Re: [Qemu-devel] sparc64-linux-user Segmentation fault

[Blue Swirl]

On Sat, May 14, 2011 at 1:23 AM, Artyom Tarasenko <address@hidden> wrote:
> Trying to run linux-user-test-0.3 from qemu.org. The programs produce
> the expected output but always end up with a segmentation fault:
>
> $ sparc64-linux-user/qemu-sparc64 ../linux-user-test-0.3/sparc64/busybox
> BusyBox v1.6.1 (2007-10-20 10:22:43 EEST) multi-call binary
> Copyright (C) 1998-2006  Erik Andersen, Rob Landley, and others.
> Licensed under GPLv2.  See source distribution for full notice.
>
> Usage: busybox [function] [arguments]...
>   or: [function] [arguments]...
>
>        BusyBox is a multi-call binary that combines many common Unix
>        utilities into a single executable.  Most people will create a
>        link to busybox for each function they wish to use and BusyBox
>        will act like whatever it was invoked as!
>
> Currently defined functions:
>        echo, expr, ls
>
> Segmentation fault
> $
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x00000000600313ce in ldl_be_p (dc=0x7fffffffd510) at ../cpu-all.h:446
> 446         asm volatile ("movl %1, %0\n"
> (gdb) bt
> #0  0x00000000600313ce in ldl_be_p (dc=0x7fffffffd510) at ../cpu-all.h:446
> #1  disas_sparc_insn (dc=0x7fffffffd510) at qemu/target-sparc/translate.c:1876
> #2  0x00000000600666b9 in gen_intermediate_code_internal
> (env=0x6224aed0, tb=0x7ffff43d71b0) at
> qemu/target-sparc/translate.c:4897
> #3  gen_intermediate_code (env=0x6224aed0, tb=0x7ffff43d71b0) at
> qemu/target-sparc/translate.c:4967
> #4  0x000000006002bb06 in cpu_sparc_gen_code (env=0x6224aed0,
> tb=0x7ffff43d71b0, gen_code_size_ptr=0x7fffffffd5f4) at
> qemu/translate-all.c:73
> #5  0x000000006002af6c in tb_gen_code (env=0x6224aed0, pc=593344,
> cs_base=<value optimized out>, flags=<value optimized out>,
> cflags=<value optimized out>)
>    at qemu/exec.c:995
> #6  0x000000006002c22d in tb_find_slow (env1=<value optimized out>) at
> qemu/cpu-exec.c:167
> #7  tb_find_fast (env1=<value optimized out>) at qemu/cpu-exec.c:194
> #8  cpu_sparc_exec (env1=<value optimized out>) at qemu/cpu-exec.c:599
> #9  0x0000000060005f60 in cpu_loop (env=0x6224aed0) at
> qemu/linux-user/main.c:1026
> #10 0x0000000060006b92 in main (argc=1646563376, argv=<value optimized
> out>, envp=<value optimized out>) at qemu/linux-user/main.c:3468
> (gdb)
>
> Is that a bad test or a qemu bug? The host runs Linux x86_64.

Bug. BPcc branch target is sign extended incorrectly in some cases.
I'll push a fix.