executable open until unmount

[Rick Macklem]

Retested modified patch and seems fine both ways. I also tried one that
couldn't be opened.

Thanks again, rick

On Thu, 17 Jul 2008, Kostik Belousov wrote:

> On Wed, Jul 16, 2008 at 06:44:07PM +0300, Kostik Belousov wrote:
>> On Wed, Jul 16, 2008 at 11:32:28AM -0400, Rick Macklem wrote:
>>> Patch looks good. It fixed my problem and hasn't crashed the system yet;-)
>> Did you tested both elf executables and #!-scripts ?
>>
>>>
>>> Thanks, rick
>
> And, in fact, the patch has a problem. Namely, it does not properly
> track the opened status of the text vnode, because exec_check_permission()
> could not opened it in case of error.
>
> Please, retest the change below.
>
> diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
> index f4335a2..e31ca37 100644
> --- a/sys/kern/kern_exec.c
> +++ b/sys/kern/kern_exec.c
> @@ -369,6 +369,7 @@ do_execve(td, args, mac_p)
> 	imgp->entry_addr = 0;
> 	imgp->vmspace_destroyed = 0;
> 	imgp->interpreted = 0;
> +	imgp->opened = 0;
> 	imgp->interpreter_name = args->buf + PATH_MAX + ARG_MAX;
> 	imgp->auxargs = NULL;
> 	imgp->vp = NULL;
> @@ -496,6 +497,10 @@ interpret:
> 		interplabel = mac_vnode_label_alloc();
> 		mac_vnode_copy_label(binvp->v_label, interplabel);
> #endif
> +		if (imgp->opened) {
> +			VOP_CLOSE(binvp, FREAD, td->td_ucred, td);
> +			imgp->opened = 0;
> +		}
> 		vput(binvp);
> 		vm_object_deallocate(imgp->object);
> 		imgp->object = NULL;
> @@ -845,6 +850,8 @@ exec_fail_dealloc:
> 	if (imgp->vp != NULL) {
> 		if (args->fname)
> 			NDFREE(ndp, NDF_ONLY_PNBUF);
> +		if (imgp->opened)
> +			VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td);
> 		vput(imgp->vp);
> 	}
>
> @@ -1326,6 +1333,8 @@ exec_check_permissions(imgp)
> 	 * general case).
> 	 */
> 	error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL);
> +	if (error == 0)
> +		imgp->opened = 1;
> 	return (error);
> }
>
> diff --git a/sys/sys/imgact.h b/sys/sys/imgact.h
> index 85eaea8..011a7ae 100644
> --- a/sys/sys/imgact.h
> +++ b/sys/sys/imgact.h
> @@ -58,6 +58,7 @@ struct image_params {
> 	unsigned long entry_addr; /* entry address of target executable */
> 	char vmspace_destroyed;	/* flag - we've blown away original vm space */
> 	char interpreted;	/* flag - this executable is interpreted */
> +	char opened;		/* flag - we have opened executable vnode */
> 	char *interpreter_name;	/* name of the interpreter */
> 	void *auxargs;		/* ELF Auxinfo structure pointer */
> 	struct sf_buf *firstpage;	/* first page that we mapped */
>