On Thu, 31 Jul 2014, Chintan Pandya wrote: > __kmap_atomic_idx is per_cpu variable. Each CPU can > use KM_TYPE_NR entries from FIXMAP i.e. from 0 to > KM_TYPE_NR - 1. Allowing __kmap_atomic_idx to over- > shoot to KM_TYPE_NR can mess up with next CPU's 0th > entry which is a bug. Hence BUG_ON if > __kmap_atomic_idx >= KM_TYPE_NR. > This appears to be a completely different patch, not a v2. Why is this check only done for CONFIG_DEBUG_HIGHMEM? I think Andrew's comment earlier was referring to the changelog only and not the patch, which looked correct. > Signed-off-by: Chintan Pandya <cpandya@xxxxxxxxxxxxxx> > --- > Changes: > > V1 --> V2 > > Not touching CONFIG_DEBUG_HIGHMEM. > > include/linux/highmem.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/highmem.h b/include/linux/highmem.h > index 7fb31da..9286a46 100644 > --- a/include/linux/highmem.h > +++ b/include/linux/highmem.h > @@ -93,7 +93,7 @@ static inline int kmap_atomic_idx_push(void) > > #ifdef CONFIG_DEBUG_HIGHMEM > WARN_ON_ONCE(in_irq() && !irqs_disabled()); > - BUG_ON(idx > KM_TYPE_NR); > + BUG_ON(idx >= KM_TYPE_NR); > #endif > return idx; > } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>