Add stubs for fork and vfork

Progress on shadow#1987
sporksmith · May 23, 2023 · 983d088 · 983d088
1 parent 9ad9861
commit 983d088
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Showing 3 changed files with 34 additions and 0 deletions.
diff --git a/src/main/host/syscall/handler/clone.rs b/src/main/host/syscall/handler/clone.rs
@@ -298,6 +298,36 @@ impl SyscallHandler {
         )
     }
 
+    #[log_syscall(/* rv */libc::pid_t)]
+    pub fn fork(ctx: &mut SyscallContext) -> Result<libc::pid_t, SyscallError> {
+        // This should be the correct call to `clone_internal`, but `clone_internal`
+        // will currently return an error.
+        Self::clone_internal(
+            ctx,
+            CloneFlags::empty(),
+            Some(Signal::SIGCHLD),
+            ForeignPtr::<()>::null(),
+            ForeignPtr::<libc::pid_t>::null(),
+            ForeignPtr::<libc::pid_t>::null(),
+            0,
+        )
+    }
+
+    #[log_syscall(/* rv */libc::pid_t)]
+    pub fn vfork(ctx: &mut SyscallContext) -> Result<libc::pid_t, SyscallError> {
+        // This should be the correct call to `clone_internal`, but `clone_internal`
+        // will currently return an error.
+        Self::clone_internal(
+            ctx,
+            CloneFlags::CLONE_VFORK | CloneFlags::CLONE_VM,
+            Some(Signal::SIGCHLD),
+            ForeignPtr::<()>::null(),
+            ForeignPtr::<libc::pid_t>::null(),
+            ForeignPtr::<libc::pid_t>::null(),
+            0,
+        )
+    }
+
     #[log_syscall(/* rv */libc::pid_t)]
     pub fn gettid(ctx: &mut SyscallContext) -> Result<libc::pid_t, SyscallError> {
         Ok(libc::pid_t::from(ctx.objs.thread.id()))

diff --git a/src/main/host/syscall/handler/mod.rs b/src/main/host/syscall/handler/mod.rs
@@ -52,6 +52,7 @@ impl SyscallHandler {
             libc::SYS_eventfd => SyscallHandlerFn::call(Self::eventfd, &mut ctx),
             libc::SYS_eventfd2 => SyscallHandlerFn::call(Self::eventfd2, &mut ctx),
             libc::SYS_fcntl => SyscallHandlerFn::call(Self::fcntl, &mut ctx),
+            libc::SYS_fork => SyscallHandlerFn::call(Self::fork, &mut ctx),
             libc::SYS_getitimer => SyscallHandlerFn::call(Self::getitimer, &mut ctx),
             libc::SYS_getpeername => SyscallHandlerFn::call(Self::getpeername, &mut ctx),
             libc::SYS_getrandom => SyscallHandlerFn::call(Self::getrandom, &mut ctx),
@@ -94,6 +95,7 @@ impl SyscallHandler {
             libc::SYS_socket => SyscallHandlerFn::call(Self::socket, &mut ctx),
             libc::SYS_socketpair => SyscallHandlerFn::call(Self::socketpair, &mut ctx),
             libc::SYS_sysinfo => SyscallHandlerFn::call(Self::sysinfo, &mut ctx),
+            libc::SYS_vfork => SyscallHandlerFn::call(Self::vfork, &mut ctx),
             libc::SYS_write => SyscallHandlerFn::call(Self::write, &mut ctx),
             libc::SYS_writev => SyscallHandlerFn::call(Self::writev, &mut ctx),
             _ => {

diff --git a/src/main/host/syscall_handler.c b/src/main/host/syscall_handler.c
@@ -352,6 +352,7 @@ SyscallReturn syscallhandler_make_syscall(SysCallHandler* sys, const SysCallArgs
             HANDLE_C(fgetxattr);
             HANDLE_C(flistxattr);
             HANDLE_C(flock);
+            HANDLE_RUST(fork);
             HANDLE_C(fremovexattr);
             HANDLE_C(fsetxattr);
             HANDLE_C(fstat);
@@ -466,6 +467,7 @@ SyscallReturn syscallhandler_make_syscall(SysCallHandler* sys, const SysCallArgs
             HANDLE_C(uname);
             HANDLE_C(unlinkat);
             HANDLE_C(utimensat);
+            HANDLE_RUST(vfork);
             HANDLE_RUST(write);
             HANDLE_RUST(writev);