From: Malcolm Crossley Date: Wed, 25 Apr 2012 10:35:56 +0000 (+0200) Subject: x86-64: Fix memory hotplug epfn upper limit test for updating the compat M2P table X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~8556^2 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=f1434c2e8e57aa9f75ea8d20612396524df8cd96;p=xen.git x86-64: Fix memory hotplug epfn upper limit test for updating the compat M2P table The epfn is being compared to (RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) without a 2 bit shift, resulting in the epfn being compared to the size of the RDWR_COMPAT_MPT table in bytes instead of the maximum page frame number that the RDWR_COMPAT_MPT table can map. Signed-off-by: Malcolm Crossley Committed-by: Jan Beulich --- diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c index 6a71c2860e..635a499d65 100644 --- a/xen/arch/x86/x86_64/mm.c +++ b/xen/arch/x86/x86_64/mm.c @@ -454,7 +454,7 @@ static int setup_compat_m2p_table(struct mem_hotadd_info *info) if ((smap > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2)) ) return 0; - if (epfn > (RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START)) + if ( epfn > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2) ) epfn = (RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2; emap = ( (epfn + ((1UL << (L2_PAGETABLE_SHIFT - 2)) - 1 )) &