Change the verifier to make trusted args the default requirement for
all kfuncs by removing is_kfunc_trusted_args() assuming it be to always
return true.

This works because:
1. Context pointers (xdp_md, __sk_buff, etc.) are handled through their
   own KF_ARG_PTR_TO_CTX case label and bypass the trusted check
2. Struct_ops callback arguments are already marked as PTR_TRUSTED during
   initialization and pass is_trusted_reg()
3. KF_RCU kfuncs are handled separately via is_kfunc_rcu() checks at
   call sites (always checked with || alongside is_kfunc_trusted_args)

This simple change makes all kfuncs require trusted args by default
while maintaining correct behavior for all existing special cases.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 Documentation/bpf/kfuncs.rst | 35 +++++++++++++++++------------------
 kernel/bpf/verifier.c        | 14 +++-----------
 2 files changed, 20 insertions(+), 29 deletions(-)

diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst
index e38941370b90..22b5a970078c 100644
--- a/Documentation/bpf/kfuncs.rst
+++ b/Documentation/bpf/kfuncs.rst
@@ -241,25 +241,23 @@ both are orthogonal to each other.
 The KF_RELEASE flag is used to indicate that the kfunc releases the pointer
 passed in to it. There can be only one referenced pointer that can be passed
 in. All copies of the pointer being released are invalidated as a result of
-invoking kfunc with this flag. KF_RELEASE kfuncs automatically receive the
-protection afforded by the KF_TRUSTED_ARGS flag described below.
+invoking kfunc with this flag.
 
-2.4.4 KF_TRUSTED_ARGS flag
---------------------------
+2.4.4 KF_TRUSTED_ARGS (default behavior)
+-----------------------------------------
 
-The KF_TRUSTED_ARGS flag is used for kfuncs taking pointer arguments. It
-indicates that the all pointer arguments are valid, and that all pointers to
-BTF objects have been passed in their unmodified form (that is, at a zero
-offset, and without having been obtained from walking another pointer, with one
-exception described below).
+All kfuncs now require trusted arguments by default. This means that all
+pointer arguments must be valid, and all pointers to BTF objects must be
+passed in their unmodified form (at a zero offset, and without having been
+obtained from walking another pointer, with exceptions described below).
 
-There are two types of pointers to kernel objects which are considered "valid":
+There are two types of pointers to kernel objects which are considered "trusted":
 
 1. Pointers which are passed as tracepoint or struct_ops callback arguments.
 2. Pointers which were returned from a KF_ACQUIRE kfunc.
 
 Pointers to non-BTF objects (e.g. scalar pointers) may also be passed to
-KF_TRUSTED_ARGS kfuncs, and may have a non-zero offset.
+kfuncs, and may have a non-zero offset.
 
 The definition of "valid" pointers is subject to change at any time, and has
 absolutely no ABI stability guarantees.
@@ -327,13 +325,14 @@ added later.
 2.4.7 KF_RCU flag
 -----------------
 
-The KF_RCU flag is a weaker version of KF_TRUSTED_ARGS. The kfuncs marked with
-KF_RCU expect either PTR_TRUSTED or MEM_RCU arguments. The verifier guarantees
-that the objects are valid and there is no use-after-free. The pointers are not
-NULL, but the object's refcount could have reached zero. The kfuncs need to
-consider doing refcnt != 0 check, especially when returning a KF_ACQUIRE
-pointer. Note as well that a KF_ACQUIRE kfunc that is KF_RCU should very likely
-also be KF_RET_NULL.
+The KF_RCU flag allows kfuncs to opt out of the default trusted args
+requirement and accept RCU pointers with weaker guarantees. The kfuncs marked
+with KF_RCU expect either PTR_TRUSTED or MEM_RCU arguments. The verifier
+guarantees that the objects are valid and there is no use-after-free. The
+pointers are not NULL, but the object's refcount could have reached zero. The
+kfuncs need to consider doing refcnt != 0 check, especially when returning a
+KF_ACQUIRE pointer. Note as well that a KF_ACQUIRE kfunc that is KF_RCU should
+very likely also be KF_RET_NULL.
 
 2.4.8 KF_RCU_PROTECTED flag
 ---------------------------
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 0baae7828af2..a31eace4a67c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -12040,11 +12040,6 @@ static bool is_kfunc_release(struct bpf_kfunc_call_arg_meta *meta)
 	return meta->kfunc_flags & KF_RELEASE;
 }
 
-static bool is_kfunc_trusted_args(struct bpf_kfunc_call_arg_meta *meta)
-{
-	return (meta->kfunc_flags & KF_TRUSTED_ARGS) || is_kfunc_release(meta);
-}
-
 static bool is_kfunc_sleepable(struct bpf_kfunc_call_arg_meta *meta)
 {
 	return meta->kfunc_flags & KF_SLEEPABLE;
@@ -13253,9 +13248,9 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_
 			return -EINVAL;
 		}
 
-		if ((is_kfunc_trusted_args(meta) || is_kfunc_rcu(meta)) &&
-		    (register_is_null(reg) || type_may_be_null(reg->type)) &&
-			!is_kfunc_arg_nullable(meta->btf, &args[i])) {
+		if ((register_is_null(reg) || type_may_be_null(reg->type)) &&
+		    !is_kfunc_arg_nullable(meta->btf, &args[i]) &&
+		    !is_kfunc_arg_optional(meta->btf, &args[i])) {
 			verbose(env, "Possibly NULL pointer passed to trusted arg%d\n", i);
 			return -EACCES;
 		}
@@ -13320,9 +13315,6 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_
 			fallthrough;
 		case KF_ARG_PTR_TO_ALLOC_BTF_ID:
 		case KF_ARG_PTR_TO_BTF_ID:
-			if (!is_kfunc_trusted_args(meta) && !is_kfunc_rcu(meta))
-				break;
-
 			if (!is_trusted_reg(reg)) {
 				if (!is_kfunc_rcu(meta)) {
 					verbose(env, "R%d must be referenced or trusted\n", regno);
-- 
2.47.3

bpf_xdp_ct_lookup() and bpf_skb_ct_lookup() receive bpf_tuple and opts
parameter that are then checked for NULL by __bpf_nf_ct_lookup(), so
these kfuns expects these arguments to be NULL.

Mark bpf_tuple and opts with __nullable so verifier allows passing NULL
pointer for these arguments.

This change is now required because verfier will now assume that every
kfunc expects trusted arguments by default, so even though these kfuns
don't have the KF_TRSUTED_ARGS flag, all arguments will be treated by
as KF_TRSUTED_ARGS by default.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 net/netfilter/nf_conntrack_bpf.c | 38 +++++++++++++++++---------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c
index 4a136fc3a9c0..a9f4b7d23fe0 100644
--- a/net/netfilter/nf_conntrack_bpf.c
+++ b/net/netfilter/nf_conntrack_bpf.c
@@ -291,16 +291,16 @@ __bpf_kfunc_start_defs();
  */
 __bpf_kfunc struct nf_conn___init *
 bpf_xdp_ct_alloc(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
-		 u32 tuple__sz, struct bpf_ct_opts *opts, u32 opts__sz)
+		 u32 tuple__sz, struct bpf_ct_opts *opts__nullable, u32 opts__sz)
 {
 	struct xdp_buff *ctx = (struct xdp_buff *)xdp_ctx;
 	struct nf_conn *nfct;
 
 	nfct = __bpf_nf_ct_alloc_entry(dev_net(ctx->rxq->dev), bpf_tuple, tuple__sz,
-				       opts, opts__sz, 10);
+				       opts__nullable, opts__sz, 10);
 	if (IS_ERR(nfct)) {
-		if (opts)
-			opts->error = PTR_ERR(nfct);
+		if (opts__nullable)
+			opts__nullable->error = PTR_ERR(nfct);
 		return NULL;
 	}
 
@@ -324,18 +324,19 @@ bpf_xdp_ct_alloc(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
  *		    Must be NF_BPF_CT_OPTS_SZ (16) or 12
  */
 __bpf_kfunc struct nf_conn *
-bpf_xdp_ct_lookup(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
-		  u32 tuple__sz, struct bpf_ct_opts *opts, u32 opts__sz)
+bpf_xdp_ct_lookup(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple__nullable,
+		  u32 tuple__sz, struct bpf_ct_opts *opts__nullable, u32 opts__sz)
 {
 	struct xdp_buff *ctx = (struct xdp_buff *)xdp_ctx;
 	struct net *caller_net;
 	struct nf_conn *nfct;
 
 	caller_net = dev_net(ctx->rxq->dev);
-	nfct = __bpf_nf_ct_lookup(caller_net, bpf_tuple, tuple__sz, opts, opts__sz);
+	nfct = __bpf_nf_ct_lookup(caller_net, bpf_tuple__nullable, tuple__sz, opts__nullable,
+				  opts__sz);
 	if (IS_ERR(nfct)) {
-		if (opts)
-			opts->error = PTR_ERR(nfct);
+		if (opts__nullable)
+			opts__nullable->error = PTR_ERR(nfct);
 		return NULL;
 	}
 	return nfct;
@@ -358,17 +359,17 @@ bpf_xdp_ct_lookup(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
  */
 __bpf_kfunc struct nf_conn___init *
 bpf_skb_ct_alloc(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple,
-		 u32 tuple__sz, struct bpf_ct_opts *opts, u32 opts__sz)
+		 u32 tuple__sz, struct bpf_ct_opts *opts__nullable, u32 opts__sz)
 {
 	struct sk_buff *skb = (struct sk_buff *)skb_ctx;
 	struct nf_conn *nfct;
 	struct net *net;
 
 	net = skb->dev ? dev_net(skb->dev) : sock_net(skb->sk);
-	nfct = __bpf_nf_ct_alloc_entry(net, bpf_tuple, tuple__sz, opts, opts__sz, 10);
+	nfct = __bpf_nf_ct_alloc_entry(net, bpf_tuple, tuple__sz, opts__nullable, opts__sz, 10);
 	if (IS_ERR(nfct)) {
-		if (opts)
-			opts->error = PTR_ERR(nfct);
+		if (opts__nullable)
+			opts__nullable->error = PTR_ERR(nfct);
 		return NULL;
 	}
 
@@ -392,18 +393,19 @@ bpf_skb_ct_alloc(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple,
  *		    Must be NF_BPF_CT_OPTS_SZ (16) or 12
  */
 __bpf_kfunc struct nf_conn *
-bpf_skb_ct_lookup(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple,
-		  u32 tuple__sz, struct bpf_ct_opts *opts, u32 opts__sz)
+bpf_skb_ct_lookup(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple__nullable,
+		  u32 tuple__sz, struct bpf_ct_opts *opts__nullable, u32 opts__sz)
 {
 	struct sk_buff *skb = (struct sk_buff *)skb_ctx;
 	struct net *caller_net;
 	struct nf_conn *nfct;
 
 	caller_net = skb->dev ? dev_net(skb->dev) : sock_net(skb->sk);
-	nfct = __bpf_nf_ct_lookup(caller_net, bpf_tuple, tuple__sz, opts, opts__sz);
+	nfct = __bpf_nf_ct_lookup(caller_net, bpf_tuple__nullable, tuple__sz, opts__nullable,
+				  opts__sz);
 	if (IS_ERR(nfct)) {
-		if (opts)
-			opts->error = PTR_ERR(nfct);
+		if (opts__nullable)
+			opts__nullable->error = PTR_ERR(nfct);
 		return NULL;
 	}
 	return nfct;
-- 
2.47.3

Now that KF_TRUSTED_ARGS is the default for all kfuncs, remove the
explicit KF_TRUSTED_ARGS flag from all kfunc definitions and remove the
flag itself.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 fs/bpf_fs_kfuncs.c                            | 13 ++++++------
 fs/verity/measure.c                           |  2 +-
 include/linux/btf.h                           |  3 +--
 kernel/bpf/arena.c                            |  6 +++---
 kernel/bpf/cpumask.c                          |  2 +-
 kernel/bpf/helpers.c                          | 20 +++++++++----------
 kernel/bpf/map_iter.c                         |  2 +-
 kernel/sched/ext.c                            |  8 ++++----
 mm/bpf_memcontrol.c                           | 10 +++++-----
 net/core/filter.c                             | 10 +++++-----
 net/core/xdp.c                                |  2 +-
 net/netfilter/nf_conntrack_bpf.c              |  8 ++++----
 net/netfilter/nf_flow_table_bpf.c             |  2 +-
 net/netfilter/nf_nat_bpf.c                    |  2 +-
 net/sched/bpf_qdisc.c                         | 12 +++++------
 .../selftests/bpf/test_kmods/bpf_testmod.c    | 20 +++++++++----------
 16 files changed, 60 insertions(+), 62 deletions(-)

diff --git a/fs/bpf_fs_kfuncs.c b/fs/bpf_fs_kfuncs.c
index 5ace2511fec5..a15d31690e0b 100644
--- a/fs/bpf_fs_kfuncs.c
+++ b/fs/bpf_fs_kfuncs.c
@@ -359,14 +359,13 @@ __bpf_kfunc int bpf_cgroup_read_xattr(struct cgroup *cgroup, const char *name__s
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(bpf_fs_kfunc_set_ids)
-BTF_ID_FLAGS(func, bpf_get_task_exe_file,
-	     KF_ACQUIRE | KF_TRUSTED_ARGS | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_get_task_exe_file, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_put_file, KF_RELEASE)
-BTF_ID_FLAGS(func, bpf_path_d_path, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_get_dentry_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_get_file_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_set_dentry_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_remove_dentry_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_path_d_path)
+BTF_ID_FLAGS(func, bpf_get_dentry_xattr, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_get_file_xattr, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_set_dentry_xattr, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_remove_dentry_xattr, KF_SLEEPABLE)
 BTF_KFUNCS_END(bpf_fs_kfunc_set_ids)
 
 static int bpf_fs_kfuncs_filter(const struct bpf_prog *prog, u32 kfunc_id)
diff --git a/fs/verity/measure.c b/fs/verity/measure.c
index 388734132f01..6a35623ebdf0 100644
--- a/fs/verity/measure.c
+++ b/fs/verity/measure.c
@@ -162,7 +162,7 @@ __bpf_kfunc int bpf_get_fsverity_digest(struct file *file, struct bpf_dynptr *di
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(fsverity_set_ids)
-BTF_ID_FLAGS(func, bpf_get_fsverity_digest, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_get_fsverity_digest)
 BTF_KFUNCS_END(fsverity_set_ids)
 
 static int bpf_get_fsverity_digest_filter(const struct bpf_prog *prog, u32 kfunc_id)
diff --git a/include/linux/btf.h b/include/linux/btf.h
index f06976ffb63f..691f09784933 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -34,7 +34,7 @@
  *
  * And the following kfunc:
  *
- *	BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
+ *	BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE)
  *
  * All invocations to the kfunc must pass the unmodified, unwalked task:
  *
@@ -66,7 +66,6 @@
  *	return 0;
  * }
  */
-#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 */
 #define KF_RCU          (1 << 7) /* kfunc takes either rcu or trusted pointer arguments */
diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c
index 456ac989269d..2274319a95e6 100644
--- a/kernel/bpf/arena.c
+++ b/kernel/bpf/arena.c
@@ -890,9 +890,9 @@ __bpf_kfunc int bpf_arena_reserve_pages(void *p__map, void *ptr__ign, u32 page_c
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(arena_kfuncs)
-BTF_ID_FLAGS(func, bpf_arena_alloc_pages, KF_TRUSTED_ARGS | KF_ARENA_RET | KF_ARENA_ARG2)
-BTF_ID_FLAGS(func, bpf_arena_free_pages, KF_TRUSTED_ARGS | KF_ARENA_ARG2)
-BTF_ID_FLAGS(func, bpf_arena_reserve_pages, KF_TRUSTED_ARGS | KF_ARENA_ARG2)
+BTF_ID_FLAGS(func, bpf_arena_alloc_pages, KF_ARENA_RET | KF_ARENA_ARG2)
+BTF_ID_FLAGS(func, bpf_arena_free_pages, KF_ARENA_ARG2)
+BTF_ID_FLAGS(func, bpf_arena_reserve_pages, KF_ARENA_ARG2)
 BTF_KFUNCS_END(arena_kfuncs)
 
 static const struct btf_kfunc_id_set common_kfunc_set = {
diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
index 9876c5fe6c2a..b8c805b4b06a 100644
--- a/kernel/bpf/cpumask.c
+++ b/kernel/bpf/cpumask.c
@@ -477,7 +477,7 @@ __bpf_kfunc_end_defs();
 BTF_KFUNCS_START(cpumask_kfunc_btf_ids)
 BTF_ID_FLAGS(func, bpf_cpumask_create, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_cpumask_release, KF_RELEASE)
-BTF_ID_FLAGS(func, bpf_cpumask_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_cpumask_acquire, KF_ACQUIRE)
 BTF_ID_FLAGS(func, bpf_cpumask_first, KF_RCU)
 BTF_ID_FLAGS(func, bpf_cpumask_first_zero, KF_RCU)
 BTF_ID_FLAGS(func, bpf_cpumask_first_and, KF_RCU)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index db72b96f9c8c..2c15f77c74db 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -4427,7 +4427,7 @@ BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_task_from_vpid, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_throw)
 #ifdef CONFIG_BPF_EVENTS
-BTF_ID_FLAGS(func, bpf_send_signal_task, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_send_signal_task)
 #endif
 #ifdef CONFIG_KEYS
 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
@@ -4467,14 +4467,14 @@ BTF_ID_FLAGS(func, bpf_iter_task_vma_new, KF_ITER_NEW | KF_RCU)
 BTF_ID_FLAGS(func, bpf_iter_task_vma_next, KF_ITER_NEXT | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_iter_task_vma_destroy, KF_ITER_DESTROY)
 #ifdef CONFIG_CGROUPS
-BTF_ID_FLAGS(func, bpf_iter_css_task_new, KF_ITER_NEW | KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_iter_css_task_new, KF_ITER_NEW)
 BTF_ID_FLAGS(func, bpf_iter_css_task_next, KF_ITER_NEXT | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_iter_css_task_destroy, KF_ITER_DESTROY)
-BTF_ID_FLAGS(func, bpf_iter_css_new, KF_ITER_NEW | KF_TRUSTED_ARGS | KF_RCU_PROTECTED)
+BTF_ID_FLAGS(func, bpf_iter_css_new, KF_ITER_NEW | KF_RCU_PROTECTED)
 BTF_ID_FLAGS(func, bpf_iter_css_next, KF_ITER_NEXT | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_iter_css_destroy, KF_ITER_DESTROY)
 #endif
-BTF_ID_FLAGS(func, bpf_iter_task_new, KF_ITER_NEW | KF_TRUSTED_ARGS | KF_RCU_PROTECTED)
+BTF_ID_FLAGS(func, bpf_iter_task_new, KF_ITER_NEW | KF_RCU_PROTECTED)
 BTF_ID_FLAGS(func, bpf_iter_task_next, KF_ITER_NEXT | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_iter_task_destroy, KF_ITER_DESTROY)
 BTF_ID_FLAGS(func, bpf_dynptr_adjust)
@@ -4510,8 +4510,8 @@ BTF_ID_FLAGS(func, bpf_probe_read_user_str_dynptr)
 BTF_ID_FLAGS(func, bpf_probe_read_kernel_str_dynptr)
 BTF_ID_FLAGS(func, bpf_copy_from_user_dynptr, KF_SLEEPABLE)
 BTF_ID_FLAGS(func, bpf_copy_from_user_str_dynptr, KF_SLEEPABLE)
-BTF_ID_FLAGS(func, bpf_copy_from_user_task_dynptr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_copy_from_user_task_str_dynptr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_copy_from_user_task_dynptr, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_copy_from_user_task_str_dynptr, KF_SLEEPABLE)
 #endif
 #ifdef CONFIG_DMA_SHARED_BUFFER
 BTF_ID_FLAGS(func, bpf_iter_dmabuf_new, KF_ITER_NEW | KF_SLEEPABLE)
@@ -4536,10 +4536,10 @@ BTF_ID_FLAGS(func, bpf_strncasestr);
 #if defined(CONFIG_BPF_LSM) && defined(CONFIG_CGROUPS)
 BTF_ID_FLAGS(func, bpf_cgroup_read_xattr, KF_RCU)
 #endif
-BTF_ID_FLAGS(func, bpf_stream_vprintk_impl, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_task_work_schedule_signal_impl, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_task_work_schedule_resume_impl, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_dynptr_from_file, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_stream_vprintk_impl)
+BTF_ID_FLAGS(func, bpf_task_work_schedule_signal_impl)
+BTF_ID_FLAGS(func, bpf_task_work_schedule_resume_impl)
+BTF_ID_FLAGS(func, bpf_dynptr_from_file)
 BTF_ID_FLAGS(func, bpf_dynptr_file_discard)
 BTF_KFUNCS_END(common_btf_ids)
 
diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
index 9575314f40a6..261a03ea73d3 100644
--- a/kernel/bpf/map_iter.c
+++ b/kernel/bpf/map_iter.c
@@ -214,7 +214,7 @@ __bpf_kfunc s64 bpf_map_sum_elem_count(const struct bpf_map *map)
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(bpf_map_iter_kfunc_ids)
-BTF_ID_FLAGS(func, bpf_map_sum_elem_count, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_map_sum_elem_count)
 BTF_KFUNCS_END(bpf_map_iter_kfunc_ids)
 
 static const struct btf_kfunc_id_set bpf_map_iter_kfunc_set = {
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 94164f2dec6d..fd5423428dde 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -7229,9 +7229,9 @@ BTF_ID_FLAGS(func, scx_bpf_dsq_peek, KF_RCU_PROTECTED | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_iter_scx_dsq_new, KF_ITER_NEW | KF_RCU_PROTECTED)
 BTF_ID_FLAGS(func, bpf_iter_scx_dsq_next, KF_ITER_NEXT | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_iter_scx_dsq_destroy, KF_ITER_DESTROY)
-BTF_ID_FLAGS(func, scx_bpf_exit_bstr, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, scx_bpf_error_bstr, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, scx_bpf_dump_bstr, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, scx_bpf_exit_bstr)
+BTF_ID_FLAGS(func, scx_bpf_error_bstr)
+BTF_ID_FLAGS(func, scx_bpf_dump_bstr)
 BTF_ID_FLAGS(func, scx_bpf_reenqueue_local___v2)
 BTF_ID_FLAGS(func, scx_bpf_cpuperf_cap)
 BTF_ID_FLAGS(func, scx_bpf_cpuperf_cur)
@@ -7250,7 +7250,7 @@ BTF_ID_FLAGS(func, scx_bpf_cpu_curr, KF_RET_NULL | KF_RCU_PROTECTED)
 BTF_ID_FLAGS(func, scx_bpf_task_cgroup, KF_RCU | KF_ACQUIRE)
 #endif
 BTF_ID_FLAGS(func, scx_bpf_now)
-BTF_ID_FLAGS(func, scx_bpf_events, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, scx_bpf_events)
 BTF_KFUNCS_END(scx_kfunc_ids_any)
 
 static const struct btf_kfunc_id_set scx_kfunc_set_any = {
diff --git a/mm/bpf_memcontrol.c b/mm/bpf_memcontrol.c
index e8fa7f5855f9..716df49d7647 100644
--- a/mm/bpf_memcontrol.c
+++ b/mm/bpf_memcontrol.c
@@ -166,11 +166,11 @@ BTF_ID_FLAGS(func, bpf_get_root_mem_cgroup, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_get_mem_cgroup, KF_ACQUIRE | KF_RET_NULL | KF_RCU)
 BTF_ID_FLAGS(func, bpf_put_mem_cgroup, KF_RELEASE)
 
-BTF_ID_FLAGS(func, bpf_mem_cgroup_vm_events, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_mem_cgroup_memory_events, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_mem_cgroup_usage, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_mem_cgroup_page_state, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_mem_cgroup_flush_stats, KF_TRUSTED_ARGS | KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_mem_cgroup_vm_events)
+BTF_ID_FLAGS(func, bpf_mem_cgroup_memory_events)
+BTF_ID_FLAGS(func, bpf_mem_cgroup_usage)
+BTF_ID_FLAGS(func, bpf_mem_cgroup_page_state)
+BTF_ID_FLAGS(func, bpf_mem_cgroup_flush_stats, KF_SLEEPABLE)
 
 BTF_KFUNCS_END(bpf_memcontrol_kfuncs)
 
diff --git a/net/core/filter.c b/net/core/filter.c
index 616e0520a0bb..d43df98e1ded 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -12438,11 +12438,11 @@ int bpf_dynptr_from_skb_rdonly(struct __sk_buff *skb, u64 flags,
 }
 
 BTF_KFUNCS_START(bpf_kfunc_check_set_skb)
-BTF_ID_FLAGS(func, bpf_dynptr_from_skb, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_dynptr_from_skb)
 BTF_KFUNCS_END(bpf_kfunc_check_set_skb)
 
 BTF_KFUNCS_START(bpf_kfunc_check_set_skb_meta)
-BTF_ID_FLAGS(func, bpf_dynptr_from_skb_meta, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_dynptr_from_skb_meta)
 BTF_KFUNCS_END(bpf_kfunc_check_set_skb_meta)
 
 BTF_KFUNCS_START(bpf_kfunc_check_set_xdp)
@@ -12455,11 +12455,11 @@ BTF_ID_FLAGS(func, bpf_sock_addr_set_sun_path)
 BTF_KFUNCS_END(bpf_kfunc_check_set_sock_addr)
 
 BTF_KFUNCS_START(bpf_kfunc_check_set_tcp_reqsk)
-BTF_ID_FLAGS(func, bpf_sk_assign_tcp_reqsk, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_sk_assign_tcp_reqsk)
 BTF_KFUNCS_END(bpf_kfunc_check_set_tcp_reqsk)
 
 BTF_KFUNCS_START(bpf_kfunc_check_set_sock_ops)
-BTF_ID_FLAGS(func, bpf_sock_ops_enable_tx_tstamp, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_sock_ops_enable_tx_tstamp)
 BTF_KFUNCS_END(bpf_kfunc_check_set_sock_ops)
 
 static const struct btf_kfunc_id_set bpf_kfunc_set_skb = {
@@ -12554,7 +12554,7 @@ __bpf_kfunc int bpf_sock_destroy(struct sock_common *sock)
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(bpf_sk_iter_kfunc_ids)
-BTF_ID_FLAGS(func, bpf_sock_destroy, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_sock_destroy)
 BTF_KFUNCS_END(bpf_sk_iter_kfunc_ids)
 
 static int tracing_iter_filter(const struct bpf_prog *prog, u32 kfunc_id)
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 9100e160113a..fee6d080ee85 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -964,7 +964,7 @@ __bpf_kfunc int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(xdp_metadata_kfunc_ids)
-#define XDP_METADATA_KFUNC(_, __, name, ___) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
+#define XDP_METADATA_KFUNC(_, __, name, ___) BTF_ID_FLAGS(func, name)
 XDP_METADATA_KFUNC_xxx
 #undef XDP_METADATA_KFUNC
 BTF_KFUNCS_END(xdp_metadata_kfunc_ids)
diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c
index a9f4b7d23fe0..a82d3388c0dd 100644
--- a/net/netfilter/nf_conntrack_bpf.c
+++ b/net/netfilter/nf_conntrack_bpf.c
@@ -518,10 +518,10 @@ BTF_ID_FLAGS(func, bpf_skb_ct_alloc, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_skb_ct_lookup, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_ct_insert_entry, KF_ACQUIRE | KF_RET_NULL | KF_RELEASE)
 BTF_ID_FLAGS(func, bpf_ct_release, KF_RELEASE)
-BTF_ID_FLAGS(func, bpf_ct_set_timeout, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_ct_change_timeout, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_ct_set_status, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_ct_change_status, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_ct_set_timeout)
+BTF_ID_FLAGS(func, bpf_ct_change_timeout)
+BTF_ID_FLAGS(func, bpf_ct_set_status)
+BTF_ID_FLAGS(func, bpf_ct_change_status)
 BTF_KFUNCS_END(nf_ct_kfunc_set)
 
 static const struct btf_kfunc_id_set nf_conntrack_kfunc_set = {
diff --git a/net/netfilter/nf_flow_table_bpf.c b/net/netfilter/nf_flow_table_bpf.c
index 4a5f5195f2d2..cbd5b97a6329 100644
--- a/net/netfilter/nf_flow_table_bpf.c
+++ b/net/netfilter/nf_flow_table_bpf.c
@@ -105,7 +105,7 @@ __diag_pop()
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(nf_ft_kfunc_set)
-BTF_ID_FLAGS(func, bpf_xdp_flow_lookup, KF_TRUSTED_ARGS | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_xdp_flow_lookup, KF_RET_NULL)
 BTF_KFUNCS_END(nf_ft_kfunc_set)
 
 static const struct btf_kfunc_id_set nf_flow_kfunc_set = {
diff --git a/net/netfilter/nf_nat_bpf.c b/net/netfilter/nf_nat_bpf.c
index 481be15609b1..f9dd85ccea01 100644
--- a/net/netfilter/nf_nat_bpf.c
+++ b/net/netfilter/nf_nat_bpf.c
@@ -55,7 +55,7 @@ __bpf_kfunc int bpf_ct_set_nat_info(struct nf_conn___init *nfct,
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(nf_nat_kfunc_set)
-BTF_ID_FLAGS(func, bpf_ct_set_nat_info, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_ct_set_nat_info)
 BTF_KFUNCS_END(nf_nat_kfunc_set)
 
 static const struct btf_kfunc_id_set nf_bpf_nat_kfunc_set = {
diff --git a/net/sched/bpf_qdisc.c b/net/sched/bpf_qdisc.c
index adcb618a2bfc..b9771788b9b3 100644
--- a/net/sched/bpf_qdisc.c
+++ b/net/sched/bpf_qdisc.c
@@ -271,14 +271,14 @@ __bpf_kfunc void bpf_qdisc_bstats_update(struct Qdisc *sch, const struct sk_buff
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(qdisc_kfunc_ids)
-BTF_ID_FLAGS(func, bpf_skb_get_hash, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_skb_get_hash)
 BTF_ID_FLAGS(func, bpf_kfree_skb, KF_RELEASE)
 BTF_ID_FLAGS(func, bpf_qdisc_skb_drop, KF_RELEASE)
-BTF_ID_FLAGS(func, bpf_dynptr_from_skb, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_qdisc_watchdog_schedule, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_qdisc_init_prologue, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_qdisc_reset_destroy_epilogue, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_qdisc_bstats_update, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_dynptr_from_skb)
+BTF_ID_FLAGS(func, bpf_qdisc_watchdog_schedule)
+BTF_ID_FLAGS(func, bpf_qdisc_init_prologue)
+BTF_ID_FLAGS(func, bpf_qdisc_reset_destroy_epilogue)
+BTF_ID_FLAGS(func, bpf_qdisc_bstats_update)
 BTF_KFUNCS_END(qdisc_kfunc_ids)
 
 BTF_SET_START(qdisc_common_kfunc_set)
diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
index 90c4b1a51de6..1c41d03bd5a1 100644
--- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
@@ -693,9 +693,9 @@ BTF_ID_FLAGS(func, bpf_kfunc_dynptr_test)
 BTF_ID_FLAGS(func, bpf_kfunc_nested_acquire_nonzero_offset_test, KF_ACQUIRE)
 BTF_ID_FLAGS(func, bpf_kfunc_nested_acquire_zero_offset_test, KF_ACQUIRE)
 BTF_ID_FLAGS(func, bpf_kfunc_nested_release_test, KF_RELEASE)
-BTF_ID_FLAGS(func, bpf_kfunc_trusted_vma_test, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_kfunc_trusted_task_test, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_kfunc_trusted_num_test, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_kfunc_trusted_vma_test)
+BTF_ID_FLAGS(func, bpf_kfunc_trusted_task_test)
+BTF_ID_FLAGS(func, bpf_kfunc_trusted_num_test)
 BTF_ID_FLAGS(func, bpf_kfunc_rcu_task_test, KF_RCU)
 BTF_ID_FLAGS(func, bpf_kfunc_ret_rcu_test, KF_RET_NULL | KF_RCU_PROTECTED)
 BTF_ID_FLAGS(func, bpf_kfunc_ret_rcu_test_nostruct, KF_RET_NULL | KF_RCU_PROTECTED)
@@ -1158,7 +1158,7 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass2)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail1)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail2)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail3)
-BTF_ID_FLAGS(func, bpf_kfunc_call_test_ref, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_ref, KF_RCU)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test_destructive, KF_DESTRUCTIVE)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test_static_unused_arg)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test_offset)
@@ -1172,12 +1172,12 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_kernel_sendmsg, KF_SLEEPABLE)
 BTF_ID_FLAGS(func, bpf_kfunc_call_sock_sendmsg, KF_SLEEPABLE)
 BTF_ID_FLAGS(func, bpf_kfunc_call_kernel_getsockname, KF_SLEEPABLE)
 BTF_ID_FLAGS(func, bpf_kfunc_call_kernel_getpeername, KF_SLEEPABLE)
-BTF_ID_FLAGS(func, bpf_kfunc_st_ops_test_prologue, KF_TRUSTED_ARGS | KF_SLEEPABLE)
-BTF_ID_FLAGS(func, bpf_kfunc_st_ops_test_epilogue, KF_TRUSTED_ARGS | KF_SLEEPABLE)
-BTF_ID_FLAGS(func, bpf_kfunc_st_ops_test_pro_epilogue, KF_TRUSTED_ARGS | KF_SLEEPABLE)
-BTF_ID_FLAGS(func, bpf_kfunc_st_ops_inc10, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_kfunc_multi_st_ops_test_1, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_kfunc_multi_st_ops_test_1_impl, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_kfunc_st_ops_test_prologue, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_kfunc_st_ops_test_epilogue, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_kfunc_st_ops_test_pro_epilogue, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_kfunc_st_ops_inc10)
+BTF_ID_FLAGS(func, bpf_kfunc_multi_st_ops_test_1)
+BTF_ID_FLAGS(func, bpf_kfunc_multi_st_ops_test_1_impl)
 BTF_KFUNCS_END(bpf_testmod_check_kfunc_ids)
 
 static int bpf_testmod_ops_init(struct btf *btf)
-- 
2.47.3

With trusted args now being the default, the NULL pointer check runs
before type-specific validation. Update test3 to expect the new error
message "Possibly NULL pointer passed to trusted arg0" instead of the
old dynptr-specific error message.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 tools/testing/selftests/bpf/progs/test_kfunc_param_nullable.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/test_kfunc_param_nullable.c b/tools/testing/selftests/bpf/progs/test_kfunc_param_nullable.c
index 0ad1bf1ede8d..967081bbcfe1 100644
--- a/tools/testing/selftests/bpf/progs/test_kfunc_param_nullable.c
+++ b/tools/testing/selftests/bpf/progs/test_kfunc_param_nullable.c
@@ -29,7 +29,7 @@ int kfunc_dynptr_nullable_test2(struct __sk_buff *skb)
 }
 
 SEC("tc")
-__failure __msg("expected pointer to stack or const struct bpf_dynptr")
+__failure __msg("Possibly NULL pointer passed to trusted arg0")
 int kfunc_dynptr_nullable_test3(struct __sk_buff *skb)
 {
 	struct bpf_dynptr data;
-- 
2.47.3

The rbtree_api_use_unchecked_remove_retval() selftest passes a pointer
received from bpf_rbtree_remove() to bpf_rbtree_add() without checking
for NULL, this was earlier caught by __check_ptr_off_reg() in the
verifier. Now the verifier assumes every kfunc only takes trusted pointer
arguments, so it catches this NULL pointer earlier in the path and
provides a more accurate failure message.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 tools/testing/selftests/bpf/progs/rbtree_fail.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/rbtree_fail.c b/tools/testing/selftests/bpf/progs/rbtree_fail.c
index 4acb6af2dfe3..70b7baf9304b 100644
--- a/tools/testing/selftests/bpf/progs/rbtree_fail.c
+++ b/tools/testing/selftests/bpf/progs/rbtree_fail.c
@@ -153,7 +153,7 @@ long rbtree_api_add_to_multiple_trees(void *ctx)
 }
 
 SEC("?tc")
-__failure __msg("dereference of modified ptr_or_null_ ptr R2 off=16 disallowed")
+__failure __msg("Possibly NULL pointer passed to trusted arg1")
 long rbtree_api_use_unchecked_remove_retval(void *ctx)
 {
 	struct bpf_rb_node *res;
-- 
2.47.3

As verifier now assumes that all kfuncs only takes trusted pointer
arguments, passing 0 (NULL) to a kfunc that doesn't mark the argument as
__nullable or __opt will be rejected with a failure message of: Possibly
NULL pointer passed to trusted arg<n>

Pass a non-null value to the kfunc to test the expected failure mode.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
index 061befb004c2..d249113ed657 100644
--- a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
+++ b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
@@ -48,10 +48,9 @@ SEC("?lsm.s/bpf")
 __failure __msg("arg#0 expected pointer to stack or const struct bpf_dynptr")
 int BPF_PROG(not_ptr_to_stack, int cmd, union bpf_attr *attr, unsigned int size, bool kernel)
 {
-	unsigned long val = 0;
+	static struct bpf_dynptr val;
 
-	return bpf_verify_pkcs7_signature((struct bpf_dynptr *)val,
-					  (struct bpf_dynptr *)val, NULL);
+	return bpf_verify_pkcs7_signature(&val, &val, NULL);
 }
 
 SEC("lsm.s/bpf")
-- 
2.47.3

The cgroup_hierarchical_stats selftests uses an fentry program attached
to cgroup_attach_task and then passes the received &dst_cgrp->self to
the css_rstat_updated() kfunc. The verifier now assumes that all kfuncs
only takes trusted pointer arguments, and pointers received by fentry
are not marked trustes by default.

Use a tp_btf program in place for fentry for this test, pointers
received by tp_btf programs are marked trusted by the verifier.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 .../testing/selftests/bpf/progs/cgroup_hierarchical_stats.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c b/tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c
index ff189a736ad8..8fc38592a87b 100644
--- a/tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c
+++ b/tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c
@@ -62,9 +62,9 @@ static int create_attach_counter(__u64 cg_id, __u64 state, __u64 pending)
 				   &init, BPF_NOEXIST);
 }
 
-SEC("fentry/cgroup_attach_task")
-int BPF_PROG(counter, struct cgroup *dst_cgrp, struct task_struct *leader,
-	     bool threadgroup)
+SEC("tp_btf/cgroup_attach_task")
+int BPF_PROG(counter, struct cgroup *dst_cgrp, const char *path,
+	     struct task_struct *task, bool threadgroup)
 {
 	__u64 cg_id = cgroup_id(dst_cgrp);
 	struct percpu_attach_counter *pcpu_counter = bpf_map_lookup_elem(
-- 
2.47.3

As KF_TRUSTED_ARGS is now considered the default for all kfuncs, the
opts parameter in bpf_xdp_get_xfrm_state() can never be NULL. Verifier
will detect this at load time and will not allow passing NULL to this
function. This matches the documentation above the kfunc that says this
parameter (opts) Cannot be NULL.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 net/xfrm/xfrm_state_bpf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/xfrm/xfrm_state_bpf.c b/net/xfrm/xfrm_state_bpf.c
index 2248eda741f8..4180c317f9bc 100644
--- a/net/xfrm/xfrm_state_bpf.c
+++ b/net/xfrm/xfrm_state_bpf.c
@@ -68,7 +68,7 @@ bpf_xdp_get_xfrm_state(struct xdp_md *ctx, struct bpf_xfrm_state_opts *opts, u32
 	struct net *net = dev_net(xdp->rxq->dev);
 	struct xfrm_state *x;
 
-	if (!opts || opts__sz < sizeof(opts->error))
+	if (opts__sz < sizeof(opts->error))
 		return NULL;
 
 	if (opts__sz != BPF_XFRM_STATE_OPTS_SZ) {
-- 
2.47.3

As KF_TRUSTED_ARGS is now considered default for all kfuns, the verifier
will not allow passing NULL pointers to these kfuns. These checks for
NULL pointers can therefore be removed.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 drivers/hid/bpf/hid_bpf_dispatch.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index 9a06f9b0e4ef..892aca026ffa 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -295,9 +295,6 @@ hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t rdwr
 {
 	struct hid_bpf_ctx_kern *ctx_kern;
 
-	if (!ctx)
-		return NULL;
-
 	ctx_kern = container_of(ctx, struct hid_bpf_ctx_kern, ctx);
 
 	if (rdwr_buf_size + offset > ctx->allocated_size)
@@ -364,7 +361,7 @@ __hid_bpf_hw_check_params(struct hid_bpf_ctx *ctx, __u8 *buf, size_t *buf__sz,
 	u32 report_len;
 
 	/* check arguments */
-	if (!ctx || !hid_ops || !buf)
+	if (!hid_ops)
 		return -EINVAL;
 
 	switch (rtype) {
-- 
2.47.3