "Verifier bug in function %s()\n", tname);
+ return -EFAULT;
+ }
+ if (prog_type == BPF_PROG_TYPE_EXT)
+ prog_type = prog->aux->linked_prog->type;
+
+ t = btf_type_by_id(btf, t->type);
+ if (!t || !btf_type_is_func_proto(t)) {
+ bpf_log(log, "Invalid type of function %s()\n", tname);
+ return -EFAULT;
+ }
+ 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);
+ return -EINVAL;
+ }
+ /* check that function returns int */
+ t = btf_type_by_id(btf, t->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)) {
+ bpf_log(log,
+ "Global function %s() doesn't return scalar. Only those are supported.\n",
+ tname);
+ return -EINVAL;
+ }
+ /* Convert BTF function arguments into verifier types.
+ * Only PTR_TO_CTX and SCALAR are supported atm.
+ */
+ for (i = 0; i < nargs; i++) {
+ 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)) {
+ reg[i + 1].type = SCALAR_VALUE;
+ continue;
+ }
+ if (btf_type_is_ptr(t) &&
+ btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
+ reg[i + 1].type = PTR_TO_CTX;
+ continue;
+ }
+ bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
+ i, btf_kind_str[BTF_INFO_KIND(t->info)], tname);
+ return -EINVAL;
+ }
return 0;
}