svn commit: r188849 - in head/sys: compat/linux kern sys
Ed Schouten
ed at FreeBSD.org
Fri Feb 20 05:05:30 PST 2009
Author: ed
Date: Fri Feb 20 13:05:29 2009
New Revision: 188849
URL: http://svn.freebsd.org/changeset/base/188849
Log:
Don't make Linux stat() open character devices to resolve its name.
The existing code calls kern_open() to resolve the vnode of a pathname
right after a stat(). This is not correct, because it causes random
character devices to be opened in /dev. This means ls'ing a tape
streamer will cause it to rewind, for example. Changes I have made:
- Add kern_statat_vnhook() to allow binary emulators to `post-process'
struct stat, using the proper vnode.
- Remove unneeded printf's from stat() and statfs().
- Make the Linuxolator use kern_statat_vnhook(), replacing
translate_path_major_minor_at().
- Let translate_fd_major_minor() use vp->v_rdev instead of
vp->v_un.vu_cdev.
Result:
crw-rw-rw- 1 root root 0, 14 Feb 20 13:54 /dev/ptmx
crw--w---- 1 root adm 136, 0 Feb 20 14:03 /dev/pts/0
crw--w---- 1 root adm 136, 1 Feb 20 14:02 /dev/pts/1
crw--w---- 1 ed tty 136, 2 Feb 20 14:03 /dev/pts/2
Before this commit, ptmx also had a major number of 136, because it
silently allocated and deallocated a pseudo-terminal. Device nodes that
cannot be opened now have proper major/minor-numbers.
Reviewed by: kib, netchild, rdivacky (thanks!)
Modified:
head/sys/compat/linux/linux_stats.c
head/sys/kern/vfs_syscalls.c
head/sys/sys/syscallsubr.h
Modified: head/sys/compat/linux/linux_stats.c
==============================================================================
--- head/sys/compat/linux/linux_stats.c Fri Feb 20 11:09:55 2009 (r188848)
+++ head/sys/compat/linux/linux_stats.c Fri Feb 20 13:05:29 2009 (r188849)
@@ -62,6 +62,44 @@ __FBSDID("$FreeBSD$");
#include <security/mac/mac_framework.h>
+static void
+translate_vnhook_major_minor(struct vnode *vp, struct stat *sb)
+{
+ int major, minor;
+
+ if (vp->v_type == VCHR && vp->v_rdev != NULL &&
+ linux_driver_get_major_minor(vp->v_rdev->si_name,
+ &major, &minor) == 0) {
+ sb->st_rdev = (major << 8 | minor);
+ }
+}
+
+static int
+linux_kern_statat(struct thread *td, int flag, int fd, char *path,
+ enum uio_seg pathseg, struct stat *sbp)
+{
+
+ return (kern_statat_vnhook(td, flag, fd, path, pathseg, sbp,
+ translate_vnhook_major_minor));
+}
+
+static int
+linux_kern_stat(struct thread *td, char *path, enum uio_seg pathseg,
+ struct stat *sbp)
+{
+
+ return (linux_kern_statat(td, 0, AT_FDCWD, path, pathseg, sbp));
+}
+
+static int
+linux_kern_lstat(struct thread *td, char *path, enum uio_seg pathseg,
+ struct stat *sbp)
+{
+
+ return (linux_kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, path,
+ pathseg, sbp));
+}
+
/*
* XXX: This was removed from newstat_copyout(), and almost identical
* XXX: code was in stat64_copyout(). findcdev() needs to be replaced
@@ -102,14 +140,15 @@ static void
translate_fd_major_minor(struct thread *td, int fd, struct stat *buf)
{
struct file *fp;
+ struct vnode *vp;
int major, minor;
if ((!S_ISCHR(buf->st_mode) && !S_ISBLK(buf->st_mode)) ||
fget(td, fd, &fp) != 0)
return;
- if (fp->f_vnode != NULL &&
- fp->f_vnode->v_un.vu_cdev != NULL &&
- linux_driver_get_major_minor(fp->f_vnode->v_un.vu_cdev->si_name,
+ vp = fp->f_vnode;
+ if (vp != NULL && vp->v_rdev != NULL &&
+ linux_driver_get_major_minor(vp->v_rdev->si_name,
&major, &minor) == 0) {
buf->st_rdev = (major << 8 | minor);
} else if (fp->f_type == DTYPE_PTS) {
@@ -124,32 +163,6 @@ translate_fd_major_minor(struct thread *
fdrop(fp, td);
}
-static void
-translate_path_major_minor_at(struct thread *td, char *path,
- struct stat *buf, int dfd)
-{
- struct proc *p = td->td_proc;
- struct filedesc *fdp = p->p_fd;
- int fd;
- int temp;
-
- if (!S_ISCHR(buf->st_mode) && !S_ISBLK(buf->st_mode))
- return;
- temp = td->td_retval[0];
- if (kern_openat(td, dfd, path, UIO_SYSSPACE, O_RDONLY, 0) != 0)
- return;
- fd = td->td_retval[0];
- td->td_retval[0] = temp;
- translate_fd_major_minor(td, fd, buf);
- fdclose(fdp, fdp->fd_ofiles[fd], fd, td);
-}
-
-static inline void
-translate_path_major_minor(struct thread *td, char *path, struct stat *buf)
-{
- translate_path_major_minor_at(td, path, buf, AT_FDCWD);
-}
-
static int
newstat_copyout(struct stat *buf, void *ubuf)
{
@@ -187,9 +200,7 @@ linux_newstat(struct thread *td, struct
printf(ARGS(newstat, "%s, *"), path);
#endif
- error = kern_stat(td, path, UIO_SYSSPACE, &buf);
- if (!error)
- translate_path_major_minor(td, path, &buf);
+ error = linux_kern_stat(td, path, UIO_SYSSPACE, &buf);
LFREEPATH(path);
if (error)
return (error);
@@ -210,9 +221,7 @@ linux_newlstat(struct thread *td, struct
printf(ARGS(newlstat, "%s, *"), path);
#endif
- error = kern_lstat(td, path, UIO_SYSSPACE, &sb);
- if (!error)
- translate_path_major_minor(td, path, &sb);
+ error = linux_kern_lstat(td, path, UIO_SYSSPACE, &sb);
LFREEPATH(path);
if (error)
return (error);
@@ -279,12 +288,11 @@ linux_stat(struct thread *td, struct lin
if (ldebug(stat))
printf(ARGS(stat, "%s, *"), path);
#endif
- error = kern_stat(td, path, UIO_SYSSPACE, &buf);
+ error = linux_kern_stat(td, path, UIO_SYSSPACE, &buf);
if (error) {
LFREEPATH(path);
return (error);
}
- translate_path_major_minor(td, path, &buf);
LFREEPATH(path);
return(stat_copyout(&buf, args->up));
}
@@ -302,12 +310,11 @@ linux_lstat(struct thread *td, struct li
if (ldebug(lstat))
printf(ARGS(lstat, "%s, *"), path);
#endif
- error = kern_lstat(td, path, UIO_SYSSPACE, &buf);
+ error = linux_kern_lstat(td, path, UIO_SYSSPACE, &buf);
if (error) {
LFREEPATH(path);
return (error);
}
- translate_path_major_minor(td, path, &buf);
LFREEPATH(path);
return(stat_copyout(&buf, args->up));
}
@@ -526,9 +533,7 @@ linux_stat64(struct thread *td, struct l
printf(ARGS(stat64, "%s, *"), filename);
#endif
- error = kern_stat(td, filename, UIO_SYSSPACE, &buf);
- if (!error)
- translate_path_major_minor(td, filename, &buf);
+ error = linux_kern_stat(td, filename, UIO_SYSSPACE, &buf);
LFREEPATH(filename);
if (error)
return (error);
@@ -549,9 +554,7 @@ linux_lstat64(struct thread *td, struct
printf(ARGS(lstat64, "%s, *"), args->filename);
#endif
- error = kern_lstat(td, filename, UIO_SYSSPACE, &sb);
- if (!error)
- translate_path_major_minor(td, filename, &sb);
+ error = linux_kern_lstat(td, filename, UIO_SYSSPACE, &sb);
LFREEPATH(filename);
if (error)
return (error);
@@ -597,8 +600,7 @@ linux_fstatat64(struct thread *td, struc
printf(ARGS(fstatat64, "%i, %s, %i"), args->dfd, path, args->flag);
#endif
- error = kern_statat(td, flag, dfd, path, UIO_SYSSPACE, &buf);
- translate_path_major_minor_at(td, args->pathname, &buf, dfd);
+ error = linux_kern_statat(td, flag, dfd, path, UIO_SYSSPACE, &buf);
if (!error)
error = stat64_copyout(&buf, args->statbuf);
LFREEPATH(path);
Modified: head/sys/kern/vfs_syscalls.c
==============================================================================
--- head/sys/kern/vfs_syscalls.c Fri Feb 20 11:09:55 2009 (r188848)
+++ head/sys/kern/vfs_syscalls.c Fri Feb 20 13:05:29 2009 (r188849)
@@ -339,8 +339,6 @@ kern_statfs(struct thread *td, char *pat
out:
vfs_unbusy(mp);
VFS_UNLOCK_GIANT(vfslocked);
- if (mtx_owned(&Giant))
- printf("statfs(%d): %s: %d\n", vfslocked, path, error);
return (error);
}
@@ -2343,6 +2341,15 @@ int
kern_statat(struct thread *td, int flag, int fd, char *path,
enum uio_seg pathseg, struct stat *sbp)
{
+
+ return (kern_statat_vnhook(td, flag, fd, path, pathseg, sbp, NULL));
+}
+
+int
+kern_statat_vnhook(struct thread *td, int flag, int fd, char *path,
+ enum uio_seg pathseg, struct stat *sbp,
+ void (*hook)(struct vnode *vp, struct stat *sbp))
+{
struct nameidata nd;
struct stat sb;
int error, vfslocked;
@@ -2362,12 +2369,12 @@ kern_statat(struct thread *td, int flag,
SDT_PROBE(vfs, , stat, mode, path, sb.st_mode, 0, 0, 0);
if (S_ISREG(sb.st_mode))
SDT_PROBE(vfs, , stat, reg, path, pathseg, 0, 0, 0);
+ if (__predict_false(hook != NULL))
+ hook(nd.ni_vp, &sb);
}
NDFREE(&nd, NDF_ONLY_PNBUF);
vput(nd.ni_vp);
VFS_UNLOCK_GIANT(vfslocked);
- if (mtx_owned(&Giant))
- printf("stat(%d): %s\n", vfslocked, path);
if (error)
return (error);
*sbp = sb;
Modified: head/sys/sys/syscallsubr.h
==============================================================================
--- head/sys/sys/syscallsubr.h Fri Feb 20 11:09:55 2009 (r188848)
+++ head/sys/sys/syscallsubr.h Fri Feb 20 13:05:29 2009 (r188849)
@@ -193,6 +193,9 @@ int kern_stat(struct thread *td, char *p
struct stat *sbp);
int kern_statat(struct thread *td, int flag, int fd, char *path,
enum uio_seg pathseg, struct stat *sbp);
+int kern_statat_vnhook(struct thread *td, int flag, int fd, char *path,
+ enum uio_seg pathseg, struct stat *sbp,
+ void (*hook)(struct vnode *vp, struct stat *sbp));
int kern_statfs(struct thread *td, char *path, enum uio_seg pathseg,
struct statfs *buf);
int kern_symlink(struct thread *td, char *path, char *link,
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