For a reason currently unknown to us, the qemu-linaro emulator
sometimes produces a Prefetch Abort exception with a fault location
(IFAR) rather different from the location of the instruction being
executed (LR corrected by 4). So far it has been observed in the
__udivmodsi4 routine of various processes, where the fault address is
for the first byte of the next page after the current instruction,
which itself is 44-64 bytes away from the start of that next page.
The affected instruction does not perform any sort of memory access.
Short of debugging qemu-linaro itself, we have no choice but to
disable the assert that previously went off in case the IFAR and
corrected LR are not equal. Since we have not yet observed this case
on actual hardware, the kernel prints a warning when detecting such a
mismatch for the first time. For the qemu-linaro case, the kernel's
actual page fault handling logic already handles this strange case
just fine.
Change-Id: Ibd19e624149ab4e68bfe75b918ec1554b825a431
- fix the reinstallation (preserve-/home) option;
- remove support for just reinstalling the bootloader, as the main
purpose of this option (allowing an upgrade from the old MINIX
boot monitor to the NetBSD bootloader) is no longer needed and was
already broken;
- do not try to copy over /etc/motd.install: it no longer exists.
This resolves issue 106.
Change-Id: Iad3805d86c4806d725f9b285c2d4378670790f78
Currently, the BSD socket API is implemented in libc, translating the
API calls to character driver operations underneath. This approach
has several issues:
- it is inefficient, as most character driver operations are specific
to the socket type, thus requiring that each operation start by
bruteforcing the socket protocol family and type of the given file
descriptor using several system calls;
- it requires that libc itself be changed every time system support
for a new protocol is added;
- various parts of the libc implementations violate the asynchronous
signal safety POSIX requirements.
In order to resolve all these issues at once, the plan is to turn the
BSD socket calls into system calls, thus making the BSD socket API the
"native" ABI, removing the complexity from libc and instead letting
VFS deal with the socket calls.
The overall change is going to break all networking functionality. In
order to smoothen the transition, this patch introduces the fifteen
new BSD socket system calls, and makes libc try these first before
falling back on the old behavior. For now, the VFS implementations of
the new calls fail such that libc will always use the fallback cases.
Later on, when we introduce the actual implementation of the native
BSD socket calls, all statically linked programs will automatically
use the new ABI, thus limiting actual application breakage.
In other words: by itself, this patch does nothing, except add a bit
of transitional overhead that will disappear in the future. The
largest part of the patch is concerned with adding full support for
the new BSD socket system calls to trace(1) - this early addition has
the advantage of making system call tracing output of several socket
calls much more readable already.
Both the system call interfaces and the trace(1) support have already
been tested using code that will be committed later on.
Change-Id: I3460812be50c78be662d857f9d3d6840f3ca917f
The reorganization allows other libc system call wrappers (namely,
sendmsg and recvmsg) to perform I/O vector coalescing as well.
Change-Id: I116b48a6db39439053280ee805e0dcbdaec667a3
There is no reason to use a single message for nonoverlapping requests
and replies combined, and in fact splitting them out allows reuse of
messages and avoids various problems with field layouts. Since the
upcoming socketpair(2) system call will be using the same reply as
pipe2(2), split up the single message used for the latter. In order
to keep the used parts of messages at the front, start a transitional
phase to move the pipe(2) flags field to the front of its request.
Change-Id: If3f1c3d348ec7e27b7f5b7147ce1b9ef490dfab9
Previously, the libc sendto(3) and recvfrom(3) implementations would
blindly assume that any unrecognized socket is a raw-IP socket. This
is not only inconsistent but also messes with returned error codes.
Change-Id: Id0328f04ea8ca0968a4e8636bc441caa0c3579b7
- GCC >4.9:
Newer toolchains trigger more warnings, which by default are
treated as errors. Disable this while building the tools as this
will be a recurring problem in the future.
close#105
- FreeBSD: Fix some fetch.sh scripts which fails as FreeBSD's patch
fails to patch two .info files. We ignore this for the time being.
Change-Id: Ic669281db6c41005119ea8f76f78b5ec60e1b386
While BSD make support both $() and ${} around variables, the NetBSD
source tree uses only ${} by convention.
Imported software is left as is, and sometimes $() is used when the
containing Makefile/Makefile fragment is used both by GNU make and BSD
make, as it can happen for the tools, and other parts as well which are
compiled using the host make tool.
Change-Id: Ic7d480812fde53e7e3e95275a30a3b720c95cc15
At least it works again now. Sprofalyze should be made aware of the
kernel information page, though (i.e., /proc/ipcvecs).
Change-Id: Id4e5f6417ad152607c4e53b323b6f65ea4b10c6e
The NetBSD bootloader attempts to load NetBSD kernel modules for
"unusual" file systems. We do not support NetBSD kernel modules,
and thus, the bootloader gives us warnings about not being able
to load them, in particular when booting CD images. This patch
disables the NetBSD file system module autoload feature.
Change-Id: I55fce53b4bb0282b7d8a005192200fe466312f62
- test3: support running the test set from a pseudoterminal;
- test60: fix number conversion bug that caused chmod errors;
- test65: remove nonworking package installation instructions;
- testisofs: work around failure due to having a timezone set;
- testisofs: exclude extra RR_MOVED directory from output.
Change-Id: Ibfcc631de7e2f4da46bac3ad9de8d7c7cd7a6189
- Fix unmounting order of slices.
- Update pkgin pre-installation commands, make them as generic as
possible.
Change-Id: Ifaa4021fed048facca8d2a170aa65491feb37702
If this directory doesn't exist, pid files are not created, which create
issues when shutting down or rebooting.
Change-Id: I52dddb57aca4368b1775606e22818fba99d05bf6
input() is used to accept filenames when saving, regular
expressions when searching, and other input. It writes
the characters into buffers such as file and exp_buf and
others which are of length LINE_LEN.
To prevent writing beyond the end of the intended buffer,
truncate the input at LINE_LEN - 1 and ensure that the
string is NULL terminated.
Change-Id: I142baa8cfae38bdd7fa648d86559d6d9b8e7a7fd
In order to resolve page faults on file-mapped pages, VM may need to
communicate (through VFS) with a file system. The file system must
therefore not be the one to cause, and thus end up being blocked on,
such page faults. To resolve this potential deadlock, the safecopy
system was previously extended with the CPF_TRY flag, which causes the
kernel to return EFAULT to the caller of a safecopy function upon
getting a pagefault, bypassing VM and thus avoiding the loop. VFS was
extended to repeat relevant file system calls that returned EFAULT,
after resolving the page fault, to keep these soft faults from being
exposed to applications.
However, general UNIX I/O semantics dictate that if an I/O transfer
partially succeeded before running into a failure, the partial result
is to be returned. Proper file system implementations may therefore
end up returning partial success rather than the EFAULT code resulting
from a soft fault. Since VFS does not get the EFAULT code in this
case, it does not know that a soft fault occurred, and thus does not
repeat the call either. The end result is that an application may get
partial I/O results (e.g., a short read(2)) even on regular files.
Applications cannot reasonably be expected to deal with this.
Due to the fact that most of the current file system implementations
do not implement proper partial-failure semantics, this problem is not
yet widespread. In fact, it has only occurred on direct block device
I/O so far. However, the next generation of file system services will
be implementing proper I/O semantics, thus exacerbating the problem.
To remedy this situation, this patch changes the CPF_TRY semantics:
whenever the kernel experiences a soft fault during a safecopy call,
in addition to returning FAULT, the kernel also stores a mark in the
grant created with CPF_TRY. Instead of testing on EFAULT, VFS checks
whether the grant was marked, as part of revoking the grant. If the
grant was indeed marked by the kernel, VFS repeats the file system
operation, regardless of its initial return value. Thus, the EFAULT
code now only serves to make the file system fail the call faster.
The approach is currently supported for both direct and magic grants,
but is used only with magic grants - arguably the only case where it
makes sense. Indirect grants should not have CPF_TRY set; in a chain
of indirect grants, the original grant is marked, as it should be.
In order to avoid potential SMP issues, the mark stored in the grant
is its grant identifier, so as to discard outdated kernel writes.
Whether this is necessary or effective remains to be evaluated.
This patch also cleans up the grant structure a bit, removing reserved
space and thus making the structure slightly smaller. The structure
is used internally between system services only, so there is no need
for binary compatibility.
Change-Id: I6bb3990dce67a80146d954546075ceda4d6567f8
With this change, obtaining an existing free grant is no longer an
operation of O(n) complexity. As a result, the now-deprecated
getgrant/setgrant part of the grants API also no longer has a
performance advantage.
Change-Id: Ic19308a76924c6242f9784244a6b3600e561e0fe
The memory grant identifier for safecopies now includes a sequence
number in its upper bits, to prevent accidental reuse of a grant ID
after revocation and subsequent reallocation. This should increase
overall system robustness by a tiny amount, and possibly help catch
bugs in system services early on. For now, the lower 20 bits of the
grant ID are used as grant table slot index (thus allowing for up to
a million grants per process), and the next 11 bits of the (signed
32-bit) grant ID are used to store the per-slot sequence number. As
grant IDs are never exposed to userland, the split can be changed
later on without breaking the userland ABI.
Change-Id: Ic34be27ff2a45db0ea5db037a24eef9efcd9ca40
Apply the x86 overflow check from git-d09f72c to ARM code as well.
Not just stack traces, but also system services can trigger this
case, possibly as a result of being handed bad pointers by userland,
ending in a kernel panic.
Change-Id: Ib817e8b682fafec8edb486a094319ad11eda7081
Changed all K&R style functions to ANSI-style declarations within the
kernel directory. The code compiles and aparently works for i386. For
arm my toolchain does not work, but I have changed the code with great
care. Also, the make command fails for the test suite. Therefore, I
strongly recommand to review the code with care.
Edited by David van Moolenbroek to convert really all K&R functions.
Change-Id: I58cde797d36f4caa9c72db4e4dc27d8545ab8866
A few MINIX3-specific changes are necessary due to the fact that we
are missing the System V IPC message queue system calls.
Change-Id: Idd252984be9df69618cef79bcf6c676cbf915d85
The kernel.ipc.sysvipc_info node is the gateway from NetBSD ipcs(1)
and ipcrm(1) to the IPC server, and thus necessary for a clean
import of these two utilities. The MIB service implementation uses
the preexisting (Linux-specific) information calls on the IPC server
to obtain the information.
Change-Id: I85d1e193162d6b689f114764254dd7f314d2cfa0
As mentioned in previous patches, services may not subscribe to
process events from specific processes only, since this results in
race conditions. However, the IPC server can safely turn on and off
its entire subscription based on whether any System V IPC semaphores
(and, in the future, message queues) are allocated at all. Since
the System V IPC facilities are not so commonly used, this removes
the extra round trip from PM to the IPC server and back for caught
signals and process exits in the common case.
Change-Id: I937259034872be32f4e26ab99270f4d475ff6134
- rewrite the semop(2) implementation so that it now conforms to the
specification, including atomicity, support for blocking more than
once, range checks, but also basic fairness support;
- fix permissions checking;
- fix missing time adjustments;
- fix off-by-one errors and other bugs;
- do not allocate dynamic memory for GETALL/SETALL;
- add test88, which properly tests the semaphore functionality.
Change-Id: I85f0d3408c0d6bba41cfb4c91a34c8b46b2a5959
Now that there are services other than PM and VFS that implement
userland system calls directly, these services may need to know about
events related to user processes. In particular, signal delivery may
have to interrupt blocking system calls, and certain cleanup tasks may
have to be performed after a user process exits.
This patch aims to implement a generic, lasting solution for this
problem, by allowing services to subscribe to "signal delivered"
and/or "process exit" events from PM. PM publishes such events by
sending messages to its subscribed services, which must then reply an
acknowledgment message.
For now, only the two aforementioned events are implemented, and only
the IPC service makes use of the process event facility.
The new process event publish/subscribe system replaces the previous
VM notify-sig/watch-exit/query-exit system, which was unsound: 1) it
allowed subscription to events from individual processes, and suffered
from fundamental race conditions as a result; 2) it relied on "not too
many" processes making use of the IPC server functionality in order to
avoid loss of notifications. In addition, it had the "ipc" process
name hardcoded, did not distinguish between signal delivery and exits,
and added a roundtrip to VM for all events from all processes.
Change-Id: I75ebad4bc54e646c6433f473294cb4003b2c3430
Closer to KNF, better coding practices, more similar to other
services, no more global variables, a few more comments, that
kind of stuff. No major functional changes.
Change-Id: I6e8f53bfafd6f41e92031fba76c40a31d2107a8e
- switch to the NetBSD identifier system; it is not only better, but
also required for porting NetBSD ipcs(1) and ipcrm(1); however, it
requires that slots not be moved, and that results in some changes;
- synchronize some other things with NetBSD: where keys are kept, as
well as various non-permission mode flags;
- fix semctl(2) vararg retrieval and message field type;
- use SUSPEND instead of weird reply exceptions in the call table;
- fix several memory leaks and at least one missing permission check;
- improve the atomicity of semop(2) by a small amount, even though
its atomicity is still broken at a fundamental level;
- use the new cheaper way to retrieve the current time;
- resolve all level-5 LLVM warnings.
Change-Id: I0c47aacde478b23bb77d628384aeab855a22fdbf
Specifically, add support for the IPC_INFO, SEM_INFO, and SEM_STAT
semctl(2) operations, similar to how information about shared memory
is already exposed as well. The MINIX3 ipcs(1) utility already had
support for these operations, and can now actually use them, too.
Change-Id: Ice5a02e729bf6df6aa8fab76e854808adc04dae3
- About 80% of PM's process table consisted of per-signal sigaction
structures. This is information not used by the MIB service, and
can safely be stored outside the main process table.
- The MIB service does not need most of the VFS process table, so VFS
now generates a "light" version of its table upon request, with just
the fields used by the MIB service.
The result is a size reduction of the MIB service of about 700KB.
Change-Id: I79fe7239361fbfb45286af8e86a10aed4c2d2be7
