Continue vfork parent after child execs

Signed-off-by: Mattias Andrée <maandree@kth.se>

2 files changed, 24 insertions, 4 deletions

diff --git a/common.h b/common.h
index 376e0f9..c4de909 100644
--- a/common.h
+++ b/common.h
@@ -70,7 +70,8 @@ enum state {
 	ForkChild,
 	VforkChild,
 	ForkParent,
-	VforkParent
+	VforkParent,
+	Exec
 };
 
 struct process {
diff --git a/sctrace.c b/sctrace.c
index 43afce7..34bd3ac 100644
--- a/sctrace.c
+++ b/sctrace.c
@@ -68,6 +68,14 @@ handle_syscall(struct process *proc)
 		proc->state = Normal;
 		break;
 
+	case Exec:
+		if (ptrace(PTRACE_SYSCALL, proc->pid, NULL, 0))
+			eprintf("ptrace PTRACE_SYSCALL %ju NULL 0", (uintmax_t)proc->pid);
+		if (ptrace(PTRACE_SYSCALL, proc->pid, NULL, 0))
+			eprintf("ptrace PTRACE_SYSCALL %ju NULL 0", (uintmax_t)proc->pid);
+		proc->state = Normal;
+		break;
+
 	case VforkParent:
 		if (ptrace(PTRACE_SYSCALL, proc->pid, NULL, 0))
 			eprintf("ptrace PTRACE_SYSCALL %ju NULL 0", (uintmax_t)proc->pid);
@@ -92,11 +100,10 @@ main(int argc, char **argv)
 	FILE *outfp = stderr;
 	const char *num = NULL;
 	int status, exit_value = 0, trace_event, with_argv0 = 0;
-	unsigned long int trace_options = PTRACE_O_EXITKILL | PTRACE_O_TRACESYSGOOD;
+	unsigned long int trace_options = PTRACE_O_EXITKILL | PTRACE_O_TRACESYSGOOD | PTRACE_O_TRACEEXEC;
 	struct process *proc, *proc2;
 	unsigned long int event;
 
-	/* TODO add support for exec after vfork */
 	/* TODO add option to trace threads (-t) */
 	/* TODO add option to trace signals (-s) */
 	ARGBEGIN {
@@ -198,7 +205,7 @@ have_outfp:
 			proc2 = proc->continue_on_exit;
 			remove_process(proc);
 			if (proc2) {
-				tprintf(proc2, "Process continue do to exit of vfork child\n");
+				tprintf(proc2, "Process continues due to exit of vfork child\n");
 				handle_syscall(proc2);
 			}
 
@@ -234,6 +241,18 @@ have_outfp:
 					handle_syscall(proc2);
 					break;
 
+				case PTRACE_EVENT_EXEC:
+					proc->state = Exec;
+					handle_syscall(proc);
+					proc2 = proc->continue_on_exit;
+					if (proc2) {
+						proc->continue_on_exit = NULL;
+						proc2->vfork_waiting_on = NULL;
+						tprintf(proc2, "Process continues due to exec(2) of vfork child\n");
+						handle_syscall(proc2);
+					}
+					break;
+
 				default:
 					goto print_signal;
 				}