From: Jan Beulich Date: Thu, 8 Nov 2012 09:52:32 +0000 (+0100) Subject: x86/emul: only emulate possibly operand sizes for POPA X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~7676 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=21a80b2bf97a76d0932b45a35af918b3409e77c1;p=xen.git x86/emul: only emulate possibly operand sizes for POPA This opcode neither supports 1-byte operands, nor does it support 8-byte ones (since the opcode is undefined in 64-bit mode). Simplify the code accordingly. Signed-off-by: Jan Beulich Acked-by: Keir Fraser --- diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c index f0ee4891f8..462d7c72fd 100644 --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -1996,13 +1996,10 @@ x86_emulate( if ( (rc = read_ulong(x86_seg_ss, sp_post_inc(op_bytes), &dst.val, op_bytes, ctxt, ops)) != 0 ) goto done; - switch ( op_bytes ) - { - case 1: *(uint8_t *)regs[i] = (uint8_t)dst.val; break; - case 2: *(uint16_t *)regs[i] = (uint16_t)dst.val; break; - case 4: *regs[i] = (uint32_t)dst.val; break; /* 64b: zero-ext */ - case 8: *regs[i] = dst.val; break; - } + if ( op_bytes == 2 ) + *(uint16_t *)regs[i] = (uint16_t)dst.val; + else + *regs[i] = dst.val; /* 64b: zero-ext done by read_ulong() */ } break; }