[PATCH net-next v6 01/11] bpf: Add eBPF program subtype and is_valid_subtype() verifier

From: MickaÃl SalaÃn
Date: Tue Mar 28 2017 - 19:48:50 EST

The goal of the program subtype is to be able to have different static
fine-grained verifications for a unique program type.

The struct bpf_verifier_ops gets a new optional function:
is_valid_subtype(). This new verifier is called at the beginning of the
eBPF program verification to check if the (optional) program subtype is
valid.

For now, only Landlock eBPF programs are using a program subtype (see
next commit) but this could be used by other program types in the future.

Changes since v5:
* use a prog_subtype pointer and make it future-proof
* add subtype test
* constify bpf_load_program()'s subtype argument
* cleanup subtype initialization
* rebase

Changes since v4:
* replace the "status" field with "version" (more generic)
* replace the "access" field with "ability" (less confusing)

Changes since v3:
* remove the "origin" field
* add an "option" field
* cleanup comments

Signed-off-by: MickaÃl SalaÃn <mic@xxxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20160827205559.GA43880@xxxxxxxxxxxxxxxxxxxxxxx
---
include/linux/bpf.h | 7 ++-
include/linux/filter.h | 2 +
include/uapi/linux/bpf.h | 11 ++++
kernel/bpf/syscall.c | 89 +++++++++++++++++++----------
kernel/bpf/verifier.c | 16 +++++-
kernel/trace/bpf_trace.c | 15 +++--
net/core/filter.c | 48 ++++++++++------
samples/bpf/bpf_load.c | 3 +-
samples/bpf/cookie_uid_helper_example.c | 2 +-
samples/bpf/fds_example.c | 2 +-
samples/bpf/sock_example.c | 3 +-
samples/bpf/test_cgrp2_attach.c | 2 +-
samples/bpf/test_cgrp2_attach2.c | 2 +-
samples/bpf/test_cgrp2_sock.c | 2 +-
tools/include/uapi/linux/bpf.h | 11 ++++
tools/lib/bpf/bpf.c | 5 +-
tools/lib/bpf/bpf.h | 2 +-
tools/lib/bpf/libbpf.c | 4 +-
tools/perf/tests/bpf.c | 2 +-
tools/testing/selftests/bpf/test_tag.c | 2 +-
tools/testing/selftests/bpf/test_verifier.c | 16 +++++-
21 files changed, 175 insertions(+), 71 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 2ae39a3e9ead..1cb407bd8ef7 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -156,19 +156,22 @@ struct bpf_prog;

struct bpf_verifier_ops {
/* return eBPF function prototype for verification */
- const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);
+ const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype);

/* return true if 'size' wide access at offset 'off' within bpf_context
* with 'type' (read or write) is allowed
*/
bool (*is_valid_access)(int off, int size, enum bpf_access_type type,
- enum bpf_reg_type *reg_type);
+ enum bpf_reg_type *reg_type,
+ union bpf_prog_subtype *prog_subtype);
int (*gen_prologue)(struct bpf_insn *insn, bool direct_write,
const struct bpf_prog *prog);
u32 (*convert_ctx_access)(enum bpf_access_type type,
const struct bpf_insn *src,
struct bpf_insn *dst,
struct bpf_prog *prog);
+ bool (*is_valid_subtype)(union bpf_prog_subtype *prog_subtype);
};

struct bpf_prog_type_list {
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 511fe910bf1d..f5eb40a9aaa1 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -419,6 +419,8 @@ struct bpf_prog {
enum bpf_prog_type type; /* Type of BPF program */
u32 len; /* Number of filter blocks */
u8 tag[BPF_TAG_SIZE];
+ u8 has_subtype;
+ union bpf_prog_subtype subtype; /* Fine-grained verifications */
struct bpf_prog_aux *aux; /* Auxiliary fields */
struct sock_fprog_kern *orig_prog; /* Original BPF program */
unsigned int (*bpf_func)(const void *ctx,
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 28317a04c34d..0eb71ab9b4fd 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -147,6 +147,15 @@ enum bpf_attach_type {
*/
#define BPF_F_NO_COMMON_LRU (1U << 1)

+union bpf_prog_subtype {
+ struct {
+ __u32 version; /* cf. documentation */
+ __u32 event; /* enum landlock_subtype_event */
+ __aligned_u64 ability; /* LANDLOCK_SUBTYPE_ABILITY_* */
+ __aligned_u64 option; /* LANDLOCK_SUBTYPE_OPTION_* */
+ } landlock_rule;
+} __attribute__((aligned(8)));
+
union bpf_attr {
struct { /* anonymous struct used by BPF_MAP_CREATE command */
__u32 map_type; /* one of enum bpf_map_type */
@@ -176,6 +185,8 @@ union bpf_attr {
__u32 log_size; /* size of user buffer */
__aligned_u64 log_buf; /* user supplied buffer */
__u32 kern_version; /* checked when prog_type=kprobe */
+ __aligned_u64 prog_subtype; /* bpf_prog_subtype address */
+ __u32 prog_subtype_size;
};

struct { /* anonymous struct used by BPF_OBJ_* commands */
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index c35ebfe6d84d..3d07b10ade5e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -783,8 +783,44 @@ struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type)
}
EXPORT_SYMBOL_GPL(bpf_prog_get_type);

+static int check_user_buf(void __user *uptr, unsigned int size_req,
+ unsigned int size_max)
+{
+ if (!access_ok(VERIFY_READ, uptr, 1))
+ return -EFAULT;
+
+ if (size_req > PAGE_SIZE) /* silly large */
+ return -E2BIG;
+
+ /* If we're handed a bigger struct than we know of,
+ * ensure all the unknown bits are 0 - i.e. new
+ * user-space does not rely on any kernel feature
+ * extensions we dont know about yet.
+ */
+ if (size_req > size_max) {
+ unsigned char __user *addr;
+ unsigned char __user *end;
+ unsigned char val;
+ int err;
+
+ addr = uptr + size_max;
+ end = uptr + size_req;
+
+ for (; addr < end; addr++) {
+ err = get_user(val, addr);
+ if (err)
+ return err;
+ if (val)
+ return -E2BIG;
+ }
+ return size_max;
+ }
+
+ return size_req;
+}
+
/* last field in 'union bpf_attr' used by this command */
-#define BPF_PROG_LOAD_LAST_FIELD kern_version
+#define BPF_PROG_LOAD_LAST_FIELD prog_subtype_size

static int bpf_prog_load(union bpf_attr *attr)
{
@@ -843,6 +879,26 @@ static int bpf_prog_load(union bpf_attr *attr)
if (err < 0)
goto free_prog;

+ /* copy eBPF program subtype from user space */
+ if (attr->prog_subtype) {
+ __u32 size;
+
+ size = check_user_buf((void __user *)attr->prog_subtype,
+ attr->prog_subtype_size,
+ sizeof(prog->subtype));
+ if (size < 0) {
+ err = size;
+ goto free_prog;
+ }
+ /* prog->subtype is __GFP_ZERO */
+ if (copy_from_user(&prog->subtype,
+ u64_to_user_ptr(attr->prog_subtype), size)
+ != 0)
+ return -EFAULT;
+ prog->has_subtype = 1;
+ } else if (attr->prog_subtype_size != 0)
+ return -EINVAL;
+
/* run eBPF verifier */
err = bpf_check(&prog, attr);
if (err < 0)
@@ -981,34 +1037,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled)
return -EPERM;

- if (!access_ok(VERIFY_READ, uattr, 1))
- return -EFAULT;
-
- if (size > PAGE_SIZE) /* silly large */
- return -E2BIG;
-
- /* If we're handed a bigger struct than we know of,
- * ensure all the unknown bits are 0 - i.e. new
- * user-space does not rely on any kernel feature
- * extensions we dont know about yet.
- */
- if (size > sizeof(attr)) {
- unsigned char __user *addr;
- unsigned char __user *end;
- unsigned char val;
-
- addr = (void __user *)uattr + sizeof(attr);
- end = (void __user *)uattr + size;
-
- for (; addr < end; addr++) {
- err = get_user(val, addr);
- if (err)
- return err;
- if (val)
- return -E2BIG;
- }
- size = sizeof(attr);
- }
+ size = check_user_buf((void __user *)uattr, size, sizeof(attr));
+ if (size < 0)
+ return size;

/* copy attributes from user space, may be less than sizeof(bpf_attr) */
if (copy_from_user(&attr, uattr, size) != 0)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 09923cc5c7c7..1f44f7ce35f4 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -742,7 +742,8 @@ static int check_ctx_access(struct bpf_verifier_env *env, int off, int size,
return 0;

if (env->prog->aux->ops->is_valid_access &&
- env->prog->aux->ops->is_valid_access(off, size, t, reg_type)) {
+ env->prog->aux->ops->is_valid_access(off, size, t, reg_type,
+ &env->prog->subtype)) {
/* remember the offset of last byte accessed in ctx */
if (env->prog->aux->max_ctx_offset < off + size)
env->prog->aux->max_ctx_offset = off + size;
@@ -1296,7 +1297,8 @@ static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
}

if (env->prog->aux->ops->get_func_proto)
- fn = env->prog->aux->ops->get_func_proto(func_id);
+ fn = env->prog->aux->ops->get_func_proto(func_id,
+ &env->prog->subtype);

if (!fn) {
verbose("unknown func %s#%d\n", func_id_name(func_id), func_id);
@@ -3365,7 +3367,7 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env)
}

patch_call_imm:
- fn = prog->aux->ops->get_func_proto(insn->imm);
+ fn = prog->aux->ops->get_func_proto(insn->imm, &prog->subtype);
/* all functions that have prototype and verifier allowed
* programs to call them, must be real in-kernel functions
*/
@@ -3408,6 +3410,14 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
struct bpf_verifier_env *env;
int ret = -EINVAL;

+ if ((*prog)->aux->ops->is_valid_subtype) {
+ if (!(*prog)->aux->ops->is_valid_subtype(&(*prog)->subtype))
+ return -EINVAL;
+ } else if ((*prog)->has_subtype) {
+ /* do not accept a subtype if the program does not handle it */
+ return -EINVAL;
+ }
+
/* 'struct bpf_verifier_env' can be global, but since it's not small,
* allocate/free it every time bpf_check() is called
*/
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index cee9802cf3e0..e71ee1bb7abf 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -469,7 +469,8 @@ static const struct bpf_func_proto *tracing_func_proto(enum bpf_func_id func_id)
}
}

-static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func_id)
+static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype)
{
switch (func_id) {
case BPF_FUNC_perf_event_output:
@@ -483,7 +484,8 @@ static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func

/* bpf+kprobe programs can access fields of 'struct pt_regs' */
static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
- enum bpf_reg_type *reg_type)
+ enum bpf_reg_type *reg_type,
+ union bpf_prog_subtype *prog_subtype)
{
if (off < 0 || off >= sizeof(struct pt_regs))
return false;
@@ -558,7 +560,8 @@ static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
.arg3_type = ARG_ANYTHING,
};

-static const struct bpf_func_proto *tp_prog_func_proto(enum bpf_func_id func_id)
+static const struct bpf_func_proto *tp_prog_func_proto(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype)
{
switch (func_id) {
case BPF_FUNC_perf_event_output:
@@ -571,7 +574,8 @@ static const struct bpf_func_proto *tp_prog_func_proto(enum bpf_func_id func_id)
}

static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
- enum bpf_reg_type *reg_type)
+ enum bpf_reg_type *reg_type,
+ union bpf_prog_subtype *prog_subtype)
{
if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
return false;
@@ -595,7 +599,8 @@ static struct bpf_prog_type_list tracepoint_tl __ro_after_init = {
};

static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
- enum bpf_reg_type *reg_type)
+ enum bpf_reg_type *reg_type,
+ union bpf_prog_subtype *prog_subtype)
{
if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
return false;
diff --git a/net/core/filter.c b/net/core/filter.c
index dfb9f61a2fd5..c7ef3938a598 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2638,7 +2638,8 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = {
};

static const struct bpf_func_proto *
-bpf_base_func_proto(enum bpf_func_id func_id)
+bpf_base_func_proto(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype)
{
switch (func_id) {
case BPF_FUNC_map_lookup_elem:
@@ -2666,7 +2667,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
}

static const struct bpf_func_proto *
-sk_filter_func_proto(enum bpf_func_id func_id)
+sk_filter_func_proto(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype)
{
switch (func_id) {
case BPF_FUNC_skb_load_bytes:
@@ -2676,12 +2678,13 @@ sk_filter_func_proto(enum bpf_func_id func_id)
case BPF_FUNC_get_socket_uid:
return &bpf_get_socket_uid_proto;
default:
- return bpf_base_func_proto(func_id);
+ return bpf_base_func_proto(func_id, prog_subtype);
}
}

static const struct bpf_func_proto *
-tc_cls_act_func_proto(enum bpf_func_id func_id)
+tc_cls_act_func_proto(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype)
{
switch (func_id) {
case BPF_FUNC_skb_store_bytes:
@@ -2739,12 +2742,13 @@ tc_cls_act_func_proto(enum bpf_func_id func_id)
case BPF_FUNC_get_socket_uid:
return &bpf_get_socket_uid_proto;
default:
- return bpf_base_func_proto(func_id);
+ return bpf_base_func_proto(func_id, prog_subtype);
}
}

static const struct bpf_func_proto *
-xdp_func_proto(enum bpf_func_id func_id)
+xdp_func_proto(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype)
{
switch (func_id) {
case BPF_FUNC_perf_event_output:
@@ -2754,23 +2758,25 @@ xdp_func_proto(enum bpf_func_id func_id)
case BPF_FUNC_xdp_adjust_head:
return &bpf_xdp_adjust_head_proto;
default:
- return bpf_base_func_proto(func_id);
+ return bpf_base_func_proto(func_id, prog_subtype);
}
}

static const struct bpf_func_proto *
-cg_skb_func_proto(enum bpf_func_id func_id)
+cg_skb_func_proto(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype)
{
switch (func_id) {
case BPF_FUNC_skb_load_bytes:
return &bpf_skb_load_bytes_proto;
default:
- return bpf_base_func_proto(func_id);
+ return bpf_base_func_proto(func_id, prog_subtype);
}
}

static const struct bpf_func_proto *
-lwt_inout_func_proto(enum bpf_func_id func_id)
+lwt_inout_func_proto(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype)
{
switch (func_id) {
case BPF_FUNC_skb_load_bytes:
@@ -2792,12 +2798,13 @@ lwt_inout_func_proto(enum bpf_func_id func_id)
case BPF_FUNC_skb_under_cgroup:
return &bpf_skb_under_cgroup_proto;
default:
- return bpf_base_func_proto(func_id);
+ return bpf_base_func_proto(func_id, prog_subtype);
}
}

static const struct bpf_func_proto *
-lwt_xmit_func_proto(enum bpf_func_id func_id)
+lwt_xmit_func_proto(enum bpf_func_id func_id,
+ union bpf_prog_subtype *prog_subtype)
{
switch (func_id) {
case BPF_FUNC_skb_get_tunnel_key:
@@ -2827,7 +2834,7 @@ lwt_xmit_func_proto(enum bpf_func_id func_id)
case BPF_FUNC_set_hash_invalid:
return &bpf_set_hash_invalid_proto;
default:
- return lwt_inout_func_proto(func_id);
+ return lwt_inout_func_proto(func_id, prog_subtype);
}
}

@@ -2857,7 +2864,8 @@ static bool __is_valid_access(int off, int size)

static bool sk_filter_is_valid_access(int off, int size,
enum bpf_access_type type,
- enum bpf_reg_type *reg_type)
+ enum bpf_reg_type *reg_type,
+ union bpf_prog_subtype *prog_subtype)
{
switch (off) {
case offsetof(struct __sk_buff, tc_classid):
@@ -2881,7 +2889,8 @@ static bool sk_filter_is_valid_access(int off, int size,

static bool lwt_is_valid_access(int off, int size,
enum bpf_access_type type,
- enum bpf_reg_type *reg_type)
+ enum bpf_reg_type *reg_type,
+ union bpf_prog_subtype *prog_subtype)
{
switch (off) {
case offsetof(struct __sk_buff, tc_classid):
@@ -2914,7 +2923,8 @@ static bool lwt_is_valid_access(int off, int size,

static bool sock_filter_is_valid_access(int off, int size,
enum bpf_access_type type,
- enum bpf_reg_type *reg_type)
+ enum bpf_reg_type *reg_type,
+ union bpf_prog_subtype *prog_subtype)
{
if (type == BPF_WRITE) {
switch (off) {
@@ -2977,7 +2987,8 @@ static int tc_cls_act_prologue(struct bpf_insn *insn_buf, bool direct_write,

static bool tc_cls_act_is_valid_access(int off, int size,
enum bpf_access_type type,
- enum bpf_reg_type *reg_type)
+ enum bpf_reg_type *reg_type,
+ union bpf_prog_subtype *prog_subtype)
{
if (type == BPF_WRITE) {
switch (off) {
@@ -3019,7 +3030,8 @@ static bool __is_valid_xdp_access(int off, int size)

static bool xdp_is_valid_access(int off, int size,
enum bpf_access_type type,
- enum bpf_reg_type *reg_type)
+ enum bpf_reg_type *reg_type,
+ union bpf_prog_subtype *prog_subtype)
{
if (type == BPF_WRITE)
return false;
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index dcdce1270d38..4a3460d7c01f 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -73,6 +73,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
char buf[256];
int fd, efd, err, id;
struct perf_event_attr attr = {};
+ union bpf_prog_subtype *st = NULL;

attr.type = PERF_TYPE_TRACEPOINT;
attr.sample_type = PERF_SAMPLE_RAW;
@@ -99,7 +100,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
}

fd = bpf_load_program(prog_type, prog, insns_cnt, license, kern_version,
- bpf_log_buf, BPF_LOG_BUF_SIZE);
+ bpf_log_buf, BPF_LOG_BUF_SIZE, st);
if (fd < 0) {
printf("bpf_load_program() err=%d\n%s", errno, bpf_log_buf);
return -1;
diff --git a/samples/bpf/cookie_uid_helper_example.c b/samples/bpf/cookie_uid_helper_example.c
index f6e5e58931c5..7427428312d6 100644
--- a/samples/bpf/cookie_uid_helper_example.c
+++ b/samples/bpf/cookie_uid_helper_example.c
@@ -148,7 +148,7 @@ static void prog_load(void)
};
prog_fd = bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog,
ARRAY_SIZE(prog), "GPL", 0,
- log_buf, sizeof(log_buf));
+ log_buf, sizeof(log_buf), NULL);
if (prog_fd < 0)
error(1, errno, "failed to load prog\n%s\n", log_buf);
}
diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c
index e29bd52ff9e8..0f4f5f6a9f9f 100644
--- a/samples/bpf/fds_example.c
+++ b/samples/bpf/fds_example.c
@@ -62,7 +62,7 @@ static int bpf_prog_create(const char *object)
} else {
return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER,
insns, insns_cnt, "GPL", 0,
- bpf_log_buf, BPF_LOG_BUF_SIZE);
+ bpf_log_buf, BPF_LOG_BUF_SIZE, NULL);
}
}

diff --git a/samples/bpf/sock_example.c b/samples/bpf/sock_example.c
index 6fc6e193ef1b..3778f66deb76 100644
--- a/samples/bpf/sock_example.c
+++ b/samples/bpf/sock_example.c
@@ -60,7 +60,8 @@ static int test_sock(void)
size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);

prog_fd = bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog, insns_cnt,
- "GPL", 0, bpf_log_buf, BPF_LOG_BUF_SIZE);
+ "GPL", 0, bpf_log_buf, BPF_LOG_BUF_SIZE,
+ NULL);
if (prog_fd < 0) {
printf("failed to load prog '%s'\n", strerror(errno));
goto cleanup;
diff --git a/samples/bpf/test_cgrp2_attach.c b/samples/bpf/test_cgrp2_attach.c
index 4bfcaf93fcf3..f8a91d2b7896 100644
--- a/samples/bpf/test_cgrp2_attach.c
+++ b/samples/bpf/test_cgrp2_attach.c
@@ -72,7 +72,7 @@ static int prog_load(int map_fd, int verdict)

return bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
prog, insns_cnt, "GPL", 0,
- bpf_log_buf, BPF_LOG_BUF_SIZE);
+ bpf_log_buf, BPF_LOG_BUF_SIZE, NULL);
}

static int usage(const char *argv0)
diff --git a/samples/bpf/test_cgrp2_attach2.c b/samples/bpf/test_cgrp2_attach2.c
index 3049b1f26267..31a0f4bd665f 100644
--- a/samples/bpf/test_cgrp2_attach2.c
+++ b/samples/bpf/test_cgrp2_attach2.c
@@ -45,7 +45,7 @@ static int prog_load(int verdict)

ret = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
prog, insns_cnt, "GPL", 0,
- bpf_log_buf, BPF_LOG_BUF_SIZE);
+ bpf_log_buf, BPF_LOG_BUF_SIZE, NULL);

if (ret < 0) {
log_err("Loading program");
diff --git a/samples/bpf/test_cgrp2_sock.c b/samples/bpf/test_cgrp2_sock.c
index c3cfb23e23b5..697f2db30e6a 100644
--- a/samples/bpf/test_cgrp2_sock.c
+++ b/samples/bpf/test_cgrp2_sock.c
@@ -38,7 +38,7 @@ static int prog_load(int idx)
size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);

return bpf_load_program(BPF_PROG_TYPE_CGROUP_SOCK, prog, insns_cnt,
- "GPL", 0, bpf_log_buf, BPF_LOG_BUF_SIZE);
+ "GPL", 0, bpf_log_buf, BPF_LOG_BUF_SIZE, NULL);
}

static int usage(const char *argv0)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 1ea08ce35567..725c9a7d3dd9 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -147,6 +147,15 @@ enum bpf_attach_type {
*/
#define BPF_F_NO_COMMON_LRU (1U << 1)

+union bpf_prog_subtype {
+ struct {
+ __u32 version; /* cf. documentation */
+ __u32 event; /* enum landlock_subtype_event */
+ __aligned_u64 ability; /* LANDLOCK_SUBTYPE_ABILITY_* */
+ __aligned_u64 option; /* LANDLOCK_SUBTYPE_OPTION_* */
+ } landlock_rule;
+} __attribute__((aligned(8)));
+
union bpf_attr {
struct { /* anonymous struct used by BPF_MAP_CREATE command */
__u32 map_type; /* one of enum bpf_map_type */
@@ -176,6 +185,8 @@ union bpf_attr {
__u32 log_size; /* size of user buffer */
__aligned_u64 log_buf; /* user supplied buffer */
__u32 kern_version; /* checked when prog_type=kprobe */
+ __aligned_u64 prog_subtype; /* bpf_prog_subtype address */
+ __u32 prog_subtype_size;
};

struct { /* anonymous struct used by BPF_OBJ_* commands */
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 9b58d20e8c93..34fa03c95389 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -88,7 +88,8 @@ int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size,

int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, const char *license,
- __u32 kern_version, char *log_buf, size_t log_buf_sz)
+ __u32 kern_version, char *log_buf, size_t log_buf_sz,
+ const union bpf_prog_subtype *subtype)
{
int fd;
union bpf_attr attr;
@@ -102,6 +103,8 @@ int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
attr.log_size = 0;
attr.log_level = 0;
attr.kern_version = kern_version;
+ attr.prog_subtype = ptr_to_u64(subtype);
+ attr.prog_subtype_size = subtype ? sizeof(*subtype) : 0;

fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
if (fd >= 0 || !log_buf || !log_buf_sz)
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 93f021932623..dfb320653ac1 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -34,7 +34,7 @@ int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size,
int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, const char *license,
__u32 kern_version, char *log_buf,
- size_t log_buf_sz);
+ size_t log_buf_sz, const union bpf_prog_subtype *subtype);

int bpf_map_update_elem(int fd, const void *key, const void *value,
__u64 flags);
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ac6eb863b2a4..645b0a96e66f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -995,7 +995,7 @@ load_program(enum bpf_prog_type type, struct bpf_insn *insns,
pr_warning("Alloc log buffer for bpf loader error, continue without log\n");

ret = bpf_load_program(type, insns, insns_cnt, license,
- kern_version, log_buf, BPF_LOG_BUF_SIZE);
+ kern_version, log_buf, BPF_LOG_BUF_SIZE, NULL);

if (ret >= 0) {
*pfd = ret;
@@ -1022,7 +1022,7 @@ load_program(enum bpf_prog_type type, struct bpf_insn *insns,

fd = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
insns_cnt, license, kern_version,
- NULL, 0);
+ NULL, 0, NULL);
if (fd >= 0) {
close(fd);
ret = -LIBBPF_ERRNO__PROGTYPE;
diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
index 1a04fe77487d..8ae07f5ecdc0 100644
--- a/tools/perf/tests/bpf.c
+++ b/tools/perf/tests/bpf.c
@@ -306,7 +306,7 @@ static int check_env(void)

err = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
sizeof(insns) / sizeof(insns[0]),
- license, kver_int, NULL, 0);
+ license, kver_int, NULL, 0, NULL);
if (err < 0) {
pr_err("Missing basic BPF support, skip this test: %s\n",
strerror(errno));
diff --git a/tools/testing/selftests/bpf/test_tag.c b/tools/testing/selftests/bpf/test_tag.c
index de409fc50c35..cf7892c87b5a 100644
--- a/tools/testing/selftests/bpf/test_tag.c
+++ b/tools/testing/selftests/bpf/test_tag.c
@@ -57,7 +57,7 @@ static int bpf_try_load_prog(int insns, int fd_map,

bpf_filler(insns, fd_map);
fd_prog = bpf_load_program(BPF_PROG_TYPE_SCHED_CLS, prog, insns, "", 0,
- NULL, 0);
+ NULL, 0, NULL);
assert(fd_prog > 0);
if (fd_map > 0)
bpf_filler(insns, 0);
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index f4f43c98cf7f..daa87dd7c80e 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -55,6 +55,8 @@ struct bpf_test {
REJECT
} result, result_unpriv;
enum bpf_prog_type prog_type;
+ bool has_prog_subtype;
+ union bpf_prog_subtype prog_subtype;
};

/* Note we want this to be 64 bit aligned so that the end of our array is
@@ -4524,6 +4526,16 @@ static struct bpf_test tests[] = {
.errstr = "R1 type=map_value_or_null expected=map_ptr",
.result = REJECT,
},
+ {
+ "superfluous subtype",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "",
+ .result = REJECT,
+ .has_prog_subtype = true,
+ },
};

static int probe_filter_length(const struct bpf_insn *fp)
@@ -4639,6 +4651,8 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
int fd_prog, expected_ret;
const char *expected_err;
int i;
+ union bpf_prog_subtype *prog_subtype =
+ test->has_prog_subtype ? &test->prog_subtype : NULL;

for (i = 0; i < MAX_NR_MAPS; i++)
map_fds[i] = -1;
@@ -4647,7 +4661,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,

fd_prog = bpf_load_program(prog_type ? : BPF_PROG_TYPE_SOCKET_FILTER,
prog, prog_len, "GPL", 0, bpf_vlog,
- sizeof(bpf_vlog));
+ sizeof(bpf_vlog), prog_subtype);

expected_ret = unpriv && test->result_unpriv != UNDEF ?
test->result_unpriv : test->result;
--
2.11.0