| Message ID | 20171221142939.1339-1-laurent@vivier.eu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12/21/2017 06:29 AM, Laurent Vivier wrote: > The first call of set_cc_op() in a new translation sequence > is done with old_op set to CC_OP_DYNAMIC (-1). > > This will do an out of bound access to the array cc_op_live[]. > > We fix that by adding an entry in cc_op_live[] for CC_OP_DYNAMIC, > and in this case we can also discard QREG_CC_OP. > > Reported-by: Thomas Huth <thuth@redhat.com> > Signed-off-by: Laurent Vivier <laurent@vivier.eu> > --- > target/m68k/cpu.h | 2 +- > target/m68k/translate.c | 6 ++++++ > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h > index afae5f68ac..5d03764eab 100644 > --- a/target/m68k/cpu.h > +++ b/target/m68k/cpu.h > @@ -182,7 +182,7 @@ void cpu_m68k_set_fpcr(CPUM68KState *env, uint32_t val); > */ > typedef enum { > /* Translator only -- use env->cc_op. */ > - CC_OP_DYNAMIC = -1, > + CC_OP_DYNAMIC, > > /* Each flag bit computed into cc_[xcnvz]. */ > CC_OP_FLAGS, > diff --git a/target/m68k/translate.c b/target/m68k/translate.c > index b60909222c..61ac1a8e83 100644 > --- a/target/m68k/translate.c > +++ b/target/m68k/translate.c > @@ -207,6 +207,7 @@ typedef void (*disas_proc)(CPUM68KState *env, DisasContext *s, uint16_t insn); > #endif > > static const uint8_t cc_op_live[CC_OP_NB] = { > + [CC_OP_DYNAMIC] = CCF_C | CCF_V | CCF_Z | CCF_N | CCF_X, > [CC_OP_FLAGS] = CCF_C | CCF_V | CCF_Z | CCF_N | CCF_X, > [CC_OP_ADDB ... CC_OP_ADDL] = CCF_X | CCF_N | CCF_V, > [CC_OP_SUBB ... CC_OP_SUBL] = CCF_X | CCF_N | CCF_V, These bits are fine. > @@ -237,6 +238,11 @@ static void set_cc_op(DisasContext *s, CCOp op) > if (dead & CCF_V) { > tcg_gen_discard_i32(QREG_CC_V); > } > + > + /* Discard any computed CC_OP value */ > + if (old_op == CC_OP_DYNAMIC) { > + tcg_gen_discard_i32(QREG_CC_OP); > + } This doesn't help, since the previous setting of CC_OP is certain to be in a different TB and therefore there is no code within the current TB to discard. r~
Le 21/12/2017 à 16:58, Richard Henderson a écrit : > On 12/21/2017 06:29 AM, Laurent Vivier wrote: >> The first call of set_cc_op() in a new translation sequence >> is done with old_op set to CC_OP_DYNAMIC (-1). >> >> This will do an out of bound access to the array cc_op_live[]. >> >> We fix that by adding an entry in cc_op_live[] for CC_OP_DYNAMIC, >> and in this case we can also discard QREG_CC_OP. >> >> Reported-by: Thomas Huth <thuth@redhat.com> >> Signed-off-by: Laurent Vivier <laurent@vivier.eu> >> --- >> target/m68k/cpu.h | 2 +- >> target/m68k/translate.c | 6 ++++++ >> 2 files changed, 7 insertions(+), 1 deletion(-) >> >> diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h >> index afae5f68ac..5d03764eab 100644 >> --- a/target/m68k/cpu.h >> +++ b/target/m68k/cpu.h >> @@ -182,7 +182,7 @@ void cpu_m68k_set_fpcr(CPUM68KState *env, uint32_t val); >> */ >> typedef enum { >> /* Translator only -- use env->cc_op. */ >> - CC_OP_DYNAMIC = -1, >> + CC_OP_DYNAMIC, >> >> /* Each flag bit computed into cc_[xcnvz]. */ >> CC_OP_FLAGS, >> diff --git a/target/m68k/translate.c b/target/m68k/translate.c >> index b60909222c..61ac1a8e83 100644 >> --- a/target/m68k/translate.c >> +++ b/target/m68k/translate.c >> @@ -207,6 +207,7 @@ typedef void (*disas_proc)(CPUM68KState *env, DisasContext *s, uint16_t insn); >> #endif >> >> static const uint8_t cc_op_live[CC_OP_NB] = { >> + [CC_OP_DYNAMIC] = CCF_C | CCF_V | CCF_Z | CCF_N | CCF_X, >> [CC_OP_FLAGS] = CCF_C | CCF_V | CCF_Z | CCF_N | CCF_X, >> [CC_OP_ADDB ... CC_OP_ADDL] = CCF_X | CCF_N | CCF_V, >> [CC_OP_SUBB ... CC_OP_SUBL] = CCF_X | CCF_N | CCF_V, > > These bits are fine. > >> @@ -237,6 +238,11 @@ static void set_cc_op(DisasContext *s, CCOp op) >> if (dead & CCF_V) { >> tcg_gen_discard_i32(QREG_CC_V); >> } >> + >> + /* Discard any computed CC_OP value */ >> + if (old_op == CC_OP_DYNAMIC) { >> + tcg_gen_discard_i32(QREG_CC_OP); >> + } > > This doesn't help, since the previous setting of CC_OP is certain to be in a > different TB and therefore there is no code within the current TB to discard. OK, I remove this. Thanks, Laurent
diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h index afae5f68ac..5d03764eab 100644 --- a/target/m68k/cpu.h +++ b/target/m68k/cpu.h @@ -182,7 +182,7 @@ void cpu_m68k_set_fpcr(CPUM68KState *env, uint32_t val); */ typedef enum { /* Translator only -- use env->cc_op. */ - CC_OP_DYNAMIC = -1, + CC_OP_DYNAMIC, /* Each flag bit computed into cc_[xcnvz]. */ CC_OP_FLAGS, diff --git a/target/m68k/translate.c b/target/m68k/translate.c index b60909222c..61ac1a8e83 100644 --- a/target/m68k/translate.c +++ b/target/m68k/translate.c @@ -207,6 +207,7 @@ typedef void (*disas_proc)(CPUM68KState *env, DisasContext *s, uint16_t insn); #endif static const uint8_t cc_op_live[CC_OP_NB] = { + [CC_OP_DYNAMIC] = CCF_C | CCF_V | CCF_Z | CCF_N | CCF_X, [CC_OP_FLAGS] = CCF_C | CCF_V | CCF_Z | CCF_N | CCF_X, [CC_OP_ADDB ... CC_OP_ADDL] = CCF_X | CCF_N | CCF_V, [CC_OP_SUBB ... CC_OP_SUBL] = CCF_X | CCF_N | CCF_V, @@ -237,6 +238,11 @@ static void set_cc_op(DisasContext *s, CCOp op) if (dead & CCF_V) { tcg_gen_discard_i32(QREG_CC_V); } + + /* Discard any computed CC_OP value */ + if (old_op == CC_OP_DYNAMIC) { + tcg_gen_discard_i32(QREG_CC_OP); + } } /* Update the CPU env CC_OP state. */
The first call of set_cc_op() in a new translation sequence is done with old_op set to CC_OP_DYNAMIC (-1). This will do an out of bound access to the array cc_op_live[]. We fix that by adding an entry in cc_op_live[] for CC_OP_DYNAMIC, and in this case we can also discard QREG_CC_OP. Reported-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu> --- target/m68k/cpu.h | 2 +- target/m68k/translate.c | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-)