Change Details

If the first page is not fully valid, or the attempt to page in subsequent pages fails, we currently free the pages. However, the pages may have already been resident and wired by mlock(). This can happen if execve() attempts to activate an image which is simultaneously mlock()ed and being truncated. In particular, if a vnode mapping is mlock()ed, truncation does not free newly invalid pages, it simply unmaps them and leaves them wired. Fix this by simply moving the pages near the head of the inactive queue instead of trying to free them. We could try and check for wirings and conditionally free the pages, but for this rare case I think it is preferable to simply enqueue the pages.

If the first page is not fully valid, or the attempt to page in subsequent pages fails, we currently free the pages. However, the pages may have already been resident and wired by mlock(). This can happen if execve() attempts to activate an image which has been mlock()ed and truncated.

If the first page is not fully valid, or the attempt to page in subsequent pages fails, we currently free the pages. However, the pages may have already been resident and wired by mlock(). This can happen if execve() attempts to activate an image which is simultaneouslyhas been mlock()edd and and being truncated. In particular, if a vnode mapping is mlock()ed, truncation does not free newly invalid pages, it simply unmaps them and leaves them wired. Fix this by simply moving the pages near the head of the inactive queue instead of trying to free them. We could try and check for wirings and conditionally free the pages, but for this rare case I think it is preferable to simply enqueue the pagestruncated.