bpf: Introduce BPF_PROG_TYPE_STRUCT_OPS
This patch allows the kernel's struct ops (i.e. func ptr) to be implemented in BPF. The first use case in this series is the "struct tcp_congestion_ops" which will be introduced in a latter patch. This patch introduces a new prog type BPF_PROG_TYPE_STRUCT_OPS. The BPF_PROG_TYPE_STRUCT_OPS prog is verified against a particular func ptr of a kernel struct. The attr->attach_btf_id is the btf id of a kernel struct. The attr->expected_attach_type is the member "index" of that kernel struct. The first member of a struct starts with member index 0. That will avoid ambiguity when a kernel struct has multiple func ptrs with the same func signature. For example, a BPF_PROG_TYPE_STRUCT_OPS prog is written to implement the "init" func ptr of the "struct tcp_congestion_ops". The attr->attach_btf_id is the btf id of the "struct tcp_congestion_ops" of the _running_ kernel. The attr->expected_attach_type is 3. The ctx of BPF_PROG_TYPE_STRUCT_OPS is an array of u64 args saved by arch_prepare_bpf_trampoline that will be done in the next patch when introducing BPF_MAP_TYPE_STRUCT_OPS. "struct bpf_struct_ops" is introduced as a common interface for the kernel struct that supports BPF_PROG_TYPE_STRUCT_OPS prog. The supporting kernel struct will need to implement an instance of the "struct bpf_struct_ops". The supporting kernel struct also needs to implement a bpf_verifier_ops. During BPF_PROG_LOAD, bpf_struct_ops_find() will find the right bpf_verifier_ops by searching the attr->attach_btf_id. A new "btf_struct_access" is also added to the bpf_verifier_ops such that the supporting kernel struct can optionally provide its own specific check on accessing the func arg (e.g. provide limited write access). After btf_vmlinux is parsed, the new bpf_struct_ops_init() is called to initialize some values (e.g. the btf id of the supporting kernel struct) and it can only be done once the btf_vmlinux is available. The R0 checks at BPF_EXIT is excluded for the BPF_PROG_TYPE_STRUCT_OPS prog if the return type of the prog->aux->attach_func_proto is "void". Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200109003503.3855825-1-kafai@fb.com
This commit is contained in:
parent
976aba002f
commit
27ae7997a6
|
@ -349,6 +349,10 @@ struct bpf_verifier_ops {
|
|||
const struct bpf_insn *src,
|
||||
struct bpf_insn *dst,
|
||||
struct bpf_prog *prog, u32 *target_size);
|
||||
int (*btf_struct_access)(struct bpf_verifier_log *log,
|
||||
const struct btf_type *t, int off, int size,
|
||||
enum bpf_access_type atype,
|
||||
u32 *next_btf_id);
|
||||
};
|
||||
|
||||
struct bpf_prog_offload_ops {
|
||||
|
@ -668,6 +672,32 @@ struct bpf_array_aux {
|
|||
struct work_struct work;
|
||||
};
|
||||
|
||||
struct btf_type;
|
||||
struct btf_member;
|
||||
|
||||
#define BPF_STRUCT_OPS_MAX_NR_MEMBERS 64
|
||||
struct bpf_struct_ops {
|
||||
const struct bpf_verifier_ops *verifier_ops;
|
||||
int (*init)(struct btf *btf);
|
||||
int (*check_member)(const struct btf_type *t,
|
||||
const struct btf_member *member);
|
||||
const struct btf_type *type;
|
||||
const char *name;
|
||||
struct btf_func_model func_models[BPF_STRUCT_OPS_MAX_NR_MEMBERS];
|
||||
u32 type_id;
|
||||
};
|
||||
|
||||
#if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL)
|
||||
const struct bpf_struct_ops *bpf_struct_ops_find(u32 type_id);
|
||||
void bpf_struct_ops_init(struct btf *btf);
|
||||
#else
|
||||
static inline const struct bpf_struct_ops *bpf_struct_ops_find(u32 type_id)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
static inline void bpf_struct_ops_init(struct btf *btf) { }
|
||||
#endif
|
||||
|
||||
struct bpf_array {
|
||||
struct bpf_map map;
|
||||
u32 elem_size;
|
||||
|
|
|
@ -65,6 +65,10 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_LIRC_MODE2, lirc_mode2,
|
|||
BPF_PROG_TYPE(BPF_PROG_TYPE_SK_REUSEPORT, sk_reuseport,
|
||||
struct sk_reuseport_md, struct sk_reuseport_kern)
|
||||
#endif
|
||||
#if defined(CONFIG_BPF_JIT)
|
||||
BPF_PROG_TYPE(BPF_PROG_TYPE_STRUCT_OPS, bpf_struct_ops,
|
||||
void *, void *)
|
||||
#endif
|
||||
|
||||
BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY, array_map_ops)
|
||||
BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_ARRAY, percpu_array_map_ops)
|
||||
|
|
|
@ -53,6 +53,18 @@ bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
|
|||
u32 expected_offset, u32 expected_size);
|
||||
int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
|
||||
bool btf_type_is_void(const struct btf_type *t);
|
||||
s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
|
||||
const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
|
||||
u32 id, u32 *res_id);
|
||||
const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
|
||||
u32 id, u32 *res_id);
|
||||
const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
|
||||
u32 id, u32 *res_id);
|
||||
|
||||
#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++)
|
||||
|
||||
static inline bool btf_type_is_ptr(const struct btf_type *t)
|
||||
{
|
||||
|
@ -84,6 +96,28 @@ static inline bool btf_type_is_func_proto(const struct btf_type *t)
|
|||
return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
|
||||
}
|
||||
|
||||
static inline u16 btf_type_vlen(const struct btf_type *t)
|
||||
{
|
||||
return BTF_INFO_VLEN(t->info);
|
||||
}
|
||||
|
||||
static inline bool btf_type_kflag(const struct btf_type *t)
|
||||
{
|
||||
return BTF_INFO_KFLAG(t->info);
|
||||
}
|
||||
|
||||
static inline 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 inline const struct btf_member *btf_type_member(const struct btf_type *t)
|
||||
{
|
||||
return (const struct btf_member *)(t + 1);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_BPF_SYSCALL
|
||||
const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
|
||||
const char *btf_name_by_offset(const struct btf *btf, u32 offset);
|
||||
|
|
|
@ -174,6 +174,7 @@ enum bpf_prog_type {
|
|||
BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
|
||||
BPF_PROG_TYPE_CGROUP_SOCKOPT,
|
||||
BPF_PROG_TYPE_TRACING,
|
||||
BPF_PROG_TYPE_STRUCT_OPS,
|
||||
};
|
||||
|
||||
enum bpf_attach_type {
|
||||
|
|
|
@ -27,3 +27,6 @@ endif
|
|||
ifeq ($(CONFIG_SYSFS),y)
|
||||
obj-$(CONFIG_DEBUG_INFO_BTF) += sysfs_btf.o
|
||||
endif
|
||||
ifeq ($(CONFIG_BPF_JIT),y)
|
||||
obj-$(CONFIG_BPF_SYSCALL) += bpf_struct_ops.o
|
||||
endif
|
||||
|
|
|
@ -0,0 +1,121 @@
|
|||
// SPDX-License-Identifier: GPL-2.0-only
|
||||
/* Copyright (c) 2019 Facebook */
|
||||
|
||||
#include <linux/bpf.h>
|
||||
#include <linux/bpf_verifier.h>
|
||||
#include <linux/btf.h>
|
||||
#include <linux/filter.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/numa.h>
|
||||
#include <linux/seq_file.h>
|
||||
#include <linux/refcount.h>
|
||||
|
||||
#define BPF_STRUCT_OPS_TYPE(_name) \
|
||||
extern struct bpf_struct_ops bpf_##_name;
|
||||
#include "bpf_struct_ops_types.h"
|
||||
#undef BPF_STRUCT_OPS_TYPE
|
||||
|
||||
enum {
|
||||
#define BPF_STRUCT_OPS_TYPE(_name) BPF_STRUCT_OPS_TYPE_##_name,
|
||||
#include "bpf_struct_ops_types.h"
|
||||
#undef BPF_STRUCT_OPS_TYPE
|
||||
__NR_BPF_STRUCT_OPS_TYPE,
|
||||
};
|
||||
|
||||
static struct bpf_struct_ops * const bpf_struct_ops[] = {
|
||||
#define BPF_STRUCT_OPS_TYPE(_name) \
|
||||
[BPF_STRUCT_OPS_TYPE_##_name] = &bpf_##_name,
|
||||
#include "bpf_struct_ops_types.h"
|
||||
#undef BPF_STRUCT_OPS_TYPE
|
||||
};
|
||||
|
||||
const struct bpf_verifier_ops bpf_struct_ops_verifier_ops = {
|
||||
};
|
||||
|
||||
const struct bpf_prog_ops bpf_struct_ops_prog_ops = {
|
||||
};
|
||||
|
||||
void bpf_struct_ops_init(struct btf *btf)
|
||||
{
|
||||
const struct btf_member *member;
|
||||
struct bpf_struct_ops *st_ops;
|
||||
struct bpf_verifier_log log = {};
|
||||
const struct btf_type *t;
|
||||
const char *mname;
|
||||
s32 type_id;
|
||||
u32 i, j;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
|
||||
st_ops = bpf_struct_ops[i];
|
||||
|
||||
type_id = btf_find_by_name_kind(btf, st_ops->name,
|
||||
BTF_KIND_STRUCT);
|
||||
if (type_id < 0) {
|
||||
pr_warn("Cannot find struct %s in btf_vmlinux\n",
|
||||
st_ops->name);
|
||||
continue;
|
||||
}
|
||||
t = btf_type_by_id(btf, type_id);
|
||||
if (btf_type_vlen(t) > BPF_STRUCT_OPS_MAX_NR_MEMBERS) {
|
||||
pr_warn("Cannot support #%u members in struct %s\n",
|
||||
btf_type_vlen(t), st_ops->name);
|
||||
continue;
|
||||
}
|
||||
|
||||
for_each_member(j, t, member) {
|
||||
const struct btf_type *func_proto;
|
||||
|
||||
mname = btf_name_by_offset(btf, member->name_off);
|
||||
if (!*mname) {
|
||||
pr_warn("anon member in struct %s is not supported\n",
|
||||
st_ops->name);
|
||||
break;
|
||||
}
|
||||
|
||||
if (btf_member_bitfield_size(t, member)) {
|
||||
pr_warn("bit field member %s in struct %s is not supported\n",
|
||||
mname, st_ops->name);
|
||||
break;
|
||||
}
|
||||
|
||||
func_proto = btf_type_resolve_func_ptr(btf,
|
||||
member->type,
|
||||
NULL);
|
||||
if (func_proto &&
|
||||
btf_distill_func_proto(&log, btf,
|
||||
func_proto, mname,
|
||||
&st_ops->func_models[j])) {
|
||||
pr_warn("Error in parsing func ptr %s in struct %s\n",
|
||||
mname, st_ops->name);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (j == btf_type_vlen(t)) {
|
||||
if (st_ops->init(btf)) {
|
||||
pr_warn("Error in init bpf_struct_ops %s\n",
|
||||
st_ops->name);
|
||||
} else {
|
||||
st_ops->type_id = type_id;
|
||||
st_ops->type = t;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
extern struct btf *btf_vmlinux;
|
||||
|
||||
const struct bpf_struct_ops *bpf_struct_ops_find(u32 type_id)
|
||||
{
|
||||
unsigned int i;
|
||||
|
||||
if (!type_id || !btf_vmlinux)
|
||||
return NULL;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
|
||||
if (bpf_struct_ops[i]->type_id == type_id)
|
||||
return bpf_struct_ops[i];
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
|
@ -0,0 +1,4 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0 */
|
||||
/* internal file - do not include directly */
|
||||
|
||||
/* To be filled in a later patch */
|
|
@ -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); \
|
||||
|
@ -382,6 +377,65 @@ 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.
|
||||
*/
|
||||
|
@ -446,16 +500,6 @@ 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)
|
||||
{
|
||||
|
@ -463,13 +507,6 @@ static u32 btf_member_bit_offset(const struct btf_type *struct_type,
|
|||
: 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 +517,6 @@ 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);
|
||||
|
@ -3605,6 +3637,8 @@ 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;
|
||||
|
|
|
@ -1672,17 +1672,22 @@ bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
|
|||
enum bpf_attach_type expected_attach_type,
|
||||
u32 btf_id, u32 prog_fd)
|
||||
{
|
||||
switch (prog_type) {
|
||||
case BPF_PROG_TYPE_TRACING:
|
||||
if (btf_id) {
|
||||
if (btf_id > BTF_MAX_TYPE)
|
||||
return -EINVAL;
|
||||
break;
|
||||
default:
|
||||
if (btf_id || prog_fd)
|
||||
|
||||
switch (prog_type) {
|
||||
case BPF_PROG_TYPE_TRACING:
|
||||
case BPF_PROG_TYPE_STRUCT_OPS:
|
||||
break;
|
||||
default:
|
||||
return -EINVAL;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (prog_fd && prog_type != BPF_PROG_TYPE_TRACING)
|
||||
return -EINVAL;
|
||||
|
||||
switch (prog_type) {
|
||||
case BPF_PROG_TYPE_CGROUP_SOCK:
|
||||
switch (expected_attach_type) {
|
||||
|
|
|
@ -2859,11 +2859,6 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
|
|||
u32 btf_id;
|
||||
int ret;
|
||||
|
||||
if (atype != BPF_READ) {
|
||||
verbose(env, "only read is supported\n");
|
||||
return -EACCES;
|
||||
}
|
||||
|
||||
if (off < 0) {
|
||||
verbose(env,
|
||||
"R%d is ptr_%s invalid negative access: off=%d\n",
|
||||
|
@ -2880,17 +2875,32 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
|
|||
return -EACCES;
|
||||
}
|
||||
|
||||
ret = btf_struct_access(&env->log, t, off, size, atype, &btf_id);
|
||||
if (env->ops->btf_struct_access) {
|
||||
ret = env->ops->btf_struct_access(&env->log, t, off, size,
|
||||
atype, &btf_id);
|
||||
} else {
|
||||
if (atype != BPF_READ) {
|
||||
verbose(env, "only read is supported\n");
|
||||
return -EACCES;
|
||||
}
|
||||
|
||||
ret = btf_struct_access(&env->log, t, off, size, atype,
|
||||
&btf_id);
|
||||
}
|
||||
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
if (ret == SCALAR_VALUE) {
|
||||
mark_reg_unknown(env, regs, value_regno);
|
||||
return 0;
|
||||
if (atype == BPF_READ) {
|
||||
if (ret == SCALAR_VALUE) {
|
||||
mark_reg_unknown(env, regs, value_regno);
|
||||
return 0;
|
||||
}
|
||||
mark_reg_known_zero(env, regs, value_regno);
|
||||
regs[value_regno].type = PTR_TO_BTF_ID;
|
||||
regs[value_regno].btf_id = btf_id;
|
||||
}
|
||||
mark_reg_known_zero(env, regs, value_regno);
|
||||
regs[value_regno].type = PTR_TO_BTF_ID;
|
||||
regs[value_regno].btf_id = btf_id;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
@ -6349,8 +6359,30 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
|
|||
static int check_return_code(struct bpf_verifier_env *env)
|
||||
{
|
||||
struct tnum enforce_attach_type_range = tnum_unknown;
|
||||
const struct bpf_prog *prog = env->prog;
|
||||
struct bpf_reg_state *reg;
|
||||
struct tnum range = tnum_range(0, 1);
|
||||
int err;
|
||||
|
||||
/* The struct_ops func-ptr's return type could be "void" */
|
||||
if (env->prog->type == BPF_PROG_TYPE_STRUCT_OPS &&
|
||||
!prog->aux->attach_func_proto->type)
|
||||
return 0;
|
||||
|
||||
/* eBPF calling convetion is such that R0 is used
|
||||
* to return the value from eBPF program.
|
||||
* Make sure that it's readable at this time
|
||||
* of bpf_exit, which means that program wrote
|
||||
* something into it earlier
|
||||
*/
|
||||
err = check_reg_arg(env, BPF_REG_0, SRC_OP);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
if (is_pointer_value(env, BPF_REG_0)) {
|
||||
verbose(env, "R0 leaks addr as return value\n");
|
||||
return -EACCES;
|
||||
}
|
||||
|
||||
switch (env->prog->type) {
|
||||
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
|
||||
|
@ -8016,21 +8048,6 @@ static int do_check(struct bpf_verifier_env *env)
|
|||
if (err)
|
||||
return err;
|
||||
|
||||
/* eBPF calling convetion is such that R0 is used
|
||||
* to return the value from eBPF program.
|
||||
* Make sure that it's readable at this time
|
||||
* of bpf_exit, which means that program wrote
|
||||
* something into it earlier
|
||||
*/
|
||||
err = check_reg_arg(env, BPF_REG_0, SRC_OP);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
if (is_pointer_value(env, BPF_REG_0)) {
|
||||
verbose(env, "R0 leaks addr as return value\n");
|
||||
return -EACCES;
|
||||
}
|
||||
|
||||
err = check_return_code(env);
|
||||
if (err)
|
||||
return err;
|
||||
|
@ -8829,12 +8846,14 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
|
|||
convert_ctx_access = bpf_xdp_sock_convert_ctx_access;
|
||||
break;
|
||||
case PTR_TO_BTF_ID:
|
||||
if (type == BPF_WRITE) {
|
||||
if (type == BPF_READ) {
|
||||
insn->code = BPF_LDX | BPF_PROBE_MEM |
|
||||
BPF_SIZE((insn)->code);
|
||||
env->prog->aux->num_exentries++;
|
||||
} else if (env->prog->type != BPF_PROG_TYPE_STRUCT_OPS) {
|
||||
verbose(env, "Writes through BTF pointers are not allowed\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
insn->code = BPF_LDX | BPF_PROBE_MEM | BPF_SIZE((insn)->code);
|
||||
env->prog->aux->num_exentries++;
|
||||
continue;
|
||||
default:
|
||||
continue;
|
||||
|
@ -9502,6 +9521,58 @@ static void print_verification_stats(struct bpf_verifier_env *env)
|
|||
env->peak_states, env->longest_mark_read_walk);
|
||||
}
|
||||
|
||||
static int check_struct_ops_btf_id(struct bpf_verifier_env *env)
|
||||
{
|
||||
const struct btf_type *t, *func_proto;
|
||||
const struct bpf_struct_ops *st_ops;
|
||||
const struct btf_member *member;
|
||||
struct bpf_prog *prog = env->prog;
|
||||
u32 btf_id, member_idx;
|
||||
const char *mname;
|
||||
|
||||
btf_id = prog->aux->attach_btf_id;
|
||||
st_ops = bpf_struct_ops_find(btf_id);
|
||||
if (!st_ops) {
|
||||
verbose(env, "attach_btf_id %u is not a supported struct\n",
|
||||
btf_id);
|
||||
return -ENOTSUPP;
|
||||
}
|
||||
|
||||
t = st_ops->type;
|
||||
member_idx = prog->expected_attach_type;
|
||||
if (member_idx >= btf_type_vlen(t)) {
|
||||
verbose(env, "attach to invalid member idx %u of struct %s\n",
|
||||
member_idx, st_ops->name);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
member = &btf_type_member(t)[member_idx];
|
||||
mname = btf_name_by_offset(btf_vmlinux, member->name_off);
|
||||
func_proto = btf_type_resolve_func_ptr(btf_vmlinux, member->type,
|
||||
NULL);
|
||||
if (!func_proto) {
|
||||
verbose(env, "attach to invalid member %s(@idx %u) of struct %s\n",
|
||||
mname, member_idx, st_ops->name);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (st_ops->check_member) {
|
||||
int err = st_ops->check_member(t, member);
|
||||
|
||||
if (err) {
|
||||
verbose(env, "attach to unsupported member %s of struct %s\n",
|
||||
mname, st_ops->name);
|
||||
return err;
|
||||
}
|
||||
}
|
||||
|
||||
prog->aux->attach_func_proto = func_proto;
|
||||
prog->aux->attach_func_name = mname;
|
||||
env->ops = st_ops->verifier_ops;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int check_attach_btf_id(struct bpf_verifier_env *env)
|
||||
{
|
||||
struct bpf_prog *prog = env->prog;
|
||||
|
@ -9517,6 +9588,9 @@ static int check_attach_btf_id(struct bpf_verifier_env *env)
|
|||
long addr;
|
||||
u64 key;
|
||||
|
||||
if (prog->type == BPF_PROG_TYPE_STRUCT_OPS)
|
||||
return check_struct_ops_btf_id(env);
|
||||
|
||||
if (prog->type != BPF_PROG_TYPE_TRACING)
|
||||
return 0;
|
||||
|
||||
|
|
Loading…
Reference in New Issue