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

File Facts

System

Linux kernel

Corpus path

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

Extension

.c

Size

5686 bytes

Lines

199

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.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
• Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• vmlinux.h
• bpf/bpf_helpers.h
• bpf/bpf_tracing.h

Detected Declarations

• function dump_task
• function dump_task_sleepable

Annotated Snippet

if (i % 2 == 0) {
			if (big_str1[i] != 'b') {
				BPF_SEQ_PRINTF(seq, "%s\n", info);
				return 0;
			}
		} else {
			if (big_str1[i] != 'a') {
				BPF_SEQ_PRINTF(seq, "%s\n", info);
				return 0;
			}
		}
	}

	/* Longer length than the string that crosses a page boundary */
	ret = bpf_copy_from_user_task_str(big_str2, 5005, user_ptr_long, task, BPF_F_PAD_ZEROS);
	if (bpf_strncmp(big_str2, 4, "baba") != 0 || ret != 5000
	    || bpf_strncmp(big_str2 + 4996, 5, "bab\0\0") != 0) {
		BPF_SEQ_PRINTF(seq, "%s\n", info);
		return 0;
	}

	/* Shorter length than the string that crosses a page boundary */
	ret = bpf_copy_from_user_task_str(big_str3, 4996, user_ptr_long, task, 0);
	if (bpf_strncmp(big_str3, 4, "baba") != 0 || ret != 4996
	    || bpf_strncmp(big_str3 + 4992, 4, "bab\0") != 0) {
		BPF_SEQ_PRINTF(seq, "%s\n", info);
		return 0;
	}

	++num_success_copy_from_user_task_str;

	if (ctx->meta->seq_num == 0)
		BPF_SEQ_PRINTF(seq, "    tgid      gid     data\n");

	BPF_SEQ_PRINTF(seq, "%8d %8d %8d\n", task->tgid, task->pid, user_data);
	return 0;
}

Annotation

• Immediate include surface: `vmlinux.h`, `bpf/bpf_helpers.h`, `bpf/bpf_tracing.h`.
• Detected declarations: `function dump_task`, `function dump_task_sleepable`.
• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: source implementation candidate.
• This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.