Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/gi…

…t/bpf/bpf

Pull bpf fixes from Alexei Starovoitov:

 - Followup fixes for resilient spinlock (Kumar Kartikeya Dwivedi):
     - Make res_spin_lock test less verbose, since it was spamming BPF
       CI on failure, and make the check for AA deadlock stronger
     - Fix rebasing mistake and use architecture provided
       res_smp_cond_load_acquire
     - Convert BPF maps (queue_stack and ringbuf) to resilient spinlock
       to address long standing syzbot reports

 - Make sure that classic BPF load instruction from SKF_[NET|LL]_OFF
   offsets works when skb is fragmeneted (Willem de Bruijn)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Convert ringbuf map to rqspinlock
  bpf: Convert queue_stack map to rqspinlock
  bpf: Use architecture provided res_smp_cond_load_acquire
  selftests/bpf: Make res_spin_lock AA test condition stronger
  selftests/net: test sk_filter support for SKF_NET_OFF on frags
  bpf: support SKF_NET_OFF and SKF_LL_OFF on skb frags
  selftests/bpf: Make res_spin_lock test less verbose

arch/arm64/include/asm/rqspinlock.h

@@ -86,7 +86,7 @@
 
 #endif
 
-#define res_smp_cond_load_acquire_timewait(v, c) smp_cond_load_acquire_timewait(v, c, 0, 1)
+#define res_smp_cond_load_acquire(v, c) smp_cond_load_acquire_timewait(v, c, 0, 1)
 
 #include <asm-generic/rqspinlock.h>
 

kernel/bpf/queue_stack_maps.c

@@ -9,13 +9,14 @@
 #include <linux/slab.h>
 #include <linux/btf_ids.h>
 #include "percpu_freelist.h"
+#include <asm/rqspinlock.h>
 
 #define QUEUE_STACK_CREATE_FLAG_MASK \
 	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
 
 struct bpf_queue_stack {
 	struct bpf_map map;
-	raw_spinlock_t lock;
+	rqspinlock_t lock;
 	u32 head, tail;
 	u32 size; /* max_entries + 1 */
 
@@ -78,7 +79,7 @@ static struct bpf_map *queue_stack_map_alloc(union bpf_attr *attr)
 
 	qs->size = size;
 
-	raw_spin_lock_init(&qs->lock);
+	raw_res_spin_lock_init(&qs->lock);
 
 	return &qs->map;
 }
@@ -98,12 +99,8 @@ static long __queue_map_get(struct bpf_map *map, void *value, bool delete)
 	int err = 0;
 	void *ptr;
 
-	if (in_nmi()) {
-		if (!raw_spin_trylock_irqsave(&qs->lock, flags))
-			return -EBUSY;
-	} else {
-		raw_spin_lock_irqsave(&qs->lock, flags);
-	}
+	if (raw_res_spin_lock_irqsave(&qs->lock, flags))
+		return -EBUSY;
 
 	if (queue_stack_map_is_empty(qs)) {
 		memset(value, 0, qs->map.value_size);
@@ -120,7 +117,7 @@ static long __queue_map_get(struct bpf_map *map, void *value, bool delete)
 	}
 
 out:
-	raw_spin_unlock_irqrestore(&qs->lock, flags);
+	raw_res_spin_unlock_irqrestore(&qs->lock, flags);
 	return err;
 }
 
@@ -133,12 +130,8 @@ static long __stack_map_get(struct bpf_map *map, void *value, bool delete)
 	void *ptr;
 	u32 index;
 
-	if (in_nmi()) {
-		if (!raw_spin_trylock_irqsave(&qs->lock, flags))
-			return -EBUSY;
-	} else {
-		raw_spin_lock_irqsave(&qs->lock, flags);
-	}
+	if (raw_res_spin_lock_irqsave(&qs->lock, flags))
+		return -EBUSY;
 
 	if (queue_stack_map_is_empty(qs)) {
 		memset(value, 0, qs->map.value_size);
@@ -157,7 +150,7 @@ static long __stack_map_get(struct bpf_map *map, void *value, bool delete)
 		qs->head = index;
 
 out:
-	raw_spin_unlock_irqrestore(&qs->lock, flags);
+	raw_res_spin_unlock_irqrestore(&qs->lock, flags);
 	return err;
 }
 
@@ -203,12 +196,8 @@ static long queue_stack_map_push_elem(struct bpf_map *map, void *value,
 	if (flags & BPF_NOEXIST || flags > BPF_EXIST)
 		return -EINVAL;
 
-	if (in_nmi()) {
-		if (!raw_spin_trylock_irqsave(&qs->lock, irq_flags))
-			return -EBUSY;
-	} else {
-		raw_spin_lock_irqsave(&qs->lock, irq_flags);
-	}
+	if (raw_res_spin_lock_irqsave(&qs->lock, irq_flags))
+		return -EBUSY;
 
 	if (queue_stack_map_is_full(qs)) {
 		if (!replace) {
@@ -227,7 +216,7 @@ static long queue_stack_map_push_elem(struct bpf_map *map, void *value,
 		qs->head = 0;
 
 out:
-	raw_spin_unlock_irqrestore(&qs->lock, irq_flags);
+	raw_res_spin_unlock_irqrestore(&qs->lock, irq_flags);
 	return err;
 }
 

kernel/bpf/ringbuf.c

@@ -11,6 +11,7 @@
 #include <linux/kmemleak.h>
 #include <uapi/linux/btf.h>
 #include <linux/btf_ids.h>
+#include <asm/rqspinlock.h>
 
 #define RINGBUF_CREATE_FLAG_MASK (BPF_F_NUMA_NODE)
 
@@ -29,7 +30,7 @@ struct bpf_ringbuf {
 	u64 mask;
 	struct page **pages;
 	int nr_pages;
-	raw_spinlock_t spinlock ____cacheline_aligned_in_smp;
+	rqspinlock_t spinlock ____cacheline_aligned_in_smp;
 	/* For user-space producer ring buffers, an atomic_t busy bit is used
 	 * to synchronize access to the ring buffers in the kernel, rather than
 	 * the spinlock that is used for kernel-producer ring buffers. This is
@@ -173,7 +174,7 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node)
 	if (!rb)
 		return NULL;
 
-	raw_spin_lock_init(&rb->spinlock);
+	raw_res_spin_lock_init(&rb->spinlock);
 	atomic_set(&rb->busy, 0);
 	init_waitqueue_head(&rb->waitq);
 	init_irq_work(&rb->work, bpf_ringbuf_notify);
@@ -416,12 +417,8 @@ static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size)
 
 	cons_pos = smp_load_acquire(&rb->consumer_pos);
 
-	if (in_nmi()) {
-		if (!raw_spin_trylock_irqsave(&rb->spinlock, flags))
-			return NULL;
-	} else {
-		raw_spin_lock_irqsave(&rb->spinlock, flags);
-	}
+	if (raw_res_spin_lock_irqsave(&rb->spinlock, flags))
+		return NULL;
 
 	pend_pos = rb->pending_pos;
 	prod_pos = rb->producer_pos;
@@ -446,7 +443,7 @@ static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size)
 	 */
 	if (new_prod_pos - cons_pos > rb->mask ||
 	    new_prod_pos - pend_pos > rb->mask) {
-		raw_spin_unlock_irqrestore(&rb->spinlock, flags);
+		raw_res_spin_unlock_irqrestore(&rb->spinlock, flags);
 		return NULL;
 	}
 
@@ -458,7 +455,7 @@ static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size)
 	/* pairs with consumer's smp_load_acquire() */
 	smp_store_release(&rb->producer_pos, new_prod_pos);
 
-	raw_spin_unlock_irqrestore(&rb->spinlock, flags);
+	raw_res_spin_unlock_irqrestore(&rb->spinlock, flags);
 
 	return (void *)hdr + BPF_RINGBUF_HDR_SZ;
 }

kernel/bpf/rqspinlock.c

@@ -253,7 +253,7 @@ static noinline int check_timeout(rqspinlock_t *lock, u32 mask,
 	})
 #else
 #define RES_CHECK_TIMEOUT(ts, ret, mask)			      \
-	({ (ret) = check_timeout(&(ts)); })
+	({ (ret) = check_timeout((lock), (mask), &(ts)); })
 #endif
 
 /*

net/core/filter.c

@@ -218,24 +218,36 @@ BPF_CALL_3(bpf_skb_get_nlattr_nest, struct sk_buff *, skb, u32, a, u32, x)
 	return 0;
 }
 
+static int bpf_skb_load_helper_convert_offset(const struct sk_buff *skb, int offset)
+{
+	if (likely(offset >= 0))
+		return offset;
+
+	if (offset >= SKF_NET_OFF)
+		return offset - SKF_NET_OFF + skb_network_offset(skb);
+
+	if (offset >= SKF_LL_OFF && skb_mac_header_was_set(skb))
+		return offset - SKF_LL_OFF + skb_mac_offset(skb);
+
+	return INT_MIN;
+}
+
 BPF_CALL_4(bpf_skb_load_helper_8, const struct sk_buff *, skb, const void *,
 	   data, int, headlen, int, offset)
 {
-	u8 tmp, *ptr;
+	u8 tmp;
 	const int len = sizeof(tmp);
 
-	if (offset >= 0) {
-		if (headlen - offset >= len)
-			return *(u8 *)(data + offset);
-		if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp)))
-			return tmp;
-	} else {
-		ptr = bpf_internal_load_pointer_neg_helper(skb, offset, len);
-		if (likely(ptr))
-			return *(u8 *)ptr;
-	}
+	offset = bpf_skb_load_helper_convert_offset(skb, offset);
+	if (offset == INT_MIN)
+		return -EFAULT;
 
-	return -EFAULT;
+	if (headlen - offset >= len)
+		return *(u8 *)(data + offset);
+	if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp)))
+		return tmp;
+	else
+		return -EFAULT;
 }
 
 BPF_CALL_2(bpf_skb_load_helper_8_no_cache, const struct sk_buff *, skb,
@@ -248,21 +260,19 @@ BPF_CALL_2(bpf_skb_load_helper_8_no_cache, const struct sk_buff *, skb,
 BPF_CALL_4(bpf_skb_load_helper_16, const struct sk_buff *, skb, const void *,
 	   data, int, headlen, int, offset)
 {
-	__be16 tmp, *ptr;
+	__be16 tmp;
 	const int len = sizeof(tmp);
 
-	if (offset >= 0) {
-		if (headlen - offset >= len)
-			return get_unaligned_be16(data + offset);
-		if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp)))
-			return be16_to_cpu(tmp);
-	} else {
-		ptr = bpf_internal_load_pointer_neg_helper(skb, offset, len);
-		if (likely(ptr))
-			return get_unaligned_be16(ptr);
-	}
+	offset = bpf_skb_load_helper_convert_offset(skb, offset);
+	if (offset == INT_MIN)
+		return -EFAULT;
 
-	return -EFAULT;
+	if (headlen - offset >= len)
+		return get_unaligned_be16(data + offset);
+	if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp)))
+		return be16_to_cpu(tmp);
+	else
+		return -EFAULT;
 }
 
 BPF_CALL_2(bpf_skb_load_helper_16_no_cache, const struct sk_buff *, skb,
@@ -275,21 +285,19 @@ BPF_CALL_2(bpf_skb_load_helper_16_no_cache, const struct sk_buff *, skb,
 BPF_CALL_4(bpf_skb_load_helper_32, const struct sk_buff *, skb, const void *,
 	   data, int, headlen, int, offset)
 {
-	__be32 tmp, *ptr;
+	__be32 tmp;
 	const int len = sizeof(tmp);
 
-	if (likely(offset >= 0)) {
-		if (headlen - offset >= len)
-			return get_unaligned_be32(data + offset);
-		if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp)))
-			return be32_to_cpu(tmp);
-	} else {
-		ptr = bpf_internal_load_pointer_neg_helper(skb, offset, len);
-		if (likely(ptr))
-			return get_unaligned_be32(ptr);
-	}
+	offset = bpf_skb_load_helper_convert_offset(skb, offset);
+	if (offset == INT_MIN)
+		return -EFAULT;
 
-	return -EFAULT;
+	if (headlen - offset >= len)
+		return get_unaligned_be32(data + offset);
+	if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp)))
+		return be32_to_cpu(tmp);
+	else
+		return -EFAULT;
 }
 
 BPF_CALL_2(bpf_skb_load_helper_32_no_cache, const struct sk_buff *, skb,

tools/testing/selftests/bpf/prog_tests/res_spin_lock.c

@@ -25,8 +25,11 @@ static void *spin_lock_thread(void *arg)
 
 	while (!READ_ONCE(skip)) {
 		err = bpf_prog_test_run_opts(prog_fd, &topts);
-		ASSERT_OK(err, "test_run");
-		ASSERT_OK(topts.retval, "test_run retval");
+		if (err || topts.retval) {
+			ASSERT_OK(err, "test_run");
+			ASSERT_OK(topts.retval, "test_run retval");
+			break;
+		}
 	}
 	pthread_exit(arg);
 }

tools/testing/selftests/bpf/progs/res_spin_lock.c

@@ -38,13 +38,14 @@ int res_spin_lock_test(struct __sk_buff *ctx)
 	r = bpf_res_spin_lock(&elem1->lock);
 	if (r)
 		return r;
-	if (!bpf_res_spin_lock(&elem2->lock)) {
+	r = bpf_res_spin_lock(&elem2->lock);
+	if (!r) {
 		bpf_res_spin_unlock(&elem2->lock);
 		bpf_res_spin_unlock(&elem1->lock);
 		return -1;
 	}
 	bpf_res_spin_unlock(&elem1->lock);
-	return 0;
+	return r != -EDEADLK;
 }
 
 SEC("tc")
@@ -124,12 +125,15 @@ int res_spin_lock_test_held_lock_max(struct __sk_buff *ctx)
 	/* Trigger AA, after exhausting entries in the held lock table. This
 	 * time, only the timeout can save us, as AA detection won't succeed.
 	 */
-	if (!bpf_res_spin_lock(locks[34])) {
+	ret = bpf_res_spin_lock(locks[34]);
+	if (!ret) {
 		bpf_res_spin_unlock(locks[34]);
 		ret = 1;
 		goto end;
 	}
 
+	ret = ret != -ETIMEDOUT ? 2 : 0;
+
 end:
 	for (i = i - 1; i >= 0; i--)
 		bpf_res_spin_unlock(locks[i]);

tools/testing/selftests/net/.gitignore

@@ -39,6 +39,7 @@ scm_rights
 sk_bind_sendto_listen
 sk_connect_zero_addr
 sk_so_peek_off
+skf_net_off
 socket
 so_incoming_cpu
 so_netns_cookie

tools/testing/selftests/net/Makefile

@@ -106,6 +106,8 @@ TEST_PROGS += ipv6_route_update_soft_lockup.sh
 TEST_PROGS += busy_poll_test.sh
 TEST_GEN_PROGS += proc_net_pktgen
 TEST_PROGS += lwt_dst_cache_ref_loop.sh
+TEST_PROGS += skf_net_off.sh
+TEST_GEN_FILES += skf_net_off
 
 # YNL files, must be before "include ..lib.mk"
 YNL_GEN_FILES := busy_poller netlink-dumps