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bpf: Add bpf_ksym_add/del functions

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Separating /proc/kallsyms add/del code and adding bpf_ksym_add/del
functions for that.

Moving bpf_prog_ksym_node_add/del functions to __bpf_ksym_add/del
and changing their argument to 'struct bpf_ksym' object. This way
we can call them for other bpf objects types like trampoline and
dispatcher.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-10-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiri Olsa 2020-03-12 20:56:04 +01:00 committed by Alexei Starovoitov
parent cbd76f8d5a
commit dba122fb5e
2 changed files with 22 additions and 14 deletions
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3
include/linux/bpf.h
View File

@ -584,6 +584,9 @@ struct bpf_image {
#define BPF_IMAGE_SIZE (PAGE_SIZE - sizeof(struct bpf_image))
bool is_bpf_image_address(unsigned long address);
void *bpf_image_alloc(void);
/* Called only from JIT-enabled code, so there's no need for stubs. */
void bpf_ksym_add(struct bpf_ksym *ksym);
void bpf_ksym_del(struct bpf_ksym *ksym);
#else
static inline struct bpf_trampoline *bpf_trampoline_lookup(u64 key)
{

33
kernel/bpf/core.c
View File

@ -607,20 +607,29 @@ static DEFINE_SPINLOCK(bpf_lock);
static LIST_HEAD(bpf_kallsyms);
static struct latch_tree_root bpf_tree __cacheline_aligned;
static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
void bpf_ksym_add(struct bpf_ksym *ksym)
{
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);
spin_lock_bh(&bpf_lock);
WARN_ON_ONCE(!list_empty(&ksym->lnode));
list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
spin_unlock_bh(&bpf_lock);
}
static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
static void __bpf_ksym_del(struct bpf_ksym *ksym)
{
if (list_empty(&aux->ksym.lnode))
if (list_empty(&ksym->lnode))
return;
latch_tree_erase(&aux->ksym.tnode, &bpf_tree, &bpf_tree_ops);
list_del_rcu(&aux->ksym.lnode);
latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
list_del_rcu(&ksym->lnode);
}
void bpf_ksym_del(struct bpf_ksym *ksym)
{
spin_lock_bh(&bpf_lock);
__bpf_ksym_del(ksym);
spin_unlock_bh(&bpf_lock);
}
static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
@ -644,9 +653,7 @@ void bpf_prog_kallsyms_add(struct bpf_prog *fp)
bpf_prog_ksym_set_name(fp);
fp->aux->ksym.prog = true;
spin_lock_bh(&bpf_lock);
bpf_prog_ksym_node_add(fp->aux);
spin_unlock_bh(&bpf_lock);
bpf_ksym_add(&fp->aux->ksym);
}
void bpf_prog_kallsyms_del(struct bpf_prog *fp)
@ -654,9 +661,7 @@ void bpf_prog_kallsyms_del(struct bpf_prog *fp)
if (!bpf_prog_kallsyms_candidate(fp))
return;
spin_lock_bh(&bpf_lock);
bpf_prog_ksym_node_del(fp->aux);
spin_unlock_bh(&bpf_lock);
bpf_ksym_del(&fp->aux->ksym);
}
static struct bpf_ksym *bpf_ksym_find(unsigned long addr)