394e3902c5
When we stop allocating percpu memory for not-possible CPUs we must not touch the percpu data for not-possible CPUs at all. The correct way of doing this is to test cpu_possible() or to use for_each_cpu(). This patch is a kernel-wide sweep of all instances of NR_CPUS. I found very few instances of this bug, if any. But the patch converts lots of open-coded test to use the preferred helper macros. Cc: Mikael Starvik <starvik@axis.com> Cc: David Howells <dhowells@redhat.com> Acked-by: Kyle McMartin <kyle@parisc-linux.org> Cc: Anton Blanchard <anton@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Andi Kleen <ak@muc.de> Cc: Christian Zankel <chris@zankel.net> Cc: Philippe Elie <phil.el@wanadoo.fr> Cc: Nathan Scott <nathans@sgi.com> Cc: Jens Axboe <axboe@suse.de> Cc: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
42 lines
1.2 KiB
C
42 lines
1.2 KiB
C
#ifndef _ASM_GENERIC_PERCPU_H_
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#define _ASM_GENERIC_PERCPU_H_
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#include <linux/compiler.h>
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#define __GENERIC_PER_CPU
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#ifdef CONFIG_SMP
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extern unsigned long __per_cpu_offset[NR_CPUS];
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/* Separate out the type, so (int[3], foo) works. */
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#define DEFINE_PER_CPU(type, name) \
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__attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name
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/* var is in discarded region: offset to particular copy we want */
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#define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]))
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#define __get_cpu_var(var) per_cpu(var, smp_processor_id())
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/* A macro to avoid #include hell... */
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#define percpu_modcopy(pcpudst, src, size) \
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do { \
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unsigned int __i; \
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for_each_cpu(__i) \
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memcpy((pcpudst)+__per_cpu_offset[__i], \
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(src), (size)); \
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} while (0)
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#else /* ! SMP */
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#define DEFINE_PER_CPU(type, name) \
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__typeof__(type) per_cpu__##name
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#define per_cpu(var, cpu) (*((void)(cpu), &per_cpu__##var))
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#define __get_cpu_var(var) per_cpu__##var
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#endif /* SMP */
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#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
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#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
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#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
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#endif /* _ASM_GENERIC_PERCPU_H_ */
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