linux/arch/arm/vfp
Stephen Boyd 568dca15aa ARM: 7627/1: Predicate preempt logic on PREEMP_COUNT not PREEMPT alone
Patrik Kluba reports that the preempt count becomes invalid due
to the preempt_enable() call being unbalanced with a
preempt_disable() call in the vfp assembly routines. This happens
because preempt_enable() and preempt_disable() update preempt
counts under PREEMPT_COUNT=y but the vfp assembly routines do so
under PREEMPT=y. In a configuration where PREEMPT=n and
DEBUG_ATOMIC_SLEEP=y, PREEMPT_COUNT=y and so the preempt_enable()
call in VFP_bounce() keeps subtracting from the preempt count
until it goes negative.

Fix this by always using PREEMPT_COUNT to decided when to update
preempt counts in the ARM assembly code.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reported-by: Patrik Kluba <pkluba@dension.com>
Tested-by: Patrik Kluba <pkluba@dension.com>
Cc: <stable@vger.kernel.org> # 2.6.30
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-01-16 16:51:10 +00:00
..
Makefile ARM: vfp: use -mfloat-abi=soft to build vfp 2011-10-01 21:08:55 +02:00
entry.S ARM: 7627/1: Predicate preempt logic on PREEMP_COUNT not PREEMPT alone 2013-01-16 16:51:10 +00:00
vfp.h [ARM] 5387/1: Add ptrace VFP support on ARM 2009-02-12 10:59:43 +00:00
vfpdouble.c [ARM] vfp: fix fuitod/fsitod instructions 2008-01-10 17:07:08 +00:00
vfphw.S ARM: 7627/1: Predicate preempt logic on PREEMP_COUNT not PREEMPT alone 2013-01-16 16:51:10 +00:00
vfpinstr.h [ARM] 4583/1: ARMv7: Add VFPv3 support 2008-01-26 14:41:28 +00:00
vfpmodule.c ARM: 7566/1: vfp: fix save and restore when running on pre-VFPv3 and CONFIG_VFPv3 set 2012-10-29 10:04:05 +00:00
vfpsingle.c [ARM] Remove unnecessary asm/ptrace.h from VFP support code 2007-04-22 10:56:40 +01:00