Commit Graph

317 Commits

Author SHA1 Message Date
Benjamin Herrenschmidt 9e1b32caa5 mm: Pass virtual address to [__]p{te,ud,md}_free_tlb()
mm: Pass virtual address to [__]p{te,ud,md}_free_tlb()

Upcoming paches to support the new 64-bit "BookE" powerpc architecture
will need to have the virtual address corresponding to PTE page when
freeing it, due to the way the HW table walker works.

Basically, the TLB can be loaded with "large" pages that cover the whole
virtual space (well, sort-of, half of it actually) represented by a PTE
page, and which contain an "indirect" bit indicating that this TLB entry
RPN points to an array of PTEs from which the TLB can then create direct
entries. Thus, in order to invalidate those when PTE pages are deleted,
we need the virtual address to pass to tlbilx or tlbivax instructions.

The old trick of sticking it somewhere in the PTE page struct page sucks
too much, the address is almost readily available in all call sites and
almost everybody implemets these as macros, so we may as well add the
argument everywhere. I added it to the pmd and pud variants for consistency.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: David Howells <dhowells@redhat.com> [MN10300 & FRV]
Acked-by: Nick Piggin <npiggin@suse.de>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-27 12:10:38 -07:00
Peter Zijlstra c99e6efe1b sched: INIT_PREEMPT_COUNT
Pull the initial preempt_count value into a single
definition site.

Maintainers for: alpha, ia64 and m68k, please have a look,
your arch code is funny.

The header magic is a bit odd, but similar to the KERNEL_DS
one, CPP waits with expanding these macros until the
INIT_THREAD_INFO macro itself is expanded, which is in
arch/*/kernel/init_task.c where we've already included
sched.h so we're good.

Cc: tony.luck@intel.com
Cc: rth@twiddle.net
Cc: geert@linux-m68k.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10 14:24:05 -07:00
Paul Menage ab420e6d9c UML: Fix some apparent bitrot
UML: Fix some apparent bitrot

- migration of net_device methods into net_device_ops
- dma_sync_single() changes

Signed-off-by: Paul Menage <menage@google.com>
Acked-by: Amerigo Wang <xiyou.wangcong@gmail.com>
--

This version is split from my earlier patch, including just the
portions that ar required for Linus' tree.

Fixes the following compile errors:

include/linux/dma-mapping.h:113: error: redefinition of 'dma_sync_single'
arch/um/include/asm/dma-mapping.h:84: error: previous definition of 'dma_sync_single' was here
include/linux/dma-mapping.h: In function 'dma_sync_single':
include/linux/dma-mapping.h:117: error: implicit declaration of function 'dma_sync_single_for_cpu'
include/linux/dma-mapping.h: At top level:
include/linux/dma-mapping.h:120: error: redefinition of 'dma_sync_sg'
arch/um/include/asm/dma-mapping.h:91: error: previous definition of 'dma_sync_sg' was here
include/linux/dma-mapping.h: In function 'dma_sync_sg':
include/linux/dma-mapping.h:124: error: implicit declaration of function 'dma_sync_sg_for_cpu'

arch/um/drivers/slirp_kern.c: In function 'slirp_init':
arch/um/drivers/slirp_kern.c:35: error: 'struct net_device' has no member named 'init'
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-25 11:22:13 -07:00
Geert Uytterhoeven ae52bb2384 fbdev: move logo externs to header file
Now we have __initconst, we can finally move the external declarations for
the various Linux logo structures to <linux/linux_logo.h>.

James' ack dates back to the previous submission (way to long ago), when the
logos were still __initdata, which caused failures on some platforms with some
toolchain versions.

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: James Simmons <jsimmons@infradead.org>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:57 -07:00
Alan Cox 7e1cb78045 uml: UML net driver does not allow for vlans
See ancient discussion at
http://marc.info/?l=user-mode-linux-devel&m=101990155831279&w=2

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=7854

Signed-off-by: Alan Cox <alan@linux.intel.com>
Reported-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Roland Kletzing <devzero@web.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:46 -07:00
Linus Torvalds cd166bd0dd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  add generic lib/checksum.c
  asm-generic: add a generic uaccess.h
  asm-generic: add generic NOMMU versions of some headers
  asm-generic: add generic atomic.h and io.h
  asm-generic: add legacy I/O header files
  asm-generic: add generic versions of common headers
  asm-generic: make bitops.h usable
  asm-generic: make pci.h usable directly
  asm-generic: make get_rtc_time overridable
  asm-generic: rename page.h and uaccess.h
  asm-generic: rename atomic.h to atomic-long.h
  asm-generic: add a generic unistd.h
  asm-generic: add generic ABI headers
  asm-generic: add generic sysv ipc headers
  asm-generic: introduce asm/bitsperlong.h
  asm-generic: rename termios.h, signal.h and mman.h
2009-06-12 18:15:51 -07:00
Magnus Damm 1380a37e3d PM: Remove unused asm/suspend.h
This patch removes unused asm/suspend.h files for
the following architectures:

 alpha, arm, ia64, m68k, mips, s390, um

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-06-12 21:32:31 +02:00
Amerigo Wang c398df30d5 module: merge module_alloc() finally
As Christoph Hellwig suggested, module_alloc() actually can be
unified for i386 and x86_64 (of course, also UML).

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: 'Ingo Molnar' <mingo@elte.hu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 21:47:03 +09:30
Arnd Bergmann 5b17e1cd89 asm-generic: rename page.h and uaccess.h
The current asm-generic/page.h only contains the get_order
function, and asm-generic/uaccess.h only implements
unaligned accesses. This renames the file to getorder.h
and uaccess-unaligned.h to make room for new page.h
and uaccess.h file that will be usable by all simple
(e.g. nommu) architectures.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2009-06-11 21:02:17 +02:00
Ingo Molnar 8302294f43 Merge branch 'tracing/core-v2' into tracing-for-linus
Conflicts:
	include/linux/slub_def.h
	lib/Kconfig.debug
	mm/slob.c
	mm/slub.c
2009-04-02 00:49:02 +02:00
WANG Cong 65bd6a9bc7 uml: remove useless comments
These comments are useless now, remove them.

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:17 -07:00
Stephen Hemminger cfa8707aa6 uml: convert network device to internal network device stats
Convert the UML network device to use internal network device stats.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-27 00:46:39 -07:00
Uwe Kleine-Koenig c79a61f557 tracing: make CALLER_ADDRx overwriteable
The current definition of CALLER_ADDRx isn't suitable for all platforms.
E.g. for ARM __builtin_return_address(N) doesn't work for N > 0 and
AFAIK for powerpc there are no frame pointers needed to have a working
__builtin_return_address.  This patch allows defining the CALLER_ADDRx
macros in <asm/ftrace.h> and let these take precedence.

Because now <asm/ftrace.h> is included unconditionally in
<linux/ftrace.h> all archs that don't already had this include get an
empty one for free.

Signed-off-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-02 16:49:37 -05:00
Al Viro 7483cb7bbc uml got broken by commit 30742d5c22
... if you revert a commit, revert the fixups elsewhere that had been
triggered by it.  Such as 8c56250f48
(lockdep, UML: fix compilation when CONFIG_TRACE_IRQFLAGS_SUPPORT is not set).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-05 17:41:45 -08:00
Ingo Molnar d1a76187a5 Merge commit 'v2.6.28-rc2' into core/locking
Conflicts:
	arch/um/include/asm/system.h
2008-10-28 16:54:49 +01:00
Al Viro 87e299e5c7 x86, um: get rid of uml-config.h
Take a few symbols we need into kern_constants.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:23 -07:00
Al Viro ec82c32d45 x86, um: get rid of arch/um/os symlink
we can get DEV_NULL defined for arch/um/drivers/null.c in less
convoluted ways, TYVM...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:22 -07:00
Al Viro 887c57d480 x86, um: get rid of excessive includes of uml-config.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:22 -07:00
Al Viro aa7bd94249 x86, um: get rid of header symlinks
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:22 -07:00
Al Viro f5ad6a42b7 x86, um: get rid of sysdep symlink
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:21 -07:00
Al Viro 17dcf75d3e x86, um: trim the junk from uml ptrace-*.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:21 -07:00
Al Viro 2985cfdb04 x86, um: take vm-flags.h to sysdep
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:21 -07:00
Al Viro 6b0eed4ef3 x86, um: get rid of uml asm/arch
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:21 -07:00
Al Viro fe1cd9876f x86, um: get rid of uml highmem.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:21 -07:00
Al Viro ff64b4c186 x86, um: get rid of uml unistd.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:21 -07:00
Al Viro 6a0eec8224 x86, um: get rid of system.h -> system.h include
Long-term we want to split system.h and include barriers part from
underlying target; for now copy that part to sysdep.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:21 -07:00
Al Viro 32926b3be1 x86, um: uml atomic.h is not needed anymore
Its only difference from underlying atomic.h used to be the include
of kernel.h; it's not needed there anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:21 -07:00
Al Viro efb21cc238 x86, um: untangle uml ldt.h
* turn asm/ldt.h into ldt.h; update the (very few) users
* take host_ldt.h into sysdep, kill symlink mess
* includes of asm/arch/ldt.h turn into asm/ldt.h now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:21 -07:00
Al Viro 5077c2a9cd x86, um: get rid of more uml asm/arch uses
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:20 -07:00
Al Viro 7127da4ee4 x86, um: remove dead header (uml module-generic.h; never used these days)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:20 -07:00
Al Viro 2e074004c6 x86, um: get rid of uml signal.h
the only theoretical reason for it these days is ppc; aside of uml/ppc
being dead, do_signal() would be happier in arch/powerpc/kernel/signal.h
anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:20 -07:00
Al Viro 3be311e324 x86, um: sanitize uml sigcontext.h uses
a) the only difference between sigcontext and sysdep/sigcontext
is that the former contains externs for two long-dead functions.
Removed, switched the only user to sysdep/sigcontext

b) asm/sigcontext.h is removable - that of underlying architecture
would get used.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:20 -07:00
Al Viro 1de1502c96 x86, um: now we can get rid of trivial uml headers
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:20 -07:00
Al Viro 8ede0bdb63 x86, um: initial part of asm-um move
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:19 -07:00
Al Viro 8569c9140b x86, um: take arch/um/include/* out of the way
We can't just plop asm/* into it - userland helpers are built with it
in search path and seeing asm/* show up there suddenly would be a bad
idea.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:19 -07:00
WANG Cong 99764fa4ce UML: make several more things static
- Make some variables and functions static, since they don't need to be
  global.

- Remove an unused function - arch/um/kernel/time.c::sched_clock().

- Clean the style a bit as complained by checkpatch.pl.

Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:24 -07:00
WANG Cong 4c182ae781 arch/um/kernel/irq.c: clean up some functions
Make activate_fd() and free_irq_by_irq_and_dev() static.  Remove
init_aio_irq() since it has no users.

Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:24 -07:00
Jeff Dike 7c1fed03b9 UML - Fix boot crash
My copying of linux/init.h didn't go far enough.  The definition of
__used singled out gcc minor version 3, but didn't care what the major
version was.  This broke when unit-at-a-time was added and gcc started
throwing out initcalls.

This results in an early boot crash when ptrace tries to initialize a
process with an empty, uninitialized register set.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-23 09:36:56 -07:00
Tom Spink 40fb16a360 uml: deal with inaccessible address space start
This patch makes os_get_task_size locate the bottom of the address space,
as well as the top.  This is for systems which put a lower limit on mmap
addresses.  It works by manually scanning pages from zero onwards until a
valid page is found.

Because the bottom of the address space may not be zero, it's not
sufficient to assume the top of the address space is the size of the
address space.  The size is the difference between the top address and
bottom address.

[jdike@addtoit.com: changed the name to reflect that this function is
supposed to return the top of the process address space, not its size and
changed the return value to reflect that.  Also some minor formatting
changes]
Signed-off-by: Tom Spink <tspink@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:10 -07:00
Jeff Dike fe2cc53ee0 uml: track and make up lost ticks
Alarm delivery could be noticably late in the !CONFIG_NOHZ case because lost
ticks weren't being taken into account.  This is now treated more carefully,
with the time between ticks being calculated and the appropriate number of
ticks delivered to the timekeeping system.

Cc: Nix <nix@esperi.org.uk>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:22 -07:00
Jeff Dike 5d33e4d7fd uml: random driver fixes
The random driver would essentially hang if the host's /dev/random returned
-EAGAIN.  There was a test of need_resched followed by a schedule inside the
loop, but that didn't help and it's the wrong way to work anyway.

The right way is to ask for an interrupt when there is input available from
the host and handle it then rather than polling.

Now, when the host's /dev/random returns -EAGAIN, the driver asks for a wakeup
when there's randomness available again and sleeps.  The interrupt routine
just wakes up whatever processes are sleeping on host_read_wait.

There is an atomic_t, host_sleep_count, which counts the number of processes
waiting for randomness.  When this reaches zero, the interrupt is disabled.

An added complication is that async I/O notification was only recently added
to /dev/random (by me), so essentially all hosts will lack it.  So, we use the
sigio workaround here, which is to have a separate thread poll on the
descriptor and send an interrupt when there is input on it.  This mechanism is
activated when a process gets -EAGAIN (activating this multiple times is
harmless, if a bit wasteful) and deactivated by the last process still
waiting.

The module name was changed from "random" to "hw_random" in order for udev to
recognize it.

The sigio workaround needed some changes.  sigio_broken was added for cases
when we know that async notification doesn't work.  This is now called from
maybe_sigio_broken, which deals with pts devices.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:22 -07:00
Cyrill Gorcunov a7dfa9403b uml: use PAGE_SIZE in linker scripts
This patch includes page.h header into linker scripts that allow us to
use PAGE_SIZE macro instead of numeric constant.

To be able to include page.h into linker scripts page.h is needed for
some modification - i.e.  we need to use __ASSEMBLY__ and _AC macro

[jdike@linux.intel.com - fixed conflict with as-layout.h]
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:22 -07:00
Jeff Dike 5563d722bf uml: use __SPIN_LOCK_UNLOCKED
From: Robert P. J. Day <rpjday@crashcourse.ca>

Use newer, non-deprecated __SPIN_LOCK_UNLOCKED macro.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:22 -07:00
Jeff Dike 43f5b3085f uml: fix build when SLOB is enabled
Reintroduce uml_kmalloc for the benefit of UML libc code.  The
previous tactic of declaring __kmalloc so it could be called directly
from the libc side of the house turned out to be getting too intimate
with slab, and it doesn't work with slob.

So, the uml_kmalloc wrapper is back.  It calls kmalloc or whatever
that translates into, and libc code calls it.

kfree is left alone since that still works, leaving a somewhat
inconsistent API.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:22 -07:00
Jeff Dike 47906dd9e6 uml: tidy ptrace interface
Tidy the ptrace interface code.  Removed a bunch of unused macros.
Started converting register sets from arrays of longs to structures.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:21 -07:00
Jeff Dike 96cee3044d uml: style fixes
A few random style fixes.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:21 -07:00
WANG Cong 3168cb98be uml: fix inconsistence due to tty_operation change
'put_char' of 'struct tty_operations' has changed from 'void' into 'int'.
This can also shut up compiler warnings.

Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-08 10:46:55 -07:00
WANG Cong 02d324b15d uml: remove a useless function
arch/um/drivers/chan_kern.c::chan_out_fd() is not used by anyone.  Remove it.

Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:28 -07:00
WANG Cong 3af7cb7bbc uml: make a function static
arch/um/drivers/chan_kern.c::open_chan() can become static.

Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:28 -07:00
Jeff Dike 2f56debd77 uml: fix FP register corruption
Commit ee3d9bd4de ("uml: simplify SIGSEGV
handling"), while greatly simplifying the kernel SIGSEGV handler that
runs in the process address space, introduced a bug which corrupts FP
state in the process.

Previously, the SIGSEGV handler called the sigreturn system call by hand - it
couldn't return through the restorer provided to it because that could try to
call the libc restorer which likely wouldn't exist in the process address
space.  So, it blocked off some signals, including SIGUSR1, on entry to the
SIGSEGV handler, queued a SIGUSR1 to itself, and invoked sigreturn.  The
SIGUSR1 was delivered, and was visible to the UML kernel after sigreturn
finished.

The commit eliminated the signal masking and the call to sigreturn.  The
handler simply hits itself with a SIGTRAP to let the UML kernel know that it
is finished.  UML then restores the process registers, which effectively
longjmps the process out of the signal handler, skipping sigreturn's restoring
of register state and the signal mask.

The bug is that the host apparently sets used_fp to 0 when it saves the
process FP state in the sigcontext on the process signal stack.  Thus, when
the process is longjmped out of the handler, its FP state is corrupt because
it wasn't saved on the context switch to the UML kernel.

This manifested itself as sleep hanging.  For some reason, sleep uses floating
point in order to calculate the sleep interval.  When a page fault corrupts
its FP state, it is faked into essentially sleeping forever.

This patch saves the FP state before entering the SIGSEGV handler and restores
it afterwards.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-23 17:12:15 -08:00