Mark Rutland e88d62cd4b percpu: make this_cpu_generic_read() atomic w.r.t. interrupts ... As raw_cpu_generic_read() is a plain read from a raw_cpu_ptr() address, it's possible (albeit unlikely) that the compiler will split the access across multiple instructions. In this_cpu_generic_read() we disable preemption but not interrupts before calling raw_cpu_generic_read(). Thus, an interrupt could be taken in the middle of the split load instructions. If a this_cpu_write() or RMW this_cpu_*() op is made to the same variable in the interrupt handling path, this_cpu_read() will return a torn value. For native word types, we can avoid tearing using READ_ONCE(), but this won't work in all cases (e.g. 64-bit types on most 32-bit platforms). This patch reworks this_cpu_generic_read() to use READ_ONCE() where possible, otherwise falling back to disabling interrupts. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Lameter <cl@linux.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>		2017-09-26 07:37:33 -07:00
..
bitops	bitops: Do not default to __clear_bit() for __clear_bit_unlock()	2016-03-21 10:50:48 +01:00
4level-fixup.h	asm-generic: introduce 5level-fixup.h	2017-03-09 11:48:47 -08:00
5level-fixup.h	asm-generic: introduce 5level-fixup.h	2017-03-09 11:48:47 -08:00
asm-offsets.h	asm-generic: Add common asm-offsets.h	2015-06-23 13:35:49 +09:00
asm-prototypes.h	asm-prototypes: Clear any CPP defines before declaring the functions	2017-01-05 12:57:42 +01:00
atomic64.h	locking/atomic: Fix atomic_set_release() for 'funny' architectures	2017-08-10 12:28:54 +02:00
atomic-long.h	locking/atomic: Introduce inc/dec variants for the atomic_fetch_$op() API	2016-07-07 09:16:20 +02:00
atomic.h	openrisc: add optimized atomic operations	2017-02-25 04:14:06 +09:00
audit_change_attr.h	audit: Modify a set of system calls in audit class definitions	2014-01-17 17:01:46 -05:00
audit_dir_write.h
audit_read.h
audit_signal.h
audit_write.h	audit: Modify a set of system calls in audit class definitions	2014-01-17 17:01:46 -05:00
barrier.h	locking/spinlock, arch: Update and fix spin_unlock_wait() implementations	2016-06-14 11:55:15 +02:00
bitops.h	arch: Prepare for smp_mb__{before,after}_atomic()	2014-04-18 11:40:30 +02:00
bitsperlong.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
bug.h	asm-generic/bug.h: declare struct pt_regs; before function prototype	2017-07-10 16:32:34 -07:00
bugs.h
cache.h
cacheflush.h
checksum.h	ipv4: Update parameters for csum_tcpudp_magic to their original types	2016-03-13 23:55:13 -04:00
clkdev.h	asm-generic: COMMON_CLK defines __clk_{get,put}	2014-09-25 18:00:45 -07:00
cmpxchg-local.h	LLVMLinux: Remove warning about returning an uninitialized variable	2014-04-09 13:44:35 -07:00
cmpxchg.h	asm-generic: cmpxchg: avoid warnings from macro-ized cmpxchg() implementations	2015-10-15 00:21:13 +02:00
current.h
delay.h
device.h
div64.h	__div64_32(): make it overridable at compile time	2015-11-16 14:42:12 -05:00
dma-contiguous.h	asm-generic: Add dma-contiguous.h	2014-09-22 13:35:51 +02:00
dma.h
early_ioremap.h	x86/mm: Extend early_memremap() support with additional attrs	2017-07-18 11:38:00 +02:00
emergency-restart.h
exec.h
export.h	modversions: treat symbol CRCs as 32 bit quantities	2017-02-03 08:28:25 -08:00
extable.h	add asm-generic/extable.h	2017-03-27 20:27:28 -04:00
fb.h
fixmap.h	asm-generic: Fix local variable shadow in __set_fixmap_offset	2016-02-16 15:10:44 +00:00
ftrace.h
futex.h	futex: Remove duplicated code and fix undefined behaviour	2017-08-25 22:49:59 +02:00
getorder.h
gpio.h	gpio: allow setting ARCH_NR_GPIOS from Kconfig	2016-02-19 00:22:54 +01:00
hardirq.h
hugetlb.h	mm/hugetlb: allow architectures to override huge_pte_clear()	2017-07-06 16:24:34 -07:00
hw_irq.h
ide_iops.h
int-ll64.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
io.h	x86/io: Remove xlate_dev_kmem_ptr() duplication	2017-07-24 11:18:21 +02:00
ioctl.h	include/asm-generic/ioctl.h: fix _IOC_TYPECHECK sparse error	2014-06-06 16:08:13 -07:00
iomap.h	asm-generic/io.h: add io{read,write}64 accessors	2016-05-31 16:41:50 +08:00
irq_regs.h
irq_work.h	irq_work: Introduce arch_irq_work_has_interrupt()	2014-09-13 18:38:07 +02:00
irq.h
irqflags.h
kdebug.h
kmap_types.h
kprobes.h	kprobes: move kprobe declarations to asm-generic/kprobes.h	2017-02-27 18:43:45 -08:00
kvm_para.h	KVM: add kvm_para_available to asm-generic/kvm_para.h	2013-06-05 13:21:29 +03:00
linkage.h
local64.h
local.h
mcs_spinlock.h	locking/mcs: Allow architecture specific asm files to be used for contended case	2014-02-09 21:18:52 +01:00
memory_model.h	mm: add PHYS_PFN, use it in __phys_to_pfn()	2016-01-14 16:00:49 -08:00
mm_hooks.h	mm/gup: Drop the arch_pte_access_permitted() MMU callback	2017-03-18 09:48:01 +01:00
mm-arch-hooks.h	mm: clean up per architecture MM hook header files	2015-07-17 16:39:53 -07:00
mmu_context.h	asm-generic: Remove asm-generic arch_bprm_mm_init()	2014-11-22 21:52:08 +01:00
mmu.h	asm-generic/mmu.h: Add support for FDPIC	2012-12-09 23:14:14 +01:00
module.h
msi.h	asm-generic: Add msi.h	2014-11-23 13:01:47 +01:00
page.h	asm-generic: page.h: Remove useless get_user_page and free_user_page	2016-02-26 15:24:55 +01:00
param.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
parport.h	include: remove __dev* attributes.	2013-01-03 15:57:16 -08:00
pci_iomap.h	PCI: Add pci_iomap_wc() variants	2015-08-25 09:59:45 +02:00
pci.h	PCI: Remove unused pcibios_select_root() (again)	2015-06-08 07:56:21 -05:00
percpu.h	percpu: make this_cpu_generic_read() atomic w.r.t. interrupts	2017-09-26 07:37:33 -07:00
pgalloc.h
pgtable-nop4d-hack.h	asm-generic: introduce __ARCH_USE_5LEVEL_HACK	2017-03-09 11:48:47 -08:00
pgtable-nop4d.h	asm-generic: introduce <asm-generic/pgtable-nop4d.h>	2017-03-09 11:48:47 -08:00
pgtable-nopmd.h
pgtable-nopud.h	asm-generic: introduce <asm-generic/pgtable-nop4d.h>	2017-03-09 11:48:47 -08:00
pgtable.h	mm: soft-dirty: keep soft-dirty bits over thp migration	2017-09-08 18:26:45 -07:00
preempt.h	sched/preempt: Fix preempt_count manipulations	2016-05-17 12:24:21 +02:00
ptrace.h
qrwlock_types.h	locking/qrwlock: Rename ->lock to ->wait_lock	2015-09-18 09:27:29 +02:00
qrwlock.h	locking/qrwlock: Fix write unlock bug on big endian systems	2016-08-10 14:13:27 +02:00
qspinlock_types.h	locking/qspinlock: Move __ARCH_SPIN_LOCK_UNLOCKED to qspinlock_types.h	2016-02-29 10:02:43 +01:00
qspinlock.h	locking: Remove spin_unlock_wait() generic definitions	2017-08-17 08:08:58 -07:00
resource.h	asm-generic: remove _STK_LIM_MAX	2014-05-15 00:32:09 +01:00
rwsem.h	locking/rwsem: Remove unnecessary atomic_long_t casts	2017-01-20 09:46:44 +01:00
seccomp.h	seccomp: Get compat syscalls from asm-generic header	2016-05-13 14:02:00 +02:00
sections.h	irq: Make the irqentry text section unconditional	2017-08-10 16:28:53 +02:00
segment.h
serial.h
set_memory.h	treewide: move set_memory_* functions away from cacheflush.h	2017-05-08 17:15:13 -07:00
signal.h	unify default ptrace_signal_deliver	2012-11-29 00:01:23 -05:00
simd.h	crypto: create generic version of ablk_helper	2013-09-24 06:02:24 +10:00
sizes.h
spinlock.h
statfs.h	UAPI: (Scripted) Disintegrate include/asm-generic	2012-10-04 18:20:15 +01:00
string.h
switch_to.h
syscall.h	syscall.h: fix doc text for syscall_get_arch()	2014-09-23 16:20:00 -04:00
syscalls.h	burying unused conditionals	2013-02-14 09:21:15 -05:00
termios-base.h	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
termios.h	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
timex.h
tlb.h	mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem	2017-08-10 15:54:07 -07:00
tlbflush.h
topology.h	cpumask: fix spurious cpumask_of_node() on non-NUMA multi-node configs	2017-08-28 16:13:16 -07:00
trace_clock.h	tracing,x86: Add a TSC trace_clock	2012-11-13 15:48:27 -05:00
uaccess.h	fix the __user misannotations in asm-generic get_user/put_user	2017-09-04 12:07:24 -04:00
unaligned.h	asm-generic: allow generic unaligned access if the arch supports it	2014-05-08 10:22:23 +02:00
unistd.h	We get rid of the general module prefix confusion with a binary config option,	2013-05-05 10:58:06 -07:00
user.h
vga.h
vmlinux.lds.h	MTD changes for 4.14:	2017-09-09 14:48:21 -07:00
vtime.h	include/asm-generic/vtime.h: avoid zero-length file	2013-09-30 14:31:02 -07:00
word-at-a-time.h	Make asm/word-at-a-time.h available on all architectures	2015-07-08 16:41:55 -04:00
xor.h	asm-generic: xor: mark static functions as __maybe_unused	2012-10-03 21:21:06 +02:00