On 21/12/2017 15:13, Laurent Vivier wrote: > Le 21/12/2017 à 15:10, Paolo Bonzini a écrit : >> On 21/12/2017 14:32, Laurent Vivier wrote: >>> Le 21/12/2017 à 14:07, Laurent Vivier a écrit : >>>> Le 21/12/2017 à 13:49, Thomas Huth a écrit : >>>>> On 20.12.2017 22:56, Paolo Bonzini wrote: >>>>>> On 20/12/2017 20:20, Peter Maydell wrote: >>>>>>> On the x86/sanitizer build, new runtime errors: >>>>>>> GTESTER check-qtest-m68k >>>>>>> /home/petmay01/linaro/qemu-for-merges/target/m68k/translate.c:230:12: >>>>>>> runtime error: index -1 out of bounds for type 'const uint8_t [11]' >>>>>>> >>>>>>> ...and similar fails on one or two boards on most of the other >>>>>>> guest architectures. >>>>>> >>>>>> These are preexisting bugs, now exposed by the boot-serial-test. >>>>>> Thomas, can you identify the architectures that have a problem and >>>>>> notify the maintainers? In the meanwhile I'll keep the boot-serial-test >>>>>> enhancements queued locally, and remove them from the pull request. >>>>> >>>>> Laurent, Richard, >>>>> >>>>> looks like old_op is -1 when set_cc_op() is called here for the first >>>>> time. The problem can be reproduced by running the mini-kernel directly. >>>>> Just get http://people.redhat.com/~thuth/m68k-uart.bin and run QEMU like >>>>> this: >>>>> >>>>> qemu-system-m68k -nographic -kernel ~/tmp/m68k-uart.bin -serial none >>>>> >>>>> That kernel only contains these few instructions: >>>>> >>>>> 0x41, 0xf9, 0xfc, 0x06, 0x00, 0x00, /* lea 0xfc060000,%a0 */ >>>>> 0x10, 0x3c, 0x00, 0x54, /* move.b #'T',%d0 */ >>>>> 0x11, 0x7c, 0x00, 0x04, 0x00, 0x08, /* move.b #4,8(%a0) */ >>>>> 0x11, 0x40, 0x00, 0x0c, /* move.b %d0,12(%a0) */ >>>>> 0x60, 0xfa /* bra.s loop */ >>>>> >>>>> The problem occurs during the second instruction (i.e. the first move.b). >>>>> >>>>> Do you have any ideas where this -1 in s->cc_op could come from? >>>> >>>> I think it comes from CCOp: it's the value of CC_OP_DYNAMIC. >>>> >>>> We should not use it to access cc_op_live[]. >>>> >>>> I try to find a fix, but I think Richard knows this better than me. >>> >>> This should fix the problem, but I'd like Richard checks it... >>> >>> diff --git a/target/m68k/translate.c b/target/m68k/translate.c >>> index b60909222c..721b5801da 100644 >>> --- a/target/m68k/translate.c >>> +++ b/target/m68k/translate.c >>> @@ -225,6 +225,11 @@ static void set_cc_op(DisasContext *s, CCOp op) >>> s->cc_op = op; >>> s->cc_op_synced = 0; >>> >>> + if (old_op == CC_OP_DYNAMIC) { >>> + tcg_gen_discard_i32(QREG_CC_OP); >>> + return; >>> + } >> >> This tcg_gen_discard_i32 is correct, but all flags were potentially live >> and can be discarded if the new op uses it(*). So I'd replace "return" >> with "old_op = CC_OP_FLAGS". > > Yes, I agree, we can also have: > > iff --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. */ > >
Yes, this is good too. After my pull request is in, feel free to take Thomas's m68k boot-serial-test patch in your tree. Paolo
