summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--include/linux/bpf.h6
-rw-r--r--include/linux/bpf_verifier.h7
-rw-r--r--include/linux/btf.h26
-rw-r--r--include/uapi/linux/bpf.h67
-rw-r--r--kernel/bpf/btf.c25
-rw-r--r--kernel/bpf/helpers.c32
-rw-r--r--kernel/bpf/verifier.c190
-rw-r--r--kernel/trace/bpf_trace.c4
-rw-r--r--tools/include/uapi/linux/bpf.h67
-rw-r--r--tools/lib/bpf/libbpf.c112
-rw-r--r--tools/testing/selftests/bpf/prog_tests/ksyms.c38
-rw-r--r--tools/testing/selftests/bpf/prog_tests/ksyms_btf.c88
-rw-r--r--tools/testing/selftests/bpf/progs/test_ksyms_btf.c55
-rw-r--r--tools/testing/selftests/bpf/trace_helpers.c27
-rw-r--r--tools/testing/selftests/bpf/trace_helpers.h4
15 files changed, 653 insertions, 95 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 50e5c4b52bd1..dc63eeed4fd9 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -293,6 +293,7 @@ enum bpf_arg_type {
ARG_PTR_TO_ALLOC_MEM_OR_NULL, /* pointer to dynamically allocated memory or NULL */
ARG_CONST_ALLOC_SIZE_OR_ZERO, /* number of allocated bytes requested */
ARG_PTR_TO_BTF_ID_SOCK_COMMON, /* pointer to in-kernel sock_common or bpf-mirrored bpf_sock */
+ ARG_PTR_TO_PERCPU_BTF_ID, /* pointer to in-kernel percpu type */
__BPF_ARG_TYPE_MAX,
};
@@ -307,6 +308,8 @@ enum bpf_return_type {
RET_PTR_TO_SOCK_COMMON_OR_NULL, /* returns a pointer to a sock_common or NULL */
RET_PTR_TO_ALLOC_MEM_OR_NULL, /* returns a pointer to dynamically allocated memory or NULL */
RET_PTR_TO_BTF_ID_OR_NULL, /* returns a pointer to a btf_id or NULL */
+ RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL, /* returns a pointer to a valid memory or a btf_id or NULL */
+ RET_PTR_TO_MEM_OR_BTF_ID, /* returns a pointer to a valid memory or a btf_id */
};
/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
@@ -405,6 +408,7 @@ enum bpf_reg_type {
PTR_TO_RDONLY_BUF_OR_NULL, /* reg points to a readonly buffer or NULL */
PTR_TO_RDWR_BUF, /* reg points to a read/write buffer */
PTR_TO_RDWR_BUF_OR_NULL, /* reg points to a read/write buffer or NULL */
+ PTR_TO_PERCPU_BTF_ID, /* reg points to a percpu kernel variable */
};
/* The information passed from prog-specific *_is_valid_access
@@ -1828,6 +1832,8 @@ extern const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto;
extern const struct bpf_func_proto bpf_skc_to_udp6_sock_proto;
extern const struct bpf_func_proto bpf_copy_from_user_proto;
extern const struct bpf_func_proto bpf_snprintf_btf_proto;
+extern const struct bpf_func_proto bpf_per_cpu_ptr_proto;
+extern const struct bpf_func_proto bpf_this_cpu_ptr_proto;
const struct bpf_func_proto *bpf_tracing_func_proto(
enum bpf_func_id func_id, const struct bpf_prog *prog);
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 363b4f1c562a..e83ef6f6bf43 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -308,6 +308,13 @@ struct bpf_insn_aux_data {
u32 map_index; /* index into used_maps[] */
u32 map_off; /* offset from value base address */
};
+ struct {
+ enum bpf_reg_type reg_type; /* type of pseudo_btf_id */
+ union {
+ u32 btf_id; /* btf_id for struct typed var */
+ u32 mem_size; /* mem_size for non-struct typed var */
+ };
+ } btf_var;
};
u64 map_key_state; /* constant (32 bit) key tracking for maps */
int ctx_field_size; /* the ctx field size for load insn, maybe 0 */
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 024e16ff7dcc..2bf641829664 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -110,6 +110,11 @@ btf_resolve_size(const struct btf *btf, const struct btf_type *type,
i < btf_type_vlen(struct_type); \
i++, member++)
+#define for_each_vsi(i, datasec_type, member) \
+ for (i = 0, member = btf_type_var_secinfo(datasec_type); \
+ i < btf_type_vlen(datasec_type); \
+ i++, member++)
+
static inline bool btf_type_is_ptr(const struct btf_type *t)
{
return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
@@ -145,6 +150,21 @@ static inline bool btf_type_is_func_proto(const struct btf_type *t)
return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
}
+static inline bool btf_type_is_var(const struct btf_type *t)
+{
+ return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
+}
+
+/* union is only a special case of struct:
+ * all its offsetof(member) == 0
+ */
+static inline bool btf_type_is_struct(const struct btf_type *t)
+{
+ u8 kind = BTF_INFO_KIND(t->info);
+
+ return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
+}
+
static inline u16 btf_type_vlen(const struct btf_type *t)
{
return BTF_INFO_VLEN(t->info);
@@ -179,6 +199,12 @@ static inline const struct btf_member *btf_type_member(const struct btf_type *t)
return (const struct btf_member *)(t + 1);
}
+static inline const struct btf_var_secinfo *btf_type_var_secinfo(
+ const struct btf_type *t)
+{
+ return (const struct btf_var_secinfo *)(t + 1);
+}
+
#ifdef CONFIG_BPF_SYSCALL
const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
const char *btf_name_by_offset(const struct btf *btf, u32 offset);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 4f556cfcbfbe..c446394135be 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -356,18 +356,36 @@ enum bpf_link_type {
#define BPF_F_SLEEPABLE (1U << 4)
/* When BPF ldimm64's insn[0].src_reg != 0 then this can have
- * two extensions:
- *
- * insn[0].src_reg: BPF_PSEUDO_MAP_FD BPF_PSEUDO_MAP_VALUE
- * insn[0].imm: map fd map fd
- * insn[1].imm: 0 offset into value
- * insn[0].off: 0 0
- * insn[1].off: 0 0
- * ldimm64 rewrite: address of map address of map[0]+offset
- * verifier type: CONST_PTR_TO_MAP PTR_TO_MAP_VALUE
+ * the following extensions:
+ *
+ * insn[0].src_reg: BPF_PSEUDO_MAP_FD
+ * insn[0].imm: map fd
+ * insn[1].imm: 0
+ * insn[0].off: 0
+ * insn[1].off: 0
+ * ldimm64 rewrite: address of map
+ * verifier type: CONST_PTR_TO_MAP
*/
#define BPF_PSEUDO_MAP_FD 1
+/* insn[0].src_reg: BPF_PSEUDO_MAP_VALUE
+ * insn[0].imm: map fd
+ * insn[1].imm: offset into value
+ * insn[0].off: 0
+ * insn[1].off: 0
+ * ldimm64 rewrite: address of map[0]+offset
+ * verifier type: PTR_TO_MAP_VALUE
+ */
#define BPF_PSEUDO_MAP_VALUE 2
+/* insn[0].src_reg: BPF_PSEUDO_BTF_ID
+ * insn[0].imm: kernel btd id of VAR
+ * insn[1].imm: 0
+ * insn[0].off: 0
+ * insn[1].off: 0
+ * ldimm64 rewrite: address of the kernel variable
+ * verifier type: PTR_TO_BTF_ID or PTR_TO_MEM, depending on whether the var
+ * is struct/union.
+ */
+#define BPF_PSEUDO_BTF_ID 3
/* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
* offset to another bpf function
@@ -3668,6 +3686,35 @@ union bpf_attr {
* Return
* The helper returns **TC_ACT_REDIRECT** on success or
* **TC_ACT_SHOT** on error.
+ *
+ * void *bpf_per_cpu_ptr(const void *percpu_ptr, u32 cpu)
+ * Description
+ * Take a pointer to a percpu ksym, *percpu_ptr*, and return a
+ * pointer to the percpu kernel variable on *cpu*. A ksym is an
+ * extern variable decorated with '__ksym'. For ksym, there is a
+ * global var (either static or global) defined of the same name
+ * in the kernel. The ksym is percpu if the global var is percpu.
+ * The returned pointer points to the global percpu var on *cpu*.
+ *
+ * bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the
+ * kernel, except that bpf_per_cpu_ptr() may return NULL. This
+ * happens if *cpu* is larger than nr_cpu_ids. The caller of
+ * bpf_per_cpu_ptr() must check the returned value.
+ * Return
+ * A pointer pointing to the kernel percpu variable on *cpu*, or
+ * NULL, if *cpu* is invalid.
+ *
+ * void *bpf_this_cpu_ptr(const void *percpu_ptr)
+ * Description
+ * Take a pointer to a percpu ksym, *percpu_ptr*, and return a
+ * pointer to the percpu kernel variable on this cpu. See the
+ * description of 'ksym' in **bpf_per_cpu_ptr**\ ().
+ *
+ * bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in
+ * the kernel. Different from **bpf_per_cpu_ptr**\ (), it would
+ * never return NULL.
+ * Return
+ * A pointer pointing to the kernel percpu variable on this cpu.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3823,6 +3870,8 @@ union bpf_attr {
FN(seq_printf_btf), \
FN(skb_cgroup_classid), \
FN(redirect_neigh), \
+ FN(bpf_per_cpu_ptr), \
+ FN(bpf_this_cpu_ptr), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 4d0ee7839fdb..ed7d02e8bc93 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -188,11 +188,6 @@
i < btf_type_vlen(struct_type); \
i++, member++)
-#define for_each_vsi(i, struct_type, member) \
- for (i = 0, member = btf_type_var_secinfo(struct_type); \
- i < btf_type_vlen(struct_type); \
- i++, member++)
-
#define for_each_vsi_from(i, from, struct_type, member) \
for (i = from, member = btf_type_var_secinfo(struct_type) + from; \
i < btf_type_vlen(struct_type); \
@@ -440,16 +435,6 @@ static bool btf_type_nosize_or_null(const struct btf_type *t)
return !t || btf_type_nosize(t);
}
-/* union is only a special case of struct:
- * all its offsetof(member) == 0
- */
-static bool btf_type_is_struct(const struct btf_type *t)
-{
- u8 kind = BTF_INFO_KIND(t->info);
-
- return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
-}
-
static bool __btf_type_is_struct(const struct btf_type *t)
{
return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
@@ -460,11 +445,6 @@ static bool btf_type_is_array(const struct btf_type *t)
return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
}
-static bool btf_type_is_var(const struct btf_type *t)
-{
- return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
-}
-
static bool btf_type_is_datasec(const struct btf_type *t)
{
return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
@@ -613,11 +593,6 @@ static const struct btf_var *btf_type_var(const struct btf_type *t)
return (const struct btf_var *)(t + 1);
}
-static const struct btf_var_secinfo *btf_type_var_secinfo(const struct btf_type *t)
-{
- return (const struct btf_var_secinfo *)(t + 1);
-}
-
static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
{
return kind_ops[BTF_INFO_KIND(t->info)];
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index e825441781ab..25520f5eeaf6 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -623,6 +623,34 @@ const struct bpf_func_proto bpf_copy_from_user_proto = {
.arg3_type = ARG_ANYTHING,
};
+BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu)
+{
+ if (cpu >= nr_cpu_ids)
+ return (unsigned long)NULL;
+
+ return (unsigned long)per_cpu_ptr((const void __percpu *)ptr, cpu);
+}
+
+const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
+ .func = bpf_per_cpu_ptr,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL,
+ .arg1_type = ARG_PTR_TO_PERCPU_BTF_ID,
+ .arg2_type = ARG_ANYTHING,
+};
+
+BPF_CALL_1(bpf_this_cpu_ptr, const void *, percpu_ptr)
+{
+ return (unsigned long)this_cpu_ptr((const void __percpu *)percpu_ptr);
+}
+
+const struct bpf_func_proto bpf_this_cpu_ptr_proto = {
+ .func = bpf_this_cpu_ptr,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_MEM_OR_BTF_ID,
+ .arg1_type = ARG_PTR_TO_PERCPU_BTF_ID,
+};
+
const struct bpf_func_proto bpf_get_current_task_proto __weak;
const struct bpf_func_proto bpf_probe_read_user_proto __weak;
const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
@@ -689,6 +717,10 @@ bpf_base_func_proto(enum bpf_func_id func_id)
return &bpf_snprintf_btf_proto;
case BPF_FUNC_jiffies64:
return &bpf_jiffies64_proto;
+ case BPF_FUNC_bpf_per_cpu_ptr:
+ return &bpf_per_cpu_ptr_proto;
+ case BPF_FUNC_bpf_this_cpu_ptr:
+ return &bpf_this_cpu_ptr_proto;
default:
break;
}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 015a1c074b6b..d9dbf271ebab 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -238,6 +238,8 @@ struct bpf_call_arg_meta {
u64 msize_max_value;
int ref_obj_id;
int func_id;
+ u32 btf_id;
+ u32 ret_btf_id;
};
struct btf *btf_vmlinux;
@@ -517,6 +519,7 @@ static const char * const reg_type_str[] = {
[PTR_TO_XDP_SOCK] = "xdp_sock",
[PTR_TO_BTF_ID] = "ptr_",
[PTR_TO_BTF_ID_OR_NULL] = "ptr_or_null_",
+ [PTR_TO_PERCPU_BTF_ID] = "percpu_ptr_",
[PTR_TO_MEM] = "mem",
[PTR_TO_MEM_OR_NULL] = "mem_or_null",
[PTR_TO_RDONLY_BUF] = "rdonly_buf",
@@ -583,7 +586,9 @@ static void print_verifier_state(struct bpf_verifier_env *env,
/* reg->off should be 0 for SCALAR_VALUE */
verbose(env, "%lld", reg->var_off.value + reg->off);
} else {
- if (t == PTR_TO_BTF_ID || t == PTR_TO_BTF_ID_OR_NULL)
+ if (t == PTR_TO_BTF_ID ||
+ t == PTR_TO_BTF_ID_OR_NULL ||
+ t == PTR_TO_PERCPU_BTF_ID)
verbose(env, "%s", kernel_type_name(reg->btf_id));
verbose(env, "(id=%d", reg->id);
if (reg_type_may_be_refcounted_or_null(t))
@@ -2204,6 +2209,7 @@ static bool is_spillable_regtype(enum bpf_reg_type type)
case PTR_TO_RDONLY_BUF_OR_NULL:
case PTR_TO_RDWR_BUF:
case PTR_TO_RDWR_BUF_OR_NULL:
+ case PTR_TO_PERCPU_BTF_ID:
return true;
default:
return false;
@@ -4017,6 +4023,7 @@ static const struct bpf_reg_types alloc_mem_types = { .types = { PTR_TO_MEM } };
static const struct bpf_reg_types const_map_ptr_types = { .types = { CONST_PTR_TO_MAP } };
static const struct bpf_reg_types btf_ptr_types = { .types = { PTR_TO_BTF_ID } };
static const struct bpf_reg_types spin_lock_types = { .types = { PTR_TO_MAP_VALUE } };
+static const struct bpf_reg_types percpu_btf_ptr_types = { .types = { PTR_TO_PERCPU_BTF_ID } };
static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = {
[ARG_PTR_TO_MAP_KEY] = &map_key_value_types,
@@ -4042,6 +4049,7 @@ static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = {
[ARG_PTR_TO_ALLOC_MEM_OR_NULL] = &alloc_mem_types,
[ARG_PTR_TO_INT] = &int_ptr_types,
[ARG_PTR_TO_LONG] = &int_ptr_types,
+ [ARG_PTR_TO_PERCPU_BTF_ID] = &percpu_btf_ptr_types,
};
static int check_reg_type(struct bpf_verifier_env *env, u32 regno,
@@ -4205,6 +4213,12 @@ skip_type_check:
err = check_helper_mem_access(env, regno,
meta->map_ptr->value_size, false,
meta);
+ } else if (arg_type == ARG_PTR_TO_PERCPU_BTF_ID) {
+ if (!reg->btf_id) {
+ verbose(env, "Helper has invalid btf_id in R%d\n", regno);
+ return -EACCES;
+ }
+ meta->ret_btf_id = reg->btf_id;
} else if (arg_type == ARG_PTR_TO_SPIN_LOCK) {
if (meta->func_id == BPF_FUNC_spin_lock) {
if (process_spin_lock(env, regno, true))
@@ -5114,6 +5128,35 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
regs[BPF_REG_0].type = PTR_TO_MEM_OR_NULL;
regs[BPF_REG_0].id = ++env->id_gen;
regs[BPF_REG_0].mem_size = meta.mem_size;
+ } else if (fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL ||
+ fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID) {
+ const struct btf_type *t;
+
+ mark_reg_known_zero(env, regs, BPF_REG_0);
+ t = btf_type_skip_modifiers(btf_vmlinux, meta.ret_btf_id, NULL);
+ if (!btf_type_is_struct(t)) {
+ u32 tsize;
+ const struct btf_type *ret;
+ const char *tname;
+
+ /* resolve the type size of ksym. */
+ ret = btf_resolve_size(btf_vmlinux, t, &tsize);
+ if (IS_ERR(ret)) {
+ tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+ verbose(env, "unable to resolve the size of type '%s': %ld\n",
+ tname, PTR_ERR(ret));
+ return -EINVAL;
+ }
+ regs[BPF_REG_0].type =
+ fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
+ PTR_TO_MEM : PTR_TO_MEM_OR_NULL;
+ regs[BPF_REG_0].mem_size = tsize;
+ } else {
+ regs[BPF_REG_0].type =
+ fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
+ PTR_TO_BTF_ID : PTR_TO_BTF_ID_OR_NULL;
+ regs[BPF_REG_0].btf_id = meta.ret_btf_id;
+ }
} else if (fn->ret_type == RET_PTR_TO_BTF_ID_OR_NULL) {
int ret_btf_id;
@@ -7488,6 +7531,7 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
{
struct bpf_insn_aux_data *aux = cur_aux(env);
struct bpf_reg_state *regs = cur_regs(env);
+ struct bpf_reg_state *dst_reg;
struct bpf_map *map;
int err;
@@ -7504,25 +7548,45 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
if (err)
return err;
+ dst_reg = &regs[insn->dst_reg];
if (insn->src_reg == 0) {
u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;
- regs[insn->dst_reg].type = SCALAR_VALUE;
+ dst_reg->type = SCALAR_VALUE;
__mark_reg_known(&regs[insn->dst_reg], imm);
return 0;
}
+ if (insn->src_reg == BPF_PSEUDO_BTF_ID) {
+ mark_reg_known_zero(env, regs, insn->dst_reg);
+
+ dst_reg->type = aux->btf_var.reg_type;
+ switch (dst_reg->type) {
+ case PTR_TO_MEM:
+ dst_reg->mem_size = aux->btf_var.mem_size;
+ break;
+ case PTR_TO_BTF_ID:
+ case PTR_TO_PERCPU_BTF_ID:
+ dst_reg->btf_id = aux->btf_var.btf_id;
+ break;
+ default:
+ verbose(env, "bpf verifier is misconfigured\n");
+ return -EFAULT;
+ }
+ return 0;
+ }
+
map = env->used_maps[aux->map_index];
mark_reg_known_zero(env, regs, insn->dst_reg);
- regs[insn->dst_reg].map_ptr = map;
+ dst_reg->map_ptr = map;
if (insn->src_reg == BPF_PSEUDO_MAP_VALUE) {
- regs[insn->dst_reg].type = PTR_TO_MAP_VALUE;
- regs[insn->dst_reg].off = aux->map_off;
+ dst_reg->type = PTR_TO_MAP_VALUE;
+ dst_reg->off = aux->map_off;
if (map_value_has_spin_lock(map))
- regs[insn->dst_reg].id = ++env->id_gen;
+ dst_reg->id = ++env->id_gen;
} else if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
- regs[insn->dst_reg].type = CONST_PTR_TO_MAP;
+ dst_reg->type = CONST_PTR_TO_MAP;
} else {
verbose(env, "bpf verifier is misconfigured\n");
return -EINVAL;
@@ -9424,6 +9488,92 @@ process_bpf_exit:
return 0;
}
+/* replace pseudo btf_id with kernel symbol address */
+static int check_pseudo_btf_id(struct bpf_verifier_env *env,
+ struct bpf_insn *insn,
+ struct bpf_insn_aux_data *aux)
+{
+ u32 datasec_id, type, id = insn->imm;
+ const struct btf_var_secinfo *vsi;
+ const struct btf_type *datasec;
+ const struct btf_type *t;
+ const char *sym_name;
+ bool percpu = false;
+ u64 addr;
+ int i;
+
+ if (!btf_vmlinux) {
+ verbose(env, "kernel is missing BTF, make sure CONFIG_DEBUG_INFO_BTF=y is specified in Kconfig.\n");
+ return -EINVAL;
+ }
+
+ if (insn[1].imm != 0) {
+ verbose(env, "reserved field (insn[1].imm) is used in pseudo_btf_id ldimm64 insn.\n");
+ return -EINVAL;
+ }
+
+ t = btf_type_by_id(btf_vmlinux, id);
+ if (!t) {
+ verbose(env, "ldimm64 insn specifies invalid btf_id %d.\n", id);
+ return -ENOENT;
+ }
+
+ if (!btf_type_is_var(t)) {
+ verbose(env, "pseudo btf_id %d in ldimm64 isn't KIND_VAR.\n",
+ id);
+ return -EINVAL;
+ }
+
+ sym_name = btf_name_by_offset(btf_vmlinux, t->name_off);
+ addr = kallsyms_lookup_name(sym_name);
+ if (!addr) {
+ verbose(env, "ldimm64 failed to find the address for kernel symbol '%s'.\n",
+ sym_name);
+ return -ENOENT;
+ }
+
+ datasec_id = btf_find_by_name_kind(btf_vmlinux, ".data..percpu",
+ BTF_KIND_DATASEC);
+ if (datasec_id > 0) {
+ datasec = btf_type_by_id(btf_vmlinux, datasec_id);
+ for_each_vsi(i, datasec, vsi) {
+ if (vsi->type == id) {
+ percpu = true;
+ break;
+ }
+ }
+ }
+
+ insn[0].imm = (u32)addr;
+ insn[1].imm = addr >> 32;
+
+ type = t->type;
+ t = btf_type_skip_modifiers(btf_vmlinux, type, NULL);
+ if (percpu) {
+ aux->btf_var.reg_type = PTR_TO_PERCPU_BTF_ID;
+ aux->btf_var.btf_id = type;
+ } else if (!btf_type_is_struct(t)) {
+ const struct btf_type *ret;
+ const char *tname;
+ u32 tsize;
+
+ /* resolve the type size of ksym. */
+ ret = btf_resolve_size(btf_vmlinux, t, &tsize);
+ if (IS_ERR(ret)) {
+ tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+ verbose(env, "ldimm64 unable to resolve the size of type '%s': %ld\n",
+ tname, PTR_ERR(ret));
+ return -EINVAL;
+ }
+ aux->btf_var.reg_type = PTR_TO_MEM;
+ aux->btf_var.mem_size = tsize;
+ } else {
+ aux->btf_var.reg_type = PTR_TO_BTF_ID;
+ aux->btf_var.btf_id = type;
+ }
+ return 0;
+}
+
static int check_map_prealloc(struct bpf_map *map)
{
return (map->map_type != BPF_MAP_TYPE_HASH &&
@@ -9534,10 +9684,14 @@ static bool bpf_map_is_cgroup_storage(struct bpf_map *map)
map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
}
-/* look for pseudo eBPF instructions that access map FDs and
- * replace them with actual map pointers
+/* find and rewrite pseudo imm in ld_imm64 instructions:
+ *
+ * 1. if it accesses map FD, replace it with actual map pointer.
+ * 2. if it accesses btf_id of a VAR, replace it with pointer to the var.
+ *
+ * NOTE: btf_vmlinux is required for converting pseudo btf_id.
*/
-static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
+static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
{
struct bpf_insn *insn = env->prog->insnsi;
int insn_cnt = env->prog->len;
@@ -9578,6 +9732,14 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
/* valid generic load 64-bit imm */
goto next_insn;
+ if (insn[0].src_reg == BPF_PSEUDO_BTF_ID) {
+ aux = &env->insn_aux_data[i];
+ err = check_pseudo_btf_id(env, insn, aux);
+ if (err)
+ return err;
+ goto next_insn;
+ }
+
/* In final convert_pseudo_ld_imm64() step, this is
* converted into regular 64-bit imm load insn.
*/
@@ -11633,10 +11795,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
if (is_priv)
env->test_state_freq = attr->prog_flags & BPF_F_TEST_STATE_FREQ;
- ret = replace_map_fd_with_map_ptr(env);
- if (ret < 0)
- goto skip_full_check;
-
if (bpf_prog_is_dev_bound(env->prog->aux)) {
ret = bpf_prog_offload_verifier_prep(env->prog);
if (ret)
@@ -11662,6 +11820,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
if (ret)
goto skip_full_check;
+ ret = resolve_pseudo_ldimm64(env);
+ if (ret < 0)
+ goto skip_full_check;
+
ret = check_cfg(env);
if (ret < 0)
goto skip_full_check;
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index e118a83439c3..a136a6a63a71 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1327,6 +1327,10 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
case BPF_FUNC_snprintf_btf:
return &bpf_snprintf_btf_proto;
+ case BPF_FUNC_bpf_per_cpu_ptr:
+ return &bpf_per_cpu_ptr_proto;
+ case BPF_FUNC_bpf_this_cpu_ptr:
+ return &bpf_this_cpu_ptr_proto;
default:
return NULL;
}
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 4f556cfcbfbe..c446394135be 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -356,18 +356,36 @@ enum bpf_link_type {
#define BPF_F_SLEEPABLE (1U << 4)
/* When BPF ldimm64's insn[0].src_reg != 0 then this can have
- * two extensions:
- *
- * insn[0].src_reg: BPF_PSEUDO_MAP_FD BPF_PSEUDO_MAP_VALUE
- * insn[0].imm: map fd map fd
- * insn[1].imm: 0 offset into value
- * insn[0].off: 0 0
- * insn[1].off: 0 0
- * ldimm64 rewrite: address of map address of map[0]+offset
- * verifier type: CONST_PTR_TO_MAP PTR_TO_MAP_VALUE
+ * the following extensions:
+ *
+ * insn[0].src_reg: BPF_PSEUDO_MAP_FD
+ * insn[0].imm: map fd
+ * insn[1].imm: 0
+ * insn[0].off: 0
+ * insn[1].off: 0
+ * ldimm64 rewrite: address of map
+ * verifier type: CONST_PTR_TO_MAP
*/
#define BPF_PSEUDO_MAP_FD 1
+/* insn[0].src_reg: BPF_PSEUDO_MAP_VALUE
+ * insn[0].imm: map fd
+ * insn[1].imm: offset into value
+ * insn[0].off: 0
+ * insn[1].off: 0
+ * ldimm64 rewrite: address of map[0]+offset
+ * verifier type: PTR_TO_MAP_VALUE
+ */
#define BPF_PSEUDO_MAP_VALUE 2
+/* insn[0].src_reg: BPF_PSEUDO_BTF_ID
+ * insn[0].imm: kernel btd id of VAR
+ * insn[1].imm: 0
+ * insn[0].off: 0
+ * insn[1].off: 0
+ * ldimm64 rewrite: address of the kernel variable
+ * verifier type: PTR_TO_BTF_ID or PTR_TO_MEM, depending on whether the var
+ * is struct/union.
+ */
+#define BPF_PSEUDO_BTF_ID 3
/* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
* offset to another bpf function
@@ -3668,6 +3686,35 @@ union bpf_attr {
* Return
* The helper returns **TC_ACT_REDIRECT** on success or
* **TC_ACT_SHOT** on error.
+ *
+ * void *bpf_per_cpu_ptr(const void *percpu_ptr, u32 cpu)
+ * Description
+ * Take a pointer to a percpu ksym, *percpu_ptr*, and return a
+ * pointer to the percpu kernel variable on *cpu*. A ksym is an
+ * extern variable decorated with '__ksym'. For ksym, there is a
+ * global var (either static or global) defined of the same name
+ * in the kernel. The ksym is percpu if the global var is percpu.
+ * The returned pointer points to the global percpu var on *cpu*.
+ *
+ * bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the
+ * kernel, except that bpf_per_cpu_ptr() may return NULL. This
+ * happens if *cpu* is larger than nr_cpu_ids. The caller of
+ * bpf_per_cpu_ptr() must check the returned value.
+ * Return
+ * A pointer pointing to the kernel percpu variable on *cpu*, or
+ * NULL, if *cpu* is invalid.
+ *
+ * void *bpf_this_cpu_ptr(const void *percpu_ptr)
+ * Description
+ * Take a pointer to a percpu ksym, *percpu_ptr*, and return a
+ * pointer to the percpu kernel variable on this cpu. See the
+ * description of 'ksym' in **bpf_per_cpu_ptr**\ ().
+ *
+ * bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in
+ * the kernel. Different from **bpf_per_cpu_ptr**\ (), it would
+ * never return NULL.
+ * Return
+ * A pointer pointing to the kernel percpu variable on this cpu.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3823,6 +3870,8 @@ union bpf_attr {
FN(seq_printf_btf), \
FN(skb_cgroup_classid), \
FN(redirect_neigh), \
+ FN(bpf_per_cpu_ptr), \
+ FN(bpf_this_cpu_ptr), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index a4f55f8a460d..9b36c52b8511 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -390,6 +390,12 @@ struct extern_desc {
} kcfg;
struct {
unsigned long long addr;
+
+ /* target btf_id of the corresponding kernel var. */
+ int vmlinux_btf_id;
+
+ /* local btf_id of the ksym extern's type. */
+ __u32 type_id;
} ksym;
};
};
@@ -2522,12 +2528,23 @@ static int bpf_object__load_vmlinux_btf(struct bpf_object *obj)
{
bool need_vmlinux_btf = false;
struct bpf_program *prog;
- int err;
+ int i, err;
/* CO-RE relocations need kernel BTF */
if (obj->btf_ext && obj->btf_ext->core_relo_info.len)
need_vmlinux_btf = true;
+ /* Support for typed ksyms needs kernel BTF */
+ for (i = 0; i < obj->nr_extern; i++) {
+ const struct extern_desc *ext;
+
+ ext = &obj->externs[i];
+ if (ext->type == EXT_KSYM && ext->ksym.type_id) {
+ need_vmlinux_btf = true;
+ break;
+ }
+ }
+
bpf_object__for_each_program(prog, obj) {
if (!prog->load)
continue;
@@ -3156,16 +3173,10 @@ static int bpf_object__collect_externs(struct bpf_object *obj)
return -ENOTSUP;
}
} else if (strcmp(sec_name, KSYMS_SEC) == 0) {
- const struct btf_type *vt;
-
ksym_sec = sec;
ext->type = EXT_KSYM;
-
- vt = skip_mods_and_typedefs(obj->btf, t->type, NULL);
- if (!btf_is_void(vt)) {
- pr_warn("extern (ksym) '%s' is not typeless (void)\n", ext_name);
- return -ENOTSUP;
- }
+ skip_mods_and_typedefs(obj->btf, t->type,
+ &ext->ksym.type_id);
} else {
pr_warn("unrecognized extern section '%s'\n", sec_name);
return -ENOTSUP;
@@ -5800,8 +5811,13 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
insn[0].imm = obj->maps[obj->kconfig_map_idx].fd;
insn[1].imm = ext->kcfg.data_off;
} else /* EXT_KSYM */ {
- insn[0].imm = (__u32)ext->ksym.addr;
- insn[1].imm = ext->ksym.addr >> 32;
+ if (ext->ksym.type_id) { /* typed ksyms */
+ insn[0].src_reg = BPF_PSEUDO_BTF_ID;
+ insn[0].imm = ext->ksym.vmlinux_btf_id;
+ } else { /* typeless ksyms */
+ insn[0].imm = (__u32)ext->ksym.addr;
+ insn[1].imm = ext->ksym.addr >> 32;
+ }
}
relo->processed = true;
break;
@@ -6933,10 +6949,72 @@ out:
return err;
}
+static int bpf_object__resolve_ksyms_btf_id(struct bpf_object *obj)
+{
+ struct extern_desc *ext;
+ int i, id;
+
+ for (i = 0; i < obj->nr_extern; i++) {
+ const struct btf_type *targ_var, *targ_type;
+ __u32 targ_type_id, local_type_id;
+ const char *targ_var_name;
+ int ret;
+
+ ext = &obj->externs[i];
+ if (ext->type != EXT_KSYM || !ext->ksym.type_id)
+ continue;
+
+ id = btf__find_by_name_kind(obj->btf_vmlinux, ext->name,
+ BTF_KIND_VAR);
+ if (id <= 0) {
+ pr_warn("extern (ksym) '%s': failed to find BTF ID in vmlinux BTF.\n",
+ ext->name);
+ return -ESRCH;
+ }
+
+ /* find local type_id */
+ local_type_id = ext->ksym.type_id;
+
+ /* find target type_id */
+ targ_var = btf__type_by_id(obj->btf_vmlinux, id);
+ targ_var_name = btf__name_by_offset(obj->btf_vmlinux,
+ targ_var->name_off);
+ targ_type = skip_mods_and_typedefs(obj->btf_vmlinux,
+ targ_var->type,
+ &targ_type_id);
+
+ ret = bpf_core_types_are_compat(obj->btf, local_type_id,
+ obj->btf_vmlinux, targ_type_id);
+ if (ret <= 0) {
+ const struct btf_type *local_type;
+ const char *targ_name, *local_name;
+
+ local_type = btf__type_by_id(obj->btf, local_type_id);
+ local_name = btf__name_by_offset(obj->btf,
+ local_type->name_off);
+ targ_name = btf__name_by_offset(obj->btf_vmlinux,
+ targ_type->name_off);
+
+ pr_warn("extern (ksym) '%s': incompatible types, expected [%d] %s %s, but kernel has [%d] %s %s\n",
+ ext->name, local_type_id,
+ btf_kind_str(local_type), local_name, targ_type_id,
+ btf_kind_str(targ_type), targ_name);
+ return -EINVAL;
+ }
+
+ ext->is_set = true;
+ ext->ksym.vmlinux_btf_id = id;
+ pr_debug("extern (ksym) '%s': resolved to [%d] %s %s\n",
+ ext->name, id, btf_kind_str(targ_var), targ_var_name);
+ }
+ return 0;
+}
+
static int bpf_object__resolve_externs(struct bpf_object *obj,
const char *extra_kconfig)
{
bool need_config = false, need_kallsyms = false;
+ bool need_vmlinux_btf = false;
struct extern_desc *ext;
void *kcfg_data = NULL;
int err, i;
@@ -6967,7 +7045,10 @@ static int bpf_object__resolve_externs(struct bpf_object *obj,
strncmp(ext->name, "CONFIG_", 7) == 0) {
need_config = true;
} else if (ext->type == EXT_KSYM) {
- need_kallsyms = true;
+ if (ext->ksym.type_id)
+ need_vmlinux_btf = true;
+ else
+ need_kallsyms = true;
} else {
pr_warn("unrecognized extern '%s'\n", ext->name);
return -EINVAL;
@@ -6996,6 +7077,11 @@ static int bpf_object__resolve_externs(struct bpf_object *obj,
if (err)
return -EINVAL;
}
+ if (need_vmlinux_btf) {
+ err = bpf_object__resolve_ksyms_btf_id(obj);
+ if (err)
+ return -EINVAL;
+ }
for (i = 0; i < obj->nr_extern; i++) {
ext = &obj->externs[i];
@@ -7028,10 +7114,10 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
}
err = bpf_object__probe_loading(obj);
+ err = err ? : bpf_object__load_vmlinux_btf(obj);
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__load_vmlinux_btf(obj);
err = err ? : bpf_object__init_kern_struct_ops_maps(obj);
err = err ? : bpf_object__create_maps(obj);
err = err ? : bpf_object__relocate(obj, attr->target_btf_path);
diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms.c b/tools/testing/selftests/bpf/prog_tests/ksyms.c
index b771804b2342..b295969b263b 100644
--- a/tools/testing/selftests/bpf/prog_tests/ksyms.c
+++ b/tools/testing/selftests/bpf/prog_tests/ksyms.c
@@ -7,40 +7,28 @@
static int duration;
-static __u64 kallsyms_find(const char *sym)
-{
- char type, name[500];
- __u64 addr, res = 0;
- FILE *f;
-
- f = fopen("/proc/kallsyms", "r");
- if (CHECK(!f, "kallsyms_fopen", "failed to open: %d\n", errno))
- return 0;
-
- while (fscanf(f, "%llx %c %499s%*[^\n]\n", &addr, &type, name) > 0) {
- if (strcmp(name, sym) == 0) {
- res = addr;
- goto out;
- }
- }
-
- CHECK(false, "not_found", "symbol %s not found\n", sym);
-out:
- fclose(f);
- return res;
-}
-
void test_ksyms(void)
{
- __u64 per_cpu_start_addr = kallsyms_find("__per_cpu_start");
- __u64 link_fops_addr = kallsyms_find("bpf_link_fops");
const char *btf_path = "/sys/kernel/btf/vmlinux";
struct test_ksyms *skel;
struct test_ksyms__data *data;
+ __u64 link_fops_addr, per_cpu_start_addr;
struct stat st;
__u64 btf_size;
int err;
+ err = kallsyms_find("bpf_link_fops", &link_fops_addr);
+ if (CHECK(err == -EINVAL, "kallsyms_fopen", "failed to open: %d\n", errno))
+ return;
+ if (CHECK(err == -ENOENT, "ksym_find", "symbol 'bpf_link_fops' not found\n"))
+ return;
+
+ err = kallsyms_find("__per_cpu_start", &per_cpu_start_addr);
+ if (CHECK(err == -EINVAL, "kallsyms_fopen", "failed to open: %d\n", errno))
+ return;
+ if (CHECK(err == -ENOENT, "ksym_find", "symbol 'per_cpu_start' not found\n"))
+ return;
+
if (CHECK(stat(btf_path, &st), "stat_btf", "err %d\n", errno))
return;
btf_size = st.st_size;
diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c
new file mode 100644
index 000000000000..28e26bd3e0ca
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Google */
+
+#include <test_progs.h>
+#include <bpf/libbpf.h>
+#include <bpf/btf.h>
+#include "test_ksyms_btf.skel.h"
+
+static int duration;
+
+void test_ksyms_btf(void)
+{
+ __u64 runqueues_addr, bpf_prog_active_addr;
+ __u32 this_rq_cpu;
+ int this_bpf_prog_active;
+ struct test_ksyms_btf *skel = NULL;
+ struct test_ksyms_btf__data *data;
+ struct btf *btf;
+ int percpu_datasec;
+ int err;
+
+ err = kallsyms_find("runqueues", &runqueues_addr);
+ if (CHECK(err == -EINVAL, "kallsyms_fopen", "failed to open: %d\n", errno))
+ return;
+ if (CHECK(err == -ENOENT, "ksym_find", "symbol 'runqueues' not found\n"))
+ return;
+
+ err = kallsyms_find("bpf_prog_active", &bpf_prog_active_addr);
+ if (CHECK(err == -EINVAL, "kallsyms_fopen", "failed to open: %d\n", errno))
+ return;
+ if (CHECK(err == -ENOENT, "ksym_find", "symbol 'bpf_prog_active' not found\n"))
+ return;
+
+ btf = libbpf_find_kernel_btf();
+ if (CHECK(IS_ERR(btf), "btf_exists", "failed to load kernel BTF: %ld\n",
+ PTR_ERR(btf)))
+ return;
+
+ percpu_datasec = btf__find_by_name_kind(btf, ".data..percpu",
+ BTF_KIND_DATASEC);
+ if (percpu_datasec < 0) {
+ printf("%s:SKIP:no PERCPU DATASEC in kernel btf\n",
+ __func__);
+ test__skip();
+ goto cleanup;
+ }
+
+ skel = test_ksyms_btf__open_and_load();
+ if (CHECK(!skel, "skel_open", "failed to open and load skeleton\n"))
+ goto cleanup;
+
+ err = test_ksyms_btf__attach(skel);
+ if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+ goto cleanup;
+
+ /* trigger tracepoint */
+ usleep(1);
+
+ data = skel->data;
+ CHECK(data->out__runqueues_addr != runqueues_addr, "runqueues_addr",
+ "got %llu, exp %llu\n",
+ (unsigned long long)data->out__runqueues_addr,
+ (unsigned long long)runqueues_addr);
+ CHECK(data->out__bpf_prog_active_addr != bpf_prog_active_addr, "bpf_prog_active_addr",
+ "got %llu, exp %llu\n",
+ (unsigned long long)data->out__bpf_prog_active_addr,
+ (unsigned long long)bpf_prog_active_addr);
+
+ CHECK(data->out__rq_cpu == -1, "rq_cpu",
+ "got %u, exp != -1\n", data->out__rq_cpu);
+ CHECK(data->out__bpf_prog_active < 0, "bpf_prog_active",
+ "got %d, exp >= 0\n", data->out__bpf_prog_active);
+ CHECK(data->out__cpu_0_rq_cpu != 0, "cpu_rq(0)->cpu",
+ "got %u, exp 0\n", data->out__cpu_0_rq_cpu);
+
+ this_rq_cpu = data->out__this_rq_cpu;
+ CHECK(this_rq_cpu != data->out__rq_cpu, "this_rq_cpu",
+ "got %u, exp %u\n", this_rq_cpu, data->out__rq_cpu);
+
+ this_bpf_prog_active = data->out__this_bpf_prog_active;
+ CHECK(this_bpf_prog_active != data->out__bpf_prog_active, "this_bpf_prog_active",
+ "got %d, exp %d\n", this_bpf_prog_active,
+ data->out__bpf_prog_active);
+
+cleanup:
+ btf__free(btf);
+ test_ksyms_btf__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_ksyms_btf.c b/tools/testing/selftests/bpf/progs/test_ksyms_btf.c
new file mode 100644
index 000000000000..bb8ea9270f29
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_ksyms_btf.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Google */
+
+#include "vmlinux.h"
+
+#include <bpf/bpf_helpers.h>
+
+__u64 out__runqueues_addr = -1;
+__u64 out__bpf_prog_active_addr = -1;
+
+__u32 out__rq_cpu = -1; /* percpu struct fields */
+int out__bpf_prog_active = -1; /* percpu int */
+
+__u32 out__this_rq_cpu = -1;
+int out__this_bpf_prog_active = -1;
+
+__u32 out__cpu_0_rq_cpu = -1; /* cpu_rq(0)->cpu */
+
+extern const struct rq runqueues __ksym; /* struct type global var. */
+extern const int bpf_prog_active __ksym; /* int type global var. */
+
+SEC("raw_tp/sys_enter")
+int handler(const void *ctx)
+{
+ struct rq *rq;
+ int *active;
+ __u32 cpu;
+
+ out__runqueues_addr = (__u64)&runqueues;
+ out__bpf_prog_active_addr = (__u64)&bpf_prog_active;
+
+ cpu = bpf_get_smp_processor_id();
+
+ /* test bpf_per_cpu_ptr() */
+ rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, cpu);
+ if (rq)
+ out__rq_cpu = rq->cpu;
+ active = (int *)bpf_per_cpu_ptr(&bpf_prog_active, cpu);
+ if (active)
+ out__bpf_prog_active = *active;
+
+ rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, 0);
+ if (rq) /* should always be valid, but we can't spare the check. */
+ out__cpu_0_rq_cpu = rq->cpu;
+
+ /* test bpf_this_cpu_ptr */
+ rq = (struct rq *)bpf_this_cpu_ptr(&runqueues);
+ out__this_rq_cpu = rq->cpu;
+ active = (int *)bpf_this_cpu_ptr(&bpf_prog_active);
+ out__this_bpf_prog_active = *active;
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index 4d0e913bbb22..1bbd1d9830c8 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -90,6 +90,33 @@ long ksym_get_addr(const char *name)
return 0;
}
+/* open kallsyms and read symbol addresses on the fly. Without caching all symbols,
+ * this is faster than load + find.
+ */
+int kallsyms_find(const char *sym, unsigned long long *addr)
+{
+ char type, name[500];
+ unsigned long long value;
+ int err = 0;
+ FILE *f;
+
+ f = fopen("/proc/kallsyms", "r");
+ if (!f)
+ return -EINVAL;
+
+ while (fscanf(f, "%llx %c %499s%*[^\n]\n", &value, &type, name) > 0) {
+ if (strcmp(name, sym) == 0) {
+ *addr = value;
+ goto out;
+ }
+ }
+ err = -ENOENT;
+
+out:
+ fclose(f);
+ return err;
+}
+
void read_trace_pipe(void)
{
int trace_fd;
diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h
index 25ef597dd03f..f62fdef9e589 100644
--- a/tools/testing/selftests/bpf/trace_helpers.h
+++ b/tools/testing/selftests/bpf/trace_helpers.h
@@ -12,6 +12,10 @@ struct ksym {
int load_kallsyms(void);
struct ksym *ksym_search(long key);
long ksym_get_addr(const char *name);
+
+/* open kallsyms and find addresses on the fly, faster than load + search. */
+int kallsyms_find(const char *sym, unsigned long long *addr);
+
void read_trace_pipe(void);
#endif
View Lorry Controller Status