From 3ada6e07acb8fed57cb9318396512ff3aea48879 Mon Sep 17 00:00:00 2001 From: Neel Natu Date: Fri, 11 Jul 2014 01:23:38 +0000 Subject: [PATCH] Use the correct offset when converting a logical address (segment:offset) to a linear address. --- sys/amd64/vmm/vmm_instruction_emul.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/sys/amd64/vmm/vmm_instruction_emul.c b/sys/amd64/vmm/vmm_instruction_emul.c index 261572db3084..a1cd9f150289 100644 --- a/sys/amd64/vmm/vmm_instruction_emul.c +++ b/sys/amd64/vmm/vmm_instruction_emul.c @@ -627,7 +627,7 @@ vie_calculate_gla(enum vm_cpu_mode cpu_mode, enum vm_reg_name seg, struct seg_desc *desc, uint64_t offset, int length, int addrsize, int prot, uint64_t *gla) { - uint64_t low_limit, high_limit, segbase; + uint64_t firstoff, low_limit, high_limit, segbase; int glasize, type; KASSERT(seg >= VM_REG_GUEST_ES && seg <= VM_REG_GUEST_GS, @@ -637,6 +637,7 @@ vie_calculate_gla(enum vm_cpu_mode cpu_mode, enum vm_reg_name seg, KASSERT((prot & ~(PROT_READ | PROT_WRITE)) == 0, ("%s: invalid prot %#x", __func__, prot)); + firstoff = offset; if (cpu_mode == CPU_MODE_64BIT) { KASSERT(addrsize == 4 || addrsize == 8, ("%s: invalid address " "size %d for cpu_mode %d", __func__, addrsize, cpu_mode)); @@ -722,11 +723,11 @@ vie_calculate_gla(enum vm_cpu_mode cpu_mode, enum vm_reg_name seg, } /* - * Truncate 'offset' to the effective address size before adding + * Truncate 'firstoff' to the effective address size before adding * it to the segment base. */ - offset &= vie_size2mask(addrsize); - *gla = (segbase + offset) & vie_size2mask(glasize); + firstoff &= vie_size2mask(addrsize); + *gla = (segbase + firstoff) & vie_size2mask(glasize); return (0); }