mm/vmalloc.c: fix align value calculation error
It causes double align requirement for __get_vm_area_node() if parameter size is power of 2 and VM_IOREMAP is set in parameter flags, for example size=0x10000 -> fls_long(0x10000)=17 -> align=0x20000 get_count_order_long() is implemented and can be used instead of fls_long() for fixing the bug, for example size=0x10000 -> get_count_order_long(0x10000)=16 -> align=0x10000 [akpm@linux-foundation.org: s/get_order_long()/get_count_order_long()/] [zijun_hu@zoho.com: fixes] Link: http://lkml.kernel.org/r/57AABC8B.1040409@zoho.com [akpm@linux-foundation.org: locate get_count_order_long() next to get_count_order()] [akpm@linux-foundation.org: move get_count_order[_long] definitions to pick up fls_long()] [zijun_hu@htc.com: move out get_count_order[_long]() from __KERNEL__ scope] Link: http://lkml.kernel.org/r/57B2C4CE.80303@zoho.com Link: http://lkml.kernel.org/r/fc045ecf-20fa-0722-b3ac-9a6140488fad@zoho.com Signed-off-by: zijun_hu <zijun_hu@htc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: zijun_hu <zijun_hu@htc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@ -65,16 +65,6 @@ static inline int get_bitmask_order(unsigned int count)
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return order; /* We could be slightly more clever with -1 here... */
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}
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static inline int get_count_order(unsigned int count)
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{
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int order;
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order = fls(count) - 1;
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if (count & (count - 1))
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order++;
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return order;
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}
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static __always_inline unsigned long hweight_long(unsigned long w)
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{
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return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
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@ -191,6 +181,32 @@ static inline unsigned fls_long(unsigned long l)
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return fls64(l);
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}
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static inline int get_count_order(unsigned int count)
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{
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int order;
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order = fls(count) - 1;
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if (count & (count - 1))
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order++;
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return order;
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}
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/**
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* get_count_order_long - get order after rounding @l up to power of 2
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* @l: parameter
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*
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* it is same as get_count_order() but with long type parameter
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*/
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static inline int get_count_order_long(unsigned long l)
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{
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if (l == 0UL)
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return -1;
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else if (l & (l - 1UL))
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return (int)fls_long(l);
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else
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return (int)fls_long(l) - 1;
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}
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/**
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* __ffs64 - find first set bit in a 64 bit word
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* @word: The 64 bit word
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@ -1359,14 +1359,14 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
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struct vm_struct *area;
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BUG_ON(in_interrupt());
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if (flags & VM_IOREMAP)
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align = 1ul << clamp_t(int, fls_long(size),
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PAGE_SHIFT, IOREMAP_MAX_ORDER);
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size = PAGE_ALIGN(size);
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if (unlikely(!size))
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return NULL;
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if (flags & VM_IOREMAP)
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align = 1ul << clamp_t(int, get_count_order_long(size),
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PAGE_SHIFT, IOREMAP_MAX_ORDER);
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area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
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if (unlikely(!area))
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return NULL;
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