UML still needed some work in order to allow CFLAGS to be passed in from the
command line.

USER_CFLAGS is produced from KBUILD_CFLAGS in part by removing all the -I
switches.  This is so that kernel headers don't accidentally get pulled into
libc files.  However, a common use of command-line CFLAGS would be to add -I
switches to the build.  This patch specifically adds any command-line -I flags
back to USER_CFLAGS.

I also corrected the spelling of LFLAGS to LDFLAGS.
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>

Give the stubs a VMA.  This allows the removal of a truly nasty kludge to make
sure that mm->nr_ptes was correct in exit_mmap.  The underlying problem was
always that the stubs, which have ptes, and thus allocated a page table,
weren't covered by a VMA.

This patch fixes that by using install_special_mapping in arch_dup_mmap and
activate_context to create the VMA.  The stubs have to be moved, since
shift_arg_pages seems to assume that the stack is the only VMA present at that
point during exec, and uses vma_adjust to fiddle its VMA.  However, that
extends the stub VMA by the amount removed from the stack VMA.

To avoid this problem, the stubs were moved to a different fixed location at
the start of the address space.

The init_stub_pte calls were moved from init_new_context to arch_dup_mmap
because I was occasionally seeing arch_dup_mmap not being called, causing
exit_mmap to die.  Rather than figure out what was really happening, I decided
it was cleaner to just move the calls so that there's no doubt that both the
pte and VMA creation happen, no matter what.  arch_exit_mmap is used to clear
the stub ptes at exit time.

The STUB_* constants in as-layout.h no longer depend on UM_TASK_SIZE, that
that definition is removed, along with the comments complaining about gcc.

Because the stubs are no longer at the top of the address space, some care is
needed while flushing TLBs.  update_pte_range checks for addresses in the stub
range and skips them.  flush_thread now issues two unmaps, one for the range
before STUB_START and one for the range after STUB_END.
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>

Clean up the calculation and use of the usable address space size on the host.

task_size is gone, replaced with TASK_SIZE, which is calculated from
CONFIG_TOP_ADDR.  get_kmem_end and set_task_sizes_skas are also gone.

host_task_size, which refers to the entire address space usable by the UML
kernel and which may be larger than the address space usable by a UML process,
since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR.

STACK_TOP is now TASK_SIZE minus the two stub pages.
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 missing space between merged string constants.
Signed-off-by: NJoe Perches <joe@perches.com>
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>

UML was panicing in the case of failures of libc calls which shouldn't happen.
 This is an overreaction since a failure from libc doesn't normally mean that
kernel data structures are in an unknown state.  Instead, the current process
should just be killed if there is no way to recover.

The case that prompted this was a failure of PTRACE_SETREGS restoring the same
state that was read by PTRACE_GETREGS.  It appears that when a process tries
to load a bogus value into a segment register, it segfaults (as expected) and
the value is actually loaded and is seen by PTRACE_GETREGS (not expected).

This case is fixed by forcing a fatal SIGSEGV on the process so that it
immediately dies.  fatal_sigsegv was added for this purpose.  It was declared
as noreturn, so in order to pursuade gcc that it actually does not return, I
added a call to os_dump_core (and declared it noreturn) so that I get a core
file if somehow the process survives.

All other calls in arch/um/os-Linux/skas/process.c got the same treatment,
with failures causing the process to die instead of a kernel panic, with some
exceptions.

userspace_tramp exits with status 1 if anything goes wrong there.  That will
cause start_userspace to return an error.  copy_context_skas0 and
map_stub_pages also now return errors instead of panicing.  Callers of thes
functions were changed to check for errors and do something appropriate.
Usually that's to return an error to their callers.
check_skas3_ptrace_faultinfo just exits since that's too early to do anything
else.

save_registers, restore_registers, and init_registers now return status
instead of panicing on failure, with their callers doing something
appropriate.

There were also duplicate declarations of save_registers and restore_registers
in os.h - these are gone.

I noticed and fixed up some whitespace damage.
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>

Some register accessor cleanups -
	userspace() was calling restore_registers and save_registers for no
reason, since userspace() is on the libc side of the house, and these
add no value over calling ptrace directly
	init_thread_registers and get_safe_registers were the same thing,
so init_thread_registers is gone
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>

Simplify the page fault stub by not masking signals while it is running.  This
allows it to signal that it is done by executing an instruction which will
generate a SIGTRAP (int3 on x86) rather than running sigreturn by hand after
queueing a blocked SIGUSR1.

userspace_tramp now no longer puts anything in the SIGSEGV sa_mask, but it
does add SA_NODEFER to sa_flags so that SIGSEGV is still enabled after the
signal handler fails to run sigreturn.

SIGWINCH is just blocked so that we don't have to deal with it and the signal
masks used by wait_stub_done are updated to reflect the smaller number of
signals that it has to worry about.
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>

Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface.

It's also made non-static and declared in pgtable.h because it'll be
needed when the stubs get a vma.
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>

Get the sizes of various pieces of data right when using three-level
page tables.  pgd and pmd entries remain at 32 bits in a 32-bit
compilation because page tables will remain in low memory.  So,
PGDIR_SHIFT, the PTRS_PER_* values, set_pud, set_pmd are conditional
on 64BIT.

More use of phys_t is made when there are physical memory addresses
floating around.

ObCheckpatchViolationJustification - the new typedef is an alternate
definition of pmd_t, which I can't really live without.
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>

Tidy current-related stuff.  There was a comment in current.h saying
that current_thread was obsolete, so this patch turns all instances of
current_thread into current_thread_info().  There's some simplifying
of the result in arch/um/sys-i386/signal.c.

current.h and thread_info also get style cleanups.
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>

Style fixes in elf-i386.h and arch/um/kernel/mem.c.
      update the copyright
      get rid of an emacs formatting comment
      some formatting fixes
      inclusion trimming
      whitespace fixes
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>

Untangle UML headers somewhat and add some includes where they were
needed explicitly, but gotten accidentally via some other header.

arch/um/include/um_uaccess.h loses asm/fixmap.h because it uses no
fixmap stuff and gains elf.h, because it needs FIXADDR_USER_*, and
archsetjmp.h, because it needs jmp_buf.

pmd_alloc_one is uninlined because it needs mm_struct, and that's
inconvenient to provide in asm-um/pgtable-3level.h.

elf_core_copy_fpregs is also uninlined from elf-i386.h and
elf-x86_64.h, which duplicated the code anyway, to
arch/um/kernel/process.c, so that the reference to current_thread
doesn't pull sched.h or anything related into asm/elf.h.

arch/um/sys-i386/ldt.c, arch/um/kernel/tlb.c and
arch/um/kernel/skas/uaccess.c got sched.h because they dereference
task_structs.  Its includes of linux and asm headers got turned from
"" to <>.

arch/um/sys-i386/bug.c gets asm/errno.h because it needs errno
constants.

asm/elf-i386 gets asm/user.h because it needs user_regs_struct.

asm/fixmap.h gets page.h because it needs PAGE_SIZE and PAGE_MASK and
system.h for BUG_ON.

asm/pgtable doesn't need sched.h.

asm/processor-generic.h defined mm_segment_t, but didn't use it.  So,
that definition is moved to uaccess.h, which defines a bunch of
mm_segment_t-related stuff.  thread_info.h uses mm_segment_t, and
includes uaccess.h, which causes a recursion.  So, the definition is
placed above the include of thread_info. in uaccess.h.  thread_info.h
also gets page.h because it needs PAGE_SIZE.

ObCheckpatchViolationJustification - I'm not adding a typedef; I'm
moving mm_segment_t from one place to another.
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>

This patchset makes UML build and run with three-level page tables on
32-bit hosts.  This is an uncommon use case, but the code here needed
fixing and cleaning up, so 32-bit three-level pages tables were tested
to make sure the changes are good.

Patch 1 - code movement
Patch 2 - header untangling
Patch 3 - style fixups in files affected so far
Patch 4 - clean up use of current.h
Patch 5 - fix sizes of types that are different between 2 and 3-level
	page tables - three-level page table support should build at
	this point
Patch 6 - tidy (i.e. eliminate much of) the code that figures out how
	big the address space is
Patch 7 - change um_virt_to_phys into virt_to_pte, clean its
	interface, and clean its (so far) one caller
Patch 8 - the stub pages are covered with a VMA, allowing some nasty
	code to be thrown out - three-level page tables now work

This patch:

um_virt_to_phys only has one user, so it can be moved to the same file
and made static.  Its declarations in pgtable.h and ksyms.c are also
gone.

current_cmd was another apparent user, but it itself isn't used, so it
is deleted.
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 some diagnostics when TLS operations on the host fail.  Also spit out more
information about the TLS environment on the host at boot time.
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>

This patch changes a few functions into returning void.  The return values
were not used anyway, so I think it should not be a problem.  Also removed a
little leftover bit from TT mode.
Signed-off-by: NKarol Swietlicki <magotari@gmail.com>
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>

This patch removes a variable which was not used in two functions.  Yet
another code cleanup, nothing really significant.

Please note that I could not test this on x86_64. I don't have the
hardware for it.

[ jdike - Bits of tidying around the affected code.  Also, it's fine on
x86_64 ]
Signed-off-by: NKarol Swietlicki <magotari@gmail.com>
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>

Signed-off-by: NLucas Woods <woodzy@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The previous const-ing patch consted a string which shouldn't have
been, and I didn't notice the gcc warning.

ubd_setup can't take a const char * because its address is assigned to
something which expects a char *arg.  Many setups modify the string
they are given, they can't be const.
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>

The earlier pgtable.h tidying patch made things a bit too tidy.  Add
back a header which is needed in VMALLOC_START and friend.  Also add
back a definition of pmd_page_vaddr, which is needed on x86_64.
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>

Large pieces of include/asm/pgtable.h were unused cruft.

This uncovered arch/um/kernel/trap.c needing skas.h in order to get
ptrace_faultinfo.
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>

Tidy kern_util.h.  It turns out that most of the function declarations
aren't used, so they can go away.  os.h no longer includes
kern_util.h, so files which got it through os.h now need to include it
directly.  A number of other files never needed it, so these includes
are deleted.

The structure which was used to pass signal handlers from the kernel
side to the userspace side is gone.  Instead, the handlers are
declared here, and used directly from libc code.  This allows
arch/um/os-Linux/trap.c to be deleted, with its remnants being moved
to arch/um/os-Linux/skas/trap.c.

arch/um/os-Linux/tty.c had its inclusions changed, and it needed some
style attention, so it got tidied.
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>

Allow LFLAGS to be given to make and have the expected effect.
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>

Robert Day noticed a few unused headers in UML, so this gets rid of them.

Cc: "Robert P. J. Day" <rpjday@crashcourse.ca>
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>

Suggested by Geert Uytterhoeven - use const.h to get constants that are usable
in both C and assembly.  I can't include it directly since this code can't
include kernel headers.  const.h is also for numeric constants that can be
typed by tacking a "UL" or similar on the end.  The constants here have to be
typed by casting them.

So, the relevant parts of const.h are copied here and modified in order to
allow the constants to be uncasted in assembly and casted in C.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

clone.c needed some style attention -
	updated copyright
	include trimming
	coding style
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>

Console driver cleanups -
	Changed an instance of foo = bar + foo to foo += bar
	Removed checks of tty->stopped - I don't think the low-level
driver has any business looking at that
	Removed an annoying warning
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>

This is a short Kconfig fix for a problem in User Mode Linux.  Frame pointers
are required for gprof support to work.
Signed-off-by: NKarol Swietlicki <magotari@gmail.com>
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>

SMP still needs to depend on BROKEN for now.
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>

This patch also does some improvements for uml code.  Improvements include
dropping unnecessary cast, killing some unnecessary code and still some
constifying for pointers etc..
Signed-off-by: NWANG Cong <xiyou.wangcong@gmail.com>
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>

bugs.c, for both i386 and x86_64, can undergo further cleaning -
	The i386 arch_check_bugs only does one thing, so we might as
well inline the cmov checking.
	The i386 includes can be trimmed down a bit.
	arch_init_thread wasn't used, so it is deleted.
	The panics in arch_handle_signal are turned into printks
because the process is about to get segfaulted anyway, so something is
dying no matter what happens here.  Also, the return value was always
the same, so it contained no information, so it can be void instead.
The name is changed to arch_examine_signal because it doesn't handle
anything.
	The caller of arch_handle_signal, relay_signal, does things in
a different order.  The kernel-mode signal check is now first, which
puts everything else together, making things a bit clearer conceptually.

[akpm@linux-foundation.org: coding-style fixes]
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>

This patch finishes what the previous one started.  The code was not used
after my first patch, and now can be removed with ease.

[ jdike - also deleted the #if 0 lcall stuff ]
Signed-off-by: NKarol Swietlicki <magotari@gmail.com>
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>

This patch introduces a new way of checking for the cmov instruction.  I use
signal handling instead of reading /proc/cpuinfo.

[ jdike - Fiddled the asm to make it obvious that it didn't mess with
any in-use registers and made test_for_host_cmov void ]

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NKarol Swietlicki <magotari@gmail.com>
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>

This patch updates links which broke during the transition to the new UML
website.
Signed-off-by: NKarol Swietlicki <magotari@gmail.com>
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>

The ubd help message didn't document the 'c' flag.
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>

Get rid of asmlinkage and remove some old cruft from asm/linkage.h.

[akpm@linux-foundation.org: coding-style fixes]
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>

Implement get_wchan - the algorithm is similar to x86.  It starts with the
stack pointer of the process in question and looks above that for addresses
that are kernel text.  The second one which isn't in the scheduler is the one
that's returned.  The first one is ignored because that will be UML's own
context switching routine.
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>

This patch contains varied fixes and improvements for some files under
arch/um/os-Linux/, such as a typo fix in a perror message, a missing
argument fix for a printf, some constifying for pointers and so on.

[ jdike - made sigprocmask failure return -errno instead of -1 ]
Signed-off-by: NWANG Cong <xiyou.wangcong@gmail.com>
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>

This patch removes some code which ran at every boot, but does not seem to do
anything anymore.  Please test.  It works for me but mistakes can happen.
Signed-off-by: NKarol Swietlicki <magotari@gmail.com>
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>

init.h started breaking now for some reason.  It turns out that there wasn't a
definition of __used.  Fixed this by copying the relevant stuff from
compiler.h in the userspace case, and including compiler.h in the kernel case.

[xiyou.wangcong@gmail.com: added definition of __section]
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is very old code, it hasn't changed since 2001 and it is not used
anywhere.  Noticed by Clemens Koller.
Signed-off-by: NJesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>