Since we now use DS prefixes instead of NOP to remove LOCK prefixes,
there are no longer any issues with instruction boundaries moving around.
Depends on :
x86 alternatives : fix LOCK_PREFIX race with preemptible kernel and CPU hotplug
On Thu, 14 Aug 2008, Mathieu Desnoyers wrote:
>
> Changing the 0x90 (single-byte nop) currently used into a 0x3E DS segment
> override prefix should fix this issue. Since the default of the atomic
> instructions is to use the DS segment anyway, it should not affect the
> behavior.
Ok, so I think this is an _excellent_ patch, but I'd like to also then use
LOCK_PREFIX in include/asm-x86/futex.h.
See commit 9d55b9923a.
Linus
Applies to 2.6.27-rc2 (and -rc3 unless hell broke loose in futex.h between rc2
and rc3).
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Jeremy Fitzhardinge <jeremy@goop.org>
CC: Roland McGrath <roland@redhat.com>
CC: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
CC: Steven Rostedt <srostedt@redhat.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: David Miller <davem@davemloft.net>
CC: Ulrich Drepper <drepper@redhat.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Gregory Haskins <ghaskins@novell.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: "Luis Claudio R. Goncalves" <lclaudio@uudg.org>
CC: Clark Williams <williams@redhat.com>
CC: Christoph Lameter <cl@linux-foundation.org>
CC: Andi Kleen <andi@firstfloor.org>
CC: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: H. 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: Vegard Nossum <vegard.nossum@gmail.com>
Lots of asm-*/futex.h call pagefault_enable and pagefault_disable, which
are declared in linux/uaccess.h, without including linux/uaccess.h.
They all include asm/uaccess.h, so this patch replaces asm/uaccess.h
with linux/uaccess.h.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Real i386 CPUs do not have cmpxchg instructions. Catch it before
crashing on an invalid opcode.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use the _ASM_EXTABLE macro from <asm/asm.h>, instead of open-coding
__ex_table entires in include/asm-x86/futex.h.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The exception fixup for the futex macros __futex_atomic_op1/2 and
futex_atomic_cmpxchg_inatomic() is missing an entry when the lock
prefix is replaced by a NOP via SMP alternatives.
Chuck Ebert tracked this down from the information provided in:
https://bugzilla.redhat.com/show_bug.cgi?id=429412
A possible solution would be to add another fixup after the
LOCK_PREFIX, so both the LOCK and NOP case have their own entry in the
exception table, but it's not really worth the trouble.
Simply replace LOCK_PREFIX with lock and keep those untouched by SMP
alternatives.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move the headers to include/asm-x86 and fixup the
header install make rules
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ingo Molnar
Mathieu Desnoyers
Vegard Nossum
Jeff Dike
Joe Perches
Thomas Gleixner
H. Peter Anvin