- Tweak kern_msgctl() to return a copy of the requested message queue id

  structure in the struct pointed to by the 3rd argument for IPC_STAT and
  get rid of the 4th argument.  The old way returned a pointer into the
  kernel array that the calling function would then access afterwards
  without holding the appropriate locks and doing non-lock-safe things like
  copyout() with the data anyways.  This change removes that unsafeness and
  resulting race conditions as well as simplifying the interface.
- Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(),
  fstatfs(), and fhstatfs().  Use these wrappers to cut out a lot of
  code duplication for freebsd4 and netbsd compatability system calls.
- Add a new lookup function kern_alternate_path() that looks up a filename
  under an alternate prefix and determines which filename should be used.
  This is basically a more general version of linux_emul_convpath() that
  can be shared by all the ABIs thus allowing for further reduction of
  code duplication.

1 files changed, 2 insertions, 3 deletions

diff --git a/sys/compat/linux/linux_ipc.c b/sys/compat/linux/linux_ipc.c
index 8fc33878..ddd4f0e 100644
--- a/sys/compat/linux/linux_ipc.c
+++ b/sys/compat/linux/linux_ipc.c
@@ -637,7 +637,6 @@ linux_msgctl(struct thread *td, struct linux_msgctl_args *args)
     int error, bsd_cmd;
     struct l_msqid_ds linux_msqid;
     struct msqid_ds bsd_msqid;
-    struct msqid_ds *bsd_msqptr;
 
     error = linux_msqid_pullup(args->cmd & LINUX_IPC_64,
       &linux_msqid, (caddr_t)PTRIN(args->buf));
@@ -647,13 +646,13 @@ linux_msgctl(struct thread *td, struct linux_msgctl_args *args)
     if (bsd_cmd == LINUX_IPC_SET)
 	linux_to_bsd_msqid_ds(&linux_msqid, &bsd_msqid);
 
-    error = kern_msgctl(td, args->msqid, bsd_cmd, &bsd_msqid, &bsd_msqptr);
+    error = kern_msgctl(td, args->msqid, bsd_cmd, &bsd_msqid);
     if (error != 0)
 	if (bsd_cmd != LINUX_IPC_RMID || error != EINVAL)
 	    return (error);
 
     if (bsd_cmd == LINUX_IPC_STAT) {
-	bsd_to_linux_msqid_ds(bsd_msqptr, &linux_msqid);
+	bsd_to_linux_msqid_ds(&bsd_msqid, &linux_msqid);
 	return (linux_msqid_pushdown(args->cmd & LINUX_IPC_64,
 	  &linux_msqid, (caddr_t)PTRIN(args->buf)));
     }