diff options
Diffstat (limited to 'internal/generate')
| -rw-r--r-- | internal/generate/codegen_test.go | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/internal/generate/codegen_test.go b/internal/generate/codegen_test.go index 1d6214c..8d348f8 100644 --- a/internal/generate/codegen_test.go +++ b/internal/generate/codegen_test.go @@ -602,6 +602,49 @@ func TestGenerateMemHandlerMlock2(t *testing.T) { requireContains(t, output, "ev->flags = (__u64)ctx->args[2];") } +// TestGenerateMemHandlerMunlock locks in the BPF handler wiring for munlock(2): +// int munlock(const void addr[.size], size_t size). munlock unlocks the page +// range [addr, addr+size) so it may be paged out again — the converse of +// mlock(2). The range is args[0]/args[1] (addr/length). Crucially munlock has +// NO flags argument (unlike its sibling mlock2(2), which carries +// MLOCK_ONFAULT at args[2]) and no second length region, so both ev->flags and +// ev->length2 must stay zero. This guards against accidentally copying the +// mlock2 wiring and surfacing a nonexistent args[2] as flags. munlock must not +// be confused with munlockall(2), which takes no address range and is +// classified KindNull. munlock returns int 0 on success / -1 on error, +// captured generically via ev->ret as UNCLASSIFIED like every other KindMem +// exit (it is not a byte-count, so it is intentionally absent from +// retClassifications). +func TestGenerateMemHandlerMunlock(t *testing.T) { + output := GenerateTracepointsC(mustParseAll(t, syntheticPair("munlock"))) + + requireContains(t, output, `SEC("tracepoint/syscalls/sys_enter_munlock")`) + requireContains(t, output, "struct mem_event *ev") + requireContains(t, output, "ev->event_type = ENTER_MEM_EVENT;") + requireContains(t, output, "ev->addr = (__u64)ctx->args[0];") + requireContains(t, output, "ev->length = (__u64)ctx->args[1];") + requireContains(t, output, "ev->length2 = 0;") + requireContains(t, output, "ev->flags = 0;") + // munlock has no flags argument; args[2] must never be wired into ev->flags + // (that is the mlock2-only MLOCK_ONFAULT slot). + if strings.Contains(output, "ev->flags = (__u64)ctx->args[2];") { + t.Error("munlock handler must keep flags zero; munlock has no flags argument (that is mlock2's args[2])") + } + // munlock has no second length region. + if strings.Contains(output, "ev->length2 = (__u64)ctx->args") { + t.Error("munlock handler must keep length2 zero; it has no second length argument") + } + // addr (args[0]) must never be reused as flags. + if strings.Contains(output, "ev->flags = (__u64)ctx->args[0];") { + t.Error("munlock handler must keep flags zero; args[0] is the addr, not a flags value") + } + // The exit handler returns the int status generically (0 on success, -1 on + // error), not via a byte-count classification. + requireContains(t, output, `SEC("tracepoint/syscalls/sys_exit_munlock")`) + requireContains(t, output, "ev->ret = ctx->ret;") + requireContains(t, output, "ev->ret_type = UNCLASSIFIED;") +} + func TestGenerateMemHandlerRemapFilePages(t *testing.T) { output := GenerateTracepointsC(mustParseAll(t, syntheticPair("remap_file_pages"))) |