tools/testing/selftests/bpf/verifier/dead_code.c
Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/verifier/dead_code.c
File Facts
- System
- Linux kernel
- Corpus path
tools/testing/selftests/bpf/verifier/dead_code.c- Extension
.c- Size
- 4035 bytes
- Lines
- 173
- 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.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
{
"dead code: start",
.insns = {
BPF_JMP_IMM(BPF_JA, 0, 0, 2),
/* unpriv: nospec (inserted to prevent "R9 !read_ok") */
BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0),
BPF_JMP_IMM(BPF_JA, 0, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 7),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 10, -4),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 7,
},
{
"dead code: mid 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 7),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 10, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 7,
},
{
"dead code: mid 2",
.insns = {
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_prandom_u32),
BPF_JMP_IMM(BPF_JSET, BPF_REG_0, 1, 4),
BPF_JMP_IMM(BPF_JSET, BPF_REG_0, 1, 1),
BPF_JMP_IMM(BPF_JA, 0, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 7),
BPF_EXIT_INSN(),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 1,
},
{
"dead code: end 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 7),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 10, 1),
BPF_EXIT_INSN(),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 7,
},
{
"dead code: end 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 7),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 10, 1),
BPF_EXIT_INSN(),
BPF_MOV64_IMM(BPF_REG_0, 12),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 7,
},
{
"dead code: end 3",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 7),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 8, 1),
BPF_EXIT_INSN(),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 10, 1),
BPF_JMP_IMM(BPF_JA, 0, 0, 1),
BPF_MOV64_IMM(BPF_REG_0, 12),
BPF_JMP_IMM(BPF_JA, 0, 0, -5),
},
.result = ACCEPT,
.retval = 7,
},
{
"dead code: tail of main + func",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 7),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 8, 1),
BPF_EXIT_INSN(),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 1),
BPF_EXIT_INSN(),
BPF_MOV64_IMM(BPF_REG_0, 12),
BPF_EXIT_INSN(),
},
.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
.result_unpriv = REJECT,
Annotation
- Atlas domain: Support Tooling And Documentation / tools.
- Implementation status: source implementation candidate.
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.