Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Andrii Nakryiko says:

====================
bpf-next 2022-08-17

We've added 45 non-merge commits during the last 14 day(s) which contain
a total of 61 files changed, 986 insertions(+), 372 deletions(-).

The main changes are:

1) New bpf_ktime_get_tai_ns() BPF helper to access CLOCK_TAI, from Kurt
   Kanzenbach and Jesper Dangaard Brouer.

2) Few clean ups and improvements for libbpf 1.0, from Andrii Nakryiko.

3) Expose crash_kexec() as kfunc for BPF programs, from Artem Savkov.

4) Add ability to define sleepable-only kfuncs, from Benjamin Tissoires.

5) Teach libbpf's bpf_prog_load() and bpf_map_create() to gracefully handle
   unsupported names on old kernels, from Hangbin Liu.

6) Allow opting out from auto-attaching BPF programs by libbpf's BPF skeleton,
   from Hao Luo.

7) Relax libbpf's requirement for shared libs to be marked executable, from
   Henqgi Chen.

8) Improve bpf_iter internals handling of error returns, from Hao Luo.

9) Few accommodations in libbpf to support GCC-BPF quirks, from James Hilliard.

10) Fix BPF verifier logic around tracking dynptr ref_obj_id, from Joanne Koong.

11) bpftool improvements to handle full BPF program names better, from Manu
    Bretelle.

12) bpftool fixes around libcap use, from Quentin Monnet.

13) BPF map internals clean ups and improvements around memory allocations,
    from Yafang Shao.

14) Allow to use cgroup_get_from_file() on cgroupv1, allowing BPF cgroup
    iterator to work on cgroupv1, from Yosry Ahmed.

15) BPF verifier internal clean ups, from Dave Marchevsky and Joanne Koong.

16) Various fixes and clean ups for selftests/bpf and vmtest.sh, from Daniel
    Xu, Artem Savkov, Joanne Koong, Andrii Nakryiko, Shibin Koikkara Reeny.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (45 commits)
  selftests/bpf: Few fixes for selftests/bpf built in release mode
  libbpf: Clean up deprecated and legacy aliases
  libbpf: Streamline bpf_attr and perf_event_attr initialization
  libbpf: Fix potential NULL dereference when parsing ELF
  selftests/bpf: Tests libbpf autoattach APIs
  libbpf: Allows disabling auto attach
  selftests/bpf: Fix attach point for non-x86 arches in test_progs/lsm
  libbpf: Making bpf_prog_load() ignore name if kernel doesn't support
  selftests/bpf: Update CI kconfig
  selftests/bpf: Add connmark read test
  selftests/bpf: Add existing connection bpf_*_ct_lookup() test
  bpftool: Clear errno after libcap's checks
  bpf: Clear up confusion in bpf_skb_adjust_room()'s documentation
  bpftool: Fix a typo in a comment
  libbpf: Add names for auxiliary maps
  bpf: Use bpf_map_area_alloc consistently on bpf map creation
  bpf: Make __GFP_NOWARN consistent in bpf map creation
  bpf: Use bpf_map_area_free instread of kvfree
  bpf: Remove unneeded memset in queue_stack_map creation
  libbpf: preserve errno across pr_warn/pr_info/pr_debug
  ...
====================

Link: https://lore.kernel.org/r/20220817215656.1180215-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/bpf/kfuncs.rst

@@ -146,6 +146,21 @@ that operate (change some property, perform some operation) on an object that
 was obtained using an acquire kfunc. Such kfuncs need an unchanged pointer to
 ensure the integrity of the operation being performed on the expected object.
 
+2.4.6 KF_SLEEPABLE flag
+-----------------------
+
+The KF_SLEEPABLE flag is used for kfuncs that may sleep. Such kfuncs can only
+be called by sleepable BPF programs (BPF_F_SLEEPABLE).
+
+2.4.7 KF_DESTRUCTIVE flag
+--------------------------
+
+The KF_DESTRUCTIVE flag is used to indicate functions calling which is
+destructive to the system. For example such a call can result in system
+rebooting or panicking. Due to this additional restrictions apply to these
+calls. At the moment they only require CAP_SYS_BOOT capability, but more can be
+added later.
+
 2.5 Registering the kfuncs
 --------------------------
 

include/linux/bpf.h

@@ -2349,6 +2349,7 @@ extern const struct bpf_func_proto bpf_get_numa_node_id_proto;
 extern const struct bpf_func_proto bpf_tail_call_proto;
 extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
 extern const struct bpf_func_proto bpf_ktime_get_boot_ns_proto;
+extern const struct bpf_func_proto bpf_ktime_get_tai_ns_proto;
 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
 extern const struct bpf_func_proto bpf_get_current_comm_proto;

include/linux/btf.h

@@ -49,6 +49,8 @@
  * for this case.
  */
 #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer arguments */
+#define KF_SLEEPABLE    (1 << 5) /* kfunc may sleep */
+#define KF_DESTRUCTIVE  (1 << 6) /* kfunc performs destructive actions */
 
 struct btf;
 struct btf_member;

include/net/netfilter/nf_conntrack_core.h

@@ -86,10 +86,6 @@ extern spinlock_t nf_conntrack_expect_lock;
 
 /* ctnetlink code shared by both ctnetlink and nf_conntrack_bpf */
 
-#if (IS_BUILTIN(CONFIG_NF_CONNTRACK) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) || \
-    (IS_MODULE(CONFIG_NF_CONNTRACK) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES) || \
-    IS_ENABLED(CONFIG_NF_CT_NETLINK))
-
 static inline void __nf_ct_set_timeout(struct nf_conn *ct, u64 timeout)
 {
 	if (timeout > INT_MAX)
@@ -101,6 +97,4 @@ int __nf_ct_change_timeout(struct nf_conn *ct, u64 cta_timeout);
 void __nf_ct_change_status(struct nf_conn *ct, unsigned long on, unsigned long off);
 int nf_ct_change_status_common(struct nf_conn *ct, unsigned int status);
 
-#endif
-
 #endif /* _NF_CONNTRACK_CORE_H */

include/uapi/linux/bpf.h

@@ -2573,10 +2573,12 @@ union bpf_attr {
  *		There are two supported modes at this time:
  *
  *		* **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer
- *		  (room space is added or removed below the layer 2 header).
+ * 		  (room space is added or removed between the layer 2 and
+ * 		  layer 3 headers).
  *
  * 		* **BPF_ADJ_ROOM_NET**: Adjust room at the network layer
- * 		  (room space is added or removed below the layer 3 header).
+ * 		  (room space is added or removed between the layer 3 and
+ * 		  layer 4 headers).
  *
  *		The following flags are supported at this time:
  *
@@ -3008,8 +3010,18 @@ union bpf_attr {
  * 		**BPF_F_USER_STACK**
  * 			Collect a user space stack instead of a kernel stack.
  * 		**BPF_F_USER_BUILD_ID**
- * 			Collect buildid+offset instead of ips for user stack,
- * 			only valid if **BPF_F_USER_STACK** is also specified.
+ * 			Collect (build_id, file_offset) instead of ips for user
+ * 			stack, only valid if **BPF_F_USER_STACK** is also
+ * 			specified.
+ *
+ * 			*file_offset* is an offset relative to the beginning
+ * 			of the executable or shared object file backing the vma
+ * 			which the *ip* falls in. It is *not* an offset relative
+ * 			to that object's base address. Accordingly, it must be
+ * 			adjusted by adding (sh_addr - sh_offset), where
+ * 			sh_{addr,offset} correspond to the executable section
+ * 			containing *file_offset* in the object, for comparisons
+ * 			to symbols' st_value to be valid.
  *
  * 		**bpf_get_stack**\ () can collect up to
  * 		**PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
@@ -5331,6 +5343,18 @@ union bpf_attr {
  *		**-EACCES** if the SYN cookie is not valid.
  *
  *		**-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin.
+ *
+ * u64 bpf_ktime_get_tai_ns(void)
+ *	Description
+ *		A nonsettable system-wide clock derived from wall-clock time but
+ *		ignoring leap seconds.  This clock does not experience
+ *		discontinuities and backwards jumps caused by NTP inserting leap
+ *		seconds as CLOCK_REALTIME does.
+ *
+ *		See: **clock_gettime**\ (**CLOCK_TAI**)
+ *	Return
+ *		Current *ktime*.
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5541,6 +5565,7 @@ union bpf_attr {
 	FN(tcp_raw_gen_syncookie_ipv6),	\
 	FN(tcp_raw_check_syncookie_ipv4),	\
 	FN(tcp_raw_check_syncookie_ipv6),	\
+	FN(ktime_get_tai_ns),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper

kernel/bpf/bpf_iter.c

@@ -202,6 +202,11 @@ static ssize_t bpf_seq_read(struct file *file, char __user *buf, size_t size,
 	}
 stop:
 	offs = seq->count;
+	if (IS_ERR(p)) {
+		seq->op->stop(seq, NULL);
+		err = PTR_ERR(p);
+		goto done;
+	}
 	/* bpf program called if !p */
 	seq->op->stop(seq, p);
 	if (!p) {

kernel/bpf/bpf_local_storage.c

@@ -582,7 +582,7 @@ void bpf_local_storage_map_free(struct bpf_local_storage_map *smap,
 	synchronize_rcu();
 
 	kvfree(smap->buckets);
-	kfree(smap);
+	bpf_map_area_free(smap);
 }
 
 int bpf_local_storage_map_alloc_check(union bpf_attr *attr)
@@ -610,7 +610,7 @@ struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
 	unsigned int i;
 	u32 nbuckets;
 
-	smap = kzalloc(sizeof(*smap), GFP_USER | __GFP_NOWARN | __GFP_ACCOUNT);
+	smap = bpf_map_area_alloc(sizeof(*smap), NUMA_NO_NODE);
 	if (!smap)
 		return ERR_PTR(-ENOMEM);
 	bpf_map_init_from_attr(&smap->map, attr);
@@ -623,7 +623,7 @@ struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
 	smap->buckets = kvcalloc(sizeof(*smap->buckets), nbuckets,
 				 GFP_USER | __GFP_NOWARN | __GFP_ACCOUNT);
 	if (!smap->buckets) {
-		kfree(smap);
+		bpf_map_area_free(smap);
 		return ERR_PTR(-ENOMEM);
 	}
 

kernel/bpf/btf.c

@@ -5864,26 +5864,25 @@ bool btf_struct_ids_match(struct bpf_verifier_log *log,
 }
 
 static int __get_type_size(struct btf *btf, u32 btf_id,
-			   const struct btf_type **bad_type)
+			   const struct btf_type **ret_type)
 {
 	const struct btf_type *t;
 
+	*ret_type = btf_type_by_id(btf, 0);
 	if (!btf_id)
 		/* void */
 		return 0;
 	t = btf_type_by_id(btf, btf_id);
 	while (t && btf_type_is_modifier(t))
 		t = btf_type_by_id(btf, t->type);
-	if (!t) {
-		*bad_type = btf_type_by_id(btf, 0);
+	if (!t)
 		return -EINVAL;
-	}
+	*ret_type = t;
 	if (btf_type_is_ptr(t))
 		/* kernel size of pointer. Not BPF's size of pointer*/
 		return sizeof(void *);
 	if (btf_type_is_int(t) || btf_is_any_enum(t))
 		return t->size;
-	*bad_type = t;
 	return -EINVAL;
 }
 
@@ -6175,6 +6174,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
 {
 	enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
 	bool rel = false, kptr_get = false, trusted_arg = false;
+	bool sleepable = false;
 	struct bpf_verifier_log *log = &env->log;
 	u32 i, nargs, ref_id, ref_obj_id = 0;
 	bool is_kfunc = btf_is_kernel(btf);
@@ -6212,6 +6212,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
 		rel = kfunc_flags & KF_RELEASE;
 		kptr_get = kfunc_flags & KF_KPTR_GET;
 		trusted_arg = kfunc_flags & KF_TRUSTED_ARGS;
+		sleepable = kfunc_flags & KF_SLEEPABLE;
 	}
 
 	/* check that BTF function arguments match actual types that the
@@ -6419,6 +6420,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
 			func_name);
 		return -EINVAL;
 	}
+
+	if (sleepable && !env->prog->aux->sleepable) {
+		bpf_log(log, "kernel function %s is sleepable but the program is not\n",
+			func_name);
+		return -EINVAL;
+	}
+
 	/* returns argument register number > 0 in case of reference release kfunc */
 	return rel ? ref_regno : 0;
 }

kernel/bpf/core.c

@@ -2623,6 +2623,7 @@ const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
+const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
 
 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;

kernel/bpf/cpumap.c

@@ -97,7 +97,7 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
 	    attr->map_flags & ~BPF_F_NUMA_NODE)
 		return ERR_PTR(-EINVAL);
 
-	cmap = kzalloc(sizeof(*cmap), GFP_USER | __GFP_ACCOUNT);
+	cmap = bpf_map_area_alloc(sizeof(*cmap), NUMA_NO_NODE);
 	if (!cmap)
 		return ERR_PTR(-ENOMEM);
 
@@ -118,7 +118,7 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
 
 	return &cmap->map;
 free_cmap:
-	kfree(cmap);
+	bpf_map_area_free(cmap);
 	return ERR_PTR(err);
 }
 
@@ -623,7 +623,7 @@ static void cpu_map_free(struct bpf_map *map)
 		__cpu_map_entry_replace(cmap, i, NULL); /* call_rcu */
 	}
 	bpf_map_area_free(cmap->cpu_map);
-	kfree(cmap);
+	bpf_map_area_free(cmap);
 }
 
 /* Elements are kept alive by RCU; either by rcu_read_lock() (from syscall) or

kernel/bpf/devmap.c

@@ -163,13 +163,13 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
 	if (!capable(CAP_NET_ADMIN))
 		return ERR_PTR(-EPERM);
 
-	dtab = kzalloc(sizeof(*dtab), GFP_USER | __GFP_ACCOUNT);
+	dtab = bpf_map_area_alloc(sizeof(*dtab), NUMA_NO_NODE);
 	if (!dtab)
 		return ERR_PTR(-ENOMEM);
 
 	err = dev_map_init_map(dtab, attr);
 	if (err) {
-		kfree(dtab);
+		bpf_map_area_free(dtab);
 		return ERR_PTR(err);
 	}
 
@@ -240,7 +240,7 @@ static void dev_map_free(struct bpf_map *map)
 		bpf_map_area_free(dtab->netdev_map);
 	}
 
-	kfree(dtab);
+	bpf_map_area_free(dtab);
 }
 
 static int dev_map_get_next_key(struct bpf_map *map, void *key, void *next_key)

kernel/bpf/hashtab.c

@@ -491,7 +491,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 	struct bpf_htab *htab;
 	int err, i;
 
-	htab = kzalloc(sizeof(*htab), GFP_USER | __GFP_ACCOUNT);
+	htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE);
 	if (!htab)
 		return ERR_PTR(-ENOMEM);
 
@@ -575,7 +575,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 	bpf_map_area_free(htab->buckets);
 free_htab:
 	lockdep_unregister_key(&htab->lockdep_key);
-	kfree(htab);
+	bpf_map_area_free(htab);
 	return ERR_PTR(err);
 }
 
@@ -1492,7 +1492,7 @@ static void htab_map_free(struct bpf_map *map)
 	for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++)
 		free_percpu(htab->map_locked[i]);
 	lockdep_unregister_key(&htab->lockdep_key);
-	kfree(htab);
+	bpf_map_area_free(htab);
 }
 
 static void htab_map_seq_show_elem(struct bpf_map *map, void *key,

kernel/bpf/helpers.c

@@ -198,6 +198,18 @@ const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto = {
 	.ret_type	= RET_INTEGER,
 };
 
+BPF_CALL_0(bpf_ktime_get_tai_ns)
+{
+	/* NMI safe access to clock tai */
+	return ktime_get_tai_fast_ns();
+}
+
+const struct bpf_func_proto bpf_ktime_get_tai_ns_proto = {
+	.func		= bpf_ktime_get_tai_ns,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
 BPF_CALL_0(bpf_get_current_pid_tgid)
 {
 	struct task_struct *task = current;
@@ -1617,6 +1629,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 		return &bpf_ktime_get_ns_proto;
 	case BPF_FUNC_ktime_get_boot_ns:
 		return &bpf_ktime_get_boot_ns_proto;
+	case BPF_FUNC_ktime_get_tai_ns:
+		return &bpf_ktime_get_tai_ns_proto;
 	case BPF_FUNC_ringbuf_output:
 		return &bpf_ringbuf_output_proto;
 	case BPF_FUNC_ringbuf_reserve:
@@ -1711,3 +1725,21 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 		return NULL;
 	}
 }
+
+BTF_SET8_START(tracing_btf_ids)
+#ifdef CONFIG_KEXEC_CORE
+BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE)
+#endif
+BTF_SET8_END(tracing_btf_ids)
+
+static const struct btf_kfunc_id_set tracing_kfunc_set = {
+	.owner = THIS_MODULE,
+	.set   = &tracing_btf_ids,
+};
+
+static int __init kfunc_init(void)
+{
+	return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &tracing_kfunc_set);
+}
+
+late_initcall(kfunc_init);

kernel/bpf/local_storage.c

@@ -313,8 +313,7 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
 		/* max_entries is not used and enforced to be 0 */
 		return ERR_PTR(-EINVAL);
 
-	map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
-			   __GFP_ZERO | GFP_USER | __GFP_ACCOUNT, numa_node);
+	map = bpf_map_area_alloc(sizeof(struct bpf_cgroup_storage_map), numa_node);
 	if (!map)
 		return ERR_PTR(-ENOMEM);
 
@@ -346,7 +345,7 @@ static void cgroup_storage_map_free(struct bpf_map *_map)
 	WARN_ON(!RB_EMPTY_ROOT(&map->root));
 	WARN_ON(!list_empty(&map->list));
 
-	kfree(map);
+	bpf_map_area_free(map);
 }
 
 static int cgroup_storage_delete_elem(struct bpf_map *map, void *key)

kernel/bpf/lpm_trie.c

@@ -558,7 +558,7 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
 	    attr->value_size > LPM_VAL_SIZE_MAX)
 		return ERR_PTR(-EINVAL);
 
-	trie = kzalloc(sizeof(*trie), GFP_USER | __GFP_NOWARN | __GFP_ACCOUNT);
+	trie = bpf_map_area_alloc(sizeof(*trie), NUMA_NO_NODE);
 	if (!trie)
 		return ERR_PTR(-ENOMEM);
 
@@ -609,7 +609,7 @@ static void trie_free(struct bpf_map *map)
 	}
 
 out:
-	kfree(trie);
+	bpf_map_area_free(trie);
 }
 
 static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)