Commit ca4424c9 authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

bpf: Move ksym_tnode to bpf_ksym 



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

We need bpf_ksym object to be linked both in bpf_kallsyms
via lnode for /proc/kallsyms and in bpf_tree via tnode for
bpf address lookup functions like __bpf_address_lookup or
bpf_prog_kallsyms_find.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-7-jolsa@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent ecb60d1c

include/linux/bpf.h

+1 −1
Original line number Diff line number Diff line
@@ -477,6 +477,7 @@ struct bpf_ksym { 
	unsigned long		 end;

	char			 name[KSYM_NAME_LEN];

	struct list_head	 lnode;

	struct latch_tree_node	 tnode;

};



enum bpf_tramp_prog_type {
@@ -659,7 +660,6 @@ struct bpf_prog_aux { 
	void *jit_data; /* JIT specific data. arch dependent */

	struct bpf_jit_poke_descriptor *poke_tab;

	u32 size_poke_tab;

	struct latch_tree_node ksym_tnode;

	struct bpf_ksym ksym;

	const struct bpf_prog_ops *ops;

	struct bpf_map **used_maps;

kernel/bpf/core.c

+10 −14
Original line number Diff line number Diff line
@@ -572,31 +572,27 @@ bpf_prog_ksym_set_name(struct bpf_prog *prog) 
		*sym = 0;

}



static __always_inline unsigned long

bpf_get_prog_addr_start(struct latch_tree_node *n)

static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)

{

	const struct bpf_prog_aux *aux;



	aux = container_of(n, struct bpf_prog_aux, ksym_tnode);

	return aux->ksym.start;

	return container_of(n, struct bpf_ksym, tnode)->start;

}



static __always_inline bool bpf_tree_less(struct latch_tree_node *a,

					  struct latch_tree_node *b)

{

	return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b);

	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);

}



static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)

{

	unsigned long val = (unsigned long)key;

	const struct bpf_prog_aux *aux;

	const struct bpf_ksym *ksym;



	aux = container_of(n, struct bpf_prog_aux, ksym_tnode);

	ksym = container_of(n, struct bpf_ksym, tnode);



	if (val < aux->ksym.start)

	if (val < ksym->start)

		return -1;

	if (val >= aux->ksym.end)

	if (val >= ksym->end)

		return  1;



	return 0;
@@ -615,7 +611,7 @@ 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);

	latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);

	latch_tree_insert(&aux->ksym.tnode, &bpf_tree, &bpf_tree_ops);

}



static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
@@ -623,7 +619,7 @@ static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) 
	if (list_empty(&aux->ksym.lnode))

		return;



	latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);

	latch_tree_erase(&aux->ksym.tnode, &bpf_tree, &bpf_tree_ops);

	list_del_rcu(&aux->ksym.lnode);

}
@@ -668,7 +664,7 @@ static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) 


	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);

	return n ?

	       container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :

	       container_of(n, struct bpf_prog_aux, ksym.tnode)->prog :

	       NULL;

}

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