Commit dba122fb authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

bpf: Add bpf_ksym_add/del functions 



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: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-10-jolsa@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent cbd76f8d

include/linux/bpf.h

+3 −0
Original line number Diff line number Diff line
@@ -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)

{

kernel/bpf/core.c

+19 −14
Original line number Diff line number Diff line
@@ -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)

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