don't seal sync_mem

Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "agent_lib"
@@ -26,6 +26,7 @@ checksum = "561d97a539a36e26a9a5fad1ea11a3039a67714694aaa379433e580854bc3dc5"
 [[package]]
 name = "shared_memory_heap"
 version = "0.1.0"
+source = "git+https://gitea.rixxc.de/rixxc/shared_memory_heap.git#ef9bcc94fb04d7191514a249c78d608d2f7cb9a6"
 dependencies = [
  "libc",
 ]

Cargo.toml

@@ -8,4 +8,4 @@ edition = "2021"
 [dependencies]
 anyhow = "1.0.82"
 libc = "0.2.153"
-shared_memory_heap = { path = "../shared_memory_heap" }
+shared_memory_heap = { git = "https://gitea.rixxc.de/rixxc/shared_memory_heap.git" }

src/agent.rs

@@ -16,7 +16,7 @@ unsafe impl Send for Agent {}
 impl Agent {
     pub(crate) unsafe fn new(agent_path: &Path, keyfile_path: &Path) -> Result<Self> {
         let data_fd = get_shared_mem_fd();
-        let sync_fd = memfd_create("sync\x00".as_ptr() as *const c_char, MFD_ALLOW_SEALING);
+        let sync_fd = memfd_create("sync\x00".as_ptr() as *const c_char, 0);
 
         if sync_fd <= 0 {
             bail!("creating memfd failed");
@@ -36,8 +36,6 @@ impl Agent {
             0,
         ) as *mut usize;
 
-        fcntl(sync_fd, F_ADD_SEALS, F_SEAL_FUTURE_WRITE);
-
         if sync_mem == MAP_FAILED as *mut usize {
             bail!("mmap failed");
         }