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ARM: fix overflow of vmalloc_limit in sanity_check_meminfo

PATCH New Konstantin Khlebnikov 1 participant 1 message Nov 18, 2014 Arm (32-bit)

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PATCH 1/1 ARM: fix overflow of vmalloc_limit in sanity_check_meminfo

vmalloc_limit easily overflows if CONFIG_VMSPLIT_1G=y and CONFIG_ARM_LPAE=n, in this case whole memory turns into "highmem" and system cannot boot. For example if PHYS_OFFSET=0x80000000 and PAGE_OFFSET=0x40000000 then vmalloc_limit should be 0x1_2F800000, but value does not fit into variable.

---
 arch/arm/mm/mmu.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
arch/arm/mm/mmu.c +5 -1
index 9f98cec..9d2cdda 100644
@@ -1075,10 +1075,14 @@ phys_addr_t arm_lowmem_limit __initdata = 0;
 void __init sanity_check_meminfo(void)
 {
 	phys_addr_t memblock_limit = 0;
+	phys_addr_t vmalloc_limit = -1;
 	int highmem = 0;
-	phys_addr_t vmalloc_limit = __pa(vmalloc_min - 1) + 1;
 	struct memblock_region *reg;
 
+	if ((unsigned long)vmalloc_min - PAGE_OFFSET <
+			vmalloc_limit - PHYS_OFFSET)
+		vmalloc_limit = __pa(vmalloc_min - 1) + 1;
+
 	for_each_memblock(memory, reg) {
 		phys_addr_t block_start = reg->base;
 		phys_addr_t block_end = reg->base + reg->size;