diff options
Diffstat (limited to 'internal/generate')
| -rw-r--r-- | internal/generate/codegen_test.go | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/internal/generate/codegen_test.go b/internal/generate/codegen_test.go index 423972d..0482dc3 100644 --- a/internal/generate/codegen_test.go +++ b/internal/generate/codegen_test.go @@ -280,6 +280,81 @@ func TestGenerateClone3Handler(t *testing.T) { requireContains(t, output, "ev->ret_type = UNCLASSIFIED;") } +// TestGenerateWait4Handler locks in how wait4(2) is generated. Per the man +// page: +// +// pid_t wait4(pid_t pid, int *wstatus, int options, struct rusage *rusage) +// +// wait4 waits for a child process to change state and optionally retrieves its +// resource usage. NONE of the arguments is an fd or a filesystem path: args[0] +// (pid) is a process/group selector — a pid, NOT a file descriptor, so it must +// never be misclassified as one; args[1] (wstatus) is a userspace output pointer +// for the wait status; args[2] (options) is an int flag set; and args[3] +// (rusage) is a userspace output pointer to a struct rusage. The return value is +// a pid_t: the pid of the child whose state changed, 0 (WNOHANG, none ready), or +// -1 on error — never a byte count. ior therefore classifies wait4 as KindProc +// in FamilyProcess, identical to its siblings waitid/clone/fork/vfork. +// Consequently: +// - The enter handler emits a struct null_event and must NOT capture any arg +// as an fd/path/addr — neither the pid selector, the status/rusage pointers, +// nor the options flags are traced I/O resources. +// - The exit handler reports the raw pid/0/-1 status as UNCLASSIFIED; it is not +// a byte count, so it must never be tagged READ/WRITE/TRANSFER. +// +// This guards against a misclassification to KindNull (which would still emit a +// null_event but break sibling/dimension consistency) or to any fd kind (which +// would wrongly treat the pid at args[0] as a file descriptor). +func TestGenerateWait4Handler(t *testing.T) { + // Classification consistency with the waitid/clone/fork/vfork siblings. We + // feed a generic pointer arg so the name-only table — not a field heuristic — + // is what pins both wait* siblings to KindProc. + for _, name := range []string{"sys_enter_wait4", "sys_enter_waitid"} { + r := ClassifyFormat(&Format{ + Name: name, + ExternalFields: []Field{ + {Type: "long", Name: "__syscall_nr"}, + {Type: "pid_t", Name: "upid"}, + }, + }) + if r.Kind != KindProc { + t.Errorf("%s kind = %v, want KindProc", name, r.Kind) + } + } + if got := ClassifySyscallFamily("sys_enter_wait4"); got != FamilyProcess { + t.Errorf("wait4 family = %q, want %q", got, FamilyProcess) + } + if got := ClassifyRet("sys_exit_wait4"); got != Unclassified { + t.Errorf("wait4 ret classification = %q, want %q (pid, not a byte count)", got, Unclassified) + } + + output := GenerateTracepointsC(mustParseAll(t, syntheticPair("wait4"))) + + enterSec := `SEC("tracepoint/syscalls/sys_enter_wait4")` + exitSec := `SEC("tracepoint/syscalls/sys_exit_wait4")` + requireContains(t, output, enterSec) + requireContains(t, output, "struct null_event *ev") + requireContains(t, output, "ev->event_type = ENTER_NULL_EVENT;") + requireContains(t, output, "ev->trace_id = SYS_ENTER_WAIT4;") + + // The KindProc enter handler must not wire any arg as an fd/path/addr — in + // particular the pid at args[0] must never be treated as an fd. Scope to the + // enter handler body (from the enter SEC up to the exit SEC). + enterStart := strings.Index(output, enterSec) + exitStart := strings.Index(output, exitSec) + if enterStart < 0 || exitStart < 0 || exitStart <= enterStart { + t.Fatalf("wait4: handlers not found in expected order") + } + enterBody := output[enterStart:exitStart] + if strings.Contains(enterBody, "ctx->args[") { + t.Error("wait4 must be KindProc: enter handler must not capture any arg (pid at args[0] is not an fd)") + } + + // The exit handler reports the raw pid/0/-1 status as UNCLASSIFIED. + requireContains(t, output, exitSec) + requireContains(t, output, "ev->ret = ctx->ret;") + requireContains(t, output, "ev->ret_type = UNCLASSIFIED;") +} + // TestGenerateSigaltstackHandler locks in how sigaltstack(2) is generated. Per // the man page: // |