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-rw-r--r--kernel/bpf/btf.c219
-rw-r--r--kernel/bpf/core.c47
-rw-r--r--kernel/bpf/disasm.c13
-rw-r--r--kernel/bpf/helpers.c15
-rw-r--r--kernel/bpf/local_storage.c5
-rw-r--r--kernel/bpf/lpm_trie.c3
-rw-r--r--kernel/bpf/syscall.c5
-rw-r--r--kernel/bpf/verifier.c390
8 files changed, 546 insertions, 151 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 369faeddf1df..0600ed325fa0 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -283,7 +283,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
[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)];
}
@@ -789,7 +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);
}
@@ -4377,7 +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)
{
@@ -5362,122 +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 > MAX_BPF_FUNC_REG_ARGS) {
- bpf_log(log, "Function %s has %d > %d args\n", tname, nargs,
+ bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs,
MAX_BPF_FUNC_REG_ARGS);
- goto out;
+ 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
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 75244ecb2389..f5423251c118 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -143,25 +143,25 @@ int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
if (!prog->aux->nr_linfo || !prog->jit_requested)
return 0;
- prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo,
- sizeof(*prog->aux->jited_linfo),
- GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
+ prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
+ sizeof(*prog->aux->jited_linfo),
+ GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
if (!prog->aux->jited_linfo)
return -ENOMEM;
return 0;
}
-void bpf_prog_free_jited_linfo(struct bpf_prog *prog)
+void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
{
- kfree(prog->aux->jited_linfo);
- prog->aux->jited_linfo = NULL;
-}
+ if (prog->aux->jited_linfo &&
+ (!prog->jited || !prog->aux->jited_linfo[0])) {
+ kvfree(prog->aux->jited_linfo);
+ prog->aux->jited_linfo = NULL;
+ }
-void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog)
-{
- if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0])
- bpf_prog_free_jited_linfo(prog);
+ kfree(prog->aux->kfunc_tab);
+ prog->aux->kfunc_tab = NULL;
}
/* The jit engine is responsible to provide an array
@@ -217,12 +217,6 @@ void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
}
-void bpf_prog_free_linfo(struct bpf_prog *prog)
-{
- bpf_prog_free_jited_linfo(prog);
- kvfree(prog->aux->linfo);
-}
-
struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
gfp_t gfp_extra_flags)
{
@@ -1849,9 +1843,15 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
/* In case of BPF to BPF calls, verifier did all the prep
* work with regards to JITing, etc.
*/
+ bool jit_needed = false;
+
if (fp->bpf_func)
goto finalize;
+ if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
+ bpf_prog_has_kfunc_call(fp))
+ jit_needed = true;
+
bpf_prog_select_func(fp);
/* eBPF JITs can rewrite the program in case constant
@@ -1866,14 +1866,10 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
return fp;
fp = bpf_int_jit_compile(fp);
- if (!fp->jited) {
- bpf_prog_free_jited_linfo(fp);
-#ifdef CONFIG_BPF_JIT_ALWAYS_ON
+ bpf_prog_jit_attempt_done(fp);
+ if (!fp->jited && jit_needed) {
*err = -ENOTSUPP;
return fp;
-#endif
- } else {
- bpf_prog_free_unused_jited_linfo(fp);
}
} else {
*err = bpf_prog_offload_compile(fp);
@@ -2354,6 +2350,11 @@ bool __weak bpf_jit_needs_zext(void)
return false;
}
+bool __weak bpf_jit_supports_kfunc_call(void)
+{
+ return false;
+}
+
/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
* skb_copy_bits(), so provide a weak definition of it for NET-less config.
*/
diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
index 3acc7e0b6916..dad821c8ecd0 100644
--- a/kernel/bpf/disasm.c
+++ b/kernel/bpf/disasm.c
@@ -19,16 +19,23 @@ static const char *__func_get_name(const struct bpf_insn_cbs *cbs,
{
BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID);
- if (insn->src_reg != BPF_PSEUDO_CALL &&
+ if (!insn->src_reg &&
insn->imm >= 0 && insn->imm < __BPF_FUNC_MAX_ID &&
func_id_str[insn->imm])
return func_id_str[insn->imm];
- if (cbs && cbs->cb_call)
- return cbs->cb_call(cbs->private_data, insn);
+ if (cbs && cbs->cb_call) {
+ const char *res;
+
+ res = cbs->cb_call(cbs->private_data, insn);
+ if (res)
+ return res;
+ }
if (insn->src_reg == BPF_PSEUDO_CALL)
snprintf(buff, len, "%+d", insn->imm);
+ else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL)
+ snprintf(buff, len, "kernel-function");
return buff;
}
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 074800226327..f306611c4ddf 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -382,8 +382,8 @@ const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = {
};
#ifdef CONFIG_CGROUP_BPF
-DECLARE_PER_CPU(struct bpf_cgroup_storage*,
- bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
+DECLARE_PER_CPU(struct bpf_cgroup_storage_info,
+ bpf_cgroup_storage_info[BPF_CGROUP_STORAGE_NEST_MAX]);
BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
{
@@ -392,10 +392,17 @@ BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
* verifier checks that its value is correct.
*/
enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
- struct bpf_cgroup_storage *storage;
+ struct bpf_cgroup_storage *storage = NULL;
void *ptr;
+ int i;
- storage = this_cpu_read(bpf_cgroup_storage[stype]);
+ for (i = 0; i < BPF_CGROUP_STORAGE_NEST_MAX; i++) {
+ if (unlikely(this_cpu_read(bpf_cgroup_storage_info[i].task) != current))
+ continue;
+
+ storage = this_cpu_read(bpf_cgroup_storage_info[i].storage[stype]);
+ break;
+ }
if (stype == BPF_CGROUP_STORAGE_SHARED)
ptr = &READ_ONCE(storage->buf)->data[0];
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index 2d4f9ac12377..bd11db9774c3 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -9,10 +9,11 @@
#include <linux/slab.h>
#include <uapi/linux/btf.h>
-DEFINE_PER_CPU(struct bpf_cgroup_storage*, bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
-
#ifdef CONFIG_CGROUP_BPF
+DEFINE_PER_CPU(struct bpf_cgroup_storage_info,
+ bpf_cgroup_storage_info[BPF_CGROUP_STORAGE_NEST_MAX]);
+
#include "../cgroup/cgroup-internal.h"
#define LOCAL_STORAGE_CREATE_FLAG_MASK \
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index cec792a17e5f..1b7b8a6f34ee 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -726,6 +726,9 @@ const struct bpf_map_ops trie_map_ops = {
.map_lookup_elem = trie_lookup_elem,
.map_update_elem = trie_update_elem,
.map_delete_elem = trie_delete_elem,
+ .map_lookup_batch = generic_map_lookup_batch,
+ .map_update_batch = generic_map_update_batch,
+ .map_delete_batch = generic_map_delete_batch,
.map_check_btf = trie_check_btf,
.map_btf_name = "lpm_trie",
.map_btf_id = &trie_map_btf_id,
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 250503482cda..6428634da57e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1694,7 +1694,9 @@ static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
{
bpf_prog_kallsyms_del_all(prog);
btf_put(prog->aux->btf);
- bpf_prog_free_linfo(prog);
+ kvfree(prog->aux->jited_linfo);
+ kvfree(prog->aux->linfo);
+ kfree(prog->aux->kfunc_tab);
if (prog->aux->attach_btf)
btf_put(prog->aux->attach_btf);
@@ -2946,6 +2948,7 @@ attach_type_to_prog_type(enum bpf_attach_type attach_type)
return BPF_PROG_TYPE_SK_MSG;
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
+ case BPF_SK_SKB_VERDICT:
return BPF_PROG_TYPE_SK_SKB;
case BPF_LIRC_MODE2:
return BPF_PROG_TYPE_LIRC_MODE2;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 210169c25ead..852541a435ef 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -234,6 +234,12 @@ static bool bpf_pseudo_call(const struct bpf_insn *insn)
insn->src_reg == BPF_PSEUDO_CALL;
}
+static bool bpf_pseudo_kfunc_call(const struct bpf_insn *insn)
+{
+ return insn->code == (BPF_JMP | BPF_CALL) &&
+ insn->src_reg == BPF_PSEUDO_KFUNC_CALL;
+}
+
static bool bpf_pseudo_func(const struct bpf_insn *insn)
{
return insn->code == (BPF_LD | BPF_IMM | BPF_DW) &&
@@ -1554,47 +1560,205 @@ static int add_subprog(struct bpf_verifier_env *env, int off)
verbose(env, "too many subprograms\n");
return -E2BIG;
}
+ /* determine subprog starts. The end is one before the next starts */
env->subprog_info[env->subprog_cnt++].start = off;
sort(env->subprog_info, env->subprog_cnt,
sizeof(env->subprog_info[0]), cmp_subprogs, NULL);
return env->subprog_cnt - 1;
}
-static int check_subprogs(struct bpf_verifier_env *env)
+struct bpf_kfunc_desc {
+ struct btf_func_model func_model;
+ u32 func_id;
+ s32 imm;
+};
+
+#define MAX_KFUNC_DESCS 256
+struct bpf_kfunc_desc_tab {
+ struct bpf_kfunc_desc descs[MAX_KFUNC_DESCS];
+ u32 nr_descs;
+};
+
+static int kfunc_desc_cmp_by_id(const void *a, const void *b)
+{
+ const struct bpf_kfunc_desc *d0 = a;
+ const struct bpf_kfunc_desc *d1 = b;
+
+ /* func_id is not greater than BTF_MAX_TYPE */
+ return d0->func_id - d1->func_id;
+}
+
+static const struct bpf_kfunc_desc *
+find_kfunc_desc(const struct bpf_prog *prog, u32 func_id)
+{
+ struct bpf_kfunc_desc desc = {
+ .func_id = func_id,
+ };
+ struct bpf_kfunc_desc_tab *tab;
+
+ tab = prog->aux->kfunc_tab;
+ return bsearch(&desc, tab->descs, tab->nr_descs,
+ sizeof(tab->descs[0]), kfunc_desc_cmp_by_id);
+}
+
+static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id)
+{
+ const struct btf_type *func, *func_proto;
+ struct bpf_kfunc_desc_tab *tab;
+ struct bpf_prog_aux *prog_aux;
+ struct bpf_kfunc_desc *desc;
+ const char *func_name;
+ unsigned long addr;
+ int err;
+
+ prog_aux = env->prog->aux;
+ tab = prog_aux->kfunc_tab;
+ if (!tab) {
+ if (!btf_vmlinux) {
+ verbose(env, "calling kernel function is not supported without CONFIG_DEBUG_INFO_BTF\n");
+ return -ENOTSUPP;
+ }
+
+ if (!env->prog->jit_requested) {
+ verbose(env, "JIT is required for calling kernel function\n");
+ return -ENOTSUPP;
+ }
+
+ if (!bpf_jit_supports_kfunc_call()) {
+ verbose(env, "JIT does not support calling kernel function\n");
+ return -ENOTSUPP;
+ }
+
+ if (!env->prog->gpl_compatible) {
+ verbose(env, "cannot call kernel function from non-GPL compatible program\n");
+ return -EINVAL;
+ }
+
+ tab = kzalloc(sizeof(*tab), GFP_KERNEL);
+ if (!tab)
+ return -ENOMEM;
+ prog_aux->kfunc_tab = tab;
+ }
+
+ if (find_kfunc_desc(env->prog, func_id))
+ return 0;
+
+ if (tab->nr_descs == MAX_KFUNC_DESCS) {
+ verbose(env, "too many different kernel function calls\n");
+ return -E2BIG;
+ }
+
+ func = btf_type_by_id(btf_vmlinux, func_id);
+ if (!func || !btf_type_is_func(func)) {
+ verbose(env, "kernel btf_id %u is not a function\n",
+ func_id);
+ return -EINVAL;
+ }
+ func_proto = btf_type_by_id(btf_vmlinux, func->type);
+ if (!func_proto || !btf_type_is_func_proto(func_proto)) {
+ verbose(env, "kernel function btf_id %u does not have a valid func_proto\n",
+ func_id);
+ return -EINVAL;
+ }
+
+ func_name = btf_name_by_offset(btf_vmlinux, func->name_off);
+ addr = kallsyms_lookup_name(func_name);
+ if (!addr) {
+ verbose(env, "cannot find address for kernel function %s\n",
+ func_name);
+ return -EINVAL;
+ }
+
+ desc = &tab->descs[tab->nr_descs++];
+ desc->func_id = func_id;
+ desc->imm = BPF_CAST_CALL(addr) - __bpf_call_base;
+ err = btf_distill_func_proto(&env->log, btf_vmlinux,
+ func_proto, func_name,
+ &desc->func_model);
+ if (!err)
+ sort(tab->descs, tab->nr_descs, sizeof(tab->descs[0]),
+ kfunc_desc_cmp_by_id, NULL);
+ return err;
+}
+
+static int kfunc_desc_cmp_by_imm(const void *a, const void *b)
+{
+ const struct bpf_kfunc_desc *d0 = a;
+ const struct bpf_kfunc_desc *d1 = b;
+
+ if (d0->imm > d1->imm)
+ return 1;
+ else if (d0->imm < d1->imm)
+ return -1;
+ return 0;
+}
+
+static void sort_kfunc_descs_by_imm(struct bpf_prog *prog)
+{
+ struct bpf_kfunc_desc_tab *tab;
+
+ tab = prog->aux->kfunc_tab;
+ if (!tab)
+ return;
+
+ sort(tab->descs, tab->nr_descs, sizeof(tab->descs[0]),
+ kfunc_desc_cmp_by_imm, NULL);
+}
+
+bool bpf_prog_has_kfunc_call(const struct bpf_prog *prog)
+{
+ return !!prog->aux->kfunc_tab;
+}
+
+const struct btf_func_model *
+bpf_jit_find_kfunc_model(const struct bpf_prog *prog,
+ const struct bpf_insn *insn)
+{
+ const struct bpf_kfunc_desc desc = {
+ .imm = insn->imm,
+ };
+ const struct bpf_kfunc_desc *res;
+ struct bpf_kfunc_desc_tab *tab;
+
+ tab = prog->aux->kfunc_tab;
+ res = bsearch(&desc, tab->descs, tab->nr_descs,
+ sizeof(tab->descs[0]), kfunc_desc_cmp_by_imm);
+
+ return res ? &res->func_model : NULL;
+}
+
+static int add_subprog_and_kfunc(struct bpf_verifier_env *env)
{
- int i, ret, subprog_start, subprog_end, off, cur_subprog = 0;
struct bpf_subprog_info *subprog = env->subprog_info;
struct bpf_insn *insn = env->prog->insnsi;
- int insn_cnt = env->prog->len;
+ int i, ret, insn_cnt = env->prog->len;
/* Add entry function. */
ret = add_subprog(env, 0);
- if (ret < 0)
+ if (ret)
return ret;
- /* determine subprog starts. The end is one before the next starts */
- for (i = 0; i < insn_cnt; i++) {
- if (bpf_pseudo_func(insn + i)) {
- if (!env->bpf_capable) {
- verbose(env,
- "function pointers are allowed for CAP_BPF and CAP_SYS_ADMIN\n");
- return -EPERM;
- }
- ret = add_subprog(env, i + insn[i].imm + 1);
- if (ret < 0)
- return ret;
- /* remember subprog */
- insn[i + 1].imm = ret;
- continue;
- }
- if (!bpf_pseudo_call(insn + i))
+ for (i = 0; i < insn_cnt; i++, insn++) {
+ if (!bpf_pseudo_func(insn) && !bpf_pseudo_call(insn) &&
+ !bpf_pseudo_kfunc_call(insn))
continue;
+
if (!env->bpf_capable) {
- verbose(env,
- "function calls to other bpf functions are allowed for CAP_BPF and CAP_SYS_ADMIN\n");
+ verbose(env, "loading/calling other bpf or kernel functions are allowed for CAP_BPF and CAP_SYS_ADMIN\n");
return -EPERM;
}
- ret = add_subprog(env, i + insn[i].imm + 1);
+
+ if (bpf_pseudo_func(insn)) {
+ ret = add_subprog(env, i + insn->imm + 1);
+ if (ret >= 0)
+ /* remember subprog */
+ insn[1].imm = ret;
+ } else if (bpf_pseudo_call(insn)) {
+ ret = add_subprog(env, i + insn->imm + 1);
+ } else {
+ ret = add_kfunc_call(env, insn->imm);
+ }
+
if (ret < 0)
return ret;
}
@@ -1608,6 +1772,16 @@ static int check_subprogs(struct bpf_verifier_env *env)
for (i = 0; i < env->subprog_cnt; i++)
verbose(env, "func#%d @%d\n", i, subprog[i].start);
+ return 0;
+}
+
+static int check_subprogs(struct bpf_verifier_env *env)
+{
+ int i, subprog_start, subprog_end, off, cur_subprog = 0;
+ struct bpf_subprog_info *subprog = env->subprog_info;
+ struct bpf_insn *insn = env->prog->insnsi;
+ int insn_cnt = env->prog->len;
+
/* now check that all jumps are within the same subprog */
subprog_start = subprog[cur_subprog].start;
subprog_end = subprog[cur_subprog + 1].start;
@@ -1916,6 +2090,17 @@ static int get_prev_insn_idx(struct bpf_verifier_state *st, int i,
return i;
}
+static const char *disasm_kfunc_name(void *data, const struct bpf_insn *insn)
+{
+ const struct btf_type *func;
+
+ if (insn->src_reg != BPF_PSEUDO_KFUNC_CALL)
+ return NULL;
+
+ func = btf_type_by_id(btf_vmlinux, insn->imm);
+ return btf_name_by_offset(btf_vmlinux, func->name_off);
+}
+
/* For given verifier state backtrack_insn() is called from the last insn to
* the first insn. Its purpose is to compute a bitmask of registers and
* stack slots that needs precision in the parent verifier state.
@@ -1924,6 +2109,7 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx,
u32 *reg_mask, u64 *stack_mask)
{
const struct bpf_insn_cbs cbs = {
+ .cb_call = disasm_kfunc_name,
.cb_print = verbose,
.private_data = env,
};
@@ -5365,7 +5551,7 @@ static int __check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn
func_info_aux = env->prog->aux->func_info_aux;
if (func_info_aux)
is_global = func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
- err = btf_check_func_arg_match(env, subprog, caller->regs);
+ err = btf_check_subprog_arg_match(env, subprog, caller->regs);
if (err == -EFAULT)
return err;
if (is_global) {
@@ -5960,6 +6146,98 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
return 0;
}
+/* mark_btf_func_reg_size() is used when the reg size is determined by
+ * the BTF func_proto's return value size and argument.
+ */
+static void mark_btf_func_reg_size(struct bpf_verifier_env *env, u32 regno,
+ size_t reg_size)
+{
+ struct bpf_reg_state *reg = &cur_regs(env)[regno];
+
+ if (regno == BPF_REG_0) {
+ /* Function return value */
+ reg->live |= REG_LIVE_WRITTEN;
+ reg->subreg_def = reg_size == sizeof(u64) ?
+ DEF_NOT_SUBREG : env->insn_idx + 1;
+ } else {
+ /* Function argument */
+ if (reg_size == sizeof(u64)) {
+ mark_insn_zext(env, reg);
+ mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
+ } else {
+ mark_reg_read(env, reg, reg->parent, REG_LIVE_READ32);
+ }
+ }
+}
+
+static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn)
+{
+ const struct btf_type *t, *func, *func_proto, *ptr_type;
+ struct bpf_reg_state *regs = cur_regs(env);
+ const char *func_name, *ptr_type_name;
+ u32 i, nargs, func_id, ptr_type_id;
+ const struct btf_param *args;
+ int err;
+
+ func_id = insn->imm;
+ func = btf_type_by_id(btf_vmlinux, func_id);
+ func_name = btf_name_by_offset(btf_vmlinux, func->name_off);
+ func_proto = btf_type_by_id(btf_vmlinux, func->type);
+
+ if (!env->ops->check_kfunc_call ||
+ !env->ops->check_kfunc_call(func_id)) {
+ verbose(env, "calling kernel function %s is not allowed\n",
+ func_name);
+ return -EACCES;
+ }
+
+ /* Check the arguments */
+ err = btf_check_kfunc_arg_match(env, btf_vmlinux, func_id, regs);
+ if (err)
+ return err;
+
+ for (i = 0; i < CALLER_SAVED_REGS; i++)
+ mark_reg_not_init(env, regs, caller_saved[i]);
+
+ /* Check return type */
+ t = btf_type_skip_modifiers(btf_vmlinux, func_proto->type, NULL);
+ if (btf_type_is_scalar(t)) {
+ mark_reg_unknown(env, regs, BPF_REG_0);
+ mark_btf_func_reg_size(env, BPF_REG_0, t->size);
+ } else if (btf_type_is_ptr(t)) {
+ ptr_type = btf_type_skip_modifiers(btf_vmlinux, t->type,
+ &ptr_type_id);
+ if (!btf_type_is_struct(ptr_type)) {
+ ptr_type_name = btf_name_by_offset(btf_vmlinux,
+ ptr_type->name_off);
+ verbose(env, "kernel function %s returns pointer type %s %s is not supported\n",
+ func_name, btf_type_str(ptr_type),
+ ptr_type_name);
+ return -EINVAL;
+ }
+ mark_reg_known_zero(env, regs, BPF_REG_0);
+ regs[BPF_REG_0].btf = btf_vmlinux;
+ regs[BPF_REG_0].type = PTR_TO_BTF_ID;
+ regs[BPF_REG_0].btf_id = ptr_type_id;
+ mark_btf_func_reg_size(env, BPF_REG_0, sizeof(void *));
+ } /* else { add_kfunc_call() ensures it is btf_type_is_void(t) } */
+
+ nargs = btf_type_vlen(func_proto);
+ args = (const struct btf_param *)(func_proto + 1);
+ for (i = 0; i < nargs; i++) {
+ u32 regno = i + 1;
+
+ t = btf_type_skip_modifiers(btf_vmlinux, args[i].type, NULL);
+ if (btf_type_is_ptr(t))
+ mark_btf_func_reg_size(env, regno, sizeof(void *));
+ else
+ /* scalar. ensured by btf_check_kfunc_arg_match() */
+ mark_btf_func_reg_size(env, regno, t->size);
+ }
+
+ return 0;
+}
+
static bool signed_add_overflows(s64 a, s64 b)
{
/* Do the add in u64, where overflow is well-defined */
@@ -6062,19 +6340,6 @@ static int retrieve_ptr_limit(const struct bpf_reg_state *ptr_reg,
else
*ptr_limit = -off - 1;
return *ptr_limit >= max ? -ERANGE : 0;
- case PTR_TO_MAP_KEY:
- /* Currently, this code is not exercised as the only use
- * is bpf_for_each_map_elem() helper which requires
- * bpf_capble. The code has been tested manually for
- * future use.
- */
- if (mask_to_left) {
- *ptr_limit = ptr_reg->umax_value + ptr_reg->off;
- } else {
- off = ptr_reg->smin_value + ptr_reg->off;
- *ptr_limit = ptr_reg->map_ptr->key_size - off;
- }
- return 0;
case PTR_TO_MAP_VALUE:
max = ptr_reg->map_ptr->value_size;
if (mask_to_left) {
@@ -6281,7 +6546,6 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
verbose(env, "R%d pointer arithmetic on %s prohibited\n",
dst, reg_type_str[ptr_reg->type]);
return -EACCES;
- case PTR_TO_MAP_KEY:
case PTR_TO_MAP_VALUE:
if (!env->allow_ptr_leaks && !known && (smin_val < 0) != (smax_val < 0)) {
verbose(env, "R%d has unknown scalar with mixed signed bounds, pointer arithmetic with it prohibited for !root\n",
@@ -10176,6 +10440,7 @@ static int do_check(struct bpf_verifier_env *env)
if (env->log.level & BPF_LOG_LEVEL) {
const struct bpf_insn_cbs cbs = {
+ .cb_call = disasm_kfunc_name,
.cb_print = verbose,
.private_data = env,
};
@@ -10323,7 +10588,8 @@ static int do_check(struct bpf_verifier_env *env)
if (BPF_SRC(insn->code) != BPF_K ||
insn->off != 0 ||
(insn->src_reg != BPF_REG_0 &&
- insn->src_reg != BPF_PSEUDO_CALL) ||
+ insn->src_reg != BPF_PSEUDO_CALL &&
+ insn->src_reg != BPF_PSEUDO_KFUNC_CALL) ||
insn->dst_reg != BPF_REG_0 ||
class == BPF_JMP32) {
verbose(env, "BPF_CALL uses reserved fields\n");
@@ -10338,6 +10604,8 @@ static int do_check(struct bpf_verifier_env *env)
}
if (insn->src_reg == BPF_PSEUDO_CALL)
err = check_func_call(env, insn, &env->insn_idx);
+ else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL)
+ err = check_kfunc_call(env, insn);
else
err = check_helper_call(env, insn, &env->insn_idx);
if (err)
@@ -11648,6 +11916,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
func[i]->aux->name[0] = 'F';
func[i]->aux->stack_depth = env->subprog_info[i].stack_depth;
func[i]->jit_requested = 1;
+ func[i]->aux->kfunc_tab = prog->aux->kfunc_tab;
func[i]->aux->linfo = prog->aux->linfo;
func[i]->aux->nr_linfo = prog->aux->nr_linfo;
func[i]->aux->jited_linfo = prog->aux->jited_linfo;
@@ -11755,7 +12024,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
prog->bpf_func = func[0]->bpf_func;
prog->aux->func = func;
prog->aux->func_cnt = env->subprog_cnt;
- bpf_prog_free_unused_jited_linfo(prog);
+ bpf_prog_jit_attempt_done(prog);
return 0;
out_free:
for (i = 0; i < env->subprog_cnt; i++) {
@@ -11778,7 +12047,7 @@ out_undo_insn:
insn->off = 0;
insn->imm = env->insn_aux_data[i].call_imm;
}
- bpf_prog_free_jited_linfo(prog);
+ bpf_prog_jit_attempt_done(prog);
return err;
}
@@ -11787,6 +12056,7 @@ static int fixup_call_args(struct bpf_verifier_env *env)
#ifndef CONFIG_BPF_JIT_ALWAYS_ON
struct bpf_prog *prog = env->prog;
struct bpf_insn *insn = prog->insnsi;
+ bool has_kfunc_call = bpf_prog_has_kfunc_call(prog);
int i, depth;
#endif
int err = 0;
@@ -11800,6 +12070,10 @@ static int fixup_call_args(struct bpf_verifier_env *env)
return err;
}
#ifndef CONFIG_BPF_JIT_ALWAYS_ON
+ if (has_kfunc_call) {
+ verbose(env, "calling kernel functions are not allowed in non-JITed programs\n");
+ return -EINVAL;
+ }
if (env->subprog_cnt > 1 && env->prog->aux->tail_call_reachable) {
/* When JIT fails the progs with bpf2bpf calls and tail_calls
* have to be rejected, since interpreter doesn't support them yet.
@@ -11828,6 +12102,26 @@ static int fixup_call_args(struct bpf_verifier_env *env)
return err;
}
+static int fixup_kfunc_call(struct bpf_verifier_env *env,
+ struct bpf_insn *insn)
+{
+ const struct bpf_kfunc_desc *desc;
+
+ /* insn->imm has the btf func_id. Replace it with
+ * an address (relative to __bpf_base_call).
+ */
+ desc = find_kfunc_desc(env->prog, insn->imm);
+ if (!desc) {
+ verbose(env, "verifier internal error: kernel function descriptor not found for func_id %u\n",
+ insn->imm);
+ return -EFAULT;
+ }
+
+ insn->imm = desc->imm;
+
+ return 0;
+}
+
/* Do various post-verification rewrites in a single program pass.
* These rewrites simplify JIT and interpreter implementations.
*/
@@ -11963,6 +12257,12 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
continue;
if (insn->src_reg == BPF_PSEUDO_CALL)
continue;
+ if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) {
+ ret = fixup_kfunc_call(env, insn);
+ if (ret)
+ return ret;
+ continue;
+ }
if (insn->imm == BPF_FUNC_get_route_realm)
prog->dst_needed = 1;
@@ -12192,6 +12492,8 @@ patch_call_imm:
}
}
+ sort_kfunc_descs_by_imm(env->prog);
+
return 0;
}
@@ -12302,7 +12604,7 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog)
/* 1st arg to a function */
regs[BPF_REG_1].type = PTR_TO_CTX;
mark_reg_known_zero(env, regs, BPF_REG_1);
- ret = btf_check_func_arg_match(env, subprog, regs);
+ ret = btf_check_subprog_arg_match(env, subprog, regs);
if (ret == -EFAULT)
/* unlikely verifier bug. abort.
* ret == 0 and ret < 0 are sadly acceptable for
@@ -12897,6 +13199,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
if (!env->explored_states)
goto skip_full_check;
+ ret = add_subprog_and_kfunc(env);
+ if (ret < 0)
+ goto skip_full_check;
+
ret = check_subprogs(env);
if (ret < 0)
goto skip_full_check;
generated by cgit (git 2.34.1) at 2025-04-23 07:44:34 +0000