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-rw-r--r--tools/lib/bpf/btf.c8
-rw-r--r--tools/lib/bpf/libbpf.c178
-rw-r--r--tools/lib/bpf/libbpf_probes.c1
-rw-r--r--tools/lib/bpf/usdt.c16
4 files changed, 125 insertions, 78 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index d88647da2c7f..675a0df5c840 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -3887,14 +3887,14 @@ static inline __u16 btf_fwd_kind(struct btf_type *t)
}
/* Check if given two types are identical ARRAY definitions */
-static int btf_dedup_identical_arrays(struct btf_dedup *d, __u32 id1, __u32 id2)
+static bool btf_dedup_identical_arrays(struct btf_dedup *d, __u32 id1, __u32 id2)
{
struct btf_type *t1, *t2;
t1 = btf_type_by_id(d->btf, id1);
t2 = btf_type_by_id(d->btf, id2);
if (!btf_is_array(t1) || !btf_is_array(t2))
- return 0;
+ return false;
return btf_equal_array(t1, t2);
}
@@ -3918,7 +3918,9 @@ static bool btf_dedup_identical_structs(struct btf_dedup *d, __u32 id1, __u32 id
m1 = btf_members(t1);
m2 = btf_members(t2);
for (i = 0, n = btf_vlen(t1); i < n; i++, m1++, m2++) {
- if (m1->type != m2->type)
+ if (m1->type != m2->type &&
+ !btf_dedup_identical_arrays(d, m1->type, m2->type) &&
+ !btf_dedup_identical_structs(d, m1->type, m2->type))
return false;
}
return true;
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 8c3f236c86e4..5d7819edf074 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -164,6 +164,7 @@ static const char * const map_type_name[] = {
[BPF_MAP_TYPE_TASK_STORAGE] = "task_storage",
[BPF_MAP_TYPE_BLOOM_FILTER] = "bloom_filter",
[BPF_MAP_TYPE_USER_RINGBUF] = "user_ringbuf",
+ [BPF_MAP_TYPE_CGRP_STORAGE] = "cgrp_storage",
};
static const char * const prog_type_name[] = {
@@ -1461,15 +1462,12 @@ static int find_elf_sec_sz(const struct bpf_object *obj, const char *name, __u32
return -ENOENT;
}
-static int find_elf_var_offset(const struct bpf_object *obj, const char *name, __u32 *off)
+static Elf64_Sym *find_elf_var_sym(const struct bpf_object *obj, const char *name)
{
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(Elf64_Sym); si++) {
Elf64_Sym *sym = elf_sym_by_idx(obj, si);
@@ -1483,15 +1481,13 @@ static int find_elf_var_offset(const struct bpf_object *obj, const char *name, _
sname = elf_sym_str(obj, sym->st_name);
if (!sname) {
pr_warn("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 ERR_PTR(-EIO);
}
+ if (strcmp(name, sname) == 0)
+ return sym;
}
- return -ENOENT;
+ return ERR_PTR(-ENOENT);
}
static struct bpf_map *bpf_object__add_map(struct bpf_object *obj)
@@ -1582,7 +1578,38 @@ static char *internal_map_name(struct bpf_object *obj, const char *real_name)
}
static int
-bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map);
+map_fill_btf_type_info(struct bpf_object *obj, struct bpf_map *map);
+
+/* Internal BPF map is mmap()'able only if at least one of corresponding
+ * DATASEC's VARs are to be exposed through BPF skeleton. I.e., it's a GLOBAL
+ * variable and it's not marked as __hidden (which turns it into, effectively,
+ * a STATIC variable).
+ */
+static bool map_is_mmapable(struct bpf_object *obj, struct bpf_map *map)
+{
+ const struct btf_type *t, *vt;
+ struct btf_var_secinfo *vsi;
+ int i, n;
+
+ if (!map->btf_value_type_id)
+ return false;
+
+ t = btf__type_by_id(obj->btf, map->btf_value_type_id);
+ if (!btf_is_datasec(t))
+ return false;
+
+ vsi = btf_var_secinfos(t);
+ for (i = 0, n = btf_vlen(t); i < n; i++, vsi++) {
+ vt = btf__type_by_id(obj->btf, vsi->type);
+ if (!btf_is_var(vt))
+ continue;
+
+ if (btf_var(vt)->linkage != BTF_VAR_STATIC)
+ return true;
+ }
+
+ return false;
+}
static int
bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
@@ -1614,7 +1641,12 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
def->max_entries = 1;
def->map_flags = type == LIBBPF_MAP_RODATA || type == LIBBPF_MAP_KCONFIG
? BPF_F_RDONLY_PROG : 0;
- def->map_flags |= BPF_F_MMAPABLE;
+
+ /* failures are fine because of maps like .rodata.str1.1 */
+ (void) map_fill_btf_type_info(obj, map);
+
+ if (map_is_mmapable(obj, map))
+ 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);
@@ -1631,9 +1663,6 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
return err;
}
- /* failures are fine because of maps like .rodata.str1.1 */
- (void) bpf_map_find_btf_info(obj, map);
-
if (data)
memcpy(map->mmaped, data, data_sz);
@@ -2545,7 +2574,7 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj,
fill_map_from_def(map->inner_map, &inner_def);
}
- err = bpf_map_find_btf_info(obj, map);
+ err = map_fill_btf_type_info(obj, map);
if (err)
return err;
@@ -2850,57 +2879,89 @@ static int compare_vsi_off(const void *_a, const void *_b)
static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
struct btf_type *t)
{
- __u32 size = 0, off = 0, i, vars = btf_vlen(t);
- const char *name = btf__name_by_offset(btf, t->name_off);
- const struct btf_type *t_var;
+ __u32 size = 0, i, vars = btf_vlen(t);
+ const char *sec_name = btf__name_by_offset(btf, t->name_off);
struct btf_var_secinfo *vsi;
- const struct btf_var *var;
- int ret;
+ bool fixup_offsets = false;
+ int err;
- if (!name) {
+ if (!sec_name) {
pr_debug("No name found in string section for DATASEC kind.\n");
return -ENOENT;
}
- /* .extern datasec size and var offsets were set correctly during
- * extern collection step, so just skip straight to sorting variables
+ /* Extern-backing datasecs (.ksyms, .kconfig) have their size and
+ * variable offsets set at the previous step. Further, not every
+ * extern BTF VAR has corresponding ELF symbol preserved, so we skip
+ * all fixups altogether for such sections and go straight to sorting
+ * VARs within their DATASEC.
*/
- if (t->size)
+ if (strcmp(sec_name, KCONFIG_SEC) == 0 || strcmp(sec_name, KSYMS_SEC) == 0)
goto sort_vars;
- ret = find_elf_sec_sz(obj, name, &size);
- if (ret || !size) {
- pr_debug("Invalid size for section %s: %u bytes\n", name, size);
- return -ENOENT;
- }
+ /* Clang leaves DATASEC size and VAR offsets as zeroes, so we need to
+ * fix this up. But BPF static linker already fixes this up and fills
+ * all the sizes and offsets during static linking. So this step has
+ * to be optional. But the STV_HIDDEN handling is non-optional for any
+ * non-extern DATASEC, so the variable fixup loop below handles both
+ * functions at the same time, paying the cost of BTF VAR <-> ELF
+ * symbol matching just once.
+ */
+ if (t->size == 0) {
+ err = find_elf_sec_sz(obj, sec_name, &size);
+ if (err || !size) {
+ pr_debug("sec '%s': failed to determine size from ELF: size %u, err %d\n",
+ sec_name, size, err);
+ return -ENOENT;
+ }
- t->size = size;
+ t->size = size;
+ fixup_offsets = true;
+ }
for (i = 0, vsi = btf_var_secinfos(t); i < vars; i++, vsi++) {
+ const struct btf_type *t_var;
+ struct btf_var *var;
+ const char *var_name;
+ Elf64_Sym *sym;
+
t_var = btf__type_by_id(btf, vsi->type);
if (!t_var || !btf_is_var(t_var)) {
- pr_debug("Non-VAR type seen in section %s\n", name);
+ pr_debug("sec '%s': unexpected non-VAR type found\n", sec_name);
return -EINVAL;
}
var = btf_var(t_var);
- if (var->linkage == BTF_VAR_STATIC)
+ if (var->linkage == BTF_VAR_STATIC || var->linkage == BTF_VAR_GLOBAL_EXTERN)
continue;
- name = btf__name_by_offset(btf, t_var->name_off);
- if (!name) {
- pr_debug("No name found in string section for VAR kind\n");
+ var_name = btf__name_by_offset(btf, t_var->name_off);
+ if (!var_name) {
+ pr_debug("sec '%s': failed to find name of DATASEC's member #%d\n",
+ sec_name, i);
return -ENOENT;
}
- ret = find_elf_var_offset(obj, name, &off);
- if (ret) {
- pr_debug("No offset found in symbol table for VAR %s\n",
- name);
+ sym = find_elf_var_sym(obj, var_name);
+ if (IS_ERR(sym)) {
+ pr_debug("sec '%s': failed to find ELF symbol for VAR '%s'\n",
+ sec_name, var_name);
return -ENOENT;
}
- vsi->offset = off;
+ if (fixup_offsets)
+ vsi->offset = sym->st_value;
+
+ /* if variable is a global/weak symbol, but has restricted
+ * (STV_HIDDEN or STV_INTERNAL) visibility, mark its BTF VAR
+ * as static. This follows similar logic for functions (BPF
+ * subprogs) and influences libbpf's further decisions about
+ * whether to make global data BPF array maps as
+ * BPF_F_MMAPABLE.
+ */
+ if (ELF64_ST_VISIBILITY(sym->st_other) == STV_HIDDEN
+ || ELF64_ST_VISIBILITY(sym->st_other) == STV_INTERNAL)
+ var->linkage = BTF_VAR_STATIC;
}
sort_vars:
@@ -2908,13 +2969,16 @@ sort_vars:
return 0;
}
-static int btf_finalize_data(struct bpf_object *obj, struct btf *btf)
+static int bpf_object_fixup_btf(struct bpf_object *obj)
{
- int err = 0;
- __u32 i, n = btf__type_cnt(btf);
+ int i, n, err = 0;
+ if (!obj->btf)
+ return 0;
+
+ n = btf__type_cnt(obj->btf);
for (i = 1; i < n; i++) {
- struct btf_type *t = btf_type_by_id(btf, i);
+ struct btf_type *t = btf_type_by_id(obj->btf, i);
/* Loader needs to fix up some of the things compiler
* couldn't get its hands on while emitting BTF. This
@@ -2922,28 +2986,12 @@ static int btf_finalize_data(struct bpf_object *obj, struct btf *btf)
* the info from the ELF itself for this purpose.
*/
if (btf_is_datasec(t)) {
- err = btf_fixup_datasec(obj, btf, t);
+ err = btf_fixup_datasec(obj, obj->btf, t);
if (err)
- break;
+ return err;
}
}
- return libbpf_err(err);
-}
-
-static int bpf_object__finalize_btf(struct bpf_object *obj)
-{
- int err;
-
- if (!obj->btf)
- return 0;
-
- err = btf_finalize_data(obj, obj->btf);
- if (err) {
- pr_warn("Error finalizing %s: %d.\n", BTF_ELF_SEC, err);
- return err;
- }
-
return 0;
}
@@ -4235,7 +4283,7 @@ bpf_object__collect_prog_relos(struct bpf_object *obj, Elf64_Shdr *shdr, Elf_Dat
return 0;
}
-static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map)
+static int map_fill_btf_type_info(struct bpf_object *obj, struct bpf_map *map)
{
int id;
@@ -7233,7 +7281,7 @@ static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf,
err = err ? : bpf_object__check_endianness(obj);
err = err ? : bpf_object__elf_collect(obj);
err = err ? : bpf_object__collect_externs(obj);
- err = err ? : bpf_object__finalize_btf(obj);
+ err = err ? : bpf_object_fixup_btf(obj);
err = err ? : bpf_object__init_maps(obj, opts);
err = err ? : bpf_object_init_progs(obj, opts);
err = err ? : bpf_object__collect_relos(obj);
diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
index f3a8e8e74eb8..bdb83d467f9a 100644
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -221,6 +221,7 @@ static int probe_map_create(enum bpf_map_type map_type)
case BPF_MAP_TYPE_SK_STORAGE:
case BPF_MAP_TYPE_INODE_STORAGE:
case BPF_MAP_TYPE_TASK_STORAGE:
+ case BPF_MAP_TYPE_CGRP_STORAGE:
btf_key_type_id = 1;
btf_value_type_id = 3;
value_size = 8;
diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c
index 49f3c3b7f609..28fa1b2283de 100644
--- a/tools/lib/bpf/usdt.c
+++ b/tools/lib/bpf/usdt.c
@@ -1225,26 +1225,24 @@ static int calc_pt_regs_off(const char *reg_name)
static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg)
{
- char *reg_name = NULL;
+ char reg_name[16];
int arg_sz, len, reg_off;
long off;
- if (sscanf(arg_str, " %d @ %ld ( %%%m[^)] ) %n", &arg_sz, &off, &reg_name, &len) == 3) {
+ if (sscanf(arg_str, " %d @ %ld ( %%%15[^)] ) %n", &arg_sz, &off, reg_name, &len) == 3) {
/* Memory dereference case, e.g., -4@-20(%rbp) */
arg->arg_type = USDT_ARG_REG_DEREF;
arg->val_off = off;
reg_off = calc_pt_regs_off(reg_name);
- free(reg_name);
if (reg_off < 0)
return reg_off;
arg->reg_off = reg_off;
- } else if (sscanf(arg_str, " %d @ %%%ms %n", &arg_sz, &reg_name, &len) == 2) {
+ } else if (sscanf(arg_str, " %d @ %%%15s %n", &arg_sz, reg_name, &len) == 2) {
/* Register read case, e.g., -4@%eax */
arg->arg_type = USDT_ARG_REG;
arg->val_off = 0;
reg_off = calc_pt_regs_off(reg_name);
- free(reg_name);
if (reg_off < 0)
return reg_off;
arg->reg_off = reg_off;
@@ -1456,16 +1454,15 @@ static int calc_pt_regs_off(const char *reg_name)
static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg)
{
- char *reg_name = NULL;
+ char reg_name[16];
int arg_sz, len, reg_off;
long off;
- if (sscanf(arg_str, " %d @ %ld ( %m[a-z0-9] ) %n", &arg_sz, &off, &reg_name, &len) == 3) {
+ if (sscanf(arg_str, " %d @ %ld ( %15[a-z0-9] ) %n", &arg_sz, &off, reg_name, &len) == 3) {
/* Memory dereference case, e.g., -8@-88(s0) */
arg->arg_type = USDT_ARG_REG_DEREF;
arg->val_off = off;
reg_off = calc_pt_regs_off(reg_name);
- free(reg_name);
if (reg_off < 0)
return reg_off;
arg->reg_off = reg_off;
@@ -1474,12 +1471,11 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec
arg->arg_type = USDT_ARG_CONST;
arg->val_off = off;
arg->reg_off = 0;
- } else if (sscanf(arg_str, " %d @ %m[a-z0-9] %n", &arg_sz, &reg_name, &len) == 2) {
+ } else if (sscanf(arg_str, " %d @ %15[a-z0-9] %n", &arg_sz, reg_name, &len) == 2) {
/* Register read case, e.g., -8@a1 */
arg->arg_type = USDT_ARG_REG;
arg->val_off = 0;
reg_off = calc_pt_regs_off(reg_name);
- free(reg_name);
if (reg_off < 0)
return reg_off;
arg->reg_off = reg_off;
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-01 17:15:20 +0000