Re: [Qemu-devel] qemu-riscv64 seg fault

[Michael Clark]

On Mon, Sep 3, 2018 at 8:16 PM, Pranith Kumar <address@hidden> wrote:

> On Mon, Sep 3, 2018 at 1:07 AM Michael Clark <address@hidden> wrote:
> >
> > Thanks. I was just about to log an issue in the riscv-qemu issue tracker
> on GitHub.
> >
> > I reproduced it on my side. The fact that it is causes QEMU user to
> crash in translate.c is interesting.
> >
> > I ran your program with -d in_asm and it appears to crash in thread::join
>
> Interestingly, qemu-x86_64 crashes too. But running natively on x86
> works fine. There is something off somewhere...
>

Indeed. Another data-point. I tested it in both qemu-2.12 and qemu-3.0. It
still crashed in translate.c in qemu-2.12, but on another line. There was
quite a bit of restructuring of target/riscv/translate.c in qemu-3.0, which
is why I tried qemu-2.12, however, it seems that is likely not the cause.

This was the backtrace from riscv-qemu-2.12:

Thread 1 "qemu-riscv64" received signal SIGSEGV, Segmentation fault.
0x00005555555e1347 in gen_intermediate_code (address@hidden,
    address@hidden <static_code_gen_buffer+9952>)
    at /home/mjc/src/sifive/riscv-qemu/target/riscv/translate.c:1934
1934         if (num_insns == max_insns && (tb->cflags & CF_LAST_IO)) {
(gdb) print tb
$1 = (TranslationBlock *) 0x5555558e1a00 <static_code_gen_buffer+9952>
(gdb) quit
A debugging session is active.

~/quickht$ qemu-x86_64 ./bench -t 2 -u 2
> qemu: uncaught target signal 11 (Segmentation fault) - core dumped
> Segmentation fault
>
> ~/quickht$ ./bench -t 2 -u 2
> Comparisons: 23922
> Buckets touched: 4933
> Operations: 2000
>