tools/testing/selftests/bpf/progs/summarization.c
Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/progs/summarization.c
File Facts
- System
- Linux kernel
- Corpus path
tools/testing/selftests/bpf/progs/summarization.c- Extension
.c- Size
- 1176 bytes
- Lines
- 79
- 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.hbpf/bpf_helpers.hbpf_misc.h
Detected Declarations
function changes_pkt_datafunction does_not_change_pkt_datafunction main_changes_with_subprogsfunction main_changesfunction main_does_not_changefunction might_sleepfunction does_not_sleepfunction main_might_sleep_with_subprogsfunction main_might_sleepfunction main_does_not_sleep
Annotated Snippet
// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
__noinline
long changes_pkt_data(struct __sk_buff *sk)
{
return bpf_skb_pull_data(sk, 0);
}
__noinline __weak
long does_not_change_pkt_data(struct __sk_buff *sk)
{
return 0;
}
SEC("?tc")
int main_changes_with_subprogs(struct __sk_buff *sk)
{
changes_pkt_data(sk);
does_not_change_pkt_data(sk);
return 0;
}
SEC("?tc")
int main_changes(struct __sk_buff *sk)
{
bpf_skb_pull_data(sk, 0);
return 0;
}
SEC("?tc")
int main_does_not_change(struct __sk_buff *sk)
{
return 0;
}
__noinline
long might_sleep(struct pt_regs *ctx __arg_ctx)
{
int i;
bpf_copy_from_user(&i, sizeof(i), NULL);
return i;
}
__noinline __weak
long does_not_sleep(struct pt_regs *ctx __arg_ctx)
{
return 0;
}
SEC("?uprobe.s")
int main_might_sleep_with_subprogs(struct pt_regs *ctx)
{
might_sleep(ctx);
does_not_sleep(ctx);
return 0;
}
SEC("?uprobe.s")
int main_might_sleep(struct pt_regs *ctx)
{
int i;
bpf_copy_from_user(&i, sizeof(i), NULL);
return i;
}
SEC("?uprobe.s")
int main_does_not_sleep(struct pt_regs *ctx)
{
return 0;
}
char _license[] SEC("license") = "GPL";
Annotation
- Immediate include surface: `vmlinux.h`, `bpf/bpf_helpers.h`, `bpf_misc.h`.
- Detected declarations: `function changes_pkt_data`, `function does_not_change_pkt_data`, `function main_changes_with_subprogs`, `function main_changes`, `function main_does_not_change`, `function might_sleep`, `function does_not_sleep`, `function main_might_sleep_with_subprogs`, `function main_might_sleep`, `function main_does_not_sleep`.
- 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.