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
[[email protected]: s/get_order_long()/get_count_order_long()/]
[[email protected]: fixes]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: locate get_count_order_long() next to get_count_order()]
[[email protected]: move get_count_order[_long] definitions to pick up fls_long()]
[[email protected]: move out get_count_order[_long]() from __KERNEL__ scope]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: zijun_hu <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: David Rientjes <[email protected]>
Signed-off-by: zijun_hu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 299e76b..a83c822 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -65,16 +65,6 @@
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 @@
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 91f44e7..80660a0 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1359,14 +1359,14 @@
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;
