bpf: Move lnode list node to struct bpf_ksym

Adding lnode list node to 'struct bpf_ksym' object,
so the struct bpf_ksym itself can be chained and used
in other objects like bpf_trampoline and bpf_dispatcher.

Changing iterator to bpf_ksym in bpf_get_kallsym function.

The ksym->start is holding the prog->bpf_func value,
so it's ok to use it as value in bpf_get_kallsym.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200312195610.346362-6-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiri Olsa 2020-03-12 20:56:00 +01:00 committed by Alexei Starovoitov
parent bfea9a8574
commit ecb60d1c67
2 changed files with 12 additions and 12 deletions

View File

@ -476,6 +476,7 @@ struct bpf_ksym {
unsigned long start;
unsigned long end;
char name[KSYM_NAME_LEN];
struct list_head lnode;
};
enum bpf_tramp_prog_type {
@ -659,7 +660,6 @@ struct bpf_prog_aux {
struct bpf_jit_poke_descriptor *poke_tab;
u32 size_poke_tab;
struct latch_tree_node ksym_tnode;
struct list_head ksym_lnode;
struct bpf_ksym ksym;
const struct bpf_prog_ops *ops;
struct bpf_map **used_maps;

View File

@ -97,7 +97,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
fp->aux->prog = fp;
fp->jit_requested = ebpf_jit_enabled();
INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode);
INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
return fp;
}
@ -613,18 +613,18 @@ static struct latch_tree_root bpf_tree __cacheline_aligned;
static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
{
WARN_ON_ONCE(!list_empty(&aux->ksym_lnode));
list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms);
WARN_ON_ONCE(!list_empty(&aux->ksym.lnode));
list_add_tail_rcu(&aux->ksym.lnode, &bpf_kallsyms);
latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
}
static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
{
if (list_empty(&aux->ksym_lnode))
if (list_empty(&aux->ksym.lnode))
return;
latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
list_del_rcu(&aux->ksym_lnode);
list_del_rcu(&aux->ksym.lnode);
}
static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
@ -634,8 +634,8 @@ static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
{
return list_empty(&fp->aux->ksym_lnode) ||
fp->aux->ksym_lnode.prev == LIST_POISON2;
return list_empty(&fp->aux->ksym.lnode) ||
fp->aux->ksym.lnode.prev == LIST_POISON2;
}
void bpf_prog_kallsyms_add(struct bpf_prog *fp)
@ -729,7 +729,7 @@ out:
int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
char *sym)
{
struct bpf_prog_aux *aux;
struct bpf_ksym *ksym;
unsigned int it = 0;
int ret = -ERANGE;
@ -737,13 +737,13 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
return ret;
rcu_read_lock();
list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) {
list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
if (it++ != symnum)
continue;
strncpy(sym, aux->ksym.name, KSYM_NAME_LEN);
strncpy(sym, ksym->name, KSYM_NAME_LEN);
*value = (unsigned long)aux->prog->bpf_func;
*value = ksym->start;
*type = BPF_SYM_ELF_TYPE;
ret = 0;