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-rw-r--r--kernel/bpf/btf.c107
1 files changed, 84 insertions, 23 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 84a36ee4a4c2..2efeb5f4b343 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -458,7 +458,7 @@ static bool btf_type_is_datasec(const struct btf_type *t)
return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
}
-static u32 btf_nr_types_total(const struct btf *btf)
+u32 btf_nr_types(const struct btf *btf)
{
u32 total = 0;
@@ -476,7 +476,7 @@ s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
const char *tname;
u32 i, total;
- total = btf_nr_types_total(btf);
+ total = btf_nr_types(btf);
for (i = 1; i < total; i++) {
t = btf_type_by_id(btf, i);
if (BTF_INFO_KIND(t->info) != kind)
@@ -3540,11 +3540,6 @@ static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
- if (!btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen == 0");
- return -EINVAL;
- }
-
if (!t->size) {
btf_verifier_log_type(env, t, "size == 0");
return -EINVAL;
@@ -5296,15 +5291,16 @@ int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *pr
* 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_reg_state *regs)
{
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 struct btf_type *t;
- u32 i, nargs, btf_id;
+ 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;
@@ -5338,38 +5334,57 @@ int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
bpf_log(log, "Function %s has %d > 5 args\n", tname, nargs);
goto out;
}
+
+ 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];
+
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)) {
- if (reg[i + 1].type == SCALAR_VALUE)
+ if (reg->type == SCALAR_VALUE)
continue;
bpf_log(log, "R%d is not a scalar\n", i + 1);
goto out;
}
if (btf_type_is_ptr(t)) {
- if (reg[i + 1].type == SCALAR_VALUE) {
- bpf_log(log, "R%d is not a pointer\n", i + 1);
- goto out;
- }
/* 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[i + 1].type != PTR_TO_CTX) {
+ 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], i + 1))
+ if (check_ctx_reg(env, reg, i + 1))
goto out;
continue;
}
+
+ 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)) {
+ 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;
+ }
+
+ if (check_mem_reg(env, reg, i + 1, type_size))
+ goto out;
+
+ continue;
}
bpf_log(log, "Unrecognized arg#%d type %s\n",
i, btf_kind_str[BTF_INFO_KIND(t->info)]);
@@ -5393,14 +5408,14 @@ out:
* (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_reg_state *regs)
{
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;
+ const struct btf_type *t, *ref_t;
u32 i, nargs, btf_id;
const char *tname;
@@ -5464,16 +5479,35 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
* Only PTR_TO_CTX and SCALAR are supported atm.
*/
for (i = 0; i < nargs; i++) {
+ struct bpf_reg_state *reg = &regs[i + 1];
+
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;
+ reg->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;
+ if (btf_type_is_ptr(t)) {
+ if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
+ reg->type = PTR_TO_CTX;
+ continue;
+ }
+
+ t = btf_type_skip_modifiers(btf, t->type, NULL);
+
+ ref_t = btf_resolve_size(btf, t, &reg->mem_size);
+ if (IS_ERR(ref_t)) {
+ 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));
+ return -EINVAL;
+ }
+
+ reg->type = PTR_TO_MEM_OR_NULL;
+ reg->id = ++env->id_gen;
+
continue;
}
bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
@@ -5743,6 +5777,11 @@ bool btf_is_kernel(const struct btf *btf)
return btf->kernel_btf;
}
+bool btf_is_module(const struct btf *btf)
+{
+ return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0;
+}
+
static int btf_id_cmp_func(const void *a, const void *b)
{
const int *pa = a, *pb = b;
@@ -5877,3 +5916,25 @@ static int __init btf_module_init(void)
fs_initcall(btf_module_init);
#endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
+
+struct module *btf_try_get_module(const struct btf *btf)
+{
+ struct module *res = NULL;
+#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
+ struct btf_module *btf_mod, *tmp;
+
+ mutex_lock(&btf_module_mutex);
+ list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
+ if (btf_mod->btf != btf)
+ continue;
+
+ if (try_module_get(btf_mod->module))
+ res = btf_mod->module;
+
+ break;
+ }
+ mutex_unlock(&btf_module_mutex);
+#endif
+
+ return res;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.