1 files changed, 310 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c
new file mode 100644
index 000000000000..1204fbc58178
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
+
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+#include "bpf_misc.h"
+#include "xdp_metadata.h"
+#include "bpf_kfuncs.h"
+
+extern struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym __weak;
+extern void bpf_task_release(struct task_struct *p) __ksym __weak;
+
+__weak int subprog_trusted_task_nullable(struct task_struct *task __arg_trusted __arg_nullable)
+{
+	if (!task)
+		return 0;
+	return task->pid + task->tgid;
+}
+
+__weak int subprog_trusted_task_nullable_extra_layer(struct task_struct *task __arg_trusted __arg_nullable)
+{
+	return subprog_trusted_task_nullable(task) + subprog_trusted_task_nullable(NULL);
+}
+
+SEC("?tp_btf/task_newtask")
+__success __log_level(2)
+__msg("Validating subprog_trusted_task_nullable() func#1...")
+__msg(": R1=trusted_ptr_or_null_task_struct(")
+int trusted_task_arg_nullable(void *ctx)
+{
+	struct task_struct *t1 = bpf_get_current_task_btf();
+	struct task_struct *t2 = bpf_task_acquire(t1);
+	int res = 0;
+
+	/* known NULL */
+	res += subprog_trusted_task_nullable(NULL);
+
+	/* known non-NULL */
+	res += subprog_trusted_task_nullable(t1);
+	res += subprog_trusted_task_nullable_extra_layer(t1);
+
+	/* unknown if NULL or not */
+	res += subprog_trusted_task_nullable(t2);
+	res += subprog_trusted_task_nullable_extra_layer(t2);
+
+	if (t2) {
+		/* known non-NULL after explicit NULL check, just in case */
+		res += subprog_trusted_task_nullable(t2);
+		res += subprog_trusted_task_nullable_extra_layer(t2);
+
+		bpf_task_release(t2);
+	}
+
+	return res;
+}
+
+__weak int subprog_trusted_task_nonnull(struct task_struct *task __arg_trusted)
+{
+	return task->pid + task->tgid;
+}
+
+SEC("?kprobe")
+__failure __log_level(2)
+__msg("R1 type=scalar expected=ptr_, trusted_ptr_, rcu_ptr_")
+__msg("Caller passes invalid args into func#1 ('subprog_trusted_task_nonnull')")
+int trusted_task_arg_nonnull_fail1(void *ctx)
+{
+	return subprog_trusted_task_nonnull(NULL);
+}
+
+SEC("?tp_btf/task_newtask")
+__failure __log_level(2)
+__msg("R1 type=ptr_or_null_ expected=ptr_, trusted_ptr_, rcu_ptr_")
+__msg("Caller passes invalid args into func#1 ('subprog_trusted_task_nonnull')")
+int trusted_task_arg_nonnull_fail2(void *ctx)
+{
+	struct task_struct *t = bpf_get_current_task_btf();
+	struct task_struct *nullable;
+	int res;
+
+	nullable = bpf_task_acquire(t);
+
+	 /* should fail, PTR_TO_BTF_ID_OR_NULL */
+	res = subprog_trusted_task_nonnull(nullable);
+
+	if (nullable)
+		bpf_task_release(nullable);
+
+	return res;
+}
+
+SEC("?kprobe")
+__success __log_level(2)
+__msg("Validating subprog_trusted_task_nonnull() func#1...")
+__msg(": R1=trusted_ptr_task_struct(")
+int trusted_task_arg_nonnull(void *ctx)
+{
+	struct task_struct *t = bpf_get_current_task_btf();
+
+	return subprog_trusted_task_nonnull(t);
+}
+
+struct task_struct___local {} __attribute__((preserve_access_index));
+
+__weak int subprog_nullable_task_flavor(
+	struct task_struct___local *task __arg_trusted __arg_nullable)
+{
+	char buf[16];
+
+	if (!task)
+		return 0;
+
+	return bpf_copy_from_user_task(&buf, sizeof(buf), NULL, (void *)task, 0);
+}
+
+SEC("?uprobe.s")
+__success __log_level(2)
+__msg("Validating subprog_nullable_task_flavor() func#1...")
+__msg(": R1=trusted_ptr_or_null_task_struct(")
+int flavor_ptr_nullable(void *ctx)
+{
+	struct task_struct___local *t = (void *)bpf_get_current_task_btf();
+
+	return subprog_nullable_task_flavor(t);
+}
+
+__weak int subprog_nonnull_task_flavor(struct task_struct___local *task __arg_trusted)
+{
+	char buf[16];
+
+	return bpf_copy_from_user_task(&buf, sizeof(buf), NULL, (void *)task, 0);
+}
+
+SEC("?uprobe.s")
+__success __log_level(2)
+__msg("Validating subprog_nonnull_task_flavor() func#1...")
+__msg(": R1=trusted_ptr_task_struct(")
+int flavor_ptr_nonnull(void *ctx)
+{
+	struct task_struct *t = bpf_get_current_task_btf();
+
+	return subprog_nonnull_task_flavor((void *)t);
+}
+
+__weak int subprog_trusted_destroy(struct task_struct *task __arg_trusted)
+{
+	bpf_task_release(task); /* should be rejected */
+
+	return 0;
+}
+
+SEC("?tp_btf/task_newtask")
+__failure __log_level(2)
+__msg("release kernel function bpf_task_release expects refcounted PTR_TO_BTF_ID")
+int BPF_PROG(trusted_destroy_fail, struct task_struct *task, u64 clone_flags)
+{
+	return subprog_trusted_destroy(task);
+}
+
+__weak int subprog_trusted_acq_rel(struct task_struct *task __arg_trusted)
+{
+	struct task_struct *owned;
+
+	owned = bpf_task_acquire(task);
+	if (!owned)
+		return 0;
+
+	bpf_task_release(owned); /* this one is OK, we acquired it locally */
+
+	return 0;
+}
+
+SEC("?tp_btf/task_newtask")
+__success __log_level(2)
+int BPF_PROG(trusted_acq_rel, struct task_struct *task, u64 clone_flags)
+{
+	return subprog_trusted_acq_rel(task);
+}
+
+__weak int subprog_untrusted_bad_tags(struct task_struct *task __arg_untrusted __arg_nullable)
+{
+	return task->pid;
+}
+
+SEC("tp_btf/sys_enter")
+__failure
+__msg("arg#0 untrusted cannot be combined with any other tags")
+int untrusted_bad_tags(void *ctx)
+{
+	return subprog_untrusted_bad_tags(0);
+}
+
+struct local_type_wont_be_accepted {};
+
+__weak int subprog_untrusted_bad_type(struct local_type_wont_be_accepted *p __arg_untrusted)
+{
+	return 0;
+}
+
+SEC("tp_btf/sys_enter")
+__failure
+__msg("arg#0 reference type('STRUCT local_type_wont_be_accepted') has no matches")
+int untrusted_bad_type(void *ctx)
+{
+	return subprog_untrusted_bad_type(bpf_rdonly_cast(0, 0));
+}
+
+__weak int subprog_untrusted(const volatile struct task_struct *restrict task __arg_untrusted)
+{
+	return task->pid;
+}
+
+SEC("tp_btf/sys_enter")
+__success
+__log_level(2)
+__msg("r1 = {{.*}}; {{.*}}R1=trusted_ptr_task_struct()")
+__msg("Func#1 ('subprog_untrusted') is global and assumed valid.")
+__msg("Validating subprog_untrusted() func#1...")
+__msg(": R1=untrusted_ptr_task_struct")
+int trusted_to_untrusted(void *ctx)
+{
+	return subprog_untrusted(bpf_get_current_task_btf());
+}
+
+char mem[16];
+u32 offset;
+
+SEC("tp_btf/sys_enter")
+__success
+int anything_to_untrusted(void *ctx)
+{
+	/* untrusted to untrusted */
+	subprog_untrusted(bpf_core_cast(0, struct task_struct));
+	/* wrong type to untrusted */
+	subprog_untrusted((void *)bpf_core_cast(0, struct bpf_verifier_env));
+	/* map value to untrusted */
+	subprog_untrusted((void *)mem);
+	/* scalar to untrusted */
+	subprog_untrusted(0);
+	/* variable offset to untrusted (map) */
+	subprog_untrusted((void *)mem + offset);
+	/* variable offset to untrusted (trusted) */
+	subprog_untrusted((void *)bpf_get_current_task_btf() + offset);
+	return 0;
+}
+
+__weak int subprog_untrusted2(struct task_struct *task __arg_untrusted)
+{
+	return subprog_trusted_task_nullable(task);
+}
+
+SEC("tp_btf/sys_enter")
+__failure
+__msg("R1 type=untrusted_ptr_ expected=ptr_, trusted_ptr_, rcu_ptr_")
+__msg("Caller passes invalid args into func#{{.*}} ('subprog_trusted_task_nullable')")
+int untrusted_to_trusted(void *ctx)
+{
+	return subprog_untrusted2(bpf_get_current_task_btf());
+}
+
+__weak int subprog_void_untrusted(void *p __arg_untrusted)
+{
+	return *(int *)p;
+}
+
+__weak int subprog_char_untrusted(char *p __arg_untrusted)
+{
+	return *(int *)p;
+}
+
+__weak int subprog_enum_untrusted(enum bpf_attach_type *p __arg_untrusted)
+{
+	return *(int *)p;
+}
+
+SEC("tp_btf/sys_enter")
+__success
+__log_level(2)
+__msg("r1 = {{.*}}; {{.*}}R1=trusted_ptr_task_struct()")
+__msg("Func#1 ('subprog_void_untrusted') is global and assumed valid.")
+__msg("Validating subprog_void_untrusted() func#1...")
+__msg(": R1=rdonly_untrusted_mem(sz=0)")
+int trusted_to_untrusted_mem(void *ctx)
+{
+	return subprog_void_untrusted(bpf_get_current_task_btf());
+}
+
+SEC("tp_btf/sys_enter")
+__success
+int anything_to_untrusted_mem(void *ctx)
+{
+	/* untrusted to untrusted mem */
+	subprog_void_untrusted(bpf_core_cast(0, struct task_struct));
+	/* map value to untrusted mem */
+	subprog_void_untrusted(mem);
+	/* scalar to untrusted mem */
+	subprog_void_untrusted(0);
+	/* variable offset to untrusted mem (map) */
+	subprog_void_untrusted((void *)mem + offset);
+	/* variable offset to untrusted mem (trusted) */
+	subprog_void_untrusted(bpf_get_current_task_btf() + offset);
+	/* variable offset to untrusted char/enum (map) */
+	subprog_char_untrusted(mem + offset);
+	subprog_enum_untrusted((void *)mem + offset);
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";