Abstract sensitive instructions in assembler code, replacing them with macros
(which currently are #defined to the native versions).  We use long names:
assembler is case-insensitive, so if something goes wrong and macros do not
expand, it would assemble anyway.

Resulting object files are exactly the same as before.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Fix
linux/arch/x86_64/kernel/process.c: In function __switch_to:
linux/arch/x86_64/kernel/process.c:626: warning: assignment makes integer from pointer without a cast
Signed-off-by: NAndi Kleen <ak@suse.de>

I just added type checking for assignments the PDA in the i386 PDA code.
Here's the x86-64 equivalent.  (Obviously this doesn't contain the latest
x86-64 PDA change.)
Signed-off-by: NJeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Apparently that is the more official way to get numbers without $ in inline
assembly
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NAndi Kleen <ak@suse.de>

Add a feature check that checks that the gcc compiler has stack-protector
support and has the bugfix for PR28281 to make this work in kernel mode.
The easiest solution I could find was to have a shell script in scripts/
to do the detection; if needed we can make this fancier in the future
without making the makefile too complex.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>
CC: Sam Ravnborg <sam@ravnborg.org>

GCC emits a call to a __stack_chk_fail() function when the stack canary is
not matching the expected value.

Since this is a bad security issue; lets panic the kernel rather than limping
along; the kernel really can't be trusted anymore when this happens.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>

This patch adds the per thread cookie field to the task struct and the PDA.
Also it makes sure that the PDA value gets the new cookie value at context
switch, and that a new task gets a new cookie at task creation time.
Signed-off-by: NArjan van Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>

This patch adds the config options for -fstack-protector.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>

Change the comments in the pda structure to make the first fields to have
their offset documented and to have the comments aligned.
The stack protector series needs a field at offset 40 (gcc ABI); annotate
upto 40 for that reason.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>

Signed-off-by: NAndi Kleen <ak@suse.de>

Because it can take spinlocks.

Suggested by Mathieu Desnoyers

Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

kexec: Avoid overwriting the current pgd (V4, i386)

This patch upgrades the i386-specific kexec code to avoid overwriting the
current pgd. Overwriting the current pgd is bad when CONFIG_CRASH_DUMP is used
to start a secondary kernel that dumps the memory of the previous kernel.

The code introduces a new set of page tables. These tables are used to provide
an executable identity mapping without overwriting the current pgd.
Signed-off-by: NMagnus Damm <magnus@valinux.co.jp>
Signed-off-by: NAndi Kleen <ak@suse.de>

kexec: Avoid overwriting the current pgd (V4, x86_64)

This patch upgrades the x86_64-specific kexec code to avoid overwriting the
current pgd. Overwriting the current pgd is bad when CONFIG_CRASH_DUMP is used
to start a secondary kernel that dumps the memory of the previous kernel.

The code introduces a new set of page tables. These tables are used to provide
an executable identity mapping without overwriting the current pgd.
Signed-off-by: NMagnus Damm <magnus@valinux.co.jp>
Signed-off-by: NAndi Kleen <ak@suse.de>

Remove most of the special cases for the debug IST stack.  This is a
follow on clean up patch, it requires the bug fix patch that adds
orig_ist.
Signed-off-by: NKeith Owens <kaos@ocs.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>

The EDD code would scan the command line as a fixed array, without
taking account of either whitespace, null-termination, the old
command-line protocol, late overrides early, or the fact that the
command line may not be reachable from INITSEG.

This should fix those problems, and enable us to use a longer command
line.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Based on a idea by Jeremy Fitzhardinge:

Replace the volatiles and memory clobbers in the PDA access with
telling gcc about access to a proxy PDA structure that doesn't
actually exist. But the dummy accesses give a defined ordering for
read/write accesses.

Also add some memory barriers to the early GS initialization to
make sure no PDA access is moved before it.

Advantage is some .text savings (probably most from better
code for accessing "current"):

   text    data     bss     dec     hex filename
4845647 1223688  615864 6685199  66020f vmlinux
4837780 1223688  615864 6677332  65e354 vmlinux-pda

1.2% smaller code

Cc:  Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

They cannot be actually freed because the FACS table has a
shared-with-the-BIOS lock.
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch updates x86_64 linker script to pack any .note.* sections
into a PT_NOTE segment in the output file.

To do this, we tell ld that we need a PT_NOTE segment.  This requires
us to start explicitly mapping sections to segments, so we also need
to explicitly create PT_LOAD segments for text and data, and map the
sections to them appropriately.  Fortunately, each section will
default to its previous section's segment, so it doesn't take many
changes to vmlinux.lds.S.

The corresponding change is already made for i386 in -mm and I'd like
this patch to join it. The section to segment mappings do change as do
the segment flags so some time in -mm would be good for that reason as
well, just in case.

In particular .data and .bss move from the text segment to the data
segment and .data.cacheline_aligned .data.read_mostly are put in the
data segment instead of a separate one.

I think that it would be possible to exactly match the existing section
to segment mapping and flags but it would be a more intrusive change and
I'm not sure there is a reason for the existing layout other than it is
what you get by default if you don't explicitly specify something else.
If there is a reason for the existing layout then I will of course make
the more intrusive change. If there is no reason we could probably drop
the executable or writable flags from some segments but I don't know how
much attention is paid to them anyway so it might not be worth the
effort.

The vsyscall related sections need to go in a different segment to the
normal data segment and so I invented a "user" segment to contain them.
I believe this should appear to be another data segment as far as the
kernel is concerned so the flags are setup accordingly.

The notes will be used in the Xen paravirt_ops backend to provide
additional information to the domain builder. I am in the process of
converting the xen-unstable kernels and tools over to this scheme at the
moment to support this in the future.

It has been suggested to me that the notes segment should have flags 0
(i.e. not readable) since it is only used by the loader and is not used
at runtime. For now I went with a readable segment since that is what
the i386 patch uses.

AK: dropped NOTES addition right now because the needed infrastructure
for that is not merged yet
Signed-off-by: NIan Campbell <ian.campbell@xensource.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

In long mode the %cs is largely a relic.  However there are a few cases
like iret where it matters that we have a valid value.  Without this
patch it is possible to enter the kernel in startup_64 without setting
%cs to a valid value.  With this patch we don't care what %cs value
we enter the kernel with, so long as the cs shadow register indicates
it is a privileged code segment.

Thanks to Magnus Damm for finding this problem and posting the
first workable patch.  I have moved the jump to set %cs down a
few instructions so we don't need to take an extra jump.  Which
keeps the code simpler.
Signed-of-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Based on patch from David Rientjes <rientjes@google.com>, but
changed by AK.

Optimizes the 64-bit hamming weight for x86_64 processors assuming they
have fast multiplication.  Uses five fewer bitops than the generic
hweight64.  Benchmark on one EMT64 showed ~25% speedup with 2^24
consecutive calls.

Define a new ARCH_HAS_FAST_MULTIPLIER that can be set by other
architectures that can also multiply fast.
Signed-off-by: NAndi Kleen <ak@suse.de>

Drop support for non e820 BIOS calls to get the memory map.

The boot assembler code still has some support, but not the C code now.
Signed-off-by: NAndi Kleen <ak@suse.de>

When compiling a 64-bit kernel on an Ubuntu 6.06 32bit system (whose GCC is also
a cross-compiler for x86_64) I've seen that head.o is compiled as a 64-bit file
(while it should not) and ld complaining about this during linking:
[AK: it happens on all systems with new binutils]

ld: warning: i386:x86-64 architecture of input file
`arch/x86_64/boot/compressed/head.o' is incompatible with i386 output

I've verified that removing -m64 from compilation flags to turn
"-m64 -traditional -m32" into "-traditional -m32" fixes the issue.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndi Kleen <ak@suse.de>

NMIs are not supposed to track the irq flags, but TRACE_IRQS_IRETQ
did it anyways. Add a check.

Cc: mingo@elte.hu
Signed-off-by: NAndi Kleen <ak@suse.de>

Give the printks a consistent prefix.
Add some missing white space.

Cc: len.brown@intel.com
Signed-off-by: NAndi Kleen <ak@suse.de>

- Remove a define that was used only once
- Remove the too large APIC ID check because we always support
the full 8bit range of APICs.
- Restructure code a bit to be simpler.

Cc: len.brown@intel.com
Signed-off-by: NAndi Kleen <ak@suse.de>

ACPI went to great trouble to get the APIC version and CPU capabilities
of different CPUs before passing them to the mpparser. But all
that data was used was to print it out.  Actually it even faked some data
based on the boot cpu, not on the actual CPU being booted.

Remove all this code because it's not needed.

Cc: len.brown@intel.com
Signed-off-by: NAndi Kleen <ak@suse.de>

Use normal pte accessors in change_page_attr() to access the PSE
bits.
Signed-off-by: NAndi Kleen <ak@suse.de>

Fix the pte_exec/mkexec page table accessor functions to really
use the NX bit. Previously they only checked the USER bit, but
weren't actually used for anything.

Then use them in change_page_attr() to manipulate the NX bit
properly.
Signed-off-by: NAndi Kleen <ak@suse.de>

It is correct for its only caller right now, but not for possible
future others.
Signed-off-by: NAndi Kleen <ak@suse.de>

And replace all users with ordinary smp_processor_id.  The function
was originally added to get some basic oops information out even
if the GS register was corrupted. However that didn't
work for some anymore because printk is needed to print the oops
and it uses smp_processor_id() already. Also GS register corruptions
are not particularly common anymore.

This also helps the Xen port which would otherwise need to
do this in a special way because it can't access the local APIC.

Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Detect the situations in which the time after a resume from disk would
be earlier than the time before the suspend and prevent them from
happening on x86_64.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NAndi Kleen <ak@suse.de>

In i386's entry.S, FIX_STACK() needs annotation because it
replaces the stack pointer.  And the rest of nmi() needs
annotation in order to compile with these new annotations.
Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Apparently IA64 needs it, but i386/x86-64 don't anymore
since gcc 2.95 support was dropped.  Nobody else on linux-arch
requested keeping it generically

Cc: tony.luck@intel.com
Cc: kaos@sgi.com
Signed-off-by: NAndi Kleen <ak@suse.de>

From i386 x86-64 inherited code to force reserve the 640k-1MB area.
That was needed on some old systems.

But we generally trust the e820 map to be correct on 64bit systems
and mark all areas that are not memory correctly.

This patch will allow to use the real memory in there.

Or rather the only way to find out if it's still needed is to
try. So far I'm optimistic.
Signed-off-by: NAndi Kleen <ak@suse.de>

This is now automatically included by kbuild.
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

A kprobe executes IRET early and that could cause NMI recursion and stack
corruption.

Note: This problem was originally spotted and solved by Andi Kleen in the
x86_64 architecture. This patch is an adaption of his patch for i386.

AK: Merged with current code which was a bit different.
AK: Removed printk in nmi handler that shouldn't be there in the first time
AK: Added missing include.
AK: added KPROBES_END
Signed-off-by: NFernando Vazquez <fernando@intellilink.co.jp>
Signed-off-by: NAndi Kleen <ak@suse.de>

A kprobe executes IRET early and that could cause NMI recursion and stack
corruption.

Note: This problem was originally spotted by Andi Kleen. This patch
      adds fixes not included in his original patch.
[AK: Jan Beulich originally discovered these classes of bugs]
Signed-off-by: NFernando Vazquez <fernando@intellilink.co.jp>
Signed-off-by: NAndi Kleen <ak@suse.de>

Mark i386-specific cpu cache functions as __cpuinit. They are all
only called from arch/i386/common.c:display_cache_info() that already is
marked as __cpuinit.
Signed-off-by: NMagnus Damm <magnus@valinux.co.jp>
Signed-off-by: NAndi Kleen <ak@suse.de>