From 25818f0f288cd5333ba5a90ad6dde3def4c4ff58 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 28 Jul 2010 15:25:10 +1000 Subject: [PATCH] memblock: Make MEMBLOCK_ERROR be 0 And ensure we don't hand out 0 as a valid allocation. We put the low limit at PAGE_SIZE arbitrarily. Signed-off-by: Benjamin Herrenschmidt --- include/linux/memblock.h | 2 +- mm/memblock.c | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 1a9c29cc92fa..dfa64494ced1 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -19,7 +19,7 @@ #include #define INIT_MEMBLOCK_REGIONS 128 -#define MEMBLOCK_ERROR (~(phys_addr_t)0) +#define MEMBLOCK_ERROR 0 struct memblock_region { phys_addr_t base; diff --git a/mm/memblock.c b/mm/memblock.c index 85cfa1d3ab28..cb520df2a414 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -105,6 +105,12 @@ static phys_addr_t __init memblock_find_region(phys_addr_t start, phys_addr_t en phys_addr_t base, res_base; long j; + /* Prevent allocations returning 0 as it's also used to + * indicate an allocation failure + */ + if (start == 0) + start = PAGE_SIZE; + base = memblock_align_down((end - size), align); while (start <= base) { j = memblock_overlaps_region(&memblock.reserved, base, size);