This patch employs one solution to resolve two independent but related
issues. Both issues are the result of one fundamental aspect of the
way VM's memory mapping works: VM uses its cache to map in blocks for
memory-mapped file regions, and for blocks already in the VM cache, VM
does not go to the file system before mapping them in. To preserve
consistency between the FS and VM caches, VM relies on being informed
about all updates to file contents through the block cache. The two
issues are both the result of VM not being properly informed about
such updates:
1. Once a file system provides libminixfs with an inode association
(inode number + inode offset) for a disk block, this association
is not broken until a new inode association is provided for it.
If a block is freed and reallocated as a metadata (non-inode)
block, its old association is maintained, and may be supplied to
VM's secondary cache. Due to reuse of inodes, it is possible
that the same inode association becomes valid for an actual file
block again. In that case, when that new file is memory-mapped,
under certain circumstances, VM may end up using the metadata
block to satisfy a page fault on the file, due to the stale inode
association. The result is a corrupted memory mapping, with the
application seeing data other than the current file contents
mapped in at the file block.
2. When a hole is created in a file, the underlying block is freed
from the device, but VM is not informed of this update, and thus,
if VM's cache contains the block with its previous inode
association, this block will remain there. As a result, if an
application subsequently memory-maps the file, VM will map in the
old block at the position of the hole, rather than an all-zeroes
block. Thus, again, the result is a corrupted memory mapping.
This patch resolves both issues by making the file system inform the
minixfs library about blocks being freed, so that libminixfs can
break the inode association for that block, both in its own cache and
in the VM cache. Since libminixfs does not know whether VM has the
block in its cache or not, it makes a call to VM for each block being
freed. Thus, this change introduces more calls to VM, but it solves
the correctness issues at hand; optimizations may be introduced
later. On the upside, all freed blocks are now marked as clean,
which should result in fewer blocks being written back to the device,
and the blocks are removed from the caches entirely, which should
result in slightly better cache usage.
This patch is necessary but not sufficient to resolve the situation
with respect to memory mapping of file holes in general. Therefore,
this patch extends test 74 with a (rather particular but effective)
test for the first issue, but not yet with a test for the second one.
This fixes#90.
Change-Id: Iad8b134d2f88a884f15d3fc303e463280749c467
This patch adds support for Unix98 pseudo terminals, that is,
posix_openpt(3), grantpt(3), unlockpt(3), /dev/ptmx, and /dev/pts/.
The latter is implemented with a new pseudo file system, PTYFS.
In effect, this patch adds secure support for unprivileged pseudo
terminal allocation, allowing programs such as tmux(1) to be used by
non-root users as well. Test77 has been extended with new tests, and
no longer needs to run as root.
The new functionality is optional. To revert to the old behavior,
remove the "ptyfs" entry from /etc/fstab.
Technical nodes:
o The reason for not implementing the NetBSD /dev/ptm approach is that
implementing the corresponding ioctl (TIOCPTMGET) would require
adding a number of extremely hairy exceptions to VFS, including the
PTY driver having to create new file descriptors for its own device
nodes.
o PTYFS is required for Unix98 PTYs in order to avoid that the PTY
driver has to be aware of old-style PTY naming schemes and even has
to call chmod(2) on a disk-backed file system. PTY cannot be its
own PTYFS since a character driver may currently not also be a file
system. However, PTYFS may be subsumed into a DEVFS in the future.
o The Unix98 PTY behavior differs somewhat from NetBSD's, in that
slave nodes are created on ptyfs only upon the first call to
grantpt(3). This approach obviates the need to revoke access as
part of the grantpt(3) call.
o Shutting down PTY may leave slave nodes on PTYFS, but once PTY is
restarted, these leftover slave nodes will be removed before they
create a security risk. Unmounting PTYFS will make existing PTY
slaves permanently unavailable, and absence of PTYFS will block
allocation of new Unix98 PTYs until PTYFS is (re)mounted.
Change-Id: I822b43ba32707c8815fd0f7d5bb7a438f51421c1
Bochs has switched from port base 0x240 to 0x300 for its default
NE2000 ISA configuration, and QEMU is using the same settings.
Change-Id: Ide6cdb14321eb4324d0bf6d6314c5970b3493e95
This patch adds (very limited) support for memory-mapping pages on
file systems that are mounted on the special "none" device and that
do not implement PEEK support by themselves. This includes hgfs,
vbfs, and procfs.
The solution is implemented in libvtreefs, and consists of allocating
pages, filling them with content by calling the file system's READ
functionality, passing the pages to VM, and freeing them again. A new
VM flag is used to indicate that these pages should be mapped in only
once, and thus not cached beyond their single use. This prevents
stale data from getting mapped in without the involvement of the file
system, which would be problematic on file systems where file contents
may become outdated at any time. No VM caching means no sharing and
poor performance, but mmap no longer fails on these file systems.
Compared to a libc-based approach, this patch retains the on-demand
nature of mmap. Especially tail(1) is known to map in a large file
area only to use a small portion of it.
All file systems now need to be given permission for the SETCACHEPAGE
and CLEARCACHE calls to VM.
A very basic regression test is added to test74.
Change-Id: I17afc4cb97315b515cad1542521b98f293b6b559
import/switch of:
init, getty, reboot, halt, shutdown, wall, last
changes:
. change reboot() call to netbsd prototype and args
. allows pristine <utmp.h>
. use clean <sys/reboot.h> instead of <minix/reboot.h>
. implement TIOCSCTTY for use by getty so getty can get
controlling terminal from init's child(ren)
. allow NULL envp for exec
Change-Id: I5ca02cb4230857140c08794bbfeba7df982c58a3
- introduce new call numbers, names, and field aliases;
- initialize request messages to zero for all ABI calls;
- format callnr.h in the same way as com.h;
- redo call tables in both servers;
- remove param.h namespace pollution in the servers;
- make brk(2) go to VM directly, rather than through PM;
- remove obsolete BRK, UTIME, and WAIT calls;
- clean up path copying routine in VFS;
- move remaining system calls from libminlib to libc;
- correct some errno-related mistakes in libc routines.
Change-Id: I2d8ec5d061cd7e0b30c51ffd77aa72ebf84e2565
This single function allows copying file descriptors from and to
processes, and closing a previously copied remote file descriptor.
This function replaces the five FD-related UDS backcalls. While it
limits the total number of in-flight file descriptors to OPEN_MAX,
this change greatly improves crash recovery support of UDS, since all
in-flight file descriptors will be closed instead of keeping them
open indefinitely (causing VFS to crash on system shutdown). With the
new copyfd call, UDS becomes simpler, and the concept of filps is no
longer exposed outside of VFS.
This patch also moves the checkperms(2) stub into libminlib, thus
fully abstracting away message details of VFS communication from UDS.
Change-Id: Idd32ad390a566143c8ef66955e5ae2c221cff966
- remove non-PCI support, since all supported platforms with at_wini
devices also have PCI support by now;
- correspondingly, stop using information from the BIOS altogether;
- limit each driver instance to one controller, to be in line with
the general MINIX3 one-instance-per-controller driver model; this
limits the number of disks per at_wini instance to four;
- go through the controllers by the order of their occurrence in the
PCI table, thus removing the exception for compatibility devices;
- let the second at_wini instance shut down silently if there is only
one IDE controller;
- clean up some extra code we don't need anymore, and resolve some
WARNS=5 level warnings.
Overall, these changes should simplify automatic loading of the right
disk drivers at boot time in the future.
Change-Id: Ia64d08cfbeb9916abd68c9c2941baeb87d02a806
- change "vid/did" to "vid:did", old form still supported for now;
- allow "vid:did/subvid:subdid" specification in system.conf, in
which case a device will be visible to a driver if the subsystem
VID/DID also match.
Change-Id: I7aef54da1b0bc81e24b5d98f1a28416f38f8b266
This commit separates the low-level keyboard driver from TTY, putting
it in a separate driver (PCKBD). The commit also separates management
of raw input devices from TTY, and puts it in a separate server
(INPUT). All keyboard and mouse input from hardware is sent by drivers
to the INPUT server, which either sends it to a process that has
opened a raw input device, or otherwise forwards it to TTY for
standard processing.
Design by Dirk Vogt. Prototype by Uli Kastlunger.
Additional changes made to the prototype:
- the event communication is now based on USB HID codes; all input
drivers have to use USB codes to describe events;
- all TTY keymaps have been converted to USB format, with the effect
that a single keymap covers all keys; there is no (static) escaped
keymap anymore;
- further keymap tweaks now allow remapping of literally all keys;
- input device renumbering and protocol rewrite;
- INPUT server rewrite, with added support for cancel and select;
- PCKBD reimplementation, including PC/AT-to-USB translation;
- support for manipulating keyboard LEDs has been added;
- keyboard and mouse multiplexer devices have been added to INPUT,
primarily so that an X server need only open two devices;
- a new "libinputdriver" library abstracts away protocol details from
input drivers, and should be used by all future input drivers;
- both INPUT and PCKBD can be restarted;
- TTY is now scheduled by KERNEL, so that it won't be punished for
running a lot; without this, simply running "yes" on the console
kills the system;
- the KIOCBELL IOCTL has been moved to /dev/console;
- support for the SCANCODES termios setting has been removed;
- obsolete keymap compression has been removed;
- the obsolete Olivetti M24 keymap has been removed.
Change-Id: I3a672fb8c4fd566734e4b46d3994b4b7fc96d578
Not all services involved in block I/O go through VM to access the
blocks they need. As a result, the blocks in VM may become stale,
possibly causing corruption when the stale copy is restored by a
service that does go through VM later on. This patch restores support
for forgetting cached blocks that belong to a particular device, and
makes the relevant file systems use this functionality 1) when
requested by VFS through REQ_FLUSH, and 2) upon unmount.
Change-Id: I0758c5ed8fe4b5ba81d432595d2113175776aff8
* port libgpio to am335x.
* increase NR_IRQ to 16 to avoid too many IRQs requested error.
* move gpio binary to /sbin (that's where mount looks for drivers).
* fix bug that re-enabled banks that were disabled due to bad revision.
* fix padconf masks for dm37xx in gpio driver (should be 16-bit).
* fix a few typos in README.txt and comments.
Change-Id: I32374415a97135174c5224f76374a870909fa90c
On the AM335X, writes to the padconf registers must be done in privileged
mode. To allow userspace drivers to dynamically change the padconf at
runtime, a kernel call has been added.
Change-Id: I4b25d2879399b1785a360912faa0e90b5c258533
Use EDID when available to configure the frame buffer driver with
good settings for the attached display.
Change-Id: I69a78155a93e55ffa1ca3ff6621a879a56cdbceb
Add support for getting/setting the am335x SoC's internal real
time clock. Also, allow the power off alarm to be set.
Make readclock an "always on" driver. This is needed for setting
power-off alarms whenever the power button is pressed on the BBB.
Replace the readclock.sh script & single run driver with a
readclock program that takes the same arguments and forwards
the requests on to the always up readclock driver.
Change-Id: Ifd6c2acd80ae4b5e79d83df510df445c24e24a71
Increase driver process priority to prevent starvation. Without
special attribute drivers will have the same priority as other
userland processes this. Posix test 1 was taking so much resources
that it triggered alarms in the MMC driver.
Change-Id: Icd3295d8f2a4a284418327a3715641fe9a3b3043
. libc: add vfs_mmap, a way for vfs to initiate mmap()s.
This is a good special case to have as vfs is a slightly
different client from regular user processes. It doesn't do it
for itself, and has the dev & inode info already so the callback
to VFS for the lookup isn't necessary. So it has different info
to have to give to VM.
. libc: also add minix_mmap64() that accepts a 64-bit offset, even
though our off_t is still 32 bit now.
. On exec() time, try to mmap() in the executable if available.
(It is not yet available in this commit.)
. To support mmap(), add do_vm_call that allows VM to lookup
(to ino+dev), do i/o from and close FD's on behalf of other
processes.
Change-Id: I831551e45a6781c74313c450eb9c967a68505932
Primary purpose of change: to support the mmap implementation, VM must
know both (a) about some block metadata for FS cache blocks, i.e.
inode numbers and inode offsets where applicable; and (b) know about
*all* cache blocks, i.e. also of the FS primary caches and not just
the blocks that spill into the secondary one. This changes the
interface and VM data structures.
This change is only for the interface (libminixfs) and VM data
structures; the filesystem code is unmodified, so although the
secondary cache will be used as normal, blocks will not be annotated
with inode information until the FS is modified to provide this
information. Until it is modified, mmap of files will fail gracefully
on such filesystems.
This is indicated to VFS/VM by returning ENOSYS for REQ_PEEK.
Change-Id: I1d2df6c485e6c5e89eb28d9055076cc02629594e
This patch introduces a framebuffer to Minix. It's written for the ARM
port of Minix, but has an architectural split that separates the
hardware dependent part from the non-hardware dependent part. Futhermore,
this driver was developed using a screen that has a native resolution of
1024x600 pixels and having lack of support for obtaining EDID from the
screen. Consequently, it uses a hardcoded resolution of 1024x600.
The driver uses an interface based on the Linux ioctl API, but supports
only a very limited subset.
* Generalize GPIO handling.
* Add libs to configure gpio's clocks and pads
* Add Interrupt handling.
* Introduce mmio.h and log.h
Change-Id: I928e4c807d15031de2eede4b3ecff62df795f8ac
* let busy loops timeout.
* Start using interrupt handlers.
* Allocate the ramdisk only when used.
Change-Id: Ie08d66eefef3c8cd3ee16c04f74a9a50cc12b021
Small GPIO driver that exports a few pins using a virtual file
system. Currently the two user leds and the user button are exported.
Change-Id: I001d017ae27cd17b635587873f7da981054da459
. new mode for sys_memset: include process so memset can be
done in physical or virtual address space.
. add a mode to mmap() that lets a process allocate uninitialized
memory.
. this allows an exec()er (RS, VFS, etc.) to request uninitialized
memory from VM and selectively clear the ranges that don't come
from a file, leaving no uninitialized memory left for the process
to see.
. use callbacks for clearing the process, clearing memory in the
process, and copying into the process; so that the libexec code
can be used from rs, vfs, and in the future, kernel (to load vm)
and vm (to load boot-time processes)
these two functions will be used to support all exec() functionality
going into a single library shared by RS and VFS and exec() knowledge
leaving VM.
. third-party mmap: allow certain processes (VFS, RS) to
do mmap() on behalf of another process
. PROCCTL: used to free and clear a process' address space
. readbios call is now a physical copy with range check in
the kernel call instead of BIOS_SEG+umap_bios
. requires all access to physical memory in bios range to go
through sys_readbios
. drivers/dpeth: wasn't using it
. adjusted printer
