| Message ID | 1431818883-14944-1-git-send-email-aurelien@aurel32.net |
|---|---|
| State | New |
| Headers | show |
On 05/17/2015 01:28 AM, Aurelien Jarno wrote: > Commit 7a6c7067f optimized CC computation by only saving cc_op before > calling helpers as they either don't touch the CC or generate a new > static value. This however doesn't work for the EX instruction as the > helper changes or not the CC value depending on the actual executed > instruction (e.g. MVC vs CLC). > > This patches force a CC computation before calling the helper. This > fixes random memory corruption occuring in guests. > > Cc: Richard Henderson <rth@twiddle.net> > Cc: Alexander Graf <agraf@suse.de> > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Sounds plausible to me, though I'm surprised I didn't run into this myself yet. Richard? Alex > --- > target-s390x/translate.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/target-s390x/translate.c b/target-s390x/translate.c > index 80e3a54..10522df 100644 > --- a/target-s390x/translate.c > +++ b/target-s390x/translate.c > @@ -2095,7 +2095,7 @@ static ExitStatus op_ex(DisasContext *s, DisasOps *o) > TCGv_i64 tmp; > > update_psw_addr(s); > - update_cc_op(s); > + gen_op_calc_cc(s); > > tmp = tcg_const_i64(s->next_pc); > gen_helper_ex(cc_op, cpu_env, cc_op, o->in1, o->in2, tmp);
On 05/16/2015 04:28 PM, Aurelien Jarno wrote: > Commit 7a6c7067f optimized CC computation by only saving cc_op before > calling helpers as they either don't touch the CC or generate a new > static value. This however doesn't work for the EX instruction as the > helper changes or not the CC value depending on the actual executed > instruction (e.g. MVC vs CLC). > > This patches force a CC computation before calling the helper. This > fixes random memory corruption occuring in guests. > > Cc: Richard Henderson <rth@twiddle.net> > Cc: Alexander Graf <agraf@suse.de> > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> > --- > target-s390x/translate.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/target-s390x/translate.c b/target-s390x/translate.c > index 80e3a54..10522df 100644 > --- a/target-s390x/translate.c > +++ b/target-s390x/translate.c > @@ -2095,7 +2095,7 @@ static ExitStatus op_ex(DisasContext *s, DisasOps *o) > TCGv_i64 tmp; > > update_psw_addr(s); > - update_cc_op(s); > + gen_op_calc_cc(s); > > tmp = tcg_const_i64(s->next_pc); > gen_helper_ex(cc_op, cpu_env, cc_op, o->in1, o->in2, tmp); I agree this is a bug, and the right fix. You can also remove the set_cc_static at the end of op_ex, since that's done by gen_op_calc_cc. r~
On 05/18/2015 05:35 PM, Richard Henderson wrote: > On 05/16/2015 04:28 PM, Aurelien Jarno wrote: >> Commit 7a6c7067f optimized CC computation by only saving cc_op before >> calling helpers as they either don't touch the CC or generate a new >> static value. This however doesn't work for the EX instruction as the >> helper changes or not the CC value depending on the actual executed >> instruction (e.g. MVC vs CLC). >> >> This patches force a CC computation before calling the helper. This >> fixes random memory corruption occuring in guests. >> >> Cc: Richard Henderson <rth@twiddle.net> >> Cc: Alexander Graf <agraf@suse.de> >> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> >> --- >> target-s390x/translate.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/target-s390x/translate.c b/target-s390x/translate.c >> index 80e3a54..10522df 100644 >> --- a/target-s390x/translate.c >> +++ b/target-s390x/translate.c >> @@ -2095,7 +2095,7 @@ static ExitStatus op_ex(DisasContext *s, DisasOps *o) >> TCGv_i64 tmp; >> >> update_psw_addr(s); >> - update_cc_op(s); >> + gen_op_calc_cc(s); >> >> tmp = tcg_const_i64(s->next_pc); >> gen_helper_ex(cc_op, cpu_env, cc_op, o->in1, o->in2, tmp); > I agree this is a bug, and the right fix. > > You can also remove the set_cc_static at the end of op_ex, since that's done by > gen_op_calc_cc. Thanks, I applied the patch and did the change to remove set_cc_static from op_ex locally. Alex
On 2015-05-18 19:07, Alexander Graf wrote: > On 05/18/2015 05:35 PM, Richard Henderson wrote: > >On 05/16/2015 04:28 PM, Aurelien Jarno wrote: > >>Commit 7a6c7067f optimized CC computation by only saving cc_op before > >>calling helpers as they either don't touch the CC or generate a new > >>static value. This however doesn't work for the EX instruction as the > >>helper changes or not the CC value depending on the actual executed > >>instruction (e.g. MVC vs CLC). > >> > >>This patches force a CC computation before calling the helper. This > >>fixes random memory corruption occuring in guests. > >> > >>Cc: Richard Henderson <rth@twiddle.net> > >>Cc: Alexander Graf <agraf@suse.de> > >>Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> > >>--- > >> target-s390x/translate.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >>diff --git a/target-s390x/translate.c b/target-s390x/translate.c > >>index 80e3a54..10522df 100644 > >>--- a/target-s390x/translate.c > >>+++ b/target-s390x/translate.c > >>@@ -2095,7 +2095,7 @@ static ExitStatus op_ex(DisasContext *s, DisasOps *o) > >> TCGv_i64 tmp; > >> update_psw_addr(s); > >>- update_cc_op(s); > >>+ gen_op_calc_cc(s); > >> tmp = tcg_const_i64(s->next_pc); > >> gen_helper_ex(cc_op, cpu_env, cc_op, o->in1, o->in2, tmp); > >I agree this is a bug, and the right fix. > > > >You can also remove the set_cc_static at the end of op_ex, since that's done by > >gen_op_calc_cc. > > Thanks, I applied the patch and did the change to remove set_cc_static from > op_ex locally. Thanks! Aurelien
diff --git a/target-s390x/translate.c b/target-s390x/translate.c index 80e3a54..10522df 100644 --- a/target-s390x/translate.c +++ b/target-s390x/translate.c @@ -2095,7 +2095,7 @@ static ExitStatus op_ex(DisasContext *s, DisasOps *o) TCGv_i64 tmp; update_psw_addr(s); - update_cc_op(s); + gen_op_calc_cc(s); tmp = tcg_const_i64(s->next_pc); gen_helper_ex(cc_op, cpu_env, cc_op, o->in1, o->in2, tmp);
Commit 7a6c7067f optimized CC computation by only saving cc_op before calling helpers as they either don't touch the CC or generate a new static value. This however doesn't work for the EX instruction as the helper changes or not the CC value depending on the actual executed instruction (e.g. MVC vs CLC). This patches force a CC computation before calling the helper. This fixes random memory corruption occuring in guests. Cc: Richard Henderson <rth@twiddle.net> Cc: Alexander Graf <agraf@suse.de> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> --- target-s390x/translate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)