William Cohen a1dd586647 Correct the race condition in aarch64_insn_patch_text_sync() ... commit 899d5933b2 upstream. When experimenting with patches to provide kprobes support for aarch64 smp machines would hang when inserting breakpoints into kernel code. The hangs were caused by a race condition in the code called by aarch64_insn_patch_text_sync(). The first processor in the aarch64_insn_patch_text_cb() function would patch the code while other processors were still entering the function and incrementing the cpu_count field. This resulted in some processors never observing the exit condition and exiting the function. Thus, processors in the system hung. The first processor to enter the patching function performs the patching and signals that the patching is complete with an increment of the cpu_count field. When all the processors have incremented the cpu_count field the cpu_count will be num_cpus_online()+1 and they will return to normal execution. Fixes: ae16480785 arm64: introduce interfaces to hotpatch kernel and module code Signed-off-by: William Cohen <wcohen@redhat.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2014-11-21 09:23:02 -08:00
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boot	arm64: dts: Reduce size of virtio block device for foundation model	2013-12-20 16:20:21 +00:00
configs	arm64: defconfig: Expand default enabled features	2014-02-07 17:17:28 +00:00
include	arm64: compat: fix compat types affecting struct compat_elf_prpsinfo	2014-10-30 09:38:24 -07:00
kernel	Correct the race condition in aarch64_insn_patch_text_sync()	2014-11-21 09:23:02 -08:00
kvm	ARM/ARM64: KVM: Nuke Hyp-mode tlbs before enabling MMU	2014-10-05 14:52:10 -07:00
lib	arm64: __clear_user: handle exceptions on strb	2014-11-21 09:23:02 -08:00
mm	arm64: mm: Make icache synchronisation logic huge page aware	2014-07-09 11:18:26 -07:00
xen	xen/arm,arm64: enable SWIOTLB_XEN	2013-10-10 13:40:44 +00:00
Kconfig	locking/mutex: Disable optimistic spinning on some architectures	2014-07-28 08:06:03 -07:00
Kconfig.debug	arm64: Remove duplicate DEBUG_STACK_USAGE config	2013-10-02 18:03:26 +01:00
Makefile	arm64: big-endian: add big-endian support to top-level arch Makefile	2013-10-25 15:59:31 +01:00