internal/prctl: rename prctl wrappers

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/fpkg/main.go

@@ -40,7 +40,7 @@ func main() {
 	// early init argv0 check, skips root check and duplicate PR_SET_DUMPABLE
 	init0.TryArgv0()
 
-	if err := internal.PR_SET_DUMPABLE__SUID_DUMP_DISABLE(); err != nil {
+	if err := internal.SetDumpable(internal.SUID_DUMP_DISABLE); err != nil {
 		log.Printf("cannot set SUID_DUMP_DISABLE: %s", err)
 		// not fatal: this program runs as the privileged user
 	}

internal/app/init/main.go

@@ -28,7 +28,7 @@ func Main() {
 	fmsg.Prepare("init")
 
 	// setting this prevents ptrace
-	if err := internal.PR_SET_DUMPABLE__SUID_DUMP_DISABLE(); err != nil {
+	if err := internal.SetDumpable(internal.SUID_DUMP_DISABLE); err != nil {
 		log.Fatalf("cannot set SUID_DUMP_DISABLE: %s", err)
 	}
 
@@ -64,7 +64,7 @@ func Main() {
 	}
 
 	// die with parent
-	if err := internal.PR_SET_PDEATHSIG__SIGKILL(); err != nil {
+	if err := internal.SetPdeathsig(syscall.SIGKILL); err != nil {
 		log.Fatalf("prctl(PR_SET_PDEATHSIG, SIGKILL): %v", err)
 	}
 

internal/app/shim/main.go

@@ -29,7 +29,7 @@ func Main() {
 	fmsg.Prepare("shim")
 
 	// setting this prevents ptrace
-	if err := internal.PR_SET_DUMPABLE__SUID_DUMP_DISABLE(); err != nil {
+	if err := internal.SetDumpable(internal.SUID_DUMP_DISABLE); err != nil {
 		log.Fatalf("cannot set SUID_DUMP_DISABLE: %s", err)
 	}
 

internal/prctl.go

@@ -2,17 +2,22 @@ package internal
 
 import "syscall"
 
-func PR_SET_DUMPABLE__SUID_DUMP_DISABLE() error {
+const (
+	SUID_DUMP_DISABLE = iota
+	SUID_DUMP_USER
+)
+
+func SetDumpable(dumpable uintptr) error {
 	// linux/sched/coredump.h
-	if _, _, errno := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_DUMPABLE, 0, 0); errno != 0 {
+	if _, _, errno := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_DUMPABLE, dumpable, 0); errno != 0 {
 		return errno
 	}
 
 	return nil
 }
 
-func PR_SET_PDEATHSIG__SIGKILL() error {
+func SetPdeathsig(sig syscall.Signal) error {
-	if _, _, errno := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_PDEATHSIG, uintptr(syscall.SIGKILL), 0); errno != 0 {
+	if _, _, errno := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_PDEATHSIG, uintptr(sig), 0); errno != 0 {
 		return errno
 	}
 

main.go

@@ -44,7 +44,7 @@ func main() {
 	// early init argv0 check, skips root check and duplicate PR_SET_DUMPABLE
 	init0.TryArgv0()
 
-	if err := internal.PR_SET_DUMPABLE__SUID_DUMP_DISABLE(); err != nil {
+	if err := internal.SetDumpable(internal.SUID_DUMP_DISABLE); err != nil {
 		log.Printf("cannot set SUID_DUMP_DISABLE: %s", err)
 		// not fatal: this program runs as the privileged user
 	}