From 2da06af8106f8f35318bb084baf8448797ef058a Mon Sep 17 00:00:00 2001 From: "zhenzhong.duan" Date: Wed, 30 May 2012 12:52:15 +0800 Subject: [PATCH] x86, mtrr: Fix a type overflow in range_to_mtrr func When boot on sun G5+ with 4T mem, see an overflow in mtrr cleanup as below. *BAD*gran_size: 2G chunk_size: 2G num_reg: 10 lose cover RAM: -18014398505283592M This is because 1<<31 sign extended. Use an unsigned long constant to fix it. Useful for mem larger than or equal to 4T. -v2: Use 64bit constant instead of explicit type conversion as suggested by Yinghai. Description updated too. Signed-off-by: Zhenzhong Duan Link: http://lkml.kernel.org/r/4FC5A77F.6060505@oracle.com Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/mtrr/cleanup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c index ac140c7be396..bdda2e6c673b 100644 --- a/arch/x86/kernel/cpu/mtrr/cleanup.c +++ b/arch/x86/kernel/cpu/mtrr/cleanup.c @@ -266,7 +266,7 @@ range_to_mtrr(unsigned int reg, unsigned long range_startk, if (align > max_align) align = max_align; - sizek = 1 << align; + sizek = 1UL << align; if (debug_print) { char start_factor = 'K', size_factor = 'K'; unsigned long start_base, size_base;