* [PATCH bpf-next 1/3] libbpf: put Kconfig externs into .kconfig section
2019-12-19 0:28 [PATCH bpf-next 0/3] Libbpf extern support improvements Andrii Nakryiko
@ 2019-12-19 0:28 ` Andrii Nakryiko
2019-12-19 0:28 ` [PATCH bpf-next 2/3] libbpf: allow to augment system Kconfig through extra optional config Andrii Nakryiko
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Andrii Nakryiko @ 2019-12-19 0:28 UTC (permalink / raw)
To: bpf, netdev, ast, daniel; +Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko
Move Kconfig-provided externs into custom .kconfig section. Add __kconfig into
bpf_helpers.h for user convenience. Update selftests accordingly.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/bpf/bpftool/gen.c | 8 +--
tools/lib/bpf/bpf_helpers.h | 2 +
tools/lib/bpf/libbpf.c | 58 +++++++++++--------
.../selftests/bpf/prog_tests/skeleton.c | 16 +++--
.../selftests/bpf/progs/test_core_extern.c | 20 +++----
.../selftests/bpf/progs/test_skeleton.c | 4 +-
6 files changed, 60 insertions(+), 48 deletions(-)
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 8d93c8f90f82..87ef7c17c61c 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -83,8 +83,8 @@ static const char *get_map_ident(const struct bpf_map *map)
return "rodata";
else if (str_has_suffix(name, ".bss"))
return "bss";
- else if (str_has_suffix(name, ".extern"))
- return "externs"; /* extern is a C keyword */
+ else if (str_has_suffix(name, ".kconfig"))
+ return "kconfig";
else
return NULL;
}
@@ -112,8 +112,8 @@ static int codegen_datasec_def(struct bpf_object *obj,
sec_ident = "bss";
else if (strcmp(sec_name, ".rodata") == 0)
sec_ident = "rodata";
- else if (strcmp(sec_name, ".extern") == 0)
- sec_ident = "externs"; /* extern is a C keyword */
+ else if (strcmp(sec_name, ".kconfig") == 0)
+ sec_ident = "kconfig";
else
return 0;
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index aa46700075e1..f69cc208778a 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -53,4 +53,6 @@ enum libbpf_tristate {
TRI_MODULE = 2,
};
+#define __kconfig __attribute__((section(".kconfig")))
+
#endif
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 906bbbf7b2e4..ed54a6a7f6f2 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -231,21 +231,21 @@ struct bpf_program {
#define DATA_SEC ".data"
#define BSS_SEC ".bss"
#define RODATA_SEC ".rodata"
-#define EXTERN_SEC ".extern"
+#define KCONFIG_SEC ".kconfig"
enum libbpf_map_type {
LIBBPF_MAP_UNSPEC,
LIBBPF_MAP_DATA,
LIBBPF_MAP_BSS,
LIBBPF_MAP_RODATA,
- LIBBPF_MAP_EXTERN,
+ LIBBPF_MAP_KCONFIG,
};
static const char * const libbpf_type_to_btf_name[] = {
[LIBBPF_MAP_DATA] = DATA_SEC,
[LIBBPF_MAP_BSS] = BSS_SEC,
[LIBBPF_MAP_RODATA] = RODATA_SEC,
- [LIBBPF_MAP_EXTERN] = EXTERN_SEC,
+ [LIBBPF_MAP_KCONFIG] = KCONFIG_SEC,
};
struct bpf_map {
@@ -305,7 +305,7 @@ struct bpf_object {
char *kconfig_path;
struct extern_desc *externs;
int nr_extern;
- int extern_map_idx;
+ int kconfig_map_idx;
bool loaded;
bool has_pseudo_calls;
@@ -606,7 +606,7 @@ static struct bpf_object *bpf_object__new(const char *path,
obj->efile.data_shndx = -1;
obj->efile.rodata_shndx = -1;
obj->efile.bss_shndx = -1;
- obj->extern_map_idx = -1;
+ obj->kconfig_map_idx = -1;
obj->kern_version = get_kernel_version();
obj->loaded = false;
@@ -902,11 +902,25 @@ static size_t bpf_map_mmap_sz(const struct bpf_map *map)
return map_sz;
}
+static char *internal_map_name(struct bpf_object *obj,
+ enum libbpf_map_type type)
+{
+ char map_name[BPF_OBJ_NAME_LEN];
+ const char *sfx = libbpf_type_to_btf_name[type];
+ int sfx_len = max((size_t)7, strlen(sfx));
+ int pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1,
+ strlen(obj->name));
+
+ snprintf(map_name, sizeof(map_name), "%.*s%.*s", pfx_len, obj->name,
+ sfx_len, libbpf_type_to_btf_name[type]);
+
+ return strdup(map_name);
+}
+
static int
bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
int sec_idx, void *data, size_t data_sz)
{
- char map_name[BPF_OBJ_NAME_LEN];
struct bpf_map_def *def;
struct bpf_map *map;
int err;
@@ -918,9 +932,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
map->libbpf_type = type;
map->sec_idx = sec_idx;
map->sec_offset = 0;
- snprintf(map_name, sizeof(map_name), "%.8s%.7s", obj->name,
- libbpf_type_to_btf_name[type]);
- map->name = strdup(map_name);
+ map->name = internal_map_name(obj, type);
if (!map->name) {
pr_warn("failed to alloc map name\n");
return -ENOMEM;
@@ -931,12 +943,12 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
def->key_size = sizeof(int);
def->value_size = data_sz;
def->max_entries = 1;
- def->map_flags = type == LIBBPF_MAP_RODATA || type == LIBBPF_MAP_EXTERN
+ def->map_flags = type == LIBBPF_MAP_RODATA || type == LIBBPF_MAP_KCONFIG
? BPF_F_RDONLY_PROG : 0;
def->map_flags |= BPF_F_MMAPABLE;
pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n",
- map_name, map->sec_idx, map->sec_offset, def->map_flags);
+ map->name, map->sec_idx, map->sec_offset, def->map_flags);
map->mmaped = mmap(NULL, bpf_map_mmap_sz(map), PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
@@ -1232,7 +1244,7 @@ static int bpf_object__read_kernel_config(struct bpf_object *obj,
return err;
}
-static int bpf_object__init_extern_map(struct bpf_object *obj)
+static int bpf_object__init_kconfig_map(struct bpf_object *obj)
{
struct extern_desc *last_ext;
size_t map_sz;
@@ -1244,13 +1256,13 @@ static int bpf_object__init_extern_map(struct bpf_object *obj)
last_ext = &obj->externs[obj->nr_extern - 1];
map_sz = last_ext->data_off + last_ext->sz;
- err = bpf_object__init_internal_map(obj, LIBBPF_MAP_EXTERN,
+ err = bpf_object__init_internal_map(obj, LIBBPF_MAP_KCONFIG,
obj->efile.symbols_shndx,
NULL, map_sz);
if (err)
return err;
- obj->extern_map_idx = obj->nr_maps - 1;
+ obj->kconfig_map_idx = obj->nr_maps - 1;
return 0;
}
@@ -1742,7 +1754,7 @@ static int bpf_object__init_maps(struct bpf_object *obj,
err = bpf_object__init_user_maps(obj, strict);
err = err ?: bpf_object__init_user_btf_maps(obj, strict, pin_root_path);
err = err ?: bpf_object__init_global_data_maps(obj);
- err = err ?: bpf_object__init_extern_map(obj);
+ err = err ?: bpf_object__init_kconfig_map(obj);
if (err)
return err;
@@ -2269,9 +2281,9 @@ static int bpf_object__collect_externs(struct bpf_object *obj)
i, ext->sym_idx, ext->data_off, ext->name);
}
- btf_id = btf__find_by_name(obj->btf, EXTERN_SEC);
+ btf_id = btf__find_by_name(obj->btf, KCONFIG_SEC);
if (btf_id <= 0) {
- pr_warn("no BTF info found for '%s' datasec\n", EXTERN_SEC);
+ pr_warn("no BTF info found for '%s' datasec\n", KCONFIG_SEC);
return -ESRCH;
}
@@ -2361,7 +2373,7 @@ bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
else if (shndx == obj->efile.rodata_shndx)
return LIBBPF_MAP_RODATA;
else if (shndx == obj->efile.symbols_shndx)
- return LIBBPF_MAP_EXTERN;
+ return LIBBPF_MAP_KCONFIG;
else
return LIBBPF_MAP_UNSPEC;
}
@@ -2908,8 +2920,8 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
return err;
}
- /* Freeze .rodata and .extern map as read-only from syscall side. */
- if (map_type == LIBBPF_MAP_RODATA || map_type == LIBBPF_MAP_EXTERN) {
+ /* Freeze .rodata and .kconfig map as read-only from syscall side. */
+ if (map_type == LIBBPF_MAP_RODATA || map_type == LIBBPF_MAP_KCONFIG) {
err = bpf_map_freeze(map->fd);
if (err) {
err = -errno;
@@ -4264,7 +4276,7 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
break;
case RELO_EXTERN:
insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
- insn[0].imm = obj->maps[obj->extern_map_idx].fd;
+ insn[0].imm = obj->maps[obj->kconfig_map_idx].fd;
insn[1].imm = relo->sym_off;
break;
case RELO_CALL:
@@ -4743,7 +4755,7 @@ static int bpf_object__resolve_externs(struct bpf_object *obj,
if (obj->nr_extern == 0)
return 0;
- data = obj->maps[obj->extern_map_idx].mmaped;
+ data = obj->maps[obj->kconfig_map_idx].mmaped;
for (i = 0; i < obj->nr_extern; i++) {
ext = &obj->externs[i];
@@ -7526,7 +7538,7 @@ int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
}
/* externs shouldn't be pre-setup from user code */
- if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_EXTERN)
+ if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_KCONFIG)
*mmaped = (*map)->mmaped;
}
diff --git a/tools/testing/selftests/bpf/prog_tests/skeleton.c b/tools/testing/selftests/bpf/prog_tests/skeleton.c
index ec6f2aec3853..9264a2736018 100644
--- a/tools/testing/selftests/bpf/prog_tests/skeleton.c
+++ b/tools/testing/selftests/bpf/prog_tests/skeleton.c
@@ -15,20 +15,18 @@ void test_skeleton(void)
int duration = 0, err;
struct test_skeleton* skel;
struct test_skeleton__bss *bss;
- struct test_skeleton__externs *exts;
+ struct test_skeleton__kconfig *kcfg;
skel = test_skeleton__open();
if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
return;
- printf("EXTERNS BEFORE: %p\n", skel->externs);
- if (CHECK(skel->externs, "skel_externs", "externs are mmaped()!\n"))
+ if (CHECK(skel->kconfig, "skel_kconfig", "kconfig is mmaped()!\n"))
goto cleanup;
err = test_skeleton__load(skel);
if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err))
goto cleanup;
- printf("EXTERNS AFTER: %p\n", skel->externs);
bss = skel->bss;
bss->in1 = 1;
@@ -37,7 +35,7 @@ void test_skeleton(void)
bss->in4 = 4;
bss->in5.a = 5;
bss->in5.b = 6;
- exts = skel->externs;
+ kcfg = skel->kconfig;
err = test_skeleton__attach(skel);
if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
@@ -55,10 +53,10 @@ void test_skeleton(void)
CHECK(bss->handler_out5.b != 6, "res6", "got %lld != exp %d\n",
bss->handler_out5.b, 6);
- CHECK(bss->bpf_syscall != exts->CONFIG_BPF_SYSCALL, "ext1",
- "got %d != exp %d\n", bss->bpf_syscall, exts->CONFIG_BPF_SYSCALL);
- CHECK(bss->kern_ver != exts->LINUX_KERNEL_VERSION, "ext2",
- "got %d != exp %d\n", bss->kern_ver, exts->LINUX_KERNEL_VERSION);
+ CHECK(bss->bpf_syscall != kcfg->CONFIG_BPF_SYSCALL, "ext1",
+ "got %d != exp %d\n", bss->bpf_syscall, kcfg->CONFIG_BPF_SYSCALL);
+ CHECK(bss->kern_ver != kcfg->LINUX_KERNEL_VERSION, "ext2",
+ "got %d != exp %d\n", bss->kern_ver, kcfg->LINUX_KERNEL_VERSION);
cleanup:
test_skeleton__destroy(skel);
diff --git a/tools/testing/selftests/bpf/progs/test_core_extern.c b/tools/testing/selftests/bpf/progs/test_core_extern.c
index e12f09f9e881..9bfc91d9d004 100644
--- a/tools/testing/selftests/bpf/progs/test_core_extern.c
+++ b/tools/testing/selftests/bpf/progs/test_core_extern.c
@@ -10,16 +10,16 @@
/* non-existing BPF helper, to test dead code elimination */
static int (*bpf_missing_helper)(const void *arg1, int arg2) = (void *) 999;
-extern int LINUX_KERNEL_VERSION;
-extern bool CONFIG_BPF_SYSCALL; /* strong */
-extern enum libbpf_tristate CONFIG_TRISTATE __weak;
-extern bool CONFIG_BOOL __weak;
-extern char CONFIG_CHAR __weak;
-extern uint16_t CONFIG_USHORT __weak;
-extern int CONFIG_INT __weak;
-extern uint64_t CONFIG_ULONG __weak;
-extern const char CONFIG_STR[8] __weak;
-extern uint64_t CONFIG_MISSING __weak;
+extern int LINUX_KERNEL_VERSION __kconfig;
+extern bool CONFIG_BPF_SYSCALL __kconfig; /* strong */
+extern enum libbpf_tristate CONFIG_TRISTATE __kconfig __weak;
+extern bool CONFIG_BOOL __kconfig __weak;
+extern char CONFIG_CHAR __kconfig __weak;
+extern uint16_t CONFIG_USHORT __kconfig __weak;
+extern int CONFIG_INT __kconfig __weak;
+extern uint64_t CONFIG_ULONG __kconfig __weak;
+extern const char CONFIG_STR[8] __kconfig __weak;
+extern uint64_t CONFIG_MISSING __kconfig __weak;
uint64_t kern_ver = -1;
uint64_t bpf_syscall = -1;
diff --git a/tools/testing/selftests/bpf/progs/test_skeleton.c b/tools/testing/selftests/bpf/progs/test_skeleton.c
index 9caa44758ea2..4f69aac5635f 100644
--- a/tools/testing/selftests/bpf/progs/test_skeleton.c
+++ b/tools/testing/selftests/bpf/progs/test_skeleton.c
@@ -21,8 +21,8 @@ char out3 = 0;
long long out4 = 0;
int out1 = 0;
-extern bool CONFIG_BPF_SYSCALL;
-extern int LINUX_KERNEL_VERSION;
+extern bool CONFIG_BPF_SYSCALL __kconfig;
+extern int LINUX_KERNEL_VERSION __kconfig;
bool bpf_syscall = 0;
int kern_ver = 0;
--
2.17.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH bpf-next 2/3] libbpf: allow to augment system Kconfig through extra optional config
2019-12-19 0:28 [PATCH bpf-next 0/3] Libbpf extern support improvements Andrii Nakryiko
2019-12-19 0:28 ` [PATCH bpf-next 1/3] libbpf: put Kconfig externs into .kconfig section Andrii Nakryiko
@ 2019-12-19 0:28 ` Andrii Nakryiko
2019-12-19 0:28 ` [PATCH bpf-next 3/3] libbpf: BTF is required when externs are present Andrii Nakryiko
2019-12-19 1:35 ` [PATCH bpf-next 0/3] Libbpf extern support improvements Alexei Starovoitov
3 siblings, 0 replies; 5+ messages in thread
From: Andrii Nakryiko @ 2019-12-19 0:28 UTC (permalink / raw)
To: bpf, netdev, ast, daniel; +Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko
Instead of all or nothing approach of overriding Kconfig file location, allow
to extend it with extra values and override chosen subset of values though
optional user-provided extra config, passed as a string through open options'
.kconfig option. If same config key is present in both user-supplied config
and Kconfig, user-supplied one wins. This allows applications to more easily
test various conditions despite host kernel's real configuration. If all of
BPF object's __kconfig externs are satisfied from user-supplied config, system
Kconfig won't be read at all.
Simplify selftests by not needing to create temporary Kconfig files.
Suggested-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/lib/bpf/libbpf.c | 204 +++++++++++-------
tools/lib/bpf/libbpf.h | 8 +-
.../selftests/bpf/prog_tests/core_extern.c | 32 +--
3 files changed, 132 insertions(+), 112 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ed54a6a7f6f2..f90db2b18e4b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -302,7 +302,7 @@ struct bpf_object {
size_t nr_maps;
size_t maps_cap;
- char *kconfig_path;
+ char *kconfig;
struct extern_desc *externs;
int nr_extern;
int kconfig_map_idx;
@@ -1149,98 +1149,129 @@ static int set_ext_value_num(struct extern_desc *ext, void *ext_val,
return 0;
}
-static int bpf_object__read_kernel_config(struct bpf_object *obj,
- const char *config_path,
- void *data)
+static int bpf_object__process_kconfig_line(struct bpf_object *obj,
+ char *buf, void *data)
{
- char buf[PATH_MAX], *sep, *value;
struct extern_desc *ext;
+ char *sep, *value;
int len, err = 0;
void *ext_val;
__u64 num;
- gzFile file;
- if (config_path) {
- file = gzopen(config_path, "r");
- } else {
- struct utsname uts;
+ if (strncmp(buf, "CONFIG_", 7))
+ return 0;
- uname(&uts);
- len = snprintf(buf, PATH_MAX, "/boot/config-%s", uts.release);
- if (len < 0)
- return -EINVAL;
- else if (len >= PATH_MAX)
- return -ENAMETOOLONG;
- /* gzopen also accepts uncompressed files. */
- file = gzopen(buf, "r");
- if (!file)
- file = gzopen("/proc/config.gz", "r");
+ sep = strchr(buf, '=');
+ if (!sep) {
+ pr_warn("failed to parse '%s': no separator\n", buf);
+ return -EINVAL;
+ }
+
+ /* Trim ending '\n' */
+ len = strlen(buf);
+ if (buf[len - 1] == '\n')
+ buf[len - 1] = '\0';
+ /* Split on '=' and ensure that a value is present. */
+ *sep = '\0';
+ if (!sep[1]) {
+ *sep = '=';
+ pr_warn("failed to parse '%s': no value\n", buf);
+ return -EINVAL;
+ }
+
+ ext = find_extern_by_name(obj, buf);
+ if (!ext || ext->is_set)
+ return 0;
+
+ ext_val = data + ext->data_off;
+ value = sep + 1;
+
+ switch (*value) {
+ case 'y': case 'n': case 'm':
+ err = set_ext_value_tri(ext, ext_val, *value);
+ break;
+ case '"':
+ err = set_ext_value_str(ext, ext_val, value);
+ break;
+ default:
+ /* assume integer */
+ err = parse_u64(value, &num);
+ if (err) {
+ pr_warn("extern %s=%s should be integer\n",
+ ext->name, value);
+ return err;
+ }
+ err = set_ext_value_num(ext, ext_val, num);
+ break;
}
+ if (err)
+ return err;
+ pr_debug("extern %s=%s\n", ext->name, value);
+ return 0;
+}
+
+static int bpf_object__read_kconfig_file(struct bpf_object *obj, void *data)
+{
+ char buf[PATH_MAX];
+ struct utsname uts;
+ int len, err = 0;
+ gzFile file;
+
+ uname(&uts);
+ len = snprintf(buf, PATH_MAX, "/boot/config-%s", uts.release);
+ if (len < 0)
+ return -EINVAL;
+ else if (len >= PATH_MAX)
+ return -ENAMETOOLONG;
+
+ /* gzopen also accepts uncompressed files. */
+ file = gzopen(buf, "r");
+ if (!file)
+ file = gzopen("/proc/config.gz", "r");
+
if (!file) {
- pr_warn("failed to read kernel config at '%s'\n", config_path);
+ pr_warn("failed to open system Kconfig\n");
return -ENOENT;
}
while (gzgets(file, buf, sizeof(buf))) {
- if (strncmp(buf, "CONFIG_", 7))
- continue;
-
- sep = strchr(buf, '=');
- if (!sep) {
- err = -EINVAL;
- pr_warn("failed to parse '%s': no separator\n", buf);
- goto out;
- }
- /* Trim ending '\n' */
- len = strlen(buf);
- if (buf[len - 1] == '\n')
- buf[len - 1] = '\0';
- /* Split on '=' and ensure that a value is present. */
- *sep = '\0';
- if (!sep[1]) {
- err = -EINVAL;
- *sep = '=';
- pr_warn("failed to parse '%s': no value\n", buf);
+ err = bpf_object__process_kconfig_line(obj, buf, data);
+ if (err) {
+ pr_warn("error parsing system Kconfig line '%s': %d\n",
+ buf, err);
goto out;
}
+ }
- ext = find_extern_by_name(obj, buf);
- if (!ext)
- continue;
- if (ext->is_set) {
- err = -EINVAL;
- pr_warn("re-defining extern '%s' not allowed\n", buf);
- goto out;
- }
+out:
+ gzclose(file);
+ return err;
+}
- ext_val = data + ext->data_off;
- value = sep + 1;
+static int bpf_object__read_kconfig_mem(struct bpf_object *obj,
+ const char *config, void *data)
+{
+ char buf[PATH_MAX];
+ int err = 0;
+ FILE *file;
- switch (*value) {
- case 'y': case 'n': case 'm':
- err = set_ext_value_tri(ext, ext_val, *value);
- break;
- case '"':
- err = set_ext_value_str(ext, ext_val, value);
- break;
- default:
- /* assume integer */
- err = parse_u64(value, &num);
- if (err) {
- pr_warn("extern %s=%s should be integer\n",
- ext->name, value);
- goto out;
- }
- err = set_ext_value_num(ext, ext_val, num);
+ file = fmemopen((void *)config, strlen(config), "r");
+ if (!file) {
+ err = -errno;
+ pr_warn("failed to open in-memory Kconfig: %d\n", err);
+ return err;
+ }
+
+ while (fgets(buf, sizeof(buf), file)) {
+ err = bpf_object__process_kconfig_line(obj, buf, data);
+ if (err) {
+ pr_warn("error parsing in-memory Kconfig line '%s': %d\n",
+ buf, err);
break;
}
- if (err)
- goto out;
- pr_debug("extern %s=%s\n", ext->name, value);
}
-out:
- gzclose(file);
+ fclose(file);
return err;
}
@@ -4567,7 +4598,7 @@ static struct bpf_object *
__bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
const struct bpf_object_open_opts *opts)
{
- const char *obj_name, *kconfig_path;
+ const char *obj_name, *kconfig;
struct bpf_program *prog;
struct bpf_object *obj;
char tmp_name[64];
@@ -4599,10 +4630,10 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
return obj;
obj->relaxed_core_relocs = OPTS_GET(opts, relaxed_core_relocs, false);
- kconfig_path = OPTS_GET(opts, kconfig_path, NULL);
- if (kconfig_path) {
- obj->kconfig_path = strdup(kconfig_path);
- if (!obj->kconfig_path)
+ kconfig = OPTS_GET(opts, kconfig, NULL);
+ if (kconfig) {
+ obj->kconfig = strdup(kconfig);
+ if (!obj->kconfig)
return ERR_PTR(-ENOMEM);
}
@@ -4745,7 +4776,7 @@ static int bpf_object__sanitize_maps(struct bpf_object *obj)
}
static int bpf_object__resolve_externs(struct bpf_object *obj,
- const char *config_path)
+ const char *extra_kconfig)
{
bool need_config = false;
struct extern_desc *ext;
@@ -4779,8 +4810,21 @@ static int bpf_object__resolve_externs(struct bpf_object *obj,
return -EINVAL;
}
}
+ if (need_config && extra_kconfig) {
+ err = bpf_object__read_kconfig_mem(obj, extra_kconfig, data);
+ if (err)
+ return -EINVAL;
+ need_config = false;
+ for (i = 0; i < obj->nr_extern; i++) {
+ ext = &obj->externs[i];
+ if (!ext->is_set) {
+ need_config = true;
+ break;
+ }
+ }
+ }
if (need_config) {
- err = bpf_object__read_kernel_config(obj, config_path, data);
+ err = bpf_object__read_kconfig_file(obj, data);
if (err)
return -EINVAL;
}
@@ -4818,7 +4862,7 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
obj->loaded = true;
err = bpf_object__probe_caps(obj);
- err = err ? : bpf_object__resolve_externs(obj, obj->kconfig_path);
+ err = err ? : bpf_object__resolve_externs(obj, obj->kconfig);
err = err ? : bpf_object__sanitize_and_load_btf(obj);
err = err ? : bpf_object__sanitize_maps(obj);
err = err ? : bpf_object__create_maps(obj);
@@ -5412,7 +5456,7 @@ void bpf_object__close(struct bpf_object *obj)
zfree(&map->pin_path);
}
- zfree(&obj->kconfig_path);
+ zfree(&obj->kconfig);
zfree(&obj->externs);
obj->nr_extern = 0;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index f7084235bae9..ffe62e3baffd 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -85,12 +85,12 @@ struct bpf_object_open_opts {
*/
const char *pin_root_path;
__u32 attach_prog_fd;
- /* kernel config file path override (for CONFIG_ externs); can point
- * to either uncompressed text file or .gz file
+ /* Additional kernel config content that augments and overrides
+ * system Kconfig for CONFIG_xxx externs.
*/
- const char *kconfig_path;
+ const char *kconfig;
};
-#define bpf_object_open_opts__last_field kconfig_path
+#define bpf_object_open_opts__last_field kconfig
LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
LIBBPF_API struct bpf_object *
diff --git a/tools/testing/selftests/bpf/prog_tests/core_extern.c b/tools/testing/selftests/bpf/prog_tests/core_extern.c
index 5f03dc1de29e..b093787e9448 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_extern.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_extern.c
@@ -23,19 +23,13 @@ static uint32_t get_kernel_version(void)
static struct test_case {
const char *name;
const char *cfg;
- const char *cfg_path;
bool fails;
struct test_core_extern__data data;
} test_cases[] = {
- { .name = "default search path", .cfg_path = NULL,
- .data = { .bpf_syscall = true } },
- { .name = "/proc/config.gz", .cfg_path = "/proc/config.gz",
- .data = { .bpf_syscall = true } },
- { .name = "missing config", .fails = true,
- .cfg_path = "/proc/invalid-config.gz" },
+ { .name = "default search path", .data = { .bpf_syscall = true } },
{
.name = "custom values",
- .cfg = "CONFIG_BPF_SYSCALL=y\n"
+ .cfg = "CONFIG_BPF_SYSCALL=n\n"
"CONFIG_TRISTATE=m\n"
"CONFIG_BOOL=y\n"
"CONFIG_CHAR=100\n"
@@ -45,7 +39,7 @@ static struct test_case {
"CONFIG_STR=\"abracad\"\n"
"CONFIG_MISSING=0",
.data = {
- .bpf_syscall = true,
+ .bpf_syscall = false,
.tristate_val = TRI_MODULE,
.bool_val = true,
.char_val = 100,
@@ -133,30 +127,14 @@ void test_core_extern(void)
int n = sizeof(*skel->data) / sizeof(uint64_t);
for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
- char tmp_cfg_path[] = "/tmp/test_core_extern_cfg.XXXXXX";
struct test_case *t = &test_cases[i];
DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
- .kconfig_path = t->cfg_path,
+ .kconfig = t->cfg,
);
if (!test__start_subtest(t->name))
continue;
- if (t->cfg) {
- size_t n = strlen(t->cfg) + 1;
- int fd = mkstemp(tmp_cfg_path);
- int written;
-
- if (CHECK(fd < 0, "mkstemp", "errno: %d\n", errno))
- continue;
- printf("using '%s' as config file\n", tmp_cfg_path);
- written = write(fd, t->cfg, n);
- close(fd);
- if (CHECK_FAIL(written != n))
- goto cleanup;
- opts.kconfig_path = tmp_cfg_path;
- }
-
skel = test_core_extern__open_opts(&opts);
if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
goto cleanup;
@@ -185,8 +163,6 @@ void test_core_extern(void)
j, exp[j], got[j]);
}
cleanup:
- if (t->cfg)
- unlink(tmp_cfg_path);
test_core_extern__destroy(skel);
skel = NULL;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH bpf-next 3/3] libbpf: BTF is required when externs are present
2019-12-19 0:28 [PATCH bpf-next 0/3] Libbpf extern support improvements Andrii Nakryiko
2019-12-19 0:28 ` [PATCH bpf-next 1/3] libbpf: put Kconfig externs into .kconfig section Andrii Nakryiko
2019-12-19 0:28 ` [PATCH bpf-next 2/3] libbpf: allow to augment system Kconfig through extra optional config Andrii Nakryiko
@ 2019-12-19 0:28 ` Andrii Nakryiko
2019-12-19 1:35 ` [PATCH bpf-next 0/3] Libbpf extern support improvements Alexei Starovoitov
3 siblings, 0 replies; 5+ messages in thread
From: Andrii Nakryiko @ 2019-12-19 0:28 UTC (permalink / raw)
To: bpf, netdev, ast, daniel; +Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko
BTF is required to get type information about extern variables.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/lib/bpf/libbpf.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index f90db2b18e4b..e1d91c64e093 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1887,7 +1887,8 @@ static void bpf_object__sanitize_btf_ext(struct bpf_object *obj)
static bool bpf_object__is_btf_mandatory(const struct bpf_object *obj)
{
- return obj->efile.btf_maps_shndx >= 0;
+ return obj->efile.btf_maps_shndx >= 0 ||
+ obj->nr_extern > 0;
}
static int bpf_object__init_btf(struct bpf_object *obj,
--
2.17.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH bpf-next 0/3] Libbpf extern support improvements
2019-12-19 0:28 [PATCH bpf-next 0/3] Libbpf extern support improvements Andrii Nakryiko
` (2 preceding siblings ...)
2019-12-19 0:28 ` [PATCH bpf-next 3/3] libbpf: BTF is required when externs are present Andrii Nakryiko
@ 2019-12-19 1:35 ` Alexei Starovoitov
3 siblings, 0 replies; 5+ messages in thread
From: Alexei Starovoitov @ 2019-12-19 1:35 UTC (permalink / raw)
To: Andrii Nakryiko; +Cc: bpf, netdev, ast, daniel, andrii.nakryiko, kernel-team
On Wed, Dec 18, 2019 at 04:28:33PM -0800, Andrii Nakryiko wrote:
> Based on latest feedback and discussions, this patch set implements the
> following changes:
>
> - Kconfig-provided externs have to be in .kconfig section, for which
> bpf_helpers.h provides convenient __kconfig macro (Daniel);
> - instead of allowing to override Kconfig file path, switch this to ability to
> extend and override system Kconfig with user-provided custom values (Alexei);
> - BTF is required when externs are used.
Applied, Thanks
^ permalink raw reply [flat|nested] 5+ messages in thread