From 43dceb97eb3e45957c5a2e8a1ec874b9eb1ee941 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Mon, 5 Jun 2017 17:19:27 +0100 Subject: [PATCH] x86/hvm: Rearange check_segment() to use a switch statement This simplifies the logic by separating the x86_segment check from the type check. No functional change. Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich --- xen/arch/x86/hvm/domain.c | 43 ++++++++++++++++++++++++++------------- 1 file changed, 29 insertions(+), 14 deletions(-) diff --git a/xen/arch/x86/hvm/domain.c b/xen/arch/x86/hvm/domain.c index dca7a0086e..293956cdad 100644 --- a/xen/arch/x86/hvm/domain.c +++ b/xen/arch/x86/hvm/domain.c @@ -70,23 +70,38 @@ static int check_segment(struct segment_register *reg, enum x86_segment seg) return -EINVAL; } - if ( seg == x86_seg_cs && !(reg->attr.fields.type & 0x8) ) + switch ( seg ) { - gprintk(XENLOG_ERR, "Non-code segment provided for CS\n"); - return -EINVAL; - } + case x86_seg_cs: + if ( !(reg->attr.fields.type & 0x8) ) + { + gprintk(XENLOG_ERR, "Non-code segment provided for CS\n"); + return -EINVAL; + } + break; - if ( seg == x86_seg_ss && - ((reg->attr.fields.type & 0x8) || !(reg->attr.fields.type & 0x2)) ) - { - gprintk(XENLOG_ERR, "Non-writeable segment provided for SS\n"); - return -EINVAL; - } + case x86_seg_ss: + if ( (reg->attr.fields.type & 0x8) || !(reg->attr.fields.type & 0x2) ) + { + gprintk(XENLOG_ERR, "Non-writeable segment provided for SS\n"); + return -EINVAL; + } + break; - if ( reg->attr.fields.s && seg != x86_seg_ss && seg != x86_seg_cs && - (reg->attr.fields.type & 0x8) && !(reg->attr.fields.type & 0x2) ) - { - gprintk(XENLOG_ERR, "Non-readable segment provided for DS or ES\n"); + case x86_seg_ds: + case x86_seg_es: + if ( (reg->attr.fields.type & 0x8) && !(reg->attr.fields.type & 0x2) ) + { + gprintk(XENLOG_ERR, "Non-readable segment provided for DS or ES\n"); + return -EINVAL; + } + break; + + case x86_seg_tr: + break; + + default: + ASSERT_UNREACHABLE(); return -EINVAL; } -- 2.30.2