Re: [Qemu-devel] [PULL v3 01/18] tcg: Support arbitrary size + alignment

[Bharata B Rao]

On Tue, Sep 13, 2016 at 5:09 AM, Richard Henderson <address@hidden> wrote:
>
> Previously we allowed fully unaligned operations, but not operations
> that are aligned but with less alignment than the operation size.
>
> In addition, arm32, ia64, mips, and sparc had been omitted from the
> previous overalignment patch, which would have led to that alignment
> being enforced.
>
> Signed-off-by: Richard Henderson <address@hidden>

This breaks ppc64 emulation on x86 pretty early during boot.

Quiescing Open Firmware ...
Booting Linux via __start() @ 0x0000000000400000 ...

Thread 4 "qemu-system-ppc" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffc3bfb700 (LWP 17798)]
0x00007fffd302030f in code_gen_buffer ()
Missing separate debuginfos, use: dnf debuginfo-install
glib2-2.48.1-1.fc24.x86_64 gmp-6.1.0-2.fc24.x86_64
gnutls-3.4.12-1.fc24.x86_64 libfdt-1.4.1-5.fc24.x86_64
libffi-3.1-9.fc24.x86_64 libgcc-6.1.1-2.fc24.x86_64
libidn-1.32-2.fc24.x86_64 libstdc++-6.1.1-2.fc24.x86_64
libtasn1-4.8-1.fc24.x86_64 libX11-1.6.3-3.fc24.x86_64
libXau-1.0.8-6.fc24.x86_64 libxcb-1.11.1-2.fc24.x86_64
ncurses-libs-6.0-6.20160709.fc24.x86_64 nettle-3.2-2.fc24.x86_64
p11-kit-0.23.2-2.fc24.x86_64 pcre-8.39-1.fc24.x86_64
pixman-0.34.0-2.fc24.x86_64 SDL-1.2.15-21.fc24.x86_64
zlib-1.2.8-10.fc24.x86_64
(gdb) bt
#0  0x00007fffd302030f in code_gen_buffer ()
#1  0x000055555576d519 in cpu_tb_exec (cpu=0x7fffc8090010,
itb=0x7fffc963c1f8) at /tmp/qemu/cpu-exec.c:166
#2  0x000055555576e035 in cpu_loop_exec_tb (cpu=0x7fffc8090010,
tb=0x7fffc963c1f8, last_tb=0x7fffc3bfab08, tb_exit=0x7fffc3bfab04,
sc=0x7fffc3bfab20)
    at /tmp/qemu/cpu-exec.c:517
#3  0x000055555576e2df in cpu_exec (cpu=0x7fffc8090010) at
/tmp/qemu/cpu-exec.c:612
#4  0x00005555557ab96c in tcg_cpu_exec (cpu=0x7fffc8090010) at
/tmp/qemu/cpus.c:1547
#5  0x00005555557aba48 in tcg_exec_all () at /tmp/qemu/cpus.c:1580
#6  0x00005555557aae3d in qemu_tcg_cpu_thread_fn (arg=0x7fffc8090010)
at /tmp/qemu/cpus.c:1177
#7  0x00007ffff6e105ba in start_thread () from /lib64/libpthread.so.0
#8  0x00007ffff50d87cd in clone () from /lib64/libc.so.6