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-rw-r--r--tools/lib/bpf/libbpf.c654
1 files changed, 555 insertions, 99 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 11c25d9ea431..11a65db4b93f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -7,6 +7,7 @@
* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
* Copyright (C) 2015 Huawei Inc.
* Copyright (C) 2017 Nicira, Inc.
+ * Copyright (C) 2019 Isovalent, Inc.
*/
#ifndef _GNU_SOURCE
@@ -52,6 +53,11 @@
#define BPF_FS_MAGIC 0xcafe4a11
#endif
+/* vsprintf() in __base_pr() uses nonliteral format string. It may break
+ * compilation if user enables corresponding warning. Disable it explicitly.
+ */
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
+
#define __printf(a, b) __attribute__((format(printf, a, b)))
static int __base_pr(enum libbpf_print_level level, const char *format,
@@ -120,6 +126,8 @@ static inline __u64 ptr_to_u64(const void *ptr)
struct bpf_capabilities {
/* v4.14: kernel support for program & map names. */
__u32 name:1;
+ /* v5.2: kernel support for global data sections. */
+ __u32 global_data:1;
};
/*
@@ -144,6 +152,7 @@ struct bpf_program {
enum {
RELO_LD64,
RELO_CALL,
+ RELO_DATA,
} type;
int insn_idx;
union {
@@ -152,6 +161,7 @@ struct bpf_program {
};
} *reloc_desc;
int nr_reloc;
+ int log_level;
struct {
int nr;
@@ -176,6 +186,19 @@ struct bpf_program {
__u32 line_info_cnt;
};
+enum libbpf_map_type {
+ LIBBPF_MAP_UNSPEC,
+ LIBBPF_MAP_DATA,
+ LIBBPF_MAP_BSS,
+ LIBBPF_MAP_RODATA,
+};
+
+static const char * const libbpf_type_to_btf_name[] = {
+ [LIBBPF_MAP_DATA] = ".data",
+ [LIBBPF_MAP_BSS] = ".bss",
+ [LIBBPF_MAP_RODATA] = ".rodata",
+};
+
struct bpf_map {
int fd;
char *name;
@@ -187,11 +210,18 @@ struct bpf_map {
__u32 btf_value_type_id;
void *priv;
bpf_map_clear_priv_t clear_priv;
+ enum libbpf_map_type libbpf_type;
+};
+
+struct bpf_secdata {
+ void *rodata;
+ void *data;
};
static LIST_HEAD(bpf_objects_list);
struct bpf_object {
+ char name[BPF_OBJ_NAME_LEN];
char license[64];
__u32 kern_version;
@@ -199,6 +229,7 @@ struct bpf_object {
size_t nr_programs;
struct bpf_map *maps;
size_t nr_maps;
+ struct bpf_secdata sections;
bool loaded;
bool has_pseudo_calls;
@@ -214,6 +245,9 @@ struct bpf_object {
Elf *elf;
GElf_Ehdr ehdr;
Elf_Data *symbols;
+ Elf_Data *data;
+ Elf_Data *rodata;
+ Elf_Data *bss;
size_t strtabidx;
struct {
GElf_Shdr shdr;
@@ -222,6 +256,9 @@ struct bpf_object {
int nr_reloc;
int maps_shndx;
int text_shndx;
+ int data_shndx;
+ int rodata_shndx;
+ int bss_shndx;
} efile;
/*
* All loaded bpf_object is linked in a list, which is
@@ -443,6 +480,7 @@ static struct bpf_object *bpf_object__new(const char *path,
size_t obj_buf_sz)
{
struct bpf_object *obj;
+ char *end;
obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
if (!obj) {
@@ -451,8 +489,14 @@ static struct bpf_object *bpf_object__new(const char *path,
}
strcpy(obj->path, path);
- obj->efile.fd = -1;
+ /* Using basename() GNU version which doesn't modify arg. */
+ strncpy(obj->name, basename((void *)path),
+ sizeof(obj->name) - 1);
+ end = strchr(obj->name, '.');
+ if (end)
+ *end = 0;
+ obj->efile.fd = -1;
/*
* Caller of this function should also calls
* bpf_object__elf_finish() after data collection to return
@@ -462,6 +506,9 @@ static struct bpf_object *bpf_object__new(const char *path,
obj->efile.obj_buf = obj_buf;
obj->efile.obj_buf_sz = obj_buf_sz;
obj->efile.maps_shndx = -1;
+ obj->efile.data_shndx = -1;
+ obj->efile.rodata_shndx = -1;
+ obj->efile.bss_shndx = -1;
obj->loaded = false;
@@ -480,6 +527,9 @@ static void bpf_object__elf_finish(struct bpf_object *obj)
obj->efile.elf = NULL;
}
obj->efile.symbols = NULL;
+ obj->efile.data = NULL;
+ obj->efile.rodata = NULL;
+ obj->efile.bss = NULL;
zfree(&obj->efile.reloc);
obj->efile.nr_reloc = 0;
@@ -621,27 +671,182 @@ static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
return false;
}
+static int bpf_object_search_section_size(const struct bpf_object *obj,
+ const char *name, size_t *d_size)
+{
+ const GElf_Ehdr *ep = &obj->efile.ehdr;
+ Elf *elf = obj->efile.elf;
+ Elf_Scn *scn = NULL;
+ int idx = 0;
+
+ while ((scn = elf_nextscn(elf, scn)) != NULL) {
+ const char *sec_name;
+ Elf_Data *data;
+ GElf_Shdr sh;
+
+ idx++;
+ if (gelf_getshdr(scn, &sh) != &sh) {
+ pr_warning("failed to get section(%d) header from %s\n",
+ idx, obj->path);
+ return -EIO;
+ }
+
+ sec_name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
+ if (!sec_name) {
+ pr_warning("failed to get section(%d) name from %s\n",
+ idx, obj->path);
+ return -EIO;
+ }
+
+ if (strcmp(name, sec_name))
+ continue;
+
+ data = elf_getdata(scn, 0);
+ if (!data) {
+ pr_warning("failed to get section(%d) data from %s(%s)\n",
+ idx, name, obj->path);
+ return -EIO;
+ }
+
+ *d_size = data->d_size;
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
+int bpf_object__section_size(const struct bpf_object *obj, const char *name,
+ __u32 *size)
+{
+ int ret = -ENOENT;
+ size_t d_size;
+
+ *size = 0;
+ if (!name) {
+ return -EINVAL;
+ } else if (!strcmp(name, ".data")) {
+ if (obj->efile.data)
+ *size = obj->efile.data->d_size;
+ } else if (!strcmp(name, ".bss")) {
+ if (obj->efile.bss)
+ *size = obj->efile.bss->d_size;
+ } else if (!strcmp(name, ".rodata")) {
+ if (obj->efile.rodata)
+ *size = obj->efile.rodata->d_size;
+ } else {
+ ret = bpf_object_search_section_size(obj, name, &d_size);
+ if (!ret)
+ *size = d_size;
+ }
+
+ return *size ? 0 : ret;
+}
+
+int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
+ __u32 *off)
+{
+ Elf_Data *symbols = obj->efile.symbols;
+ const char *sname;
+ size_t si;
+
+ if (!name || !off)
+ return -EINVAL;
+
+ for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) {
+ GElf_Sym sym;
+
+ if (!gelf_getsym(symbols, si, &sym))
+ continue;
+ if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
+ GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
+ continue;
+
+ sname = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
+ sym.st_name);
+ if (!sname) {
+ pr_warning("failed to get sym name string for var %s\n",
+ name);
+ return -EIO;
+ }
+ if (strcmp(name, sname) == 0) {
+ *off = sym.st_value;
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+
+static bool bpf_object__has_maps(const struct bpf_object *obj)
+{
+ return obj->efile.maps_shndx >= 0 ||
+ obj->efile.data_shndx >= 0 ||
+ obj->efile.rodata_shndx >= 0 ||
+ obj->efile.bss_shndx >= 0;
+}
+
+static int
+bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map,
+ enum libbpf_map_type type, Elf_Data *data,
+ void **data_buff)
+{
+ struct bpf_map_def *def = &map->def;
+ char map_name[BPF_OBJ_NAME_LEN];
+
+ map->libbpf_type = type;
+ map->offset = ~(typeof(map->offset))0;
+ snprintf(map_name, sizeof(map_name), "%.8s%.7s", obj->name,
+ libbpf_type_to_btf_name[type]);
+ map->name = strdup(map_name);
+ if (!map->name) {
+ pr_warning("failed to alloc map name\n");
+ return -ENOMEM;
+ }
+
+ def->type = BPF_MAP_TYPE_ARRAY;
+ def->key_size = sizeof(int);
+ def->value_size = data->d_size;
+ def->max_entries = 1;
+ def->map_flags = type == LIBBPF_MAP_RODATA ?
+ BPF_F_RDONLY_PROG : 0;
+ if (data_buff) {
+ *data_buff = malloc(data->d_size);
+ if (!*data_buff) {
+ zfree(&map->name);
+ pr_warning("failed to alloc map content buffer\n");
+ return -ENOMEM;
+ }
+ memcpy(*data_buff, data->d_buf, data->d_size);
+ }
+
+ pr_debug("map %td is \"%s\"\n", map - obj->maps, map->name);
+ return 0;
+}
+
static int
bpf_object__init_maps(struct bpf_object *obj, int flags)
{
+ int i, map_idx, map_def_sz = 0, nr_syms, nr_maps = 0, nr_maps_glob = 0;
bool strict = !(flags & MAPS_RELAX_COMPAT);
- int i, map_idx, map_def_sz, nr_maps = 0;
- Elf_Scn *scn;
- Elf_Data *data = NULL;
Elf_Data *symbols = obj->efile.symbols;
+ Elf_Data *data = NULL;
+ int ret = 0;
- if (obj->efile.maps_shndx < 0)
- return -EINVAL;
if (!symbols)
return -EINVAL;
+ nr_syms = symbols->d_size / sizeof(GElf_Sym);
- scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx);
- if (scn)
- data = elf_getdata(scn, NULL);
- if (!scn || !data) {
- pr_warning("failed to get Elf_Data from map section %d\n",
- obj->efile.maps_shndx);
- return -EINVAL;
+ if (obj->efile.maps_shndx >= 0) {
+ Elf_Scn *scn = elf_getscn(obj->efile.elf,
+ obj->efile.maps_shndx);
+
+ if (scn)
+ data = elf_getdata(scn, NULL);
+ if (!scn || !data) {
+ pr_warning("failed to get Elf_Data from map section %d\n",
+ obj->efile.maps_shndx);
+ return -EINVAL;
+ }
}
/*
@@ -651,7 +856,16 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
*
* TODO: Detect array of map and report error.
*/
- for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
+ if (obj->caps.global_data) {
+ if (obj->efile.data_shndx >= 0)
+ nr_maps_glob++;
+ if (obj->efile.rodata_shndx >= 0)
+ nr_maps_glob++;
+ if (obj->efile.bss_shndx >= 0)
+ nr_maps_glob++;
+ }
+
+ for (i = 0; data && i < nr_syms; i++) {
GElf_Sym sym;
if (!gelf_getsym(symbols, i, &sym))
@@ -661,22 +875,24 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
nr_maps++;
}
- /* Alloc obj->maps and fill nr_maps. */
- pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path,
- nr_maps, data->d_size);
-
- if (!nr_maps)
+ if (!nr_maps && !nr_maps_glob)
return 0;
/* Assume equally sized map definitions */
- map_def_sz = data->d_size / nr_maps;
- if (!data->d_size || (data->d_size % nr_maps) != 0) {
- pr_warning("unable to determine map definition size "
- "section %s, %d maps in %zd bytes\n",
- obj->path, nr_maps, data->d_size);
- return -EINVAL;
+ if (data) {
+ pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path,
+ nr_maps, data->d_size);
+
+ map_def_sz = data->d_size / nr_maps;
+ if (!data->d_size || (data->d_size % nr_maps) != 0) {
+ pr_warning("unable to determine map definition size "
+ "section %s, %d maps in %zd bytes\n",
+ obj->path, nr_maps, data->d_size);
+ return -EINVAL;
+ }
}
+ nr_maps += nr_maps_glob;
obj->maps = calloc(nr_maps, sizeof(obj->maps[0]));
if (!obj->maps) {
pr_warning("alloc maps for object failed\n");
@@ -697,7 +913,7 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
/*
* Fill obj->maps using data in "maps" section.
*/
- for (i = 0, map_idx = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
+ for (i = 0, map_idx = 0; data && i < nr_syms; i++) {
GElf_Sym sym;
const char *map_name;
struct bpf_map_def *def;
@@ -710,6 +926,8 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
map_name = elf_strptr(obj->efile.elf,
obj->efile.strtabidx,
sym.st_name);
+
+ obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC;
obj->maps[map_idx].offset = sym.st_value;
if (sym.st_value + map_def_sz > data->d_size) {
pr_warning("corrupted maps section in %s: last map \"%s\" too small\n",
@@ -758,8 +976,31 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
map_idx++;
}
- qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map);
- return 0;
+ if (!obj->caps.global_data)
+ goto finalize;
+
+ /*
+ * Populate rest of obj->maps with libbpf internal maps.
+ */
+ if (obj->efile.data_shndx >= 0)
+ ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
+ LIBBPF_MAP_DATA,
+ obj->efile.data,
+ &obj->sections.data);
+ if (!ret && obj->efile.rodata_shndx >= 0)
+ ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
+ LIBBPF_MAP_RODATA,
+ obj->efile.rodata,
+ &obj->sections.rodata);
+ if (!ret && obj->efile.bss_shndx >= 0)
+ ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
+ LIBBPF_MAP_BSS,
+ obj->efile.bss, NULL);
+finalize:
+ if (!ret)
+ qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]),
+ compare_bpf_map);
+ return ret;
}
static bool section_have_execinstr(struct bpf_object *obj, int idx)
@@ -785,6 +1026,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
Elf *elf = obj->efile.elf;
GElf_Ehdr *ep = &obj->efile.ehdr;
Elf_Data *btf_ext_data = NULL;
+ Elf_Data *btf_data = NULL;
Elf_Scn *scn = NULL;
int idx = 0, err = 0;
@@ -828,32 +1070,18 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
(int)sh.sh_link, (unsigned long)sh.sh_flags,
(int)sh.sh_type);
- if (strcmp(name, "license") == 0)
+ if (strcmp(name, "license") == 0) {
err = bpf_object__init_license(obj,
data->d_buf,
data->d_size);
- else if (strcmp(name, "version") == 0)
+ } else if (strcmp(name, "version") == 0) {
err = bpf_object__init_kversion(obj,
data->d_buf,
data->d_size);
- else if (strcmp(name, "maps") == 0)
+ } else if (strcmp(name, "maps") == 0) {
obj->efile.maps_shndx = idx;
- else if (strcmp(name, BTF_ELF_SEC) == 0) {
- obj->btf = btf__new(data->d_buf, data->d_size);
- if (IS_ERR(obj->btf)) {
- pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
- BTF_ELF_SEC, PTR_ERR(obj->btf));
- obj->btf = NULL;
- continue;
- }
- err = btf__load(obj->btf);
- if (err) {
- pr_warning("Error loading %s into kernel: %d. Ignored and continue.\n",
- BTF_ELF_SEC, err);
- btf__free(obj->btf);
- obj->btf = NULL;
- err = 0;
- }
+ } else if (strcmp(name, BTF_ELF_SEC) == 0) {
+ btf_data = data;
} else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
btf_ext_data = data;
} else if (sh.sh_type == SHT_SYMTAB) {
@@ -865,20 +1093,28 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
obj->efile.symbols = data;
obj->efile.strtabidx = sh.sh_link;
}
- } else if ((sh.sh_type == SHT_PROGBITS) &&
- (sh.sh_flags & SHF_EXECINSTR) &&
- (data->d_size > 0)) {
- if (strcmp(name, ".text") == 0)
- obj->efile.text_shndx = idx;
- err = bpf_object__add_program(obj, data->d_buf,
- data->d_size, name, idx);
- if (err) {
- char errmsg[STRERR_BUFSIZE];
- char *cp = libbpf_strerror_r(-err, errmsg,
- sizeof(errmsg));
-
- pr_warning("failed to alloc program %s (%s): %s",
- name, obj->path, cp);
+ } else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {
+ if (sh.sh_flags & SHF_EXECINSTR) {
+ if (strcmp(name, ".text") == 0)
+ obj->efile.text_shndx = idx;
+ err = bpf_object__add_program(obj, data->d_buf,
+ data->d_size, name, idx);
+ if (err) {
+ char errmsg[STRERR_BUFSIZE];
+ char *cp = libbpf_strerror_r(-err, errmsg,
+ sizeof(errmsg));
+
+ pr_warning("failed to alloc program %s (%s): %s",
+ name, obj->path, cp);
+ }
+ } else if (strcmp(name, ".data") == 0) {
+ obj->efile.data = data;
+ obj->efile.data_shndx = idx;
+ } else if (strcmp(name, ".rodata") == 0) {
+ obj->efile.rodata = data;
+ obj->efile.rodata_shndx = idx;
+ } else {
+ pr_debug("skip section(%d) %s\n", idx, name);
}
} else if (sh.sh_type == SHT_REL) {
void *reloc = obj->efile.reloc;
@@ -906,6 +1142,9 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
obj->efile.reloc[n].shdr = sh;
obj->efile.reloc[n].data = data;
}
+ } else if (sh.sh_type == SHT_NOBITS && strcmp(name, ".bss") == 0) {
+ obj->efile.bss = data;
+ obj->efile.bss_shndx = idx;
} else {
pr_debug("skip section(%d) %s\n", idx, name);
}
@@ -917,6 +1156,25 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
pr_warning("Corrupted ELF file: index of strtab invalid\n");
return LIBBPF_ERRNO__FORMAT;
}
+ if (btf_data) {
+ obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
+ if (IS_ERR(obj->btf)) {
+ pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
+ BTF_ELF_SEC, PTR_ERR(obj->btf));
+ obj->btf = NULL;
+ } else {
+ err = btf__finalize_data(obj, obj->btf);
+ if (!err)
+ err = btf__load(obj->btf);
+ if (err) {
+ pr_warning("Error finalizing and loading %s into kernel: %d. Ignored and continue.\n",
+ BTF_ELF_SEC, err);
+ btf__free(obj->btf);
+ obj->btf = NULL;
+ err = 0;
+ }
+ }
+ }
if (btf_ext_data) {
if (!obj->btf) {
pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
@@ -932,7 +1190,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
}
}
}
- if (obj->efile.maps_shndx >= 0) {
+ if (bpf_object__has_maps(obj)) {
err = bpf_object__init_maps(obj, flags);
if (err)
goto out;
@@ -968,13 +1226,46 @@ bpf_object__find_program_by_title(struct bpf_object *obj, const char *title)
return NULL;
}
+static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
+ int shndx)
+{
+ return shndx == obj->efile.data_shndx ||
+ shndx == obj->efile.bss_shndx ||
+ shndx == obj->efile.rodata_shndx;
+}
+
+static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
+ int shndx)
+{
+ return shndx == obj->efile.maps_shndx;
+}
+
+static bool bpf_object__relo_in_known_section(const struct bpf_object *obj,
+ int shndx)
+{
+ return shndx == obj->efile.text_shndx ||
+ bpf_object__shndx_is_maps(obj, shndx) ||
+ bpf_object__shndx_is_data(obj, shndx);
+}
+
+static enum libbpf_map_type
+bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
+{
+ if (shndx == obj->efile.data_shndx)
+ return LIBBPF_MAP_DATA;
+ else if (shndx == obj->efile.bss_shndx)
+ return LIBBPF_MAP_BSS;
+ else if (shndx == obj->efile.rodata_shndx)
+ return LIBBPF_MAP_RODATA;
+ else
+ return LIBBPF_MAP_UNSPEC;
+}
+
static int
bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
Elf_Data *data, struct bpf_object *obj)
{
Elf_Data *symbols = obj->efile.symbols;
- int text_shndx = obj->efile.text_shndx;
- int maps_shndx = obj->efile.maps_shndx;
struct bpf_map *maps = obj->maps;
size_t nr_maps = obj->nr_maps;
int i, nrels;
@@ -994,7 +1285,10 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
GElf_Sym sym;
GElf_Rel rel;
unsigned int insn_idx;
+ unsigned int shdr_idx;
struct bpf_insn *insns = prog->insns;
+ enum libbpf_map_type type;
+ const char *name;
size_t map_idx;
if (!gelf_getrel(data, i, &rel)) {
@@ -1009,13 +1303,18 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
GELF_R_SYM(rel.r_info));
return -LIBBPF_ERRNO__FORMAT;
}
- pr_debug("relo for %lld value %lld name %d\n",
+
+ name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
+ sym.st_name) ? : "<?>";
+
+ pr_debug("relo for %lld value %lld name %d (\'%s\')\n",
(long long) (rel.r_info >> 32),
- (long long) sym.st_value, sym.st_name);
+ (long long) sym.st_value, sym.st_name, name);
- if (sym.st_shndx != maps_shndx && sym.st_shndx != text_shndx) {
- pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n",
- prog->section_name, sym.st_shndx);
+ shdr_idx = sym.st_shndx;
+ if (!bpf_object__relo_in_known_section(obj, shdr_idx)) {
+ pr_warning("Program '%s' contains unrecognized relo data pointing to section %u\n",
+ prog->section_name, shdr_idx);
return -LIBBPF_ERRNO__RELOC;
}
@@ -1040,24 +1339,45 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
return -LIBBPF_ERRNO__RELOC;
}
- /* TODO: 'maps' is sorted. We can use bsearch to make it faster. */
- for (map_idx = 0; map_idx < nr_maps; map_idx++) {
- if (maps[map_idx].offset == sym.st_value) {
- pr_debug("relocation: find map %zd (%s) for insn %u\n",
- map_idx, maps[map_idx].name, insn_idx);
- break;
+ if (bpf_object__shndx_is_maps(obj, shdr_idx) ||
+ bpf_object__shndx_is_data(obj, shdr_idx)) {
+ type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
+ if (type != LIBBPF_MAP_UNSPEC) {
+ if (GELF_ST_BIND(sym.st_info) == STB_GLOBAL) {
+ pr_warning("bpf: relocation: not yet supported relo for non-static global \'%s\' variable found in insns[%d].code 0x%x\n",
+ name, insn_idx, insns[insn_idx].code);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ if (!obj->caps.global_data) {
+ pr_warning("bpf: relocation: kernel does not support global \'%s\' variable access in insns[%d]\n",
+ name, insn_idx);
+ return -LIBBPF_ERRNO__RELOC;
+ }
}
- }
- if (map_idx >= nr_maps) {
- pr_warning("bpf relocation: map_idx %d large than %d\n",
- (int)map_idx, (int)nr_maps - 1);
- return -LIBBPF_ERRNO__RELOC;
- }
+ for (map_idx = 0; map_idx < nr_maps; map_idx++) {
+ if (maps[map_idx].libbpf_type != type)
+ continue;
+ if (type != LIBBPF_MAP_UNSPEC ||
+ (type == LIBBPF_MAP_UNSPEC &&
+ maps[map_idx].offset == sym.st_value)) {
+ pr_debug("relocation: find map %zd (%s) for insn %u\n",
+ map_idx, maps[map_idx].name, insn_idx);
+ break;
+ }
+ }
- prog->reloc_desc[i].type = RELO_LD64;
- prog->reloc_desc[i].insn_idx = insn_idx;
- prog->reloc_desc[i].map_idx = map_idx;
+ if (map_idx >= nr_maps) {
+ pr_warning("bpf relocation: map_idx %d large than %d\n",
+ (int)map_idx, (int)nr_maps - 1);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+
+ prog->reloc_desc[i].type = type != LIBBPF_MAP_UNSPEC ?
+ RELO_DATA : RELO_LD64;
+ prog->reloc_desc[i].insn_idx = insn_idx;
+ prog->reloc_desc[i].map_idx = map_idx;
+ }
}
return 0;
}
@@ -1065,18 +1385,27 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
{
struct bpf_map_def *def = &map->def;
- __u32 key_type_id, value_type_id;
+ __u32 key_type_id = 0, value_type_id = 0;
int ret;
- ret = btf__get_map_kv_tids(btf, map->name, def->key_size,
- def->value_size, &key_type_id,
- &value_type_id);
- if (ret)
+ if (!bpf_map__is_internal(map)) {
+ ret = btf__get_map_kv_tids(btf, map->name, def->key_size,
+ def->value_size, &key_type_id,
+ &value_type_id);
+ } else {
+ /*
+ * LLVM annotates global data differently in BTF, that is,
+ * only as '.data', '.bss' or '.rodata'.
+ */
+ ret = btf__find_by_name(btf,
+ libbpf_type_to_btf_name[map->libbpf_type]);
+ }
+ if (ret < 0)
return ret;
map->btf_key_type_id = key_type_id;
- map->btf_value_type_id = value_type_id;
-
+ map->btf_value_type_id = bpf_map__is_internal(map) ?
+ ret : value_type_id;
return 0;
}
@@ -1182,9 +1511,95 @@ bpf_object__probe_name(struct bpf_object *obj)
}
static int
+bpf_object__probe_global_data(struct bpf_object *obj)
+{
+ struct bpf_load_program_attr prg_attr;
+ struct bpf_create_map_attr map_attr;
+ char *cp, errmsg[STRERR_BUFSIZE];
+ struct bpf_insn insns[] = {
+ BPF_LD_MAP_VALUE(BPF_REG_1, 0, 16),
+ BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 42),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ int ret, map;
+
+ memset(&map_attr, 0, sizeof(map_attr));
+ map_attr.map_type = BPF_MAP_TYPE_ARRAY;
+ map_attr.key_size = sizeof(int);
+ map_attr.value_size = 32;
+ map_attr.max_entries = 1;
+
+ map = bpf_create_map_xattr(&map_attr);
+ if (map < 0) {
+ cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warning("Error in %s():%s(%d). Couldn't create simple array map.\n",
+ __func__, cp, errno);
+ return -errno;
+ }
+
+ insns[0].imm = map;
+
+ memset(&prg_attr, 0, sizeof(prg_attr));
+ prg_attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ prg_attr.insns = insns;
+ prg_attr.insns_cnt = ARRAY_SIZE(insns);
+ prg_attr.license = "GPL";
+
+ ret = bpf_load_program_xattr(&prg_attr, NULL, 0);
+ if (ret >= 0) {
+ obj->caps.global_data = 1;
+ close(ret);
+ }
+
+ close(map);
+ return 0;
+}
+
+static int
bpf_object__probe_caps(struct bpf_object *obj)
{
- return bpf_object__probe_name(obj);
+ int (*probe_fn[])(struct bpf_object *obj) = {
+ bpf_object__probe_name,
+ bpf_object__probe_global_data,
+ };
+ int i, ret;
+
+ for (i = 0; i < ARRAY_SIZE(probe_fn); i++) {
+ ret = probe_fn[i](obj);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int
+bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
+{
+ char *cp, errmsg[STRERR_BUFSIZE];
+ int err, zero = 0;
+ __u8 *data;
+
+ /* Nothing to do here since kernel already zero-initializes .bss map. */
+ if (map->libbpf_type == LIBBPF_MAP_BSS)
+ return 0;
+
+ data = map->libbpf_type == LIBBPF_MAP_DATA ?
+ obj->sections.data : obj->sections.rodata;
+
+ err = bpf_map_update_elem(map->fd, &zero, data, 0);
+ /* Freeze .rodata map as read-only from syscall side. */
+ if (!err && map->libbpf_type == LIBBPF_MAP_RODATA) {
+ err = bpf_map_freeze(map->fd);
+ if (err) {
+ cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warning("Error freezing map(%s) as read-only: %s\n",
+ map->name, cp);
+ err = 0;
+ }
+ }
+ return err;
}
static int
@@ -1244,6 +1659,7 @@ bpf_object__create_maps(struct bpf_object *obj)
size_t j;
err = *pfd;
+err_out:
cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
pr_warning("failed to create map (name: '%s'): %s\n",
map->name, cp);
@@ -1251,6 +1667,15 @@ bpf_object__create_maps(struct bpf_object *obj)
zclose(obj->maps[j].fd);
return err;
}
+
+ if (bpf_map__is_internal(map)) {
+ err = bpf_object__populate_internal_map(obj, map);
+ if (err < 0) {
+ zclose(*pfd);
+ goto err_out;
+ }
+ }
+
pr_debug("create map %s: fd=%d\n", map->name, *pfd);
}
@@ -1405,21 +1830,29 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
return 0;
for (i = 0; i < prog->nr_reloc; i++) {
- if (prog->reloc_desc[i].type == RELO_LD64) {
+ if (prog->reloc_desc[i].type == RELO_LD64 ||
+ prog->reloc_desc[i].type == RELO_DATA) {
+ bool relo_data = prog->reloc_desc[i].type == RELO_DATA;
struct bpf_insn *insns = prog->insns;
int insn_idx, map_idx;
insn_idx = prog->reloc_desc[i].insn_idx;
map_idx = prog->reloc_desc[i].map_idx;
- if (insn_idx >= (int)prog->insns_cnt) {
+ if (insn_idx + 1 >= (int)prog->insns_cnt) {
pr_warning("relocation out of range: '%s'\n",
prog->section_name);
return -LIBBPF_ERRNO__RELOC;
}
- insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+
+ if (!relo_data) {
+ insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+ } else {
+ insns[insn_idx].src_reg = BPF_PSEUDO_MAP_VALUE;
+ insns[insn_idx + 1].imm = insns[insn_idx].imm;
+ }
insns[insn_idx].imm = obj->maps[map_idx].fd;
- } else {
+ } else if (prog->reloc_desc[i].type == RELO_CALL) {
err = bpf_program__reloc_text(prog, obj,
&prog->reloc_desc[i]);
if (err)
@@ -1494,6 +1927,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
{
struct bpf_load_program_attr load_attr;
char *cp, errmsg[STRERR_BUFSIZE];
+ int log_buf_size = BPF_LOG_BUF_SIZE;
char *log_buf;
int ret;
@@ -1514,21 +1948,30 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
load_attr.line_info = prog->line_info;
load_attr.line_info_rec_size = prog->line_info_rec_size;
load_attr.line_info_cnt = prog->line_info_cnt;
+ load_attr.log_level = prog->log_level;
if (!load_attr.insns || !load_attr.insns_cnt)
return -EINVAL;
- log_buf = malloc(BPF_LOG_BUF_SIZE);
+retry_load:
+ log_buf = malloc(log_buf_size);
if (!log_buf)
pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
- ret = bpf_load_program_xattr(&load_attr, log_buf, BPF_LOG_BUF_SIZE);
+ ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size);
if (ret >= 0) {
+ if (load_attr.log_level)
+ pr_debug("verifier log:\n%s", log_buf);
*pfd = ret;
ret = 0;
goto out;
}
+ if (errno == ENOSPC) {
+ log_buf_size <<= 1;
+ free(log_buf);
+ goto retry_load;
+ }
ret = -LIBBPF_ERRNO__LOAD;
cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
pr_warning("load bpf program failed: %s\n", cp);
@@ -1693,7 +2136,9 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
case BPF_PROG_TYPE_UNSPEC:
case BPF_PROG_TYPE_TRACEPOINT:
case BPF_PROG_TYPE_RAW_TRACEPOINT:
+ case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
case BPF_PROG_TYPE_PERF_EVENT:
+ case BPF_PROG_TYPE_CGROUP_SYSCTL:
return false;
case BPF_PROG_TYPE_KPROBE:
default:
@@ -1729,6 +2174,7 @@ __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz,
CHECK_ERR(bpf_object__elf_init(obj), err, out);
CHECK_ERR(bpf_object__check_endianness(obj), err, out);
+ CHECK_ERR(bpf_object__probe_caps(obj), err, out);
CHECK_ERR(bpf_object__elf_collect(obj, flags), err, out);
CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out);
@@ -1822,7 +2268,6 @@ int bpf_object__load(struct bpf_object *obj)
obj->loaded = true;
- CHECK_ERR(bpf_object__probe_caps(obj), err, out);
CHECK_ERR(bpf_object__create_maps(obj), err, out);
CHECK_ERR(bpf_object__relocate(obj), err, out);
CHECK_ERR(bpf_object__load_progs(obj), err, out);
@@ -2303,6 +2748,9 @@ void bpf_object__close(struct bpf_object *obj)
obj->maps[i].priv = NULL;
obj->maps[i].clear_priv = NULL;
}
+
+ zfree(&obj->sections.rodata);
+ zfree(&obj->sections.data);
zfree(&obj->maps);
obj->nr_maps = 0;
@@ -2631,6 +3079,8 @@ static const struct {
BPF_CGROUP_UDP4_SENDMSG),
BPF_EAPROG_SEC("cgroup/sendmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
BPF_CGROUP_UDP6_SENDMSG),
+ BPF_EAPROG_SEC("cgroup/sysctl", BPF_PROG_TYPE_CGROUP_SYSCTL,
+ BPF_CGROUP_SYSCTL),
};
#undef BPF_PROG_SEC_IMPL
@@ -2780,6 +3230,11 @@ bool bpf_map__is_offload_neutral(struct bpf_map *map)
return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;
}
+bool bpf_map__is_internal(struct bpf_map *map)
+{
+ return map->libbpf_type != LIBBPF_MAP_UNSPEC;
+}
+
void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
{
map->map_ifindex = ifindex;
@@ -2938,6 +3393,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
bpf_program__set_expected_attach_type(prog,
expected_attach_type);
+ prog->log_level = attr->log_level;
if (!first_prog)
first_prog = prog;
}