The current lock prefix UP/SMP alternative code doesn't allow
LOCK_PREFIX to be used in alternatives code.

This patch solves the problem by adding a new LOCK_PREFIX_ALTERNATIVE_PATCH
macro that only records the lock prefix location but does not emit
the prefix.

The user of this macro can then start any alternative sequence with
"lock" and have it UP/SMP patched.

To make this work, the UP/SMP alternative code is changed to do the
lock/DS prefix switching only if the byte actually contains a lock or
DS prefix.

Thus, if an alternative without the "lock" is selected, it will now do
nothing instead of clobbering the code.

Changes in v2:
- Naming change
- Change label to not conflict with alternatives
Signed-off-by: NLuca Barbieri <luca@luca-barbieri.com>
LKML-Reference: <1267005265-27958-2-git-send-email-luca@luca-barbieri.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

In order to avoid unnecessary chains of branches, rather than
implementing copy_user_generic() as a function consisting of
just a single (possibly patched) branch, instead properly deal
with patching call instructions in the alternative instructions
framework, and move the patching into the callers.

As a follow-on, one could also introduce something like
__EXPORT_SYMBOL_ALT() to avoid patching call sites in modules.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4B2BB8180200007800026AE7@vpn.id2.novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Having run into the run-(boot-)time check a couple of times lately,
I finally took time to find a build-time check so that one doesn't
need to analyze the register/stack dump and resolve this (through
manual lookup in vmlinux) to the offending construct.

The assembler will emit a message like "Error: value of <num> too
large for field of 1 bytes at <offset>", which while not pointing
out the source location still makes analysis quite a bit easier.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
LKML-Reference: <4B0FF8AA0200007800022703@vpn.id2.novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Some of the NOPs tables aren't used on 64-bits, quite some code and
data is needed post-init for module loading only, and a couple of
functions aren't used outside that file (i.e. can be static, and don't
need to be exported).

The change to __INITDATA/__INITRODATA is needed to avoid an assembler
warning.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
LKML-Reference: <4A8BC8A00200007800010823@vpn.id2.novell.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Alternative header duplicates assembly that could be merged in
one single macro.  Merging this into this macro also allows to
directly declare ALTERNATIVE() statements within assembly code.

Uses a __stringify() of the feature bits rather than passing a
"i" operand.  Leave the old %0 operand as-is (set to 0), unused
to stay compatible with API.

(v2: tab alignment fixes)

[ Impact: cleanup ]
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
LKML-Reference: <20090428151346.GA31212@Krystal>
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>

This patch patches the call to mcount with nops instead
of a jmp over the mcount call.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix a memcpy that should be a text_poke (in apply_alternatives).

Use kernel_wp_save/kernel_wp_restore in text_poke to support DEBUG_RODATA
correctly and so the CPU HOTPLUG special case can be removed.

Add text_poke_early, for alternatives and paravirt boot-time and module load
time patching.

Changelog:

- Fix text_set and text_poke alignment check (mixed up bitwise and and or)
- Remove text_set
- Export add_nops, so it can be used by others.
- Document text_poke_early.
- Remove clflush, since it breaks some VIA architectures and is not strictly
  necessary.
- Add kerneldoc to text_poke and text_poke_early.
- Create a second vmap instead of using the WP bit to support Xen and VMI.
- Move local_irq disable within text_poke and text_poke_early to be able to
  be sleepable in these functions.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Andi Kleen <andi@firstfloor.org>
CC: pageexec@freemail.hu
CC: H. Peter Anvin <hpa@zytor.com>
CC: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This actually merges <asm-x86/alternative_{32,64}.h> into
<asm-x86/alternative.h>.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

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>