Replace deprecated 0-length array in struct bpf_lpm_trie_key with
flexible array. Found with GCC 13:
./kernel/bpf/lpm_trie.c:207:51: warning: array subscript i is outside array bounds of 'const __u8[0]' {aka 'const unsigned char[]'} [-Warray-bounds=]
207 | *(__be16 *)&key->data[i]);
| ^~~~~~~~~~~~~
./include/uapi/linux/swab.h:102:54: note: in definition of macro '__swab16'
102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
| ^
./include/linux/byteorder/generic.h:97:21: note: in expansion of macro '__be16_to_cpu'
97 | #define be16_to_cpu __be16_to_cpu
| ^~~~~~~~~~~~~
./kernel/bpf/lpm_trie.c:206:28: note: in expansion of macro 'be16_to_cpu'
206 | u16 diff = be16_to_cpu(*(__be16 *)&node->data[i]
^
| ^~~~~~~~~~~
In file included from ../include/linux/bpf.h:7:
./include/uapi/linux/bpf.h:82:17: note: while referencing 'data'
82 | __u8 data[0]; /* Arbitrary size */
| ^~~~
And found at run-time under CONFIG_FORTIFY_SOURCE:
UBSAN: array-index-out-of-bounds in kernel/bpf/lpm_trie.c:218:49
index 0 is out of range for type '__u8 [*]'
Changing struct bpf_lpm_trie_key is difficult since has been used by
userspace. For example, in Cilium:
struct egress_gw_policy_key {
struct bpf_lpm_trie_key lpm_key;
__u32 saddr;
__u32 daddr;
};
While direct references to the "data" member haven't been found, there
are static initializers what include the final member. For example,
the "{}" here:
struct egress_gw_policy_key in_key = {
.lpm_key = { 32 + 24, {} },
.saddr = CLIENT_IP,
.daddr = EXTERNAL_SVC_IP & 0Xffffff,
};
To avoid the build time and run time warnings seen with a 0-sized
trailing array for struct bpf_lpm_trie_key, introduce a new struct
that correctly uses a flexible array for the trailing bytes,
struct bpf_lpm_trie_key_u8. As part of this, include the "header"
portion (which is just the "prefixlen" member), so it can be used
by anything building a bpf_lpr_trie_key that has trailing members that
aren't a u8 flexible array (like the self-test[1]), which is named
struct bpf_lpm_trie_key_hdr.
Adjust the kernel code to use struct bpf_lpm_trie_key_u8 through-out,
and for the selftest to use struct bpf_lpm_trie_key_hdr. Add a comment
to the UAPI header directing folks to the two new options.
Link: https://lore.kernel.org/all/202206281009.4332AA33@keescook/ [1]
Reported-by: Mark Rutland <[email protected]>
Closes: https://paste.debian.net/hidden/ca500597/
Signed-off-by: Kees Cook <[email protected]>
---
v3- create a new pair of structs -- leave old struct alone
v2- https://lore.kernel.org/lkml/[email protected]/
v1- https://lore.kernel.org/lkml/[email protected]/
Cc: Daniel Borkmann <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Yonghong Song <[email protected]>
Cc: John Fastabend <[email protected]>
Cc: KP Singh <[email protected]>
Cc: Stanislav Fomichev <[email protected]>
Cc: Hao Luo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mykola Lysenko <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Haowen Bai <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
Documentation/bpf/map_lpm_trie.rst | 2 +-
include/uapi/linux/bpf.h | 14 ++++++++++++-
kernel/bpf/lpm_trie.c | 20 +++++++++----------
samples/bpf/map_perf_test_user.c | 2 +-
samples/bpf/xdp_router_ipv4_user.c | 2 +-
tools/include/uapi/linux/bpf.h | 14 ++++++++++++-
.../selftests/bpf/progs/map_ptr_kern.c | 2 +-
tools/testing/selftests/bpf/test_lpm_map.c | 18 ++++++++---------
8 files changed, 49 insertions(+), 25 deletions(-)
diff --git a/Documentation/bpf/map_lpm_trie.rst b/Documentation/bpf/map_lpm_trie.rst
index 74d64a30f500..f9cd579496c9 100644
--- a/Documentation/bpf/map_lpm_trie.rst
+++ b/Documentation/bpf/map_lpm_trie.rst
@@ -17,7 +17,7 @@ significant byte.
LPM tries may be created with a maximum prefix length that is a multiple
of 8, in the range from 8 to 2048. The key used for lookup and update
-operations is a ``struct bpf_lpm_trie_key``, extended by
+operations is a ``struct bpf_lpm_trie_key_u8``, extended by
``max_prefixlen/8`` bytes.
- For IPv4 addresses the data length is 4 bytes
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 754e68ca8744..c5a46d12076e 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -77,12 +77,24 @@ struct bpf_insn {
__s32 imm; /* signed immediate constant */
};
-/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
+/* Deprecated: use struct bpf_lpm_trie_key_u8 (when the "data" member is needed for
+ * byte access) or struct bpf_lpm_trie_key_hdr (when using an alternative type for
+ * the trailing flexible array member) instead.
+ */
struct bpf_lpm_trie_key {
__u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
__u8 data[0]; /* Arbitrary size */
};
+/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry, with trailing byte array. */
+struct bpf_lpm_trie_key_u8 {
+ __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
+ /* up to 32 for AF_INET, 128 for AF_INET6 */
+ __u32 prefixlen;
+ );
+ __u8 data[]; /* Arbitrary size */
+};
+
struct bpf_cgroup_storage_key {
__u64 cgroup_inode_id; /* cgroup inode id */
__u32 attach_type; /* program attach type (enum bpf_attach_type) */
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index b32be680da6c..050fe1ebf0f7 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -164,13 +164,13 @@ static inline int extract_bit(const u8 *data, size_t index)
*/
static size_t longest_prefix_match(const struct lpm_trie *trie,
const struct lpm_trie_node *node,
- const struct bpf_lpm_trie_key *key)
+ const struct bpf_lpm_trie_key_u8 *key)
{
u32 limit = min(node->prefixlen, key->prefixlen);
u32 prefixlen = 0, i = 0;
BUILD_BUG_ON(offsetof(struct lpm_trie_node, data) % sizeof(u32));
- BUILD_BUG_ON(offsetof(struct bpf_lpm_trie_key, data) % sizeof(u32));
+ BUILD_BUG_ON(offsetof(struct bpf_lpm_trie_key_u8, data) % sizeof(u32));
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(CONFIG_64BIT)
@@ -229,7 +229,7 @@ static void *trie_lookup_elem(struct bpf_map *map, void *_key)
{
struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
struct lpm_trie_node *node, *found = NULL;
- struct bpf_lpm_trie_key *key = _key;
+ struct bpf_lpm_trie_key_u8 *key = _key;
if (key->prefixlen > trie->max_prefixlen)
return NULL;
@@ -309,7 +309,7 @@ static long trie_update_elem(struct bpf_map *map,
struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
struct lpm_trie_node *node, *im_node = NULL, *new_node = NULL;
struct lpm_trie_node __rcu **slot;
- struct bpf_lpm_trie_key *key = _key;
+ struct bpf_lpm_trie_key_u8 *key = _key;
unsigned long irq_flags;
unsigned int next_bit;
size_t matchlen = 0;
@@ -437,7 +437,7 @@ static long trie_update_elem(struct bpf_map *map,
static long trie_delete_elem(struct bpf_map *map, void *_key)
{
struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
- struct bpf_lpm_trie_key *key = _key;
+ struct bpf_lpm_trie_key_u8 *key = _key;
struct lpm_trie_node __rcu **trim, **trim2;
struct lpm_trie_node *node, *parent;
unsigned long irq_flags;
@@ -536,7 +536,7 @@ static long trie_delete_elem(struct bpf_map *map, void *_key)
sizeof(struct lpm_trie_node))
#define LPM_VAL_SIZE_MIN 1
-#define LPM_KEY_SIZE(X) (sizeof(struct bpf_lpm_trie_key) + (X))
+#define LPM_KEY_SIZE(X) (sizeof(struct bpf_lpm_trie_key_u8) + (X))
#define LPM_KEY_SIZE_MAX LPM_KEY_SIZE(LPM_DATA_SIZE_MAX)
#define LPM_KEY_SIZE_MIN LPM_KEY_SIZE(LPM_DATA_SIZE_MIN)
@@ -565,7 +565,7 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
/* copy mandatory map attributes */
bpf_map_init_from_attr(&trie->map, attr);
trie->data_size = attr->key_size -
- offsetof(struct bpf_lpm_trie_key, data);
+ offsetof(struct bpf_lpm_trie_key_u8, data);
trie->max_prefixlen = trie->data_size * 8;
spin_lock_init(&trie->lock);
@@ -616,7 +616,7 @@ static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)
{
struct lpm_trie_node *node, *next_node = NULL, *parent, *search_root;
struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
- struct bpf_lpm_trie_key *key = _key, *next_key = _next_key;
+ struct bpf_lpm_trie_key_u8 *key = _key, *next_key = _next_key;
struct lpm_trie_node **node_stack = NULL;
int err = 0, stack_ptr = -1;
unsigned int next_bit;
@@ -703,7 +703,7 @@ static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)
}
do_copy:
next_key->prefixlen = next_node->prefixlen;
- memcpy((void *)next_key + offsetof(struct bpf_lpm_trie_key, data),
+ memcpy((void *)next_key + offsetof(struct bpf_lpm_trie_key_u8, data),
next_node->data, trie->data_size);
free_stack:
kfree(node_stack);
@@ -715,7 +715,7 @@ static int trie_check_btf(const struct bpf_map *map,
const struct btf_type *key_type,
const struct btf_type *value_type)
{
- /* Keys must have struct bpf_lpm_trie_key embedded. */
+ /* Keys must have struct bpf_lpm_trie_key_u8 embedded. */
return BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ?
-EINVAL : 0;
}
diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
index d2fbcf963cdf..07ff471ed6ae 100644
--- a/samples/bpf/map_perf_test_user.c
+++ b/samples/bpf/map_perf_test_user.c
@@ -370,7 +370,7 @@ static void run_perf_test(int tasks)
static void fill_lpm_trie(void)
{
- struct bpf_lpm_trie_key *key;
+ struct bpf_lpm_trie_key_u8 *key;
unsigned long value = 0;
unsigned int i;
int r;
diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c
index 9d41db09c480..266fdd0b025d 100644
--- a/samples/bpf/xdp_router_ipv4_user.c
+++ b/samples/bpf/xdp_router_ipv4_user.c
@@ -91,7 +91,7 @@ static int recv_msg(struct sockaddr_nl sock_addr, int sock)
static void read_route(struct nlmsghdr *nh, int nll)
{
char dsts[24], gws[24], ifs[16], dsts_len[24], metrics[24];
- struct bpf_lpm_trie_key *prefix_key;
+ struct bpf_lpm_trie_key_u8 *prefix_key;
struct rtattr *rt_attr;
struct rtmsg *rt_msg;
int rtm_family;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 7f24d898efbb..c55244bf1a20 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -77,12 +77,24 @@ struct bpf_insn {
__s32 imm; /* signed immediate constant */
};
-/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
+/* Deprecated: use struct bpf_lpm_trie_key_u8 (when the "data" member is needed for
+ * byte access) or struct bpf_lpm_trie_key_hdr (when using an alternative type for
+ * the trailing flexible array member) instead.
+ */
struct bpf_lpm_trie_key {
__u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
__u8 data[0]; /* Arbitrary size */
};
+/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry, with trailing byte array. */
+struct bpf_lpm_trie_key_u8 {
+ __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
+ /* up to 32 for AF_INET, 128 for AF_INET6 */
+ __u32 prefixlen;
+ );
+ __u8 data[]; /* Arbitrary size */
+};
+
struct bpf_cgroup_storage_key {
__u64 cgroup_inode_id; /* cgroup inode id */
__u32 attach_type; /* program attach type (enum bpf_attach_type) */
diff --git a/tools/testing/selftests/bpf/progs/map_ptr_kern.c b/tools/testing/selftests/bpf/progs/map_ptr_kern.c
index 3325da17ec81..efaf622c28dd 100644
--- a/tools/testing/selftests/bpf/progs/map_ptr_kern.c
+++ b/tools/testing/selftests/bpf/progs/map_ptr_kern.c
@@ -316,7 +316,7 @@ struct lpm_trie {
} __attribute__((preserve_access_index));
struct lpm_key {
- struct bpf_lpm_trie_key trie_key;
+ struct bpf_lpm_trie_key_hdr trie_key;
__u32 data;
};
diff --git a/tools/testing/selftests/bpf/test_lpm_map.c b/tools/testing/selftests/bpf/test_lpm_map.c
index c028d621c744..d98c72dc563e 100644
--- a/tools/testing/selftests/bpf/test_lpm_map.c
+++ b/tools/testing/selftests/bpf/test_lpm_map.c
@@ -211,7 +211,7 @@ static void test_lpm_map(int keysize)
volatile size_t n_matches, n_matches_after_delete;
size_t i, j, n_nodes, n_lookups;
struct tlpm_node *t, *list = NULL;
- struct bpf_lpm_trie_key *key;
+ struct bpf_lpm_trie_key_u8 *key;
uint8_t *data, *value;
int r, map;
@@ -331,8 +331,8 @@ static void test_lpm_map(int keysize)
static void test_lpm_ipaddr(void)
{
LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
- struct bpf_lpm_trie_key *key_ipv4;
- struct bpf_lpm_trie_key *key_ipv6;
+ struct bpf_lpm_trie_key_u8 *key_ipv4;
+ struct bpf_lpm_trie_key_u8 *key_ipv6;
size_t key_size_ipv4;
size_t key_size_ipv6;
int map_fd_ipv4;
@@ -423,7 +423,7 @@ static void test_lpm_ipaddr(void)
static void test_lpm_delete(void)
{
LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
- struct bpf_lpm_trie_key *key;
+ struct bpf_lpm_trie_key_u8 *key;
size_t key_size;
int map_fd;
__u64 value;
@@ -532,7 +532,7 @@ static void test_lpm_delete(void)
static void test_lpm_get_next_key(void)
{
LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
- struct bpf_lpm_trie_key *key_p, *next_key_p;
+ struct bpf_lpm_trie_key_u8 *key_p, *next_key_p;
size_t key_size;
__u32 value = 0;
int map_fd;
@@ -693,9 +693,9 @@ static void *lpm_test_command(void *arg)
{
int i, j, ret, iter, key_size;
struct lpm_mt_test_info *info = arg;
- struct bpf_lpm_trie_key *key_p;
+ struct bpf_lpm_trie_key_u8 *key_p;
- key_size = sizeof(struct bpf_lpm_trie_key) + sizeof(__u32);
+ key_size = sizeof(*key_p) + sizeof(__u32);
key_p = alloca(key_size);
for (iter = 0; iter < info->iter; iter++)
for (i = 0; i < MAX_TEST_KEYS; i++) {
@@ -717,7 +717,7 @@ static void *lpm_test_command(void *arg)
ret = bpf_map_lookup_elem(info->map_fd, key_p, &value);
assert(ret == 0 || errno == ENOENT);
} else {
- struct bpf_lpm_trie_key *next_key_p = alloca(key_size);
+ struct bpf_lpm_trie_key_u8 *next_key_p = alloca(key_size);
ret = bpf_map_get_next_key(info->map_fd, key_p, next_key_p);
assert(ret == 0 || errno == ENOENT || errno == ENOMEM);
}
@@ -752,7 +752,7 @@ static void test_lpm_multi_thread(void)
/* create a trie */
value_size = sizeof(__u32);
- key_size = sizeof(struct bpf_lpm_trie_key) + value_size;
+ key_size = sizeof(struct bpf_lpm_trie_key_hdr) + value_size;
map_fd = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL, key_size, value_size, 100, &opts);
/* create 4 threads to test update, delete, lookup and get_next_key */
--
2.34.1
On 2/19/24 17:41, Kees Cook wrote:
> Replace deprecated 0-length array in struct bpf_lpm_trie_key with
> flexible array. Found with GCC 13:
>
> ../kernel/bpf/lpm_trie.c:207:51: warning: array subscript i is outside array bounds of 'const __u8[0]' {aka 'const unsigned char[]'} [-Warray-bounds=]
> 207 | *(__be16 *)&key->data[i]);
> | ^~~~~~~~~~~~~
> ../include/uapi/linux/swab.h:102:54: note: in definition of macro '__swab16'
> 102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
> | ^
> ../include/linux/byteorder/generic.h:97:21: note: in expansion of macro '__be16_to_cpu'
> 97 | #define be16_to_cpu __be16_to_cpu
> | ^~~~~~~~~~~~~
> ../kernel/bpf/lpm_trie.c:206:28: note: in expansion of macro 'be16_to_cpu'
> 206 | u16 diff = be16_to_cpu(*(__be16 *)&node->data[i]
> ^
> | ^~~~~~~~~~~
> In file included from ../include/linux/bpf.h:7:
> ../include/uapi/linux/bpf.h:82:17: note: while referencing 'data'
> 82 | __u8 data[0]; /* Arbitrary size */
> | ^~~~
>
> And found at run-time under CONFIG_FORTIFY_SOURCE:
>
> UBSAN: array-index-out-of-bounds in kernel/bpf/lpm_trie.c:218:49
> index 0 is out of range for type '__u8 [*]'
>
> Changing struct bpf_lpm_trie_key is difficult since has been used by
> userspace. For example, in Cilium:
>
> struct egress_gw_policy_key {
> struct bpf_lpm_trie_key lpm_key;
> __u32 saddr;
> __u32 daddr;
> };
>
> While direct references to the "data" member haven't been found, there
> are static initializers what include the final member. For example,
> the "{}" here:
>
> struct egress_gw_policy_key in_key = {
> .lpm_key = { 32 + 24, {} },
> .saddr = CLIENT_IP,
> .daddr = EXTERNAL_SVC_IP & 0Xffffff,
> };
>
> To avoid the build time and run time warnings seen with a 0-sized
> trailing array for struct bpf_lpm_trie_key, introduce a new struct
> that correctly uses a flexible array for the trailing bytes,
> struct bpf_lpm_trie_key_u8. As part of this, include the "header"
> portion (which is just the "prefixlen" member), so it can be used
> by anything building a bpf_lpr_trie_key that has trailing members that
> aren't a u8 flexible array (like the self-test[1]), which is named
> struct bpf_lpm_trie_key_hdr.
Yep, this `_hdr` tagged struct adds flexibility (no pun intended :p)
to flexible structures currently nested in the middle of other
structs. We can just use the header members grouped together in the
`_hdr` struct, and avoid embedding the flexible-array member. :)
>
> Adjust the kernel code to use struct bpf_lpm_trie_key_u8 through-out,
> and for the selftest to use struct bpf_lpm_trie_key_hdr. Add a comment
> to the UAPI header directing folks to the two new options.
>
> Link: https://lore.kernel.org/all/202206281009.4332AA33@keescook/ [1]
> Reported-by: Mark Rutland <[email protected]>
> Closes: https://paste.debian.net/hidden/ca500597/
> Signed-off-by: Kees Cook <[email protected]>
Acked-by: Gustavo A. R. Silva <[email protected]>
Thanks!
--
Gustavo
> ---
> v3- create a new pair of structs -- leave old struct alone
> v2- https://lore.kernel.org/lkml/[email protected]/
> v1- https://lore.kernel.org/lkml/[email protected]/
> Cc: Daniel Borkmann <[email protected]>
> Cc: Alexei Starovoitov <[email protected]>
> Cc: Andrii Nakryiko <[email protected]>
> Cc: Martin KaFai Lau <[email protected]>
> Cc: Song Liu <[email protected]>
> Cc: Yonghong Song <[email protected]>
> Cc: John Fastabend <[email protected]>
> Cc: KP Singh <[email protected]>
> Cc: Stanislav Fomichev <[email protected]>
> Cc: Hao Luo <[email protected]>
> Cc: Jiri Olsa <[email protected]>
> Cc: Mykola Lysenko <[email protected]>
> Cc: Shuah Khan <[email protected]>
> Cc: Haowen Bai <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> Documentation/bpf/map_lpm_trie.rst | 2 +-
> include/uapi/linux/bpf.h | 14 ++++++++++++-
> kernel/bpf/lpm_trie.c | 20 +++++++++----------
> samples/bpf/map_perf_test_user.c | 2 +-
> samples/bpf/xdp_router_ipv4_user.c | 2 +-
> tools/include/uapi/linux/bpf.h | 14 ++++++++++++-
> .../selftests/bpf/progs/map_ptr_kern.c | 2 +-
> tools/testing/selftests/bpf/test_lpm_map.c | 18 ++++++++---------
> 8 files changed, 49 insertions(+), 25 deletions(-)
>
> diff --git a/Documentation/bpf/map_lpm_trie.rst b/Documentation/bpf/map_lpm_trie.rst
> index 74d64a30f500..f9cd579496c9 100644
> --- a/Documentation/bpf/map_lpm_trie.rst
> +++ b/Documentation/bpf/map_lpm_trie.rst
> @@ -17,7 +17,7 @@ significant byte.
>
> LPM tries may be created with a maximum prefix length that is a multiple
> of 8, in the range from 8 to 2048. The key used for lookup and update
> -operations is a ``struct bpf_lpm_trie_key``, extended by
> +operations is a ``struct bpf_lpm_trie_key_u8``, extended by
> ``max_prefixlen/8`` bytes.
>
> - For IPv4 addresses the data length is 4 bytes
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 754e68ca8744..c5a46d12076e 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -77,12 +77,24 @@ struct bpf_insn {
> __s32 imm; /* signed immediate constant */
> };
>
> -/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
> +/* Deprecated: use struct bpf_lpm_trie_key_u8 (when the "data" member is needed for
> + * byte access) or struct bpf_lpm_trie_key_hdr (when using an alternative type for
> + * the trailing flexible array member) instead.
> + */
> struct bpf_lpm_trie_key {
> __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
> __u8 data[0]; /* Arbitrary size */
> };
>
> +/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry, with trailing byte array. */
> +struct bpf_lpm_trie_key_u8 {
> + __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
> + /* up to 32 for AF_INET, 128 for AF_INET6 */
> + __u32 prefixlen;
> + );
> + __u8 data[]; /* Arbitrary size */
> +};
> +
> struct bpf_cgroup_storage_key {
> __u64 cgroup_inode_id; /* cgroup inode id */
> __u32 attach_type; /* program attach type (enum bpf_attach_type) */
> diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
> index b32be680da6c..050fe1ebf0f7 100644
> --- a/kernel/bpf/lpm_trie.c
> +++ b/kernel/bpf/lpm_trie.c
> @@ -164,13 +164,13 @@ static inline int extract_bit(const u8 *data, size_t index)
> */
> static size_t longest_prefix_match(const struct lpm_trie *trie,
> const struct lpm_trie_node *node,
> - const struct bpf_lpm_trie_key *key)
> + const struct bpf_lpm_trie_key_u8 *key)
> {
> u32 limit = min(node->prefixlen, key->prefixlen);
> u32 prefixlen = 0, i = 0;
>
> BUILD_BUG_ON(offsetof(struct lpm_trie_node, data) % sizeof(u32));
> - BUILD_BUG_ON(offsetof(struct bpf_lpm_trie_key, data) % sizeof(u32));
> + BUILD_BUG_ON(offsetof(struct bpf_lpm_trie_key_u8, data) % sizeof(u32));
>
> #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(CONFIG_64BIT)
>
> @@ -229,7 +229,7 @@ static void *trie_lookup_elem(struct bpf_map *map, void *_key)
> {
> struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
> struct lpm_trie_node *node, *found = NULL;
> - struct bpf_lpm_trie_key *key = _key;
> + struct bpf_lpm_trie_key_u8 *key = _key;
>
> if (key->prefixlen > trie->max_prefixlen)
> return NULL;
> @@ -309,7 +309,7 @@ static long trie_update_elem(struct bpf_map *map,
> struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
> struct lpm_trie_node *node, *im_node = NULL, *new_node = NULL;
> struct lpm_trie_node __rcu **slot;
> - struct bpf_lpm_trie_key *key = _key;
> + struct bpf_lpm_trie_key_u8 *key = _key;
> unsigned long irq_flags;
> unsigned int next_bit;
> size_t matchlen = 0;
> @@ -437,7 +437,7 @@ static long trie_update_elem(struct bpf_map *map,
> static long trie_delete_elem(struct bpf_map *map, void *_key)
> {
> struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
> - struct bpf_lpm_trie_key *key = _key;
> + struct bpf_lpm_trie_key_u8 *key = _key;
> struct lpm_trie_node __rcu **trim, **trim2;
> struct lpm_trie_node *node, *parent;
> unsigned long irq_flags;
> @@ -536,7 +536,7 @@ static long trie_delete_elem(struct bpf_map *map, void *_key)
> sizeof(struct lpm_trie_node))
> #define LPM_VAL_SIZE_MIN 1
>
> -#define LPM_KEY_SIZE(X) (sizeof(struct bpf_lpm_trie_key) + (X))
> +#define LPM_KEY_SIZE(X) (sizeof(struct bpf_lpm_trie_key_u8) + (X))
> #define LPM_KEY_SIZE_MAX LPM_KEY_SIZE(LPM_DATA_SIZE_MAX)
> #define LPM_KEY_SIZE_MIN LPM_KEY_SIZE(LPM_DATA_SIZE_MIN)
>
> @@ -565,7 +565,7 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
> /* copy mandatory map attributes */
> bpf_map_init_from_attr(&trie->map, attr);
> trie->data_size = attr->key_size -
> - offsetof(struct bpf_lpm_trie_key, data);
> + offsetof(struct bpf_lpm_trie_key_u8, data);
> trie->max_prefixlen = trie->data_size * 8;
>
> spin_lock_init(&trie->lock);
> @@ -616,7 +616,7 @@ static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)
> {
> struct lpm_trie_node *node, *next_node = NULL, *parent, *search_root;
> struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
> - struct bpf_lpm_trie_key *key = _key, *next_key = _next_key;
> + struct bpf_lpm_trie_key_u8 *key = _key, *next_key = _next_key;
> struct lpm_trie_node **node_stack = NULL;
> int err = 0, stack_ptr = -1;
> unsigned int next_bit;
> @@ -703,7 +703,7 @@ static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)
> }
> do_copy:
> next_key->prefixlen = next_node->prefixlen;
> - memcpy((void *)next_key + offsetof(struct bpf_lpm_trie_key, data),
> + memcpy((void *)next_key + offsetof(struct bpf_lpm_trie_key_u8, data),
> next_node->data, trie->data_size);
> free_stack:
> kfree(node_stack);
> @@ -715,7 +715,7 @@ static int trie_check_btf(const struct bpf_map *map,
> const struct btf_type *key_type,
> const struct btf_type *value_type)
> {
> - /* Keys must have struct bpf_lpm_trie_key embedded. */
> + /* Keys must have struct bpf_lpm_trie_key_u8 embedded. */
> return BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ?
> -EINVAL : 0;
> }
> diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
> index d2fbcf963cdf..07ff471ed6ae 100644
> --- a/samples/bpf/map_perf_test_user.c
> +++ b/samples/bpf/map_perf_test_user.c
> @@ -370,7 +370,7 @@ static void run_perf_test(int tasks)
>
> static void fill_lpm_trie(void)
> {
> - struct bpf_lpm_trie_key *key;
> + struct bpf_lpm_trie_key_u8 *key;
> unsigned long value = 0;
> unsigned int i;
> int r;
> diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c
> index 9d41db09c480..266fdd0b025d 100644
> --- a/samples/bpf/xdp_router_ipv4_user.c
> +++ b/samples/bpf/xdp_router_ipv4_user.c
> @@ -91,7 +91,7 @@ static int recv_msg(struct sockaddr_nl sock_addr, int sock)
> static void read_route(struct nlmsghdr *nh, int nll)
> {
> char dsts[24], gws[24], ifs[16], dsts_len[24], metrics[24];
> - struct bpf_lpm_trie_key *prefix_key;
> + struct bpf_lpm_trie_key_u8 *prefix_key;
> struct rtattr *rt_attr;
> struct rtmsg *rt_msg;
> int rtm_family;
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index 7f24d898efbb..c55244bf1a20 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -77,12 +77,24 @@ struct bpf_insn {
> __s32 imm; /* signed immediate constant */
> };
>
> -/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
> +/* Deprecated: use struct bpf_lpm_trie_key_u8 (when the "data" member is needed for
> + * byte access) or struct bpf_lpm_trie_key_hdr (when using an alternative type for
> + * the trailing flexible array member) instead.
> + */
> struct bpf_lpm_trie_key {
> __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
> __u8 data[0]; /* Arbitrary size */
> };
>
> +/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry, with trailing byte array. */
> +struct bpf_lpm_trie_key_u8 {
> + __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
> + /* up to 32 for AF_INET, 128 for AF_INET6 */
> + __u32 prefixlen;
> + );
> + __u8 data[]; /* Arbitrary size */
> +};
> +
> struct bpf_cgroup_storage_key {
> __u64 cgroup_inode_id; /* cgroup inode id */
> __u32 attach_type; /* program attach type (enum bpf_attach_type) */
> diff --git a/tools/testing/selftests/bpf/progs/map_ptr_kern.c b/tools/testing/selftests/bpf/progs/map_ptr_kern.c
> index 3325da17ec81..efaf622c28dd 100644
> --- a/tools/testing/selftests/bpf/progs/map_ptr_kern.c
> +++ b/tools/testing/selftests/bpf/progs/map_ptr_kern.c
> @@ -316,7 +316,7 @@ struct lpm_trie {
> } __attribute__((preserve_access_index));
>
> struct lpm_key {
> - struct bpf_lpm_trie_key trie_key;
> + struct bpf_lpm_trie_key_hdr trie_key;
> __u32 data;
> };
>
> diff --git a/tools/testing/selftests/bpf/test_lpm_map.c b/tools/testing/selftests/bpf/test_lpm_map.c
> index c028d621c744..d98c72dc563e 100644
> --- a/tools/testing/selftests/bpf/test_lpm_map.c
> +++ b/tools/testing/selftests/bpf/test_lpm_map.c
> @@ -211,7 +211,7 @@ static void test_lpm_map(int keysize)
> volatile size_t n_matches, n_matches_after_delete;
> size_t i, j, n_nodes, n_lookups;
> struct tlpm_node *t, *list = NULL;
> - struct bpf_lpm_trie_key *key;
> + struct bpf_lpm_trie_key_u8 *key;
> uint8_t *data, *value;
> int r, map;
>
> @@ -331,8 +331,8 @@ static void test_lpm_map(int keysize)
> static void test_lpm_ipaddr(void)
> {
> LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
> - struct bpf_lpm_trie_key *key_ipv4;
> - struct bpf_lpm_trie_key *key_ipv6;
> + struct bpf_lpm_trie_key_u8 *key_ipv4;
> + struct bpf_lpm_trie_key_u8 *key_ipv6;
> size_t key_size_ipv4;
> size_t key_size_ipv6;
> int map_fd_ipv4;
> @@ -423,7 +423,7 @@ static void test_lpm_ipaddr(void)
> static void test_lpm_delete(void)
> {
> LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
> - struct bpf_lpm_trie_key *key;
> + struct bpf_lpm_trie_key_u8 *key;
> size_t key_size;
> int map_fd;
> __u64 value;
> @@ -532,7 +532,7 @@ static void test_lpm_delete(void)
> static void test_lpm_get_next_key(void)
> {
> LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
> - struct bpf_lpm_trie_key *key_p, *next_key_p;
> + struct bpf_lpm_trie_key_u8 *key_p, *next_key_p;
> size_t key_size;
> __u32 value = 0;
> int map_fd;
> @@ -693,9 +693,9 @@ static void *lpm_test_command(void *arg)
> {
> int i, j, ret, iter, key_size;
> struct lpm_mt_test_info *info = arg;
> - struct bpf_lpm_trie_key *key_p;
> + struct bpf_lpm_trie_key_u8 *key_p;
>
> - key_size = sizeof(struct bpf_lpm_trie_key) + sizeof(__u32);
> + key_size = sizeof(*key_p) + sizeof(__u32);
> key_p = alloca(key_size);
> for (iter = 0; iter < info->iter; iter++)
> for (i = 0; i < MAX_TEST_KEYS; i++) {
> @@ -717,7 +717,7 @@ static void *lpm_test_command(void *arg)
> ret = bpf_map_lookup_elem(info->map_fd, key_p, &value);
> assert(ret == 0 || errno == ENOENT);
> } else {
> - struct bpf_lpm_trie_key *next_key_p = alloca(key_size);
> + struct bpf_lpm_trie_key_u8 *next_key_p = alloca(key_size);
> ret = bpf_map_get_next_key(info->map_fd, key_p, next_key_p);
> assert(ret == 0 || errno == ENOENT || errno == ENOMEM);
> }
> @@ -752,7 +752,7 @@ static void test_lpm_multi_thread(void)
>
> /* create a trie */
> value_size = sizeof(__u32);
> - key_size = sizeof(struct bpf_lpm_trie_key) + value_size;
> + key_size = sizeof(struct bpf_lpm_trie_key_hdr) + value_size;
> map_fd = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL, key_size, value_size, 100, &opts);
>
> /* create 4 threads to test update, delete, lookup and get_next_key */
On 2/20/24 12:41 AM, Kees Cook wrote:
> Replace deprecated 0-length array in struct bpf_lpm_trie_key with
> flexible array. Found with GCC 13:
>
> ../kernel/bpf/lpm_trie.c:207:51: warning: array subscript i is outside array bounds of 'const __u8[0]' {aka 'const unsigned char[]'} [-Warray-bounds=]
> 207 | *(__be16 *)&key->data[i]);
> | ^~~~~~~~~~~~~
> ../include/uapi/linux/swab.h:102:54: note: in definition of macro '__swab16'
> 102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
> | ^
> ../include/linux/byteorder/generic.h:97:21: note: in expansion of macro '__be16_to_cpu'
> 97 | #define be16_to_cpu __be16_to_cpu
> | ^~~~~~~~~~~~~
> ../kernel/bpf/lpm_trie.c:206:28: note: in expansion of macro 'be16_to_cpu'
> 206 | u16 diff = be16_to_cpu(*(__be16 *)&node->data[i]
> ^
> | ^~~~~~~~~~~
> In file included from ../include/linux/bpf.h:7:
> ../include/uapi/linux/bpf.h:82:17: note: while referencing 'data'
> 82 | __u8 data[0]; /* Arbitrary size */
> | ^~~~
>
> And found at run-time under CONFIG_FORTIFY_SOURCE:
>
> UBSAN: array-index-out-of-bounds in kernel/bpf/lpm_trie.c:218:49
> index 0 is out of range for type '__u8 [*]'
>
> Changing struct bpf_lpm_trie_key is difficult since has been used by
> userspace. For example, in Cilium:
>
> struct egress_gw_policy_key {
> struct bpf_lpm_trie_key lpm_key;
> __u32 saddr;
> __u32 daddr;
> };
>
> While direct references to the "data" member haven't been found, there
> are static initializers what include the final member. For example,
> the "{}" here:
>
> struct egress_gw_policy_key in_key = {
> .lpm_key = { 32 + 24, {} },
> .saddr = CLIENT_IP,
> .daddr = EXTERNAL_SVC_IP & 0Xffffff,
> };
>
> To avoid the build time and run time warnings seen with a 0-sized
> trailing array for struct bpf_lpm_trie_key, introduce a new struct
> that correctly uses a flexible array for the trailing bytes,
> struct bpf_lpm_trie_key_u8. As part of this, include the "header"
> portion (which is just the "prefixlen" member), so it can be used
> by anything building a bpf_lpr_trie_key that has trailing members that
> aren't a u8 flexible array (like the self-test[1]), which is named
> struct bpf_lpm_trie_key_hdr.
>
> Adjust the kernel code to use struct bpf_lpm_trie_key_u8 through-out,
> and for the selftest to use struct bpf_lpm_trie_key_hdr. Add a comment
> to the UAPI header directing folks to the two new options.
>
> Link: https://lore.kernel.org/all/202206281009.4332AA33@keescook/ [1]
> Reported-by: Mark Rutland <[email protected]>
> Closes: https://paste.debian.net/hidden/ca500597/
> Signed-off-by: Kees Cook <[email protected]>
> ---
> v3- create a new pair of structs -- leave old struct alone
> v2- https://lore.kernel.org/lkml/[email protected]/
> v1- https://lore.kernel.org/lkml/[email protected]/
> Cc: Daniel Borkmann <[email protected]>
> Cc: Alexei Starovoitov <[email protected]>
> Cc: Andrii Nakryiko <[email protected]>
> Cc: Martin KaFai Lau <[email protected]>
> Cc: Song Liu <[email protected]>
> Cc: Yonghong Song <[email protected]>
> Cc: John Fastabend <[email protected]>
> Cc: KP Singh <[email protected]>
> Cc: Stanislav Fomichev <[email protected]>
> Cc: Hao Luo <[email protected]>
> Cc: Jiri Olsa <[email protected]>
> Cc: Mykola Lysenko <[email protected]>
> Cc: Shuah Khan <[email protected]>
> Cc: Haowen Bai <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> Documentation/bpf/map_lpm_trie.rst | 2 +-
> include/uapi/linux/bpf.h | 14 ++++++++++++-
> kernel/bpf/lpm_trie.c | 20 +++++++++----------
> samples/bpf/map_perf_test_user.c | 2 +-
> samples/bpf/xdp_router_ipv4_user.c | 2 +-
> tools/include/uapi/linux/bpf.h | 14 ++++++++++++-
> .../selftests/bpf/progs/map_ptr_kern.c | 2 +-
> tools/testing/selftests/bpf/test_lpm_map.c | 18 ++++++++---------
> 8 files changed, 49 insertions(+), 25 deletions(-)
>
> diff --git a/Documentation/bpf/map_lpm_trie.rst b/Documentation/bpf/map_lpm_trie.rst
> index 74d64a30f500..f9cd579496c9 100644
> --- a/Documentation/bpf/map_lpm_trie.rst
> +++ b/Documentation/bpf/map_lpm_trie.rst
> @@ -17,7 +17,7 @@ significant byte.
>
> LPM tries may be created with a maximum prefix length that is a multiple
> of 8, in the range from 8 to 2048. The key used for lookup and update
> -operations is a ``struct bpf_lpm_trie_key``, extended by
> +operations is a ``struct bpf_lpm_trie_key_u8``, extended by
> ``max_prefixlen/8`` bytes.
>
> - For IPv4 addresses the data length is 4 bytes
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 754e68ca8744..c5a46d12076e 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -77,12 +77,24 @@ struct bpf_insn {
> __s32 imm; /* signed immediate constant */
> };
>
> -/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
> +/* Deprecated: use struct bpf_lpm_trie_key_u8 (when the "data" member is needed for
> + * byte access) or struct bpf_lpm_trie_key_hdr (when using an alternative type for
> + * the trailing flexible array member) instead.
> + */
> struct bpf_lpm_trie_key {
> __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
> __u8 data[0]; /* Arbitrary size */
> };
>
> +/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry, with trailing byte array. */
> +struct bpf_lpm_trie_key_u8 {
> + __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
> + /* up to 32 for AF_INET, 128 for AF_INET6 */
> + __u32 prefixlen;
> + );
> + __u8 data[]; /* Arbitrary size */
> +};
> +
> struct bpf_cgroup_storage_key {
> __u64 cgroup_inode_id; /* cgroup inode id */
> __u32 attach_type; /* program attach type (enum bpf_attach_type) */
> diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
> index b32be680da6c..050fe1ebf0f7 100644
> --- a/kernel/bpf/lpm_trie.c
> +++ b/kernel/bpf/lpm_trie.c
> @@ -164,13 +164,13 @@ static inline int extract_bit(const u8 *data, size_t index)
> */
> static size_t longest_prefix_match(const struct lpm_trie *trie,
> const struct lpm_trie_node *node,
> - const struct bpf_lpm_trie_key *key)
> + const struct bpf_lpm_trie_key_u8 *key)
> {
> u32 limit = min(node->prefixlen, key->prefixlen);
> u32 prefixlen = 0, i = 0;
>
> BUILD_BUG_ON(offsetof(struct lpm_trie_node, data) % sizeof(u32));
> - BUILD_BUG_ON(offsetof(struct bpf_lpm_trie_key, data) % sizeof(u32));
> + BUILD_BUG_ON(offsetof(struct bpf_lpm_trie_key_u8, data) % sizeof(u32));
>
> #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(CONFIG_64BIT)
>
> @@ -229,7 +229,7 @@ static void *trie_lookup_elem(struct bpf_map *map, void *_key)
> {
> struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
> struct lpm_trie_node *node, *found = NULL;
> - struct bpf_lpm_trie_key *key = _key;
> + struct bpf_lpm_trie_key_u8 *key = _key;
>
> if (key->prefixlen > trie->max_prefixlen)
> return NULL;
> @@ -309,7 +309,7 @@ static long trie_update_elem(struct bpf_map *map,
> struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
> struct lpm_trie_node *node, *im_node = NULL, *new_node = NULL;
> struct lpm_trie_node __rcu **slot;
> - struct bpf_lpm_trie_key *key = _key;
> + struct bpf_lpm_trie_key_u8 *key = _key;
> unsigned long irq_flags;
> unsigned int next_bit;
> size_t matchlen = 0;
> @@ -437,7 +437,7 @@ static long trie_update_elem(struct bpf_map *map,
> static long trie_delete_elem(struct bpf_map *map, void *_key)
> {
> struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
> - struct bpf_lpm_trie_key *key = _key;
> + struct bpf_lpm_trie_key_u8 *key = _key;
> struct lpm_trie_node __rcu **trim, **trim2;
> struct lpm_trie_node *node, *parent;
> unsigned long irq_flags;
> @@ -536,7 +536,7 @@ static long trie_delete_elem(struct bpf_map *map, void *_key)
> sizeof(struct lpm_trie_node))
> #define LPM_VAL_SIZE_MIN 1
>
> -#define LPM_KEY_SIZE(X) (sizeof(struct bpf_lpm_trie_key) + (X))
> +#define LPM_KEY_SIZE(X) (sizeof(struct bpf_lpm_trie_key_u8) + (X))
> #define LPM_KEY_SIZE_MAX LPM_KEY_SIZE(LPM_DATA_SIZE_MAX)
> #define LPM_KEY_SIZE_MIN LPM_KEY_SIZE(LPM_DATA_SIZE_MIN)
>
> @@ -565,7 +565,7 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
> /* copy mandatory map attributes */
> bpf_map_init_from_attr(&trie->map, attr);
> trie->data_size = attr->key_size -
> - offsetof(struct bpf_lpm_trie_key, data);
> + offsetof(struct bpf_lpm_trie_key_u8, data);
> trie->max_prefixlen = trie->data_size * 8;
>
> spin_lock_init(&trie->lock);
> @@ -616,7 +616,7 @@ static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)
> {
> struct lpm_trie_node *node, *next_node = NULL, *parent, *search_root;
> struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
> - struct bpf_lpm_trie_key *key = _key, *next_key = _next_key;
> + struct bpf_lpm_trie_key_u8 *key = _key, *next_key = _next_key;
> struct lpm_trie_node **node_stack = NULL;
> int err = 0, stack_ptr = -1;
> unsigned int next_bit;
> @@ -703,7 +703,7 @@ static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)
> }
> do_copy:
> next_key->prefixlen = next_node->prefixlen;
> - memcpy((void *)next_key + offsetof(struct bpf_lpm_trie_key, data),
> + memcpy((void *)next_key + offsetof(struct bpf_lpm_trie_key_u8, data),
> next_node->data, trie->data_size);
> free_stack:
> kfree(node_stack);
> @@ -715,7 +715,7 @@ static int trie_check_btf(const struct bpf_map *map,
> const struct btf_type *key_type,
> const struct btf_type *value_type)
> {
> - /* Keys must have struct bpf_lpm_trie_key embedded. */
> + /* Keys must have struct bpf_lpm_trie_key_u8 embedded. */
> return BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ?
> -EINVAL : 0;
> }
> diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
> index d2fbcf963cdf..07ff471ed6ae 100644
> --- a/samples/bpf/map_perf_test_user.c
> +++ b/samples/bpf/map_perf_test_user.c
> @@ -370,7 +370,7 @@ static void run_perf_test(int tasks)
>
> static void fill_lpm_trie(void)
> {
> - struct bpf_lpm_trie_key *key;
> + struct bpf_lpm_trie_key_u8 *key;
> unsigned long value = 0;
> unsigned int i;
> int r;
> diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c
> index 9d41db09c480..266fdd0b025d 100644
> --- a/samples/bpf/xdp_router_ipv4_user.c
> +++ b/samples/bpf/xdp_router_ipv4_user.c
> @@ -91,7 +91,7 @@ static int recv_msg(struct sockaddr_nl sock_addr, int sock)
> static void read_route(struct nlmsghdr *nh, int nll)
> {
> char dsts[24], gws[24], ifs[16], dsts_len[24], metrics[24];
> - struct bpf_lpm_trie_key *prefix_key;
> + struct bpf_lpm_trie_key_u8 *prefix_key;
> struct rtattr *rt_attr;
> struct rtmsg *rt_msg;
> int rtm_family;
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index 7f24d898efbb..c55244bf1a20 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -77,12 +77,24 @@ struct bpf_insn {
> __s32 imm; /* signed immediate constant */
> };
>
> -/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
> +/* Deprecated: use struct bpf_lpm_trie_key_u8 (when the "data" member is needed for
> + * byte access) or struct bpf_lpm_trie_key_hdr (when using an alternative type for
> + * the trailing flexible array member) instead.
> + */
> struct bpf_lpm_trie_key {
> __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
> __u8 data[0]; /* Arbitrary size */
> };
>
> +/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry, with trailing byte array. */
> +struct bpf_lpm_trie_key_u8 {
> + __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
> + /* up to 32 for AF_INET, 128 for AF_INET6 */
> + __u32 prefixlen;
> + );
> + __u8 data[]; /* Arbitrary size */
> +};
> +
> struct bpf_cgroup_storage_key {
> __u64 cgroup_inode_id; /* cgroup inode id */
> __u32 attach_type; /* program attach type (enum bpf_attach_type) */
This fails the BPF CI :
[...]
INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/bpf/skel_internal.h
INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/bpf/libbpf_version.h
INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/bpf/usdt.bpf.h
In file included from urandom_read_lib1.c:7:
In file included from /tmp/work/bpf/bpf/tools/lib/bpf/libbpf_internal.h:20:
In file included from /tmp/work/bpf/bpf/tools/lib/bpf/relo_core.h:7:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: type name requires a specifier or qualifier
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:58: error: expected identifier
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:93:18: error: unexpected ';' before ')'
93 | __u32 prefixlen;
| ^
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:95:7: error: flexible array member 'data' not allowed in otherwise empty struct
95 | __u8 data[]; /* Arbitrary size */
| ^
HOSTCC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/fixdep.o
4 errors generated.
GEN /tmp/work/bpf/bpf/tools/testing/selftests/bpf/bpf-syscall.2
HOSTLD /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/fixdep-in.o
LINK /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/fixdep
make: *** [Makefile:230: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/liburandom_read.so] Error 1
make: *** Waiting for unfinished jobs....
INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/bpf/bpf_helper_defs.h
INSTALL libbpf_headers
GEN /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.pc
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/libbpf.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/str_error.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/bpf.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/nlattr.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/btf.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/netlink.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/bpf_prog_linfo.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/libbpf_probes.o
Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/hashmap.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/libbpf_errno.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/btf_dump.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/ringbuf.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/strset.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/linker.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/gen_loader.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/relo_core.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/usdt.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/zip.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/elf.o
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/features.o
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/
MKDIR /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/netlink.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/bpf.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/nlattr.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/bpf_prog_linfo.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/btf.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf_errno.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/str_error.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf_probes.o
In file included from /tmp/work/bpf/bpf/tools/include/linux/filter.h:8,
from features.c:4:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/hashmap.o
In file included from bpf_prog_linfo.c:7:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from libbpf.h:18,
from libbpf_errno.c:14:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from /tmp/work/bpf/bpf/tools/include/linux/filter.h:8,
from gen_loader.c:7:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from bpf.c:30:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from libbpf.c:31:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from libbpf.h:18,
from relo_core.c:64:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from bpf_prog_linfo.c:7:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from libbpf.h:18,
from libbpf_errno.c:14:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from bpf.c:30:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from ringbuf.c:15:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from libbpf.h:18,
from btf_dump.c:22:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from relo_core.h:7,
from libbpf_internal.h:20,
from strset.c:9:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from bpf.h:26,
from usdt.c:18:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from relo_core.h:7,
from libbpf_internal.h:20,
from nlattr.c:14:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from relo_core.h:7,
from libbpf_internal.h:20,
from elf.c:11:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from libbpf.h:18,
from linker.c:19:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/btf_dump.o
In file included from bpf.h:26,
from btf.c:20:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from libbpf.c:31:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from relo_core.h:7,
from libbpf_internal.h:20,
from zip.c:16:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from relo_core.h:7,
from libbpf_internal.h:20,
from nlattr.c:14:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/bpf_prog_linfo.o] Error 1
make[3]: *** Waiting for unfinished jobs....
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/strset.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/nlattr.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/libbpf_errno.o] Error 1
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/ringbuf.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/strset.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/linker.o
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/gen_loader.o
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:106: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/bpf_prog_linfo.o] Error 1
make[3]: *** Waiting for unfinished jobs....
In file included from bpf.h:26,
from btf.c:20:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/elf.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:106: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf_errno.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/zip.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/features.o] Error 1
GEN /tmp/work/bpf/bpf/tools/testing/selftests/bpf/bpf-helpers.7
In file included from libbpf.h:18,
from btf_dump.c:22:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/usdt.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:106: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/nlattr.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/ringbuf.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/relo_core.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/gen_loader.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/bpf.o] Error 1
In file included from /tmp/work/bpf/bpf/tools/include/linux/filter.h:8,
from gen_loader.c:7:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from ringbuf.c:15:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:106: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/bpf.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/btf_dump.o] Error 1
In file included from relo_core.h:7,
from libbpf_internal.h:20,
from strset.c:9:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
In file included from libbpf.h:18,
from linker.c:19:
/tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: expected specifier-qualifier-list before ‘__struct_group’
91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
| ^~~~~~~~~~~~~~
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/linker.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/strset.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/btf_dump.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/ringbuf.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/gen_loader.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/btf.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/linker.o] Error 1
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/btf.o] Error 1
GEN /tmp/work/bpf/bpf/tools/testing/selftests/bpf/bpf-syscall.2
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/libbpf.o] Error 1
make[2]: *** [Makefile:157: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/staticobjs/libbpf-in.o] Error 2
make[2]: *** Waiting for unfinished jobs....
make[3]: *** [/tmp/work/bpf/bpf/tools/build/Makefile.build:105: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf.o] Error 1
make[2]: *** [Makefile:148: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf-in.o] Error 2
make[1]: *** [Makefile:140: all] Error 2
make: *** [Makefile:344: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.a] Error 2
GEN /tmp/work/bpf/bpf/tools/testing/selftests/bpf/bpf-helpers.7
make: Leaving directory '/tmp/work/bpf/bpf/tools/testing/selftests/bpf'
Error: Process completed with exit code 2.
On Tue, Feb 20, 2024 at 11:18:40AM +0100, Daniel Borkmann wrote:
> On 2/20/24 12:41 AM, Kees Cook wrote:
> > Replace deprecated 0-length array in struct bpf_lpm_trie_key with
> > flexible array. Found with GCC 13:
> [...]
> This fails the BPF CI :
>
> [...]
> INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/bpf/skel_internal.h
> INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/bpf/libbpf_version.h
> INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/bpf/usdt.bpf.h
> In file included from urandom_read_lib1.c:7:
> In file included from /tmp/work/bpf/bpf/tools/lib/bpf/libbpf_internal.h:20:
> In file included from /tmp/work/bpf/bpf/tools/lib/bpf/relo_core.h:7:
> /tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:2: error: type name requires a specifier or qualifier
> 91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
> | ^
> /tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:91:58: error: expected identifier
> 91 | __struct_group(bpf_lpm_trie_key_hdr, hdr, /* no attrs */,
> | ^
> /tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:93:18: error: unexpected ';' before ')'
> 93 | __u32 prefixlen;
> | ^
> /tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:95:7: error: flexible array member 'data' not allowed in otherwise empty struct
> 95 | __u8 data[]; /* Arbitrary size */
> | ^
Ah-ha, my test build of cilium happened to cover up the lack of
stddef.h. Fixed now and sending a v4...
--
Kees Cook