Commit 644bfe51 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Daniel Borkmann
Browse files

cpumap: Formalize map value as a named struct 



As it has been already done for devmap, introduce 'struct bpf_cpumap_val'
to formalize the expected values that can be passed in for a CPUMAP.
Update cpumap code to use the struct.

Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/754f950674665dae6139c061d28c1d982aaf4170.1594734381.git.lorenzo@kernel.org
parent a4e76f1b

include/uapi/linux/bpf.h

+9 −0
Original line number Diff line number Diff line
@@ -3849,6 +3849,15 @@ struct bpf_devmap_val { 
	} bpf_prog;

};



/* CPUMAP map-value layout

 *

 * The struct data-layout of map-value is a configuration interface.

 * New members can only be added to the end of this structure.

 */

struct bpf_cpumap_val {

	__u32 qsize;	/* queue size to remote target CPU */

};



enum sk_action {

	SK_DROP = 0,

	SK_PASS,

kernel/bpf/cpumap.c

+15 −13
Original line number Diff line number Diff line
@@ -52,7 +52,6 @@ struct xdp_bulk_queue { 
struct bpf_cpu_map_entry {

	u32 cpu;    /* kthread CPU and map index */

	int map_id; /* Back reference to map */

	u32 qsize;  /* Queue size placeholder for map lookup */



	/* XDP can run multiple RX-ring queues, need __percpu enqueue store */

	struct xdp_bulk_queue __percpu *bulkq;
@@ -62,10 +61,13 @@ struct bpf_cpu_map_entry { 
	/* Queue with potential multi-producers, and single-consumer kthread */

	struct ptr_ring *queue;

	struct task_struct *kthread;

	struct work_struct kthread_stop_wq;



	struct bpf_cpumap_val value;



	atomic_t refcnt; /* Control when this struct can be free'ed */

	struct rcu_head rcu;



	struct work_struct kthread_stop_wq;

};



struct bpf_cpu_map {
@@ -307,8 +309,8 @@ static int cpu_map_kthread_run(void *data) 
	return 0;

}



static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu,

						       int map_id)

static struct bpf_cpu_map_entry *

__cpu_map_entry_alloc(struct bpf_cpumap_val *value, u32 cpu, int map_id)

{

	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;

	struct bpf_cpu_map_entry *rcpu;
@@ -338,13 +340,13 @@ static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu, 
	if (!rcpu->queue)

		goto free_bulkq;



	err = ptr_ring_init(rcpu->queue, qsize, gfp);

	err = ptr_ring_init(rcpu->queue, value->qsize, gfp);

	if (err)

		goto free_queue;



	rcpu->cpu    = cpu;

	rcpu->map_id = map_id;

	rcpu->qsize  = qsize;

	rcpu->value.qsize  = value->qsize;



	/* Setup kthread */

	rcpu->kthread = kthread_create_on_node(cpu_map_kthread_run, rcpu, numa,
@@ -437,12 +439,12 @@ static int cpu_map_update_elem(struct bpf_map *map, void *key, void *value, 
			       u64 map_flags)

{

	struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);

	struct bpf_cpumap_val cpumap_value = {};

	struct bpf_cpu_map_entry *rcpu;



	/* Array index key correspond to CPU number */

	u32 key_cpu = *(u32 *)key;

	/* Value is the queue size */

	u32 qsize = *(u32 *)value;



	memcpy(&cpumap_value, value, map->value_size);



	if (unlikely(map_flags > BPF_EXIST))

		return -EINVAL;
@@ -450,18 +452,18 @@ static int cpu_map_update_elem(struct bpf_map *map, void *key, void *value, 
		return -E2BIG;

	if (unlikely(map_flags == BPF_NOEXIST))

		return -EEXIST;

	if (unlikely(qsize > 16384)) /* sanity limit on qsize */

	if (unlikely(cpumap_value.qsize > 16384)) /* sanity limit on qsize */

		return -EOVERFLOW;



	/* Make sure CPU is a valid possible cpu */

	if (key_cpu >= nr_cpumask_bits || !cpu_possible(key_cpu))

		return -ENODEV;



	if (qsize == 0) {

	if (cpumap_value.qsize == 0) {

		rcpu = NULL; /* Same as deleting */

	} else {

		/* Updating qsize cause re-allocation of bpf_cpu_map_entry */

		rcpu = __cpu_map_entry_alloc(qsize, key_cpu, map->id);

		rcpu = __cpu_map_entry_alloc(&cpumap_value, key_cpu, map->id);

		if (!rcpu)

			return -ENOMEM;

		rcpu->cmap = cmap;
@@ -523,7 +525,7 @@ static void *cpu_map_lookup_elem(struct bpf_map *map, void *key) 
	struct bpf_cpu_map_entry *rcpu =

		__cpu_map_lookup_elem(map, *(u32 *)key);



	return rcpu ? &rcpu->qsize : NULL;

	return rcpu ? &rcpu->value : NULL;

}



static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key)

tools/include/uapi/linux/bpf.h

+9 −0
Original line number Diff line number Diff line
@@ -3849,6 +3849,15 @@ struct bpf_devmap_val { 
	} bpf_prog;

};



/* CPUMAP map-value layout

 *

 * The struct data-layout of map-value is a configuration interface.

 * New members can only be added to the end of this structure.

 */

struct bpf_cpumap_val {

	__u32 qsize;	/* queue size to remote target CPU */

};



enum sk_action {

	SK_DROP = 0,

	SK_PASS,