PERFORCE change 122752 for review

[Roman Divacky]

http://perforce.freebsd.org/chv.cgi?CH=122752

Change 122752 by rdivacky at rdivacky_witten on 2007/07/03 08:05:17

	O_EXEC support. it is able to fexecve "/bin/date" when opened with O_RDONLY
	or O_EXEC.
	
	I am a little suspicious about this patch because audacious (mp3 player) acts
	really weird now. Needs some more investigation.

Affected files ...

.. //depot/projects/soc2007/rdivacky/linux_at/sys/kern/imgact_elf.c#3 edit
.. //depot/projects/soc2007/rdivacky/linux_at/sys/kern/kern_exec.c#10 edit
.. //depot/projects/soc2007/rdivacky/linux_at/sys/sys/fcntl.h#8 edit
.. //depot/projects/soc2007/rdivacky/linux_at/sys/sys/imgact.h#3 edit

Differences ...

==== //depot/projects/soc2007/rdivacky/linux_at/sys/kern/imgact_elf.c#3 (text+ko) ====

@@ -512,7 +512,7 @@
 	/*
 	 * Check permissions, modes, uid, etc on the file, and "open" it.
 	 */
-	error = exec_check_permissions(imgp);
+	error = exec_check_permissions(imgp, 0, 0);
 	if (error)
 		goto fail;
 

==== //depot/projects/soc2007/rdivacky/linux_at/sys/kern/kern_exec.c#10 (text+ko) ====

@@ -402,7 +402,7 @@
 	/*
 	 * Check file permissions (also 'opens' file)
 	 */
-	error = exec_check_permissions(imgp);
+	error = exec_check_permissions(imgp, args->fname == NULL, args->fd);
 	if (error)
 		goto exec_fail_dealloc;
 
@@ -1226,8 +1226,10 @@
  *	Return 0 for success or error code on failure.
  */
 int
-exec_check_permissions(imgp)
+exec_check_permissions(imgp, fexecve, fd)
 	struct image_params *imgp;
+	int fexecve;
+	int fd;
 {
 	struct vnode *vp = imgp->vp;
 	struct vattr *attr = imgp->attr;
@@ -1281,6 +1283,27 @@
 		return (ETXTBSY);
 
 	/*
+	 *  Check for the mode the file was opened with
+	 */
+	if (fexecve) {
+		struct file f;
+		struct file *fp = &f;
+
+		FILEDESC_SLOCK(td->td_proc->p_fd);
+		fp = fget_locked(td->td_proc->p_fd, fd);
+		if (fp == NULL || fp->f_ops == &badfileops) {
+			FILEDESC_SUNLOCK(td->td_proc->p_fd);
+			return (EBADF);
+		}
+		fhold(fp);
+		FILEDESC_SUNLOCK(td->td_proc->p_fd);
+		if (!(fp->f_flag & FREAD) && !(fp->f_flag & O_EXEC)) {
+			fdrop(fp, td);
+			return (EACCES);
+		}
+		fdrop(fp, td);
+	}
+	/*
 	 * Call filesystem specific open routine (which does nothing in the
 	 * general case).
 	 */

==== //depot/projects/soc2007/rdivacky/linux_at/sys/sys/fcntl.h#8 (text+ko) ====

@@ -74,10 +74,6 @@
 #define	O_WRONLY	0x0001		/* open for writing only */
 #define	O_RDWR		0x0002		/* open for reading and writing */
 #define	O_ACCMODE	0x0003		/* mask for above modes */
-#if 0
-#define	O_EXEC		0x0004		/* open for execute only */
-#define	O_ACCMODE	0x0007		/* mask for above modes */
-#endif
 
 /*
  * Kernel encoding of open mode; separate read and write bits that are
@@ -107,6 +103,7 @@
 #ifdef _KERNEL
 #define	FHASLOCK	0x4000		/* descriptor holds advisory lock */
 #endif
+#define	O_EXEC		0x8000		/* open for execute only */
 /* Defined by POSIX Extended API ... TODO: number of the spec */
 #define	AT_FDCWD		-100	/* Use the current working directory
 					   to determine the target of relative
@@ -138,7 +135,7 @@
 #define	OFLAGS(fflags)	((fflags) - 1)
 
 /* bits to save after open */
-#define	FMASK		(FREAD|FWRITE|FAPPEND|FASYNC|FFSYNC|FNONBLOCK|O_DIRECT)
+#define	FMASK		(FREAD|FWRITE|FAPPEND|FASYNC|FFSYNC|FNONBLOCK|O_DIRECT|O_EXEC)
 /* bits settable by fcntl(F_SETFL, ...) */
 #define	FCNTLFLAGS	(FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM|O_DIRECT)
 #endif

==== //depot/projects/soc2007/rdivacky/linux_at/sys/sys/imgact.h#3 (text+ko) ====

@@ -71,7 +71,7 @@
 struct sysentvec;
 struct thread;
 
-int	exec_check_permissions(struct image_params *);
+int	exec_check_permissions(struct image_params *, int fexecve, int fd);
 register_t *exec_copyout_strings(struct image_params *);
 int	exec_new_vmspace(struct image_params *, struct sysentvec *);
 void	exec_setregs(struct thread *, u_long, u_long, u_long);