From: zijun_hu <[email protected]> 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 used instead of fls_long() for fixing the bug, for example size=0x10000 -> get_count_order_long(0x10000)=16 -> align=0x10000 Andrew Morton help to names the function get_count_order_long and place it near its counterpart get_count_order() Signed-off-by: zijun_hu <[email protected]> Signed-off-by: Andrew Morton <[email protected]> --- Hi Andrew, please help to replace the following 6 patch series by this patch to make commit logs clear kindly, this patch is resulted from rebasing the 6 patch series into one, it maybe an alternative for you to rebasing them manually as we known, the 6 patch series fix the same issue together they are applied in mmotm and linux-next tree currently, not yet mainline the 6 patch series are listed as follows mm-vmalloc-fix-align-value-calculation-error.patch mm-vmalloc-fix-align-value-calculation-error-fix.patch mm-vmalloc-fix-align-value-calculation-error-v2.patch mm-vmalloc-fix-align-value-calculation-error-v2-fix.patch mm-vmalloc-fix-align-value-calculation-error-v2-fix-fix.patch mm-vmalloc-fix-align-value-calculation-error-v2-fix-fix-fix.patch include/linux/bitops.h | 36 ++++++++++++++++++++++++++---------- mm/vmalloc.c | 8 ++++---- 2 files changed, 30 insertions(+), 14 deletions(-) diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 299e76b59fe9..a83c822c35c2 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -65,16 +65,6 @@ static inline int get_bitmask_order(unsigned int count) return order; /* We could be slightly more clever with -1 here... */ } -static inline int get_count_order(unsigned int count) -{ - int order; - - order = fls(count) - 1; - if (count & (count - 1)) - order++; - return order; -} - static __always_inline unsigned long hweight_long(unsigned long w) { return sizeof(w) == 4 ? hweight32(w) : hweight64(w); @@ -191,6 +181,32 @@ static inline unsigned fls_long(unsigned long l) return fls64(l); } +static inline int get_count_order(unsigned int count) +{ + int order; + + order = fls(count) - 1; + if (count & (count - 1)) + order++; + return order; +} + +/** + * get_count_order_long - get order after rounding @l up to power of 2 + * @l: parameter + * + * it is same as get_count_order() but with long type parameter + */ +static inline int get_count_order_long(unsigned long l) +{ + if (l == 0UL) + return -1; + else if (l & (l - 1UL)) + return (int)fls_long(l); + else + return (int)fls_long(l) - 1; +} + /** * __ffs64 - find first set bit in a 64 bit word * @word: The 64 bit word diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 91f44e78c516..80660a0f989b 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1359,14 +1359,14 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, struct vm_struct *area; BUG_ON(in_interrupt()); - if (flags & VM_IOREMAP) - align = 1ul << clamp_t(int, fls_long(size), - PAGE_SHIFT, IOREMAP_MAX_ORDER); - size = PAGE_ALIGN(size); if (unlikely(!size)) return NULL; + if (flags & VM_IOREMAP) + align = 1ul << clamp_t(int, get_count_order_long(size), + PAGE_SHIFT, IOREMAP_MAX_ORDER); + area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node); if (unlikely(!area)) return NULL; -- 1.9.1
