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authorRichard Henderson <rth@twiddle.net>2015-07-07 14:38:58 +0100
committerRichard Henderson <rth@twiddle.net>2016-02-15 14:50:00 +1100
commit7d117ce81ef6258cdcc0d24c774d045fa4b5fd26 (patch)
tree527dc8dd09070f575ed06e0677e5e3b9cf206f4a
parentbdd87b3b591add6e4d7c6b6125fcf0d706cc8bc4 (diff)
target-i386: Clear bndregs during legacy near jumps
Signed-off-by: Richard Henderson <rth@twiddle.net>
-rw-r--r--target-i386/helper.h1
-rw-r--r--target-i386/mpx_helper.c8
-rw-r--r--target-i386/translate.c20
3 files changed, 29 insertions, 0 deletions
diff --git a/target-i386/helper.h b/target-i386/helper.h
index 709b195fe4..60a615f65b 100644
--- a/target-i386/helper.h
+++ b/target-i386/helper.h
@@ -21,6 +21,7 @@ DEF_HELPER_FLAGS_3(bndldx32, TCG_CALL_NO_WG, i64, env, tl, tl)
DEF_HELPER_FLAGS_3(bndldx64, TCG_CALL_NO_WG, i64, env, tl, tl)
DEF_HELPER_FLAGS_5(bndstx32, TCG_CALL_NO_WG, void, env, tl, tl, i64, i64)
DEF_HELPER_FLAGS_5(bndstx64, TCG_CALL_NO_WG, void, env, tl, tl, i64, i64)
+DEF_HELPER_1(bnd_jmp, void, env)
DEF_HELPER_2(aam, void, env, int)
DEF_HELPER_2(aad, void, env, int)
diff --git a/target-i386/mpx_helper.c b/target-i386/mpx_helper.c
index 53d98347d9..1bf717af05 100644
--- a/target-i386/mpx_helper.c
+++ b/target-i386/mpx_helper.c
@@ -156,3 +156,11 @@ void helper_bndstx32(CPUX86State *env, target_ulong base, target_ulong ptr,
cpu_stl_data_ra(env, bte + 4, ub, ra);
cpu_stl_data_ra(env, bte + 8, ptr, ra);
}
+
+void helper_bnd_jmp(CPUX86State *env)
+{
+ if (!(env->hflags2 & HF2_MPX_PR_MASK)) {
+ memset(env->bnd_regs, 0, sizeof(env->bnd_regs));
+ env->hflags &= ~HF_MPX_IU_MASK;
+ }
+}
diff --git a/target-i386/translate.c b/target-i386/translate.c
index 013c4592aa..ad7053ea1a 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -2406,6 +2406,19 @@ static void gen_reset_hflag(DisasContext *s, uint32_t mask)
}
}
+/* Clear BND registers during legacy branches. */
+static void gen_bnd_jmp(DisasContext *s)
+{
+ /* Do nothing if BND prefix present, MPX is disabled, or if the
+ BNDREGs are known to be in INIT state already. The helper
+ itself will check BNDPRESERVE at runtime. */
+ if ((s->prefix & PREFIX_REPNZ) == 0
+ && (s->flags & HF_MPX_EN_MASK) == 0
+ && (s->flags & HF_MPX_IU_MASK) == 0) {
+ gen_helper_bnd_jmp(cpu_env);
+ }
+}
+
/* generate a generic end of block. Trace exception is also generated
if needed */
static void gen_eob(DisasContext *s)
@@ -4795,6 +4808,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
tcg_gen_movi_tl(cpu_T1, next_eip);
gen_push_v(s, cpu_T1);
gen_op_jmp_v(cpu_T0);
+ gen_bnd_jmp(s);
gen_eob(s);
break;
case 3: /* lcall Ev */
@@ -4820,6 +4834,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
tcg_gen_ext16u_tl(cpu_T0, cpu_T0);
}
gen_op_jmp_v(cpu_T0);
+ gen_bnd_jmp(s);
gen_eob(s);
break;
case 5: /* ljmp Ev */
@@ -6201,6 +6216,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
gen_stack_update(s, val + (1 << ot));
/* Note that gen_pop_T0 uses a zero-extending load. */
gen_op_jmp_v(cpu_T0);
+ gen_bnd_jmp(s);
gen_eob(s);
break;
case 0xc3: /* ret */
@@ -6208,6 +6224,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
gen_pop_update(s, ot);
/* Note that gen_pop_T0 uses a zero-extending load. */
gen_op_jmp_v(cpu_T0);
+ gen_bnd_jmp(s);
gen_eob(s);
break;
case 0xca: /* lret im */
@@ -6274,6 +6291,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
}
tcg_gen_movi_tl(cpu_T0, next_eip);
gen_push_v(s, cpu_T0);
+ gen_bnd_jmp(s);
gen_jmp(s, tval);
}
break;
@@ -6303,6 +6321,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
} else if (!CODE64(s)) {
tval &= 0xffffffff;
}
+ gen_bnd_jmp(s);
gen_jmp(s, tval);
break;
case 0xea: /* ljmp im */
@@ -6342,6 +6361,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
if (dflag == MO_16) {
tval &= 0xffff;
}
+ gen_bnd_jmp(s);
gen_jcc(s, b, tval, next_eip);
break;