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authorPaolo Bonzini <pbonzini@redhat.com>2016-03-02 16:04:38 +0100
committerRichard Henderson <rth@twiddle.net>2016-03-14 10:52:48 -0700
commite2e02a820741ec4d96b8f313b06a2a7ed5e94fbd (patch)
tree6e0df6c61fbf4b602e6bccc175830d95222c6319 /target-i386/translate.c
parenta657f79e32422634415c09f3f15c73d610297af5 (diff)
downloadqemu-arm-e2e02a820741ec4d96b8f313b06a2a7ed5e94fbd.tar.gz
target-i386: Fix addr16 prefix
While ADDSEG will only be false in 16-bit mode for LEA, it can be false even in other cases when 16-bit addresses are obtained via the 67h prefix in 32-bit mode. In this case, gen_lea_v_seg forgets to add a nonzero FS or GS base if CS/DS/ES/SS are all zero. This case is pretty rare but happens when booting Windows 95/98, and this patch fixes it. The bug is visible since commit d6a291498, but it was introduced together with gen_lea_v_seg and it probably could be reproduced with a "addr16 gs movsb" instruction as early as in commit ca2f29f555805d07fb0b9ebfbbfc4e3656530977. Reported-by: Hervé Poussineau <hpoussin@reactos.org> Tested-by: Hervé Poussineau <hpoussin@reactos.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1456931078-21635-1-git-send-email-pbonzini@redhat.com> Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'target-i386/translate.c')
-rw-r--r--target-i386/translate.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/target-i386/translate.c b/target-i386/translate.c
index b73c237c9e..0b67165c51 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -466,15 +466,15 @@ static void gen_lea_v_seg(DisasContext *s, TCGMemOp aflag, TCGv a0,
break;
case MO_16:
/* 16 bit address */
- if (ovr_seg < 0) {
- ovr_seg = def_seg;
- }
tcg_gen_ext16u_tl(cpu_A0, a0);
- /* ADDSEG will only be false in 16-bit mode for LEA. */
- if (!s->addseg) {
- return;
- }
a0 = cpu_A0;
+ if (ovr_seg < 0) {
+ if (s->addseg) {
+ ovr_seg = def_seg;
+ } else {
+ return;
+ }
+ }
break;
default:
tcg_abort();