This adds CONFIG_X86_VSYSCALL_EMULATION, guarded by CONFIG_EXPERT.
Turning it off completely disables vsyscall emulation, saving ~3.5k
for vsyscall_64.c, 4k for vsyscall_emu_64.S (the fake vsyscall
page), some tiny amount of core mm code that supports a gate area,
and possibly 4k for a wasted pagetable.  The latter is because the
vsyscall addresses are misaligned and fit poorly in the fixmap.
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/406db88b8dd5f0cbbf38216d11be34bbb43c7eae.1414618407.git.luto@amacapital.netSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The temp fixed area is only used during boot for early_ioremap(), and
it is unused when ioremap() is functional. vmalloc/pkmap area become
available after early boot so the temp fixed area is available for
re-use.

The virtual address is more precious on i386, especially turning on
high memory. So we can re-use the virtual address space.

Remove the now unused defines FIXADDR_BOOT_START and FIXADDR_BOOT_SIZE.
Signed-off-by: NMinfei Huang <mnfhuang@gmail.com>
Cc: pbonzini@redhat.com
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/1414582717-32729-1-git-send-email-mnfhuang@gmail.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

3.16 kernel boot fail with earlyprintk=efi, it keeps scrolling at the
bottom line of screen.

Bisected, the first bad commit is below:
commit 86dfc6f3
Author: Lv Zheng <lv.zheng@intel.com>
Date:   Fri Apr 4 12:38:57 2014 +0800

    ACPICA: Tables: Fix table checksums verification before installation.

I did some debugging by enabling both serial and efi earlyprintk, below is
some debug dmesg, seems early_ioremap fails in scroll up function due to
no free slot, see below dmesg output:

  WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:116 __early_ioremap+0x90/0x1c4()
  __early_ioremap(ed00c800, 00000c80) not found slot
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-rc1+ #204
  Hardware name: Hewlett-Packard HP Z420 Workstation/1589, BIOS J61 v03.15 05/09/2013
  Call Trace:
    dump_stack+0x4e/0x7a
    warn_slowpath_common+0x75/0x8e
    ? __early_ioremap+0x90/0x1c4
    warn_slowpath_fmt+0x47/0x49
    __early_ioremap+0x90/0x1c4
    ? sprintf+0x46/0x48
    early_ioremap+0x13/0x15
    early_efi_map+0x24/0x26
    early_efi_scroll_up+0x6d/0xc0
    early_efi_write+0x1b0/0x214
    call_console_drivers.constprop.21+0x73/0x7e
    console_unlock+0x151/0x3b2
    ? vprintk_emit+0x49f/0x532
    vprintk_emit+0x521/0x532
    ? console_unlock+0x383/0x3b2
    printk+0x4f/0x51
    acpi_os_vprintf+0x2b/0x2d
    acpi_os_printf+0x43/0x45
    acpi_info+0x5c/0x63
    ? __acpi_map_table+0x13/0x18
    ? acpi_os_map_iomem+0x21/0x147
    acpi_tb_print_table_header+0x177/0x186
    acpi_tb_install_table_with_override+0x4b/0x62
    acpi_tb_install_standard_table+0xd9/0x215
    ? early_ioremap+0x13/0x15
    ? __acpi_map_table+0x13/0x18
    acpi_tb_parse_root_table+0x16e/0x1b4
    acpi_initialize_tables+0x57/0x59
    acpi_table_init+0x50/0xce
    acpi_boot_table_init+0x1e/0x85
    setup_arch+0x9b7/0xcc4
    start_kernel+0x94/0x42d
    ? early_idt_handlers+0x120/0x120
    x86_64_start_reservations+0x2a/0x2c
    x86_64_start_kernel+0xf3/0x100

Quote reply from Lv.zheng about the early ioremap slot usage in this case:

"""
In early_efi_scroll_up(), 2 mapping entries will be used for the src/dst screen buffer.
In drivers/acpi/acpica/tbutils.c, we've improved the early table loading code in acpi_tb_parse_root_table().
We now need 2 mapping entries:
1. One mapping entry is used for RSDT table mapping. Each RSDT entry contains an address for another ACPI table.
2. For each entry in RSDP, we need another mapping entry to map the table to perform necessary check/override before installing it.

When acpi_tb_parse_root_table() prints something through EFI earlyprintk console, we'll have 4 mapping entries used.
The current 4 slots setting of early_ioremap() seems to be too small for such a use case.
"""

Thus increase the slot to 8 in this patch to fix this issue.
boot-time mappings become 512 page with this patch.
Signed-off-by: NDave Young <dyoung@redhat.com>
Cc: <stable@vger.kernel.org> # v3.16
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This makes the 64-bit and x32 vdsos use the same mechanism as the
32-bit vdso.  Most of the churn is deleting all the old fixmap code.
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/8af87023f57f6bb96ec8d17fce3f88018195b49b.1399317206.git.luto@amacapital.netSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Move x86 over to the generic early ioremap implementation.
Signed-off-by: NMark Salter <msalter@redhat.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The compat vDSO is a complicated hack that's needed to maintain
compatibility with a small range of glibc versions.

This removes it and replaces it with a much simpler hack: a config
option to disable the 32-bit vDSO by default.

This also changes the default value of CONFIG_COMPAT_VDSO to n --
users configuring kernels from scratch almost certainly want that
choice.
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/4bb4690899106eb11430b1186d5cc66ca9d1660c.1394751608.git.luto@amacapital.netSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The SGI Visual Workstation seems to be dead; remove support so we
don't have to continue maintaining it.

Cc: Andrey Panin <pazke@donpac.ru>
Cc: Michael Reed <mdr@sgi.com>
Link: http://lkml.kernel.org/r/530CFD6C.7040705@zytor.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Signed-off-by: NMark Salter <msalter@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The vsyscall related pvclock entries can only ever be used on
x86-64, and hence they shouldn't even get allocated for 32-bit
kernels (the more that it is there where address space is
relatively precious).
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/51A60F1F02000078000D997C@nat28.tlf.novell.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The last users of FIX_CYCLONE_TIMER were removed in v2.6.18. We
can remove this unneeded constant.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Link: http://lkml.kernel.org/r/1365698982.1427.3.camel@x61.thuisdomeinSigned-off-by: NIngo Molnar <mingo@kernel.org>

Make a copy of the IDT (as seen via the "sidt" instruction) read-only.
This primarily removes the IDT from being a target for arbitrary memory
write attacks, and has the added benefit of also not leaking the kernel
base offset, if it has been relocated.

We already did this on vendor == Intel and family == 5 because of the
F0 0F bug -- regardless of if a particular CPU had the F0 0F bug or
not.  Since the workaround was so cheap, there simply was no reason to
be very specific.  This patch extends the readonly alias to all CPUs,
but does not activate the #PF to #UD conversion code needed to deliver
the proper exception in the F0 0F case except on Intel family 5
processors.
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20130410192422.GA17344@www.outflux.net
Cc: Eric Northup <digitaleric@google.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Originally from Jeremy Fitzhardinge.

Introduce generic, non hypervisor specific, pvclock initialization
routines.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This sets all up the other bits that need to be INTEL_MID
specific rather than Moorestown specific.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/20111217174318.7207.91543.stgit@bob.linux.org.ukSigned-off-by: NIngo Molnar <mingo@elte.hu>

Move vvars out of the vsyscall page into their own page and mark
it NX.

Without this patch, an attacker who can force a daemon to call
some fixed address could wait until the time contains, say,
0xCD80, and then execute the current time.
Signed-off-by: NAndy Lutomirski <luto@mit.edu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/b1460f81dc4463d66ea3f2b5ce240f58d48effec.1307292171.git.luto@mit.eduSigned-off-by: NIngo Molnar <mingo@elte.hu>

The x86 fixmaps need to be all together... unfortunately the
VRTC one was misplaced.

This patch makes sure the MRST VRTC fixmap is put prior to the
__end_of_permanent_fixed_addresses marker.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
LKML-Reference: <20110111105544.24448.27607.stgit@bob.linux.org.uk>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When compiling arch/x86/kernel/early_printk_mrst.c with i386
allmodconfig, gcc-4.1.0 generates an out-of-line copy of
__set_fixmap_offset() which contains a reference to
__this_fixmap_does_not_exist which the compiler cannot elide.

Marking __set_fixmap_offset() as __always_inline prevents this.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Feng Tang <feng.tang@intel.com>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Moorestown platform doesn't have a m146818 RTC device like traditional
x86 PC, but a firmware emulated virtual RTC device(vrtc), which provides
some basic RTC functions like get/set time. vrtc serves as the only
wall clock device on Moorestown platform.

[ tglx: Changed the exports to _GPL ]
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
LKML-Reference: <20101110172837.3311.40483.stgit@localhost.localdomain>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Sometimes fixmap will be used to map an physical address which
is not PAGE align, so to use it we need first map it and then
add the address offset to the mapped fixed address. These 2 new
helpers are suggested by Ingo Molnar to make the process
simpler.

For a physicall address like "phys", a directly usable virtual
address can be get by
	virt = (void *)set_fixmap_offset(fixed_idx, phys);
or
	virt = (void *)set_fixmap_offset_nocache(fixed_idx, phys);
(depends on whether the physical address is cachable or not).
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Cc: alan@linux.intel.com
Cc: greg@kroah.com
Cc: x86@kernel.org
LKML-Reference: <1284361736-23011-3-git-send-email-feng.tang@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Ever for 32-bit with sufficiently high NR_CPUS, and starting
with commit 789d03f5 also for
64-bit, the statically allocated early fixmap page tables were
not covering FIX_OHCI1394_BASE, leading to a boot time crash
when "ohci1394_dma=early" was used. Despite this entry not being
a permanently used one, it needs to be moved into the permanent
range since it has to be close to FIX_DBGP_BASE and
FIX_EARLYCON_MEM_BASE.
Reported-bisected-and-tested-by: NJustin P. Mattock <justinmattock@gmail.com>
Fixes-bug: http://bugzilla.kernel.org/show_bug.cgi?id=14487Signed-off-by: NJan Beulich <jbeulich@novell.com>
Cc: <stable@kernel.org> # [as far back as long as it still applies]
LKML-Reference: <4B9E15D30200007800034D23@vpn.id2.novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The early ioremap fixmap entries cover half (or for 32-bit
non-PAE, a quarter) of a page table, yet they got
uncondtitionally aligned so far to a 256-entry boundary. This is
not necessary if the range of page table entries anyway falls
into a single page table.

This buys back, for (theoretically) 50% of all configurations
(25% of all non-PAE ones), at least some of the lowmem
necessarily lost with commit e621bd18.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4B2BB66F0200007800026AD6@vpn.id2.novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch adds kernel configuration and boot support for Intel Trusted
Execution Technology (Intel TXT).

Intel's technology for safer computing, Intel Trusted Execution
Technology (Intel TXT), defines platform-level enhancements that
provide the building blocks for creating trusted platforms.

Intel TXT was formerly known by the code name LaGrande Technology (LT).

Intel TXT in Brief:
o  Provides dynamic root of trust for measurement (DRTM)
o  Data protection in case of improper shutdown
o  Measurement and verification of launched environment

Intel TXT is part of the vPro(TM) brand and is also available some
non-vPro systems.  It is currently available on desktop systems based on
the Q35, X38, Q45, and Q43 Express chipsets (e.g. Dell Optiplex 755, HP
dc7800, etc.) and mobile systems based on the GM45, PM45, and GS45
Express chipsets.

For more information, see http://www.intel.com/technology/security/.
This site also has a link to the Intel TXT MLE Developers Manual, which
has been updated for the new released platforms.

A much more complete description of how these patches support TXT, how to
configure a system for it, etc. is in the Documentation/intel_txt.txt file
in this patch.

This patch provides the TXT support routines for complete functionality,
documentation for TXT support and for the changes to the boot_params structure,
and boot detection of a TXT launch.  Attempts to shutdown (reboot, Sx) the system
will result in platform resets; subsequent patches will support these shutdown modes
properly.

 Documentation/intel_txt.txt      |  210 +++++++++++++++++++++
 Documentation/x86/zero-page.txt  |    1
 arch/x86/include/asm/bootparam.h |    3
 arch/x86/include/asm/fixmap.h    |    3
 arch/x86/include/asm/tboot.h     |  197 ++++++++++++++++++++
 arch/x86/kernel/Makefile         |    1
 arch/x86/kernel/setup.c          |    4
 arch/x86/kernel/tboot.c          |  379 +++++++++++++++++++++++++++++++++++++++
 security/Kconfig                 |   30 +++
 9 files changed, 827 insertions(+), 1 deletion(-)
Signed-off-by: NJoseph Cihula <joseph.cihula@intel.com>
Signed-off-by: NShane Wang <shane.wang@intel.com>
Signed-off-by: NGang Wei <gang.wei@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Masami reported:

> Since the fixmap pages are assigned higher address to lower,
> text_poke() has to use it with inverted order (FIX_TEXT_POKE1
> to FIX_TEXT_POKE0).

I prefer to just invert the order of the fixmap declaration.
It's simpler and more straightforward.

Backward fixmaps seems to be used by both x86 32 and 64.

It's really rare but a nasty bug, because it only hurts when
instructions to patch are crossing a page boundary. If this
happens, the fixmap write accesses will spill on the following
fixmap, which may very well crash the system. And this does not
crash the system, it could leave illegal instructions in place.
Thanks Masami for finding this.

It seems to have crept into the 2.6.30-rc series, so this calls
for a -stable inclusion.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: <stable@kernel.org>
LKML-Reference: <20090701213722.GH19926@Krystal>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The merge of the 32- and 64-bit fixmap headers made a latent
bug on x86-64 a real one: with the right config settings
it is possible for FIX_OHCI1394_BASE to overlap the FIX_BTMAP_*
range.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Cc: <stable@kernel.org> # for 2.6.30.x
LKML-Reference: <4A4A0A8702000078000082E8@vpn.id2.novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix kprobes crash on 32-bit with RAM above 4G

Use phys_addr_t for receiving a physical address argument
instead of unsigned long. This allows fixmap to handle
pages higher than 4GB on x86-32.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Acked-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: systemtap-ml <systemtap@sources.redhat.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <49DE3695.6040800@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Use phys_addr_t for receiving a physical address argument instead of
unsigned long.  This allows fixmap to handle pages higher than 4GB on
x86-32.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use fixmaps instead of vmap/vunmap in text_poke() for avoiding
page allocation and delayed unmapping.

At the result of above change, text_poke() becomes atomic and can be called
from stop_machine() etc.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Acked-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
LKML-Reference: <49B14352.2040705@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: unification

This patch unify fixmap_32.h and fixmap_64.h into fixmap.h.
Things that we can't merge now are using CONFIG_X86_{32,64}
(e.g.:vsyscall and EFI)
Signed-off-by: NGustavo F. Padovan <gustavo@las.ic.unicamp.br>
Acked-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Impact: introduce new APIs, separate kmap code from CONFIG_HIGHMEM

This takes the code used for CONFIG_HIGHMEM memory mappings except that
it's designed for dynamic IO resource mapping.

These fixmaps are available even with CONFIG_HIGHMEM turned off.
Signed-off-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Change header guards named "ASM_X86__*" to "_ASM_X86_*" since:

a. the double underscore is ugly and pointless.
b. no leading underscore violates namespace constraints.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

This patch is the result of an automatic script that consolidates the
format of all the headers in include/asm-x86/.

The format:

1. No leading underscore. Names with leading underscores are reserved.
2. Pathname components are separated by two underscores. So we can
   distinguish between mm_types.h and mm/types.h.
3. Everything except letters and numbers are turned into single
   underscores.
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>

Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In both cases, I went with the 32-bit behaviour.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move the headers to include/asm-x86 and fixup the
header install make rules
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>