* [PATCH bpf-next 0/4] libbpf: deprecate legacy BPF map definitions
@ 2022-01-19 22:57 Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 1/4] selftests/bpf: fail build on compilation warning Andrii Nakryiko
` (3 more replies)
0 siblings, 4 replies; 7+ messages in thread
From: Andrii Nakryiko @ 2022-01-19 22:57 UTC (permalink / raw)
To: bpf, ast, daniel; +Cc: andrii, kernel-team
Officially deprecate legacy BPF map definitions in libbpf. They've been slated
for deprecation for a while in favor of more powerful BTF-defined map
definitions and this patch set adds warnings and a way to enforce this in
libbpf through LIBBPF_STRICT_MAP_DEFINITIONS strict mode flag.
Selftests are fixed up and updated, BPF documentation is updated, bpftool's
strict mode usage is adjusted to avoid breaking users unnecessarily.
Andrii Nakryiko (4):
selftests/bpf: fail build on compilation warning
selftests/bpf: convert remaining legacy map definitions
libbpf: deprecate legacy BPF map definitions
docs/bpf: update BPF map definition example
Documentation/bpf/btf.rst | 21 +++++++---------
tools/bpf/bpftool/main.c | 9 ++++++-
tools/lib/bpf/bpf_helpers.h | 2 +-
tools/lib/bpf/libbpf.c | 8 +++++++
tools/lib/bpf/libbpf_legacy.h | 5 ++++
tools/testing/selftests/bpf/Makefile | 4 ++--
tools/testing/selftests/bpf/prog_tests/btf.c | 4 ++++
.../bpf/progs/freplace_cls_redirect.c | 12 +++++-----
.../selftests/bpf/progs/sample_map_ret0.c | 24 +++++++++----------
.../selftests/bpf/progs/test_btf_haskv.c | 3 +++
.../selftests/bpf/progs/test_btf_newkv.c | 3 +++
.../selftests/bpf/progs/test_btf_nokv.c | 12 +++++-----
.../bpf/progs/test_skb_cgroup_id_kern.c | 12 +++++-----
.../testing/selftests/bpf/progs/test_tc_edt.c | 12 +++++-----
.../bpf/progs/test_tcp_check_syncookie_kern.c | 12 +++++-----
15 files changed, 85 insertions(+), 58 deletions(-)
--
2.30.2
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH bpf-next 1/4] selftests/bpf: fail build on compilation warning
2022-01-19 22:57 [PATCH bpf-next 0/4] libbpf: deprecate legacy BPF map definitions Andrii Nakryiko
@ 2022-01-19 22:57 ` Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 2/4] selftests/bpf: convert remaining legacy map definitions Andrii Nakryiko
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Andrii Nakryiko @ 2022-01-19 22:57 UTC (permalink / raw)
To: bpf, ast, daniel; +Cc: andrii, kernel-team
It's very easy to miss compilation warnings without -Werror, which is
not set for selftests. libbpf and bpftool are already strict about this,
so make selftests/bpf also treat compilation warnings as errors to catch
such regressions early.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
tools/testing/selftests/bpf/Makefile | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 42ffc24e9e71..945f92d71db3 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -21,7 +21,7 @@ endif
BPF_GCC ?= $(shell command -v bpf-gcc;)
SAN_CFLAGS ?=
-CFLAGS += -g -O0 -rdynamic -Wall $(GENFLAGS) $(SAN_CFLAGS) \
+CFLAGS += -g -O0 -rdynamic -Wall -Werror $(GENFLAGS) $(SAN_CFLAGS) \
-I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) \
-I$(TOOLSINCDIR) -I$(APIDIR) -I$(OUTPUT)
LDFLAGS += $(SAN_CFLAGS)
@@ -292,7 +292,7 @@ IS_LITTLE_ENDIAN = $(shell $(CC) -dM -E - </dev/null | \
MENDIAN=$(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian)
CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG))
-BPF_CFLAGS = -g -D__TARGET_ARCH_$(SRCARCH) $(MENDIAN) \
+BPF_CFLAGS = -g -Werror -D__TARGET_ARCH_$(SRCARCH) $(MENDIAN) \
-I$(INCLUDE_DIR) -I$(CURDIR) -I$(APIDIR) \
-I$(abspath $(OUTPUT)/../usr/include)
--
2.30.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH bpf-next 2/4] selftests/bpf: convert remaining legacy map definitions
2022-01-19 22:57 [PATCH bpf-next 0/4] libbpf: deprecate legacy BPF map definitions Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 1/4] selftests/bpf: fail build on compilation warning Andrii Nakryiko
@ 2022-01-19 22:57 ` Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 3/4] libbpf: deprecate legacy BPF " Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 4/4] docs/bpf: update BPF map definition example Andrii Nakryiko
3 siblings, 0 replies; 7+ messages in thread
From: Andrii Nakryiko @ 2022-01-19 22:57 UTC (permalink / raw)
To: bpf, ast, daniel; +Cc: andrii, kernel-team
Converted few remaining legacy BPF map definition to BTF-defined ones.
For the remaining two bpf_map_def-based legacy definitions that we want
to keep for testing purposes until libbpf 1.0 release, guard them in
pragma to suppres deprecation warnings which will be added in libbpf in
the next commit.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
.../bpf/progs/freplace_cls_redirect.c | 12 +++++-----
.../selftests/bpf/progs/sample_map_ret0.c | 24 +++++++++----------
.../selftests/bpf/progs/test_btf_haskv.c | 3 +++
.../selftests/bpf/progs/test_btf_newkv.c | 3 +++
.../selftests/bpf/progs/test_btf_nokv.c | 12 +++++-----
.../bpf/progs/test_skb_cgroup_id_kern.c | 12 +++++-----
.../testing/selftests/bpf/progs/test_tc_edt.c | 12 +++++-----
.../bpf/progs/test_tcp_check_syncookie_kern.c | 12 +++++-----
8 files changed, 48 insertions(+), 42 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/freplace_cls_redirect.c b/tools/testing/selftests/bpf/progs/freplace_cls_redirect.c
index 68a5a9db928a..7e94412d47a5 100644
--- a/tools/testing/selftests/bpf/progs/freplace_cls_redirect.c
+++ b/tools/testing/selftests/bpf/progs/freplace_cls_redirect.c
@@ -7,12 +7,12 @@
#include <bpf/bpf_endian.h>
#include <bpf/bpf_helpers.h>
-struct bpf_map_def SEC("maps") sock_map = {
- .type = BPF_MAP_TYPE_SOCKMAP,
- .key_size = sizeof(int),
- .value_size = sizeof(int),
- .max_entries = 2,
-};
+struct {
+ __uint(type, BPF_MAP_TYPE_SOCKMAP);
+ __type(key, int);
+ __type(value, int);
+ __uint(max_entries, 2);
+} sock_map SEC(".maps");
SEC("freplace/cls_redirect")
int freplace_cls_redirect_test(struct __sk_buff *skb)
diff --git a/tools/testing/selftests/bpf/progs/sample_map_ret0.c b/tools/testing/selftests/bpf/progs/sample_map_ret0.c
index 1612a32007b6..495990d355ef 100644
--- a/tools/testing/selftests/bpf/progs/sample_map_ret0.c
+++ b/tools/testing/selftests/bpf/progs/sample_map_ret0.c
@@ -2,19 +2,19 @@
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
-struct bpf_map_def SEC("maps") htab = {
- .type = BPF_MAP_TYPE_HASH,
- .key_size = sizeof(__u32),
- .value_size = sizeof(long),
- .max_entries = 2,
-};
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, __u32);
+ __type(value, long);
+ __uint(max_entries, 2);
+} htab SEC(".maps");
-struct bpf_map_def SEC("maps") array = {
- .type = BPF_MAP_TYPE_ARRAY,
- .key_size = sizeof(__u32),
- .value_size = sizeof(long),
- .max_entries = 2,
-};
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, __u32);
+ __type(value, long);
+ __uint(max_entries, 2);
+} array SEC(".maps");
/* Sample program which should always load for testing control paths. */
SEC(".text") int func()
diff --git a/tools/testing/selftests/bpf/progs/test_btf_haskv.c b/tools/testing/selftests/bpf/progs/test_btf_haskv.c
index 160ead6c67b2..07c94df13660 100644
--- a/tools/testing/selftests/bpf/progs/test_btf_haskv.c
+++ b/tools/testing/selftests/bpf/progs/test_btf_haskv.c
@@ -9,12 +9,15 @@ struct ipv_counts {
unsigned int v6;
};
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
struct bpf_map_def SEC("maps") btf_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(struct ipv_counts),
.max_entries = 4,
};
+#pragma GCC diagnostic pop
BPF_ANNOTATE_KV_PAIR(btf_map, int, struct ipv_counts);
diff --git a/tools/testing/selftests/bpf/progs/test_btf_newkv.c b/tools/testing/selftests/bpf/progs/test_btf_newkv.c
index 1884a5bd10f5..762671a2e90c 100644
--- a/tools/testing/selftests/bpf/progs/test_btf_newkv.c
+++ b/tools/testing/selftests/bpf/progs/test_btf_newkv.c
@@ -9,6 +9,8 @@ struct ipv_counts {
unsigned int v6;
};
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
/* just to validate we can handle maps in multiple sections */
struct bpf_map_def SEC("maps") btf_map_legacy = {
.type = BPF_MAP_TYPE_ARRAY,
@@ -16,6 +18,7 @@ struct bpf_map_def SEC("maps") btf_map_legacy = {
.value_size = sizeof(long long),
.max_entries = 4,
};
+#pragma GCC diagnostic pop
BPF_ANNOTATE_KV_PAIR(btf_map_legacy, int, struct ipv_counts);
diff --git a/tools/testing/selftests/bpf/progs/test_btf_nokv.c b/tools/testing/selftests/bpf/progs/test_btf_nokv.c
index 15e0f9945fe4..1dabb88f8cb4 100644
--- a/tools/testing/selftests/bpf/progs/test_btf_nokv.c
+++ b/tools/testing/selftests/bpf/progs/test_btf_nokv.c
@@ -8,12 +8,12 @@ struct ipv_counts {
unsigned int v6;
};
-struct bpf_map_def SEC("maps") btf_map = {
- .type = BPF_MAP_TYPE_ARRAY,
- .key_size = sizeof(int),
- .value_size = sizeof(struct ipv_counts),
- .max_entries = 4,
-};
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(key_size, sizeof(int));
+ __uint(value_size, sizeof(struct ipv_counts));
+ __uint(max_entries, 4);
+} btf_map SEC(".maps");
__attribute__((noinline))
int test_long_fname_2(void)
diff --git a/tools/testing/selftests/bpf/progs/test_skb_cgroup_id_kern.c b/tools/testing/selftests/bpf/progs/test_skb_cgroup_id_kern.c
index c304cd5b8cad..37aacc66cd68 100644
--- a/tools/testing/selftests/bpf/progs/test_skb_cgroup_id_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_skb_cgroup_id_kern.c
@@ -10,12 +10,12 @@
#define NUM_CGROUP_LEVELS 4
-struct bpf_map_def SEC("maps") cgroup_ids = {
- .type = BPF_MAP_TYPE_ARRAY,
- .key_size = sizeof(__u32),
- .value_size = sizeof(__u64),
- .max_entries = NUM_CGROUP_LEVELS,
-};
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, __u32);
+ __type(value, __u64);
+ __uint(max_entries, NUM_CGROUP_LEVELS);
+} cgroup_ids SEC(".maps");
static __always_inline void log_nth_level(struct __sk_buff *skb, __u32 level)
{
diff --git a/tools/testing/selftests/bpf/progs/test_tc_edt.c b/tools/testing/selftests/bpf/progs/test_tc_edt.c
index bf28814bfde5..950a70b61e74 100644
--- a/tools/testing/selftests/bpf/progs/test_tc_edt.c
+++ b/tools/testing/selftests/bpf/progs/test_tc_edt.c
@@ -17,12 +17,12 @@
#define THROTTLE_RATE_BPS (5 * 1000 * 1000)
/* flow_key => last_tstamp timestamp used */
-struct bpf_map_def SEC("maps") flow_map = {
- .type = BPF_MAP_TYPE_HASH,
- .key_size = sizeof(uint32_t),
- .value_size = sizeof(uint64_t),
- .max_entries = 1,
-};
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, uint32_t);
+ __type(value, uint64_t);
+ __uint(max_entries, 1);
+} flow_map SEC(".maps");
static inline int throttle_flow(struct __sk_buff *skb)
{
diff --git a/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c b/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c
index cd747cd93dbe..6edebce563b5 100644
--- a/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c
@@ -16,12 +16,12 @@
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
-struct bpf_map_def SEC("maps") results = {
- .type = BPF_MAP_TYPE_ARRAY,
- .key_size = sizeof(__u32),
- .value_size = sizeof(__u32),
- .max_entries = 3,
-};
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, __u32);
+ __type(value, __u32);
+ __uint(max_entries, 3);
+} results SEC(".maps");
static __always_inline __s64 gen_syncookie(void *data_end, struct bpf_sock *sk,
void *iph, __u32 ip_size,
--
2.30.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH bpf-next 3/4] libbpf: deprecate legacy BPF map definitions
2022-01-19 22:57 [PATCH bpf-next 0/4] libbpf: deprecate legacy BPF map definitions Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 1/4] selftests/bpf: fail build on compilation warning Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 2/4] selftests/bpf: convert remaining legacy map definitions Andrii Nakryiko
@ 2022-01-19 22:57 ` Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 4/4] docs/bpf: update BPF map definition example Andrii Nakryiko
3 siblings, 0 replies; 7+ messages in thread
From: Andrii Nakryiko @ 2022-01-19 22:57 UTC (permalink / raw)
To: bpf, ast, daniel; +Cc: andrii, kernel-team
Enact deprecation of legacy BPF map definition in SEC("maps") ([0]). For
the definitions themselves introduce LIBBPF_STRICT_MAP_DEFINITIONS flag
for libbpf strict mode. If it is set, error out on any struct
bpf_map_def-based map definition. If not set, libbpf will print out
a warning for each legacy BPF map to raise awareness that it goes away.
For any use of BPF_ANNOTATE_KV_PAIR() macro providing a legacy way to
associate BTF key/value type information with legacy BPF map definition,
warn through libbpf's pr_warn() error message (but don't fail BPF object
open).
BPF-side struct bpf_map_def is marked as deprecated. User-space struct
bpf_map_def has to be used internally in libbpf, so it is left
untouched. It should be enough for bpf_map__def() to be marked
deprecated to raise awareness that it goes away.
bpftool is an interesting case that utilizes libbpf to open BPF ELF
object to generate skeleton. As such, even though bpftool itself uses
full on strict libbpf mode (LIBBPF_STRICT_ALL), it has to relax it a bit
for BPF map definition handling to minimize unnecessary disruptions. So
opt-out of LIBBPF_STRICT_MAP_DEFINITIONS for bpftool. User's code that
will later use generated skeleton will make its own decision whether to
enforce LIBBPF_STRICT_MAP_DEFINITIONS or not.
There are few tests in selftests/bpf that are consciously using legacy
BPF map definitions to test libbpf functionality. For those, temporary
opt out of LIBBPF_STRICT_MAP_DEFINITIONS mode for the duration of those
tests.
[0] Closes: https://github.com/libbpf/libbpf/issues/272
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
tools/bpf/bpftool/main.c | 9 ++++++++-
tools/lib/bpf/bpf_helpers.h | 2 +-
tools/lib/bpf/libbpf.c | 8 ++++++++
tools/lib/bpf/libbpf_legacy.h | 5 +++++
tools/testing/selftests/bpf/prog_tests/btf.c | 4 ++++
5 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index 020e91a542d5..9d01fa9de033 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -478,7 +478,14 @@ int main(int argc, char **argv)
}
if (!legacy_libbpf) {
- ret = libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
+ enum libbpf_strict_mode mode;
+
+ /* Allow legacy map definitions for skeleton generation.
+ * It will still be rejected if users use LIBBPF_STRICT_ALL
+ * mode for loading generated skeleton.
+ */
+ mode = (__LIBBPF_STRICT_LAST - 1) & ~LIBBPF_STRICT_MAP_DEFINITIONS;
+ ret = libbpf_set_strict_mode(mode);
if (ret)
p_err("failed to enable libbpf strict mode: %d", ret);
}
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 963b1060d944..44df982d2a5c 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -133,7 +133,7 @@ struct bpf_map_def {
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
-};
+} __attribute__((deprecated("use BTF-defined maps in .maps section")));
enum libbpf_pin_type {
LIBBPF_PIN_NONE,
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index fdb3536afa7d..fc6d530e20db 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1937,6 +1937,11 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
if (obj->efile.maps_shndx < 0)
return 0;
+ if (libbpf_mode & LIBBPF_STRICT_MAP_DEFINITIONS) {
+ pr_warn("legacy map definitions in SEC(\"maps\") are not supported\n");
+ return -EOPNOTSUPP;
+ }
+
if (!symbols)
return -EINVAL;
@@ -1999,6 +2004,8 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
return -LIBBPF_ERRNO__FORMAT;
}
+ pr_warn("map '%s' (legacy): legacy map definitions are deprecated, use BTF-defined maps instead\n", map_name);
+
if (ELF64_ST_BIND(sym->st_info) == STB_LOCAL) {
pr_warn("map '%s' (legacy): static maps are not supported\n", map_name);
return -ENOTSUP;
@@ -4190,6 +4197,7 @@ static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map)
return 0;
if (!bpf_map__is_internal(map)) {
+ pr_warn("Use of BPF_ANNOTATE_KV_PAIR is deprecated, use BTF-defined maps in .maps section instead\n");
ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size,
def->value_size, &key_type_id,
&value_type_id);
diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h
index 79131f761a27..3c2b281c2bc3 100644
--- a/tools/lib/bpf/libbpf_legacy.h
+++ b/tools/lib/bpf/libbpf_legacy.h
@@ -73,6 +73,11 @@ enum libbpf_strict_mode {
* operation.
*/
LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK = 0x10,
+ /*
+ * Error out on any SEC("maps") map definition, which are deprecated
+ * in favor of BTF-defined map definitions in SEC(".maps").
+ */
+ LIBBPF_STRICT_MAP_DEFINITIONS = 0x20,
__LIBBPF_STRICT_LAST,
};
diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index 8ba53acf9eb4..14f9b6136794 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -4560,6 +4560,8 @@ static void do_test_file(unsigned int test_num)
has_btf_ext = btf_ext != NULL;
btf_ext__free(btf_ext);
+ /* temporary disable LIBBPF_STRICT_MAP_DEFINITIONS to test legacy maps */
+ libbpf_set_strict_mode((__LIBBPF_STRICT_LAST - 1) & ~LIBBPF_STRICT_MAP_DEFINITIONS);
obj = bpf_object__open(test->file);
err = libbpf_get_error(obj);
if (CHECK(err, "obj: %d", err))
@@ -4684,6 +4686,8 @@ static void do_test_file(unsigned int test_num)
fprintf(stderr, "OK");
done:
+ libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
+
btf__free(btf);
free(func_info);
bpf_object__close(obj);
--
2.30.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH bpf-next 4/4] docs/bpf: update BPF map definition example
2022-01-19 22:57 [PATCH bpf-next 0/4] libbpf: deprecate legacy BPF map definitions Andrii Nakryiko
` (2 preceding siblings ...)
2022-01-19 22:57 ` [PATCH bpf-next 3/4] libbpf: deprecate legacy BPF " Andrii Nakryiko
@ 2022-01-19 22:57 ` Andrii Nakryiko
2022-01-20 4:01 ` Alexei Starovoitov
3 siblings, 1 reply; 7+ messages in thread
From: Andrii Nakryiko @ 2022-01-19 22:57 UTC (permalink / raw)
To: bpf, ast, daniel; +Cc: andrii, kernel-team
Use BTF-defined map definition in the documentation example.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
Documentation/bpf/btf.rst | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst
index 1ebf4c5c7ddc..07165682da2b 100644
--- a/Documentation/bpf/btf.rst
+++ b/Documentation/bpf/btf.rst
@@ -565,18 +565,15 @@ A map can be created with ``btf_fd`` and specified key/value type id.::
In libbpf, the map can be defined with extra annotation like below:
::
- struct bpf_map_def SEC("maps") btf_map = {
- .type = BPF_MAP_TYPE_ARRAY,
- .key_size = sizeof(int),
- .value_size = sizeof(struct ipv_counts),
- .max_entries = 4,
- };
- BPF_ANNOTATE_KV_PAIR(btf_map, int, struct ipv_counts);
-
-Here, the parameters for macro BPF_ANNOTATE_KV_PAIR are map name, key and
-value types for the map. During ELF parsing, libbpf is able to extract
-key/value type_id's and assign them to BPF_MAP_CREATE attributes
-automatically.
+ struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, int);
+ __type(value, struct ipv_counts);
+ __uint(max_entries, 4);
+ } btf_map SEC(".maps");
+
+During ELF parsing, libbpf is able to extract key/value type_id's and assign
+them to BPF_MAP_CREATE attributes automatically.
.. _BPF_Prog_Load:
--
2.30.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH bpf-next 4/4] docs/bpf: update BPF map definition example
2022-01-19 22:57 ` [PATCH bpf-next 4/4] docs/bpf: update BPF map definition example Andrii Nakryiko
@ 2022-01-20 4:01 ` Alexei Starovoitov
2022-01-20 4:58 ` Andrii Nakryiko
0 siblings, 1 reply; 7+ messages in thread
From: Alexei Starovoitov @ 2022-01-20 4:01 UTC (permalink / raw)
To: Andrii Nakryiko, bpf, ast, daniel; +Cc: kernel-team
On 1/19/22 2:57 PM, Andrii Nakryiko wrote:
> Use BTF-defined map definition in the documentation example.
>
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
> ---
> Documentation/bpf/btf.rst | 21 +++++++++------------
> 1 file changed, 9 insertions(+), 12 deletions(-)
>
> diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst
> index 1ebf4c5c7ddc..07165682da2b 100644
> --- a/Documentation/bpf/btf.rst
> +++ b/Documentation/bpf/btf.rst
> @@ -565,18 +565,15 @@ A map can be created with ``btf_fd`` and specified key/value type id.::
> In libbpf, the map can be defined with extra annotation like below:
> ::
>
> - struct bpf_map_def SEC("maps") btf_map = {
> - .type = BPF_MAP_TYPE_ARRAY,
> - .key_size = sizeof(int),
> - .value_size = sizeof(struct ipv_counts),
> - .max_entries = 4,
> - };
> - BPF_ANNOTATE_KV_PAIR(btf_map, int, struct ipv_counts);
There is another bpf_map_def in btf.rst.
Maybe convert it as well? Especially considering it's an example of
BTF enabled pretty printing.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH bpf-next 4/4] docs/bpf: update BPF map definition example
2022-01-20 4:01 ` Alexei Starovoitov
@ 2022-01-20 4:58 ` Andrii Nakryiko
0 siblings, 0 replies; 7+ messages in thread
From: Andrii Nakryiko @ 2022-01-20 4:58 UTC (permalink / raw)
To: Alexei Starovoitov
Cc: Andrii Nakryiko, bpf, Alexei Starovoitov, Daniel Borkmann, Kernel Team
On Wed, Jan 19, 2022 at 8:01 PM Alexei Starovoitov <ast@fb.com> wrote:
>
> On 1/19/22 2:57 PM, Andrii Nakryiko wrote:
> > Use BTF-defined map definition in the documentation example.
> >
> > Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
> > ---
> > Documentation/bpf/btf.rst | 21 +++++++++------------
> > 1 file changed, 9 insertions(+), 12 deletions(-)
> >
> > diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst
> > index 1ebf4c5c7ddc..07165682da2b 100644
> > --- a/Documentation/bpf/btf.rst
> > +++ b/Documentation/bpf/btf.rst
> > @@ -565,18 +565,15 @@ A map can be created with ``btf_fd`` and specified key/value type id.::
> > In libbpf, the map can be defined with extra annotation like below:
> > ::
> >
> > - struct bpf_map_def SEC("maps") btf_map = {
> > - .type = BPF_MAP_TYPE_ARRAY,
> > - .key_size = sizeof(int),
> > - .value_size = sizeof(struct ipv_counts),
> > - .max_entries = 4,
> > - };
> > - BPF_ANNOTATE_KV_PAIR(btf_map, int, struct ipv_counts);
>
> There is another bpf_map_def in btf.rst.
> Maybe convert it as well? Especially considering it's an example of
> BTF enabled pretty printing.
My bad, not sure how I missed it while grepping. I'll convert that one
as well in v2.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-01-20 4:58 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-19 22:57 [PATCH bpf-next 0/4] libbpf: deprecate legacy BPF map definitions Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 1/4] selftests/bpf: fail build on compilation warning Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 2/4] selftests/bpf: convert remaining legacy map definitions Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 3/4] libbpf: deprecate legacy BPF " Andrii Nakryiko
2022-01-19 22:57 ` [PATCH bpf-next 4/4] docs/bpf: update BPF map definition example Andrii Nakryiko
2022-01-20 4:01 ` Alexei Starovoitov
2022-01-20 4:58 ` Andrii Nakryiko
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