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.

Jiri Olsa committed 6 years ago

Commit ca4424c1 parent ecb60d12 files · +11 −15Browse files

Unified · Split

2 files

include/linux/bpf.h +1 −1
kernel/bpf/core.c +10 −14

include/linux/bpf.h+1−1

@@ -477,6 +477,7 @@ struct bpf_ksym { · 476 unmodified lines
477	477	unsigned long end;
478	478	char name[KSYM_NAME_LEN];
479	479	struct list_head lnode;
	480	+ struct latch_tree_node tnode;
480	481	};
481	482
482	483	enum bpf_tramp_prog_type {
@@ -659,7 +660,6 @@ struct bpf_prog_aux { · 176 unmodified lines
659	660	void jit_data; / JIT specific data. arch dependent */
660	661	struct bpf_jit_poke_descriptor *poke_tab;
661	662	u32 size_poke_tab;
662		− struct latch_tree_node ksym_tnode;
663	663	struct bpf_ksym ksym;
664	664	const struct bpf_prog_ops *ops;
665	665	struct bpf_map **used_maps;

kernel/bpf/core.c+10−14

@@ -572,31 +572,27 @@ bpf_prog_ksym_set_name(struct bpf_prog *prog) · 571 unmodified lines
572	572	*sym = 0;
573	573	}
574	574
575		−static __always_inline unsigned long
576		−bpf_get_prog_addr_start(struct latch_tree_node *n)
	575	+static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
577	576	{
578		− const struct bpf_prog_aux *aux;
579		−
580		− aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
581		− return aux->ksym.start;
	577	+ return container_of(n, struct bpf_ksym, tnode)->start;
582	578	}
583	579
584	580	static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
585	581	struct latch_tree_node *b)
586	582	{
587		− return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b);
	583	+ return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
588	584	}
589	585
590	586	static __always_inline int bpf_tree_comp(void key, struct latch_tree_node n)
591	587	{
592	588	unsigned long val = (unsigned long)key;
593		− const struct bpf_prog_aux *aux;
	589	+ const struct bpf_ksym *ksym;
594	590
595		− aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
	591	+ ksym = container_of(n, struct bpf_ksym, tnode);
596	592
597		− if (val < aux->ksym.start)
	593	+ if (val < ksym->start)
598	594	return -1;
599		− if (val >= aux->ksym.end)
	595	+ if (val >= ksym->end)
600	596	return 1;
601	597
602	598	return 0;
@@ -615,7 +611,7 @@ static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) · 12 unmodified lines
615	611	{
616	612	WARN_ON_ONCE(!list_empty(&aux->ksym.lnode));
617	613	list_add_tail_rcu(&aux->ksym.lnode, &bpf_kallsyms);
618		− latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
	614	+ latch_tree_insert(&aux->ksym.tnode, &bpf_tree, &bpf_tree_ops);
619	615	}
620	616
621	617	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) · 1 unmodified line
623	619	if (list_empty(&aux->ksym.lnode))
624	620	return;
625	621
626		− latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
	622	+ latch_tree_erase(&aux->ksym.tnode, &bpf_tree, &bpf_tree_ops);
627	623	list_del_rcu(&aux->ksym.lnode);
628	624	}
629	625
@@ -668,7 +664,7 @@ static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) · 38 unmodified lines
668	664
669	665	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
670	666	return n ?
671		− container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :
	667	+ container_of(n, struct bpf_prog_aux, ksym.tnode)->prog :
672	668	NULL;
673	669	}
674	670