do_ubd is actually just a boolean variable - the way it is used currently is a
leftover from the old 2.4 block layer, but it is still used; its use is
suspicious, but removing it would be too intrusive for now and needs more
thinking.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add some comments about requirements for ubd_io_lock and expand its use.

When an irq signals that the "controller" (i.e.  another thread on the host,
which does the actual requests and is the only one blocked on I/O on the host)
has done some work, we call again the request function ourselves
(do_ubd_request).

We now do that with ubd_io_lock held - that's useful to protect against
concurrent calls to elv_next_request and so on.

XXX: Maybe we shouldn't call at all the request function.  Input needed on
this.  Are we supposed to plug and unplug the queue?  That code "indirectly"
does that by setting a flag, called do_ubd, which makes the request function
return (it's a residual of 2.4 block layer interface).

Meanwhile, however, merge this patch, which improves things.

Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This lock protects ubd setup and teardown, so is only used in process context;
beyond that, during such setup memory allocations must be performed and some
generic functions which can sleep must be called (such as add_disk()).  So the
only correct solution is to make it a mutex instead of a spin_lock.  No other
change is done - this lock must be acquired in different places but it's done
afterwards.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

To rethink locking, I needed to understand well what each function does.
While doing this I renamed some:

* ubd_close -> ubd_close_dev (since it pairs with ubd_open_dev)

* ubd_new_disk -> ubd_disk_register (it handles registration with the block
  layer - one hopes this makes clearer the difference with ubd_add())
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Rename the ubd_dev array to ubd_devs and then call any "struct ubd" ubd_dev
instead of dev, which doesn't make clear what we're treating (and no, it's not
hungarian notation - not any more than calling all vm_area_struct vma or all
inodes inode).
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add documentation about some fields in struct ubd, whose meaning is
non-obvious due to struct names (should change names altogether, I agree).
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

With 256 minors and 16 minors used per each UBD device, we can allow the use
of up to 16 UBD devices per UML.

Also chnage parse_unit and leave to the caller (which already do it) the check
for excess numbers, since this is just supposed to do raw parsing.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

From: Jeff Dike <jdike@addtoit.com>, Paolo Giarrusso <blaisorblade@yahoo.it>

Make sure that when compiling USER_OBJS the correct compilation options are
passed; since they are compiled with USER_CFLAGS which is derived from
CFLAGS, make sure it is a recursively evaluated variable, so that changes
to CFLAGS done afterwards the inclusion of arch/$(ARCH)/Makefile are
reflected in USER_CFLAGS.

For instance, without this patch userspace objects are never compiled with
debug info active.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix commit 5f4c6bc1: it spits out warnings
about missing syscall prototype (it is in <unistd.h>) and it does not
recognize that two uses of _syscallX are to be resolved against kernel
headers in the source tree, not against _syscallX; they in fact do not
compile and would not work anyway.

If _syscallX macros will be removed from the kernel tree altogether, the
only reasonable solution for that piece of code is switching to open-coded
inline assembly (it's remapping the whole executable from memory, except
the page containing this code).
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 * when we have stop/sysrq/go, we get pt_regs of whatever executes
   mc_work_proc().  Would be better to see what we had at the time of
   interrupt that got us stop.

 * stop/stop/stop.....  will give stack overflow.  Shouldn't allow stop
   from mconsole_stop().

 * stop/stop/go leaves us inside mconsole_stop() with
	os_set_fd_block(req->originating_fd, 0);
	reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
   just done by nested mconsole_stop().  Ditto.

 * once we'd seen stop, there's a period when INTR commands are executed
   out of order (as they should; we might have the things stuck badly
   enough to never reach mconsole_stop(), but still not badly enough to
   block mconsole_interrupt(); in that situation we _want_ things like
   "cad" to be executed immediately).  Once we enter monsole_stop(), all
   INTR commands will be executed in order, mixed with PROC ones.  We'd
   better let user see that such change of behaviour has happened.
   (Suggested by lennert).

 * stack footprint of monsole_interrupt() is an atrocity; AFAICS we can
   safely make struct mc_request req; static in function there.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When enabling the mmapper driver I got warnings because this "const"
miscdevice structure is passed to function as non-const pointer; unlike struct
tty_operations, however, I verified that misc_{de,}register _do_ modify their
parameter, so this const attribute must be removed.

Since the purpose of the change was to guarantee that no lock was needed, add
a comment to prove this differently.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Silence useless warning about undefined symbol in Kconfig.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Freeing the stack is left uselessly to the caller of run_helper in some cases
- this is taken from run_helper_thread, but here it is useless, so no caller
needs it and the only place where this happens has a potential leak - in case
of error neither run_helper() nor xterm_open() call free_stack().  At this
point passing a pointer is not needed - the stack pointer should be passed
directly, but this change is not done here.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This should make sure that, for UML, host's configuration files are not
considered, which avoids various pains to the user.  Our dependency are such
that the obtained Kconfig will be valid and will lead to successful
compilation - however they cannot prevent an user from disabling any boot
device, and if an option is not set in the read .config (say
/boot/config-XXX), with make menuconfig ARCH=um, it is not set.  This always
disables UBD and all console I/O channels, which leads to non-working UML
kernels, so this bothers users - especially now, since it will happen on
almost every machine (/boot/config-`uname -r` exists almost on every machine).
 It can be workarounded with make defconfig ARCH=um, but it is non-obvious and
can be avoided, so please _do_ merge this patch.

Given the existence of options, it could be interesting to implement
(additionally) "option required" - with it, Kconfig will refuse reading a
.config file (from wherever it comes) if the given option is not set.  With
this, one could mark with it the option characteristic of the given
architecture (it was an old proposal of Roman Zippel, when I pointed out our
problem):

config UML
	option required
	default y

However this should be further discussed:
*) for x86, it must support constructs like:

==arch/i386/Kconfig==
config 64BIT
	option required
	default n
where Kconfig must require that CONFIG_64BIT is disabled or not present in the
read .config.

*) do we want to do such checks only for the starting defconfig or also for
   .config? Which leads to:
*) I may want to port a x86_64 .config to x86 and viceversa, or even among more
   different archs. Should that be allowed, and in which measure (the user may
   force skipping the check for a .config or it is only given a warning by
   default)?

Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <kbuild-devel@lists.sourceforge.net>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

CONFIG_MODE_TT does not work there, the UML_ prefixed version must be used -
this causes a link-time failure when CONFIG_MODE_TT is enabled (i.e.  always
here, never by Jeff).
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix coding conventions violations is arch/um/os-Linux/helper.c.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

user.h is too generic a header name.  I've split out allocation routines from
it.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/um/sys-x86_64/ptrace.c:20:1: warning: "SC_SS" redefined
In file included from arch/um/include/sysdep/ptrace.h:18,
                 from include/asm/ptrace-generic.h:12,
                 from include/asm/ptrace.h:15,
                 from arch/um/sys-x86_64/ptrace.c:8:
arch/um/include/sysdep/sc.h:38:1: warning: this is the location of the previous definition
arch/um/sys-x86_64/ptrace.c: In function 'putreg':
arch/um/sys-x86_64/ptrace.c:63: warning: implicit declaration of function 'SC_FS_BASE'
arch/um/sys-x86_64/ptrace.c:63: error: invalid lvalue in unary '&'
arch/um/sys-x86_64/ptrace.c:63: warning: implicit declaration of function 'SC_GS_BASE'
arch/um/sys-x86_64/ptrace.c:63: error: invalid lvalue in unary '&'
arch/um/sys-x86_64/ptrace.c: In function 'getreg':
arch/um/sys-x86_64/ptrace.c:101: error: invalid lvalue in unary '&'
arch/um/sys-x86_64/ptrace.c:101: error: invalid lvalue in unary '&'

I'd have to say that the fix for this, for now, is this:

Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I need this patch to get a UML kernel to compile.  This is with the
kernel headers in FC6 which are automatically generated from the kernel
tree.  Some headers are missing but those files don't need them.  At
least it appears so since the resuling kernel works fine.

Tested on x86-64.
Signed-off-by: NUlrich Drepper <drepper@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Now that various memory splits are enabled, add a config option allowing the
user to compile UML for its need - HOST_2G_2G allowed to choose either 3G/1G
or 2G/2G, and enabling it reduced the usable virtual memory.

Detecting this at run time should be implemented in the future, but we must
make the stop-gap measure work well enough (this is valid in _many_ cases).
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Deprecate TT mode in Kconfig so that users won't select it, update the
MODE_SKAS description (it was largely obsolete and misleadin) and btw describe
advantages for high memory usage with CONFIG_STATIC_LINK.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The export is together with the definition, in arch/x86_64/lib/csum-partial.c,
which is compiled in by arch/um/sys-x86_64/Makefile.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Unify macros common to x86 and x86_64 kernel-offsets.h files.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Enable compilation of x86_64 crypto code;, and add the needed constant to make
the code compile again (that macro was added to i386 asm-offsets between
2.6.17 and 2.6.18, in 6c2bb98b).

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Declare UML partial support for LOCKDEP - however IRQFLAGS tracing requires
some coding which nobody did yet, so we cannot run full lockdep on UML.  Grep
for CONFIG_TRACE_IRQFLAGS on i386 code to find their implementation.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On a 64bit Uml, if run under "setarch i386" (which a user did), uname()
currently returns the obtained i686 as machine - fix that.  Btw, I'm quite
surprised that under setarch i386 a 64-bit binary can run.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If enable is moved by GCC in a register its value may not be preserved after
coming back there with longjmp().  So, mark it as volatile to prevent this;
this is suggested (it seems) in info gcc, when it talks about -Wuninitialized.
 I re-read this and it seems to say something different, but I still believe
this may be needed.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make TT mode compile after the introduction of klibc's implementation of
setjmp.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This was forgot in a previous patch so UML does not compile with TT mode
enabled.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Correct commit 5906e417 - this makes more
sense: we turn pte_mkexec + pte_wrprotect to pte_mkread.  However, due to a
bug in pte_mkread, it does the exact same thing as pte_mkwrite, so this patch
improves the code but does not change anything in practice.  The pte_mkread
bug is fixed separately, as it may have big impact.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Andi Kleen pointed out that -mcmodel=kernel does not make sense for userspace
code and would stop everything from working, and pointed out the correct fix
for the original bug (not easy to do for me).

Reverts part of commit 06837504.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use the new typedef for interrupt handler function pointers rather than
actually spelling out the full thing each time.  This was scripted with the
following small shell script:

#!/bin/sh
egrep -nHrl -e 'irqreturn_t[ 	]*[(][*]' $* |
while read i
do
    echo $i
    perl -pi -e 's/irqreturn_t\s*[(]\s*[*]\s*([_a-zA-Z0-9]*)\s*[)]\s*[(]\s*int\s*,\s*void\s*[*]\s*[)]/irq_handler_t \1/g' $i || exit $?
done
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

Real fix for UML pt_regs stuff.  Note set_irq_regs() logics in there...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Fixup broken UML build due to 7d12e780
"IRQ: Maintain regs pointer globally rather than passing to IRQ handlers".

Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo "Blaisorblade" Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kbuild explicitly includes this at build time.
Signed-off-by: NDave Jones <davej@redhat.com>

Signed-off-by: NAdrian Bunk <bunk@stusta.de>

The patch below corrects multiple occurances of "the the"
typos across several files, both in source comments and KConfig files.
There is no actual code changed, only text.  Note this only affects the /arch
directory, and I believe I could find many more elsewhere. :)
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

User mode linux uses _syscallX() to call into the host kernel.  The
recommended way to do this is to use the syscall() function from libc.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>