ash: minor changes to forkshell error handling

forkshell_prepare() now returns NULL if it fails to map its view of
the data block.  Detect and report this error in spawn_forkshell().

If forkshell_init() fails it now returns to ash_main() where a generic
error is reported.

1 files changed, 9 insertions, 3 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 241846380..951e241ad 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -15314,7 +15314,7 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
         if (argc == 3 && !strcmp(argv[1], "--fs")) {
                 forkshell_init(argv[2]);
 
-                /* NOTREACHED */
+                /* only reached in case of error */
                 bb_error_msg_and_die("forkshell failed");
         }
 #endif
@@ -15620,6 +15620,9 @@ spawn_forkshell(struct forkshell *fs, struct job *jp, union node *n, int mode)
         intptr_t ret;
 
         new = forkshell_prepare(fs);
+        if (new == NULL)
+                goto fail;
+
         new->mode = mode;
         new->nprocs = jp == NULL ? 0 : jp->nprocs;
         sprintf(buf, "%p", new->hMapFile);
@@ -15628,6 +15631,7 @@ spawn_forkshell(struct forkshell *fs, struct job *jp, union node *n, int mode)
         CloseHandle(new->hMapFile);
         UnmapViewOfFile(new);
         if (ret == -1) {
+ fail:
                 if (jp)
                         freejob(jp);
                 ash_msg_and_raise_error("unable to spawn shell");
@@ -16233,6 +16237,8 @@ forkshell_prepare(struct forkshell *fs)
 
         /* Initialise pointers */
         new = (struct forkshell *)MapViewOfFile(h, FILE_MAP_WRITE, 0,0, 0);
+        if (new == NULL)
+                return NULL;
         fs_size = size;
         funcblock = (char *)(new + 1);
         funcstring_end = (char *)new + size;
@@ -16305,12 +16311,12 @@ forkshell_init(const char *idstr)
         char *lrelocate;
 
         if (sscanf(idstr, "%p", &map_handle) != 1)
-                bb_error_msg_and_die("invalid forkshell ID");
+                return;
 
         h = (HANDLE)map_handle;
         fs = (struct forkshell *)MapViewOfFile(h, FILE_MAP_WRITE, 0,0, 0);
         if (!fs)
-                bb_error_msg_and_die("Invalid forkshell memory");
+                return;
 
         /* this memory can't be freed */
         sticky_mem_start = fs;