[LibOS] Close open fds on process exit

Signed-off-by: Kailun Qin <[email protected]>
gramineproject · Aug 16, 2022 · 2e700c1 · 2e700c1
1 parent 6a46851
commit 2e700c1
Show file tree

Hide file tree

Showing 3 changed files with 18 additions and 5 deletions.
diff --git a/libos/include/libos_handle.h b/libos/include/libos_handle.h
@@ -268,6 +268,7 @@ int set_new_fd_handle_above_fd(uint32_t fd, struct libos_handle* hdl, int fd_fla
 struct libos_handle* __detach_fd_handle(struct libos_fd_handle* fd, int* flags,
                                         struct libos_handle_map* map);
 struct libos_handle* detach_fd_handle(uint32_t fd, int* flags, struct libos_handle_map* map);
+void detach_all_fds(void);
 
 /* manage handle mapping */
 int dup_handle_map(struct libos_handle_map** new_map, struct libos_handle_map* old_map);

diff --git a/libos/src/bookkeep/libos_handle.c b/libos/src/bookkeep/libos_handle.c
@@ -323,6 +323,19 @@ struct libos_handle* detach_fd_handle(uint32_t fd, int* flags,
     return handle;
 }
 
+static int detach_fd(struct libos_fd_handle* fd_hdl, struct libos_handle_map* map) {
+    struct libos_handle* hdl = __detach_fd_handle(fd_hdl, NULL, map);
+    put_handle(hdl);
+    return 0;
+}
+
+void detach_all_fds(void) {
+    struct libos_handle_map* handle_map = get_thread_handle_map(NULL);
+    assert(handle_map);
+
+    walk_handle_map(&detach_fd, handle_map);
+}
+
 struct libos_handle* get_new_handle(void) {
     struct libos_handle* new_handle =
         get_mem_obj_from_mgr_enlarge(handle_mgr, size_align_up(HANDLE_MGR_ALLOC));
@@ -651,18 +664,14 @@ int walk_handle_map(int (*callback)(struct libos_fd_handle*, struct libos_handle
     int ret = 0;
     lock(&map->lock);
 
-    if (map->fd_top == FD_NULL)
-        goto done;
-
-    for (uint32_t i = 0; i <= map->fd_top; i++) {
+    for (uint32_t i = 0; map->fd_top != FD_NULL && i <= map->fd_top; i++) {
         if (!HANDLE_ALLOCATED(map->map[i]))
             continue;
 
         if ((ret = (*callback)(map->map[i], map)) < 0)
             break;
     }
 
-done:
     unlock(&map->lock);
     return ret;
 }

diff --git a/libos/src/sys/libos_exit.c b/libos/src/sys/libos_exit.c
@@ -7,6 +7,7 @@
  */
 
 #include "libos_fs_lock.h"
+#include "libos_handle.h"
 #include "libos_ipc.h"
 #include "libos_lock.h"
 #include "libos_process.h"
@@ -99,6 +100,8 @@ noreturn void thread_exit(int error_code, int term_signal) {
     if (ret < 0)
         log_warning("error clearing POSIX locks: %d", ret);
 
+    detach_all_fds();
+
     /* This is the last thread of the process. Let parent know we exited. */
     ret = ipc_cld_exit_send(error_code, term_signal);
     if (ret < 0) {