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

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c
Extension
.c
Size
8553 bytes
Lines
330
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

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 kfunc bpf_task_release expects referenced PTR_TO_BTF_ID passed to R1")
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);
}

Annotation

Implementation Notes