Cleanup, mostly style violations.

Tidied the includes.

getmaster returns a real errno, which pty_open returns if there's a
problem.

The printks now have severity.

Changed os_* calls to call libc directly.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Major tidying of the xterm console driver:
	got rid of the tt-mode gdb support
	tidied up the includes
	fixed lots of style violations
	replaced os_* calls with glibc calls in xterm.c
	all printk calls now have a severity indicator
	the error paths of xterm_open are closer to being right
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

DEBUG_SHIRQ generates spurious interrupts, triggering handlers such as
mconsole_interrupt() or line_interrupt().  They expect data to be available to
be read from their sockets/pipes, but in the case of spurious interrupts, the
host didn't actually send anything, so UML hangs in read() and friends.
Setting those fd's as O_NONBLOCK makes DEBUG_SHIRQ-enabled UML kernels boot
and run correctly.
Signed-off-by: NEduard-Gabriel Munteanu <maxdamage@aladin.ro>
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add generic exit-time stack-depth checking to CONFIG_DEBUG_STACK_USAGE.

This also adds UML support.

Tested on UML and i386.

[akpm@linux-foundation.org: cleanups, speedups, tweaks]
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It is theoretically possible for a request to finish and be freed between
writing it to the I/O thread and updating the sector count.  In this case, the
update will dereference a freed pointer.

To avoid this, I delay the update until processing the next sg segment, when
the request pointer is known to be good.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Distros seem to be removing PAGE_SIZE from asm/page.h.  So, the libc side of
UML should stop using it.

I replace it with UM_KERN_PAGE_SIZE, which is defined to be the same as
PAGE_SIZE on the kernel side of the house.  I could also use getpagesize(),
but it's more important that UML have the same value of PAGE_SIZE everywhere.
It's conceivable that it could be built with a larger PAGE_SIZE, and use of
getpagesize() would break that badly.

PAGE_MASK got the same treatment, as it is closely tied to PAGE_SIZE.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Include linux/kernel.h wherever simple_strtoul is used.  This kills a
compile warning in stderr_console.c and potential ones in the other files.

This also fixes a bunch of style violations in exitcode.c.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Force KERNEL_STACK_ORDER to be at least 1 on UML/x86_64, to avoid overflows.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make the PTRACE_SYSEMU checking more robust.  It will make sure that system
call numbers are reported correctly.  If there is a problem, it will disable
PTRACE_SYSEMU use and use PTRACE_SYSCALL instead.

Thanks to Balaji G for helping reproduce this problem.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With this consolidation we can now modify the .data
section definition in one spot for all archs.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Move definition of .text section to asm-generic.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

__NR_syscall_max is done in x86_64 asm-offsets; do an equivalent in
uml kern_constants.h
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make kernel stacks be 1 page on i386 and 2 pages on x86_64.  These match the
host values.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a separate IRQ stack.  This differs from i386 in having the entire
interrupt run on a separate stack rather than starting on the normal kernel
stack and switching over once some preparation has been done.  The underlying
mechanism, is of course, sigaltstack.

Another difference is that interrupts that happen in userspace are handled on
the normal kernel stack.  These cause a wait wakeup instead of a signal
delivery so there is no point in trying to switch stacks for these.  There's
no other stuff on the stack, so there is no extra stack consumption.

This quirk makes it possible to have the entire interrupt run on a separate
stack - process preemption (and calls to schedule()) happens on a normal
kernel stack.  If we enable CONFIG_PREEMPT, this will need to be rethought.

The IRQ stack for CPU 0 is declared in the same way as the initial kernel
stack.  IRQ stacks for other CPUs will be allocated dynamically.

An extra field was added to the thread_info structure.  When the active
thread_info is copied to the IRQ stack, the real_thread field points back to
the original stack.  This makes it easy to tell where to copy the thread_info
struct back to when the interrupt is finished.  It also serves as a marker of
a nested interrupt.  It is NULL for the first interrupt on the stack, and
non-NULL for any nested interrupts.

Care is taken to behave correctly if a second interrupt comes in when the
thread_info structure is being set up or taken down.  I could just disable
interrupts here, but I don't feel like giving up any of the performance gained
by not flipping signals on and off.

If an interrupt comes in during these critical periods, the handler can't run
because it has no idea what shape the stack is in.  So, it sets a bit for its
signal in a global mask and returns.  The outer handler will deal with this
signal itself.

Atomicity is had with xchg.  A nested interrupt that needs to bail out will
xchg its signal mask into pending_mask and repeat in case yet another
interrupt hit at the same time, until the mask stabilizes.

The outermost interrupt will set up the thread_info and xchg a zero into
pending_mask when it is done.  At this point, nested interrupts will look at
->real_thread and see that no setup needs to be done.  They can just continue
normally.

Similar care needs to be taken when exiting the outer handler.  If another
interrupt comes in while it is copying the thread_info, it will drop a bit
into pending_mask.  The outer handler will check this and if it is non-zero,
will loop, set up the stack again, and handle the interrupt.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some tidying of the irq code before introducing irq stacks.  Mostly
style fixes, but the timer handler calls the timer code directly
rather than going through the generic sig_handler_common_skas.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that we have UM_THREAD_SIZE, we can replace the calculations in
user-space code (an earlier patch took care of the kernel side of the
house).
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replaced task_protections with stack_protections since they do the same
thing, and task_protections was misnamed anyway.

This needs THREAD_SIZE, so that's imported via common-offsets.h

Also tidied up the code in the vicinity.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These haven't been fixed for ages.  Just make comments out of them.

arch/um/kernel/skas/process.c:181:2: warning: #warning Need to look up
+userspace_pid by cpu
arch/um/kernel/skas/process.c:187:2: warning: #warning Need to look up
+userspace_pid by cpu
arch/um/kernel/skas/process.c:194:2: warning: #warning need to loop over
+userspace_pids in kill_off_processes_skas
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mark another function as tt-mode only.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Enable (i)SCSI on UML, dunno why SCSI was deemed broken, it works like a
charm.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many files include the filename at the beginning, serveral used a wrong one.
Signed-off-by: NUwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Allow a pcap device to be assigned a MAC on the command line.  They don't
really need one, but it is handy to be able to do when your distro assigns a
new ethernet device whenever it sees a new MAC.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some network device cleanup.

When setup_etheraddr found a globally valid MAC being assigned to an
interface, it went ahead and used it rather than assigning a random MAC like
the other cases do.  This isn't really an error like the others, but it seems
consistent to make it behave the same.

We were getting some duplicate kfree() in the error case in eth_configure
because platform_device_unregister frees buffers that the error cases
following tried to free again.

The pcap initialization routine wasn't doing the proper printk of its
information, causing a printk of the first part of that line to be
unterminated by a newline.

The pcap code had a bunch of style violations, which are now fixed.

pcap_setup wasn't returning false when it detected an unrecognized
option.

The printks in pcap_user all got UM_KERN_BLAH prepended to their
format strings.

pcap_remove now checks for a non-NULL pcap structure before it calls
pcap_close.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Acked-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ever-vigilant users of linode.com noticed that an idle 2.6 UML has a
persistent load average of ~.4.

It turns out that because the UML timer handler processed softirqs before
actually delivering the tick, the tick was counted in the context of the idle
thread about half the time.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Declare strlcpy and strlcat more correctly.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the current timekeeping, !CONFIG_UML_REAL_TIME_CLOCK has
inconsistent behavior.  Previously, gettimeofday could be (and was)
isolated from the clock ticking.  Now, it's not, so when
CONFIG_UML_REAL_TIME_CLOCK is disabled, gettimeofday must progress in
lockstep with the clock, making it fully virtual.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It turns out that the message complaining about a lack of tmpfs space
on the host can be misunderstood as referring to the UML.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When doing a full address space flush, only look at areas covered by a VMA.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

More trimming of the page fault path.

Permissions are passed around in a single int rather than one bit per
int.  The permission values are copied from libc so that they can be
passed to mmap and mprotect without any further conversion.

The register sets used by do_syscall_stub and copy_context_skas0 are
initialized once, at boot time, rather than once per call.

wait_stub_done checks whether it is getting the signals it expects by
comparing the wait status to a mask containing bits for the signals of
interest rather than comparing individually to the signal numbers.  It
also has one check for a wait failure instead of two.  The caller is
expected to do the initial continue of the stub.  This gets rid of an
argument and some logic.  The fname argument is gone, as that can be
had from a stack trace.

user_signal() is collapsed into userspace() as it is basically one or
two lines of code afterwards.

The physical memory remapping stuff is gone, as it is unused.

flush_tlb_page is inlined.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I missed removing another piece of debugging in an earlier patch.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Give the page fault code a specialized path.  There is only one page to look
at, so there's no point in going into the general page table walking code.
There's only going to be one host operation, so there are no opportunities for
merging.  So, we go straight to the pte we want, figure out what needs doing,
and do it.

While I was in here, I fixed the wart where the address passed to unmap was a
void *, but an unsigned long to map and protect.

This gives me just under 10% on a kernel build.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Allow deadlocks to be avoided in the AIO code by setting the pipe to the I/O
thread non-blocking.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename os_{read_write}_file_k back to os_{read_write}_file, delete
the originals and their bogus infrastructure, and fix all the callers.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I accidentally left the remnants of some debugging in an earlier patch.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Formatting fixes ahead of renaming os_{read_write}_file_k to
os_{read_write}_file and fixing all the callers.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert all remaining os_{read_write}_file users to use the simple
{read,write} wrappers, os_{read_write}_file_k.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Code running on the initial UML stack can't receive or process signals since
current must be valid when IRQs are handled, and there is no current for this
stack.

So, instead of using UML_LONGJMP and UML_SETJMP, which are careful to save and
restore signal state, and, as a side-effect, handle any deferred signals,
start_idle_thread must use the bare equivalents, which don't do anything with
signals.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Dump core after a panic.  This will provide better debugging information than
is currently available.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sanitise gfp flags; it actually is an atomic context, so drop the
GFP_KERNEL part.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Instead of writing entire structures between UML and the I/O thread, we send
pointers.  This cuts down on the amount of data being copied and possibly
allows more requests to be pending between the two.

This requires that the requests be kmalloced and freed instead of living on
the stack.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>