to construct the full pathname. It starts to search at the default
mountpoint which is /dev/shm. If this fails it runs through fstab
and searches for shmfs and tmpfs. Whatever it finds will be
statfs()'ed to be checked for Linux' fs magic for shmfs (0x01021994).
Ideally our tmpfs should deliver this fs magic to Linux processes, but
as our tmpfs is considered to be an experimental feature we can not
assume that there is always a tmpfs available.
To make shared memory work in the Linuxulator, force the fs type of
/dev/shm (which can be a symlink) to match what Linux expects. The user
is responsible (info has to be added to the linux base ports and the docs)
to setup a suitable link for /dev/shm.
Noticed by: Andre Albsmeier <Andre.Albsmeier@siemens.com>
Submitted by: Andre Albsmeier <Andre.Albsmeier@siemens.com>
MFC after: 1 month
A nice thing about POSIX 2008 is that it finally standardizes a way to
obtain file access/modification/change times in sub-second precision,
namely using struct timespec, which we already have for a very long
time. Unfortunately POSIX uses different names.
This commit adds compatibility macros, so existing code should still
build properly. Also change all source code in the kernel to work
without any of the compatibility macros. This makes it all a less
ambiguous.
I am also renaming st_birthtime to st_birthtim, even though it was a
local extension anyway. It seems Cygwin also has a st_birthtim.
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.
Discussed with: pjd
OSD-based jail extensions. This allows the Linux MIB to accessed via
jail_set and jail_get, and serves as a demonstration of adding jail support
to a module.
Reviewed by: dchagin, kib
Approved by: bz (mentor)
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!)
Inside the kernel, the minor() function was responsible for obtaining
the device minor number of a character device. Because we made device
numbers dynamically allocated and independent of the unit number passed
to make_dev() a long time ago, it was actually a misnomer. If you really
want to obtain the device number, you should use dev2udev().
We already converted all the drivers to use dev2unit() to obtain the
device unit number, which is still used by a lot of drivers. I've
noticed not a single driver passes NULL to dev2unit(). Even if they
would, its behaviour would make little sense. This is why I've removed
the NULL check.
Ths commit removes minor(), minor2unit() and unit2minor() from the
kernel. Because there was a naming collision with uminor(), we can
rename umajor() and uminor() back to major() and minor(). This means
that the makedev(3) manual page also applies to kernel space code now.
I suspect umajor() and uminor() isn't used that often in external code,
but to make it easier for other parties to port their code, I've
increased __FreeBSD_version to 800062.
The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:
- Improved driver model:
The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.
If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.
- Improved hotplugging:
With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).
The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.
- Improved performance:
One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.
Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.
Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan
In the mpsafetty branch, Linux sshd seems to work properly inside a
jail. Some small modifications had to be made to the Linux compatibility
layer.
The Linux PTY routines always expect the device major number to be 136
or higher. Our code always set the major/minor number pair to 136:0.
This makes routines like ttyname() and ptsname() fail, because we'll end
up having ambiguous device numbers.
The conversion was not performed on all *stat() routines, which meant in
some cases the numbers didn't get transformed. By pushing the conversion
into linux_driver_get_major_minor(), the transformation will take place
on all calls.
Approved by: philip (mentor), rdivacky
Without it, code has two problems:
- behaviour of the old and new [l]stat are different with regard of
the /compat/linux
- directly accessing the userspace data from the kernel asks for
the panics.
Reported and tested by: Peter Holm
Reviewed by: rdivacky
MFC after: 3 days
3 arguments, but we had forgotten the second argument. Also make the
Linux statfs64 struct depend on the architecture because it has an
extra 4 bytes padding on amd64 compared to i386.
The three argument fix is from David Taylor, the struct statfs64
stuff is my fault. With this patch I can install i386 Linux matlab
on an amd64 machine.
Submitted by: David Taylor <davidt_at_yadt.co.uk>
Approved by: re (kensmith)
Fixes for 'blocking in fifoor state' problem of LTP tests.
linux_*stat*() functions were opening files with O_RDONLY to get
major/minor pair for char/block special files. Unfortunately,
when these functions are used against fifo, it is blocked forever
because there is no writer. Instead, we only open char/block special
files for major/minor conversion. We have to get rid of kern_open()
entirely from translate_path_major_minor() but today is not the day.
While I am here, add checks for errors before calling
translate_path_major_minor().
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.
This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA
but further on -current (still not successful, but a step into the right
direction).
Sponsored by: Google SoC 2006
Submitted by: rdivacky
Tested by: Paul Mather <paul@gromit.dlib.vt.edu>
Add back in a scheme to emulate old type major/minor numbers via hooks into
stat, linprocfs to return major/minors that Linux app's expect. Currently
only /dev/null is always registered. Drivers can register via the Linux
type shim similar to the ioctl shim but by using
linux_device_register_handler/linux_device_unregister_handler functions.
The structure is:
struct linux_device_handler {
char *bsd_driver_name;
char *linux_driver_name;
char *bsd_device_name;
char *linux_device_name;
int linux_major;
int linux_minor;
int linux_char_device;
};
Linprocfs uses this to display the major number of the driver. The
soon to be available linsysfs will use it to fill in the driver name.
Linux_stat uses it to translate the major/minor into Linux type values.
Note major numbers are dynamically assigned via passing in a -1 for
the major number so we don't need to keep track of them.
This is somewhat needed due to us switching to our devfs. MegaCli
will not run until I add in the linsysfs and mfi Linux compat changes.
Sponsored by: IronPort Systems
linux_ioctl.[ch] : Implement LINUX_TIOCGPTN, which returns the pty number
linux_stats.c :
- Return the magic number for devfs.
- In various stats()-related functions, check that we're stating a
file in /dev/pts, and if so, change the st_rdev field to match what linux
expects to be there for a slave pty device. The glibc checks for this, and
their openpty() fails if it is no correct.
and extend its functionality:
value policy
0 show all mount-points without any restrictions
1 show only mount-points below jail's chroot and show only part of the
mount-point's path (if jail's chroot directory is /jails/foo and
mount-point is /jails/foo/usr/home only /usr/home will be shown)
2 show only mount-point where jail's chroot directory is placed.
Default value is 2.
Discussed with: rwatson
so do not duplicate the code in cvtstatfs().
Note, that we now need to clear fsid in freebsd4_getfsstat().
This moves all security related checks from functions like cvtstatfs()
and will allow to add more security related stuff (like statfs(2), etc.
protection for jails) a bit easier.
The fundamental problem is that we get only the lower 8 bits of the
minor device number so there is no guarantee that we can actually
find the disk device in question at all.
This was probably a bigger issue pre-GEOM where the upper bits
signaled which slice were in use.
The secondary problem is how we get from (partial) dev_t to vnode.
The correct implementation will involve traversing the mount list
looking for a perfect match or a possible match (for truncated
minor).
duplicating the contents of the same functions inline.
- Consolidate common code to convert a BSD statfs struct to a Linux struct
into a static worker function.
on AMD64, and the general case where the emulated platform has different
size pointers than we use natively:
- declare certain structure members as l_uintptr_t and use the new PTRIN
and PTROUT macros to convert to and from native pointers.
- declare some structures __packed on amd64 when the layout would differ
from that used on i386.
- include <machine/../linux32/linux.h> instead of <machine/../linux/linux.h>
if compiling with COMPAT_LINUX32. This will need to be revisited before
32-bit and 64-bit Linux emulation support can coexist in the same kernel.
- other small scattered changes.
This should be a no-op on i386 and Alpha.
The big lines are:
NODEV -> NULL
NOUDEV -> NODEV
udev_t -> dev_t
udev2dev() -> findcdev()
Various minor adjustments including handling of userland access to kernel
space struct cdev etc.
Remove the unused second argument from udev2dev().
Convert all remaining users of makedev() to use udev2dev(). The
semantic difference is that udev2dev() will only locate a pre-existing
dev_t, it will not line makedev() create a new one.
Apart from the tiny well controlled windown in D_PSEUDO drivers,
there should no longer be any "anonymous" dev_t's in the system
now, only dev_t's created with make_dev() and make_dev_alias()
Several of the subtypes have an associated vnode which is used for
stuff like the f*() functions.
By giving the vnode a speparate field, a number of checks for the specific
subtype can be replaced simply with a check for f_vnode != NULL, and
we can later free f_data up to subtype specific use.
At this point in time, f_data still points to the vnode, so any code I
might have overlooked will still work.
do for newstat_copyout().
Lie about disk drives which are character devices
in FreeBSD but block devices under Linux.
PR: 37227
Submitted by: Vladimir B. Grebenschikov <vova@sw.ru>
Reviewed by: phk
MFC after: 2 weeks
