Hi Mark, Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk> writes: > Hi Nikunj, > > Testing git master locally I see the following segfault when trying to > boot my test MacOS 9.2.1 image: > > > $ gdb --args ./qemu-system-ppc -bios > /home/build/src/openbios/openbios.git/openbios/obj-ppc/openbios-qemu.elf.nostrip > -cdrom /home/build/src/qemu/image/ppc/MacOS921.iso -boot d -m 512 -M mac99
Is it possible for you to share the iso image for MAC ? > GNU gdb (GDB) 7.4.1-debian > Copyright (C) 2012 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later > <http://gnu.org/licenses/gpl.html> > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > and "show warranty" for details. > This GDB was configured as "x86_64-linux-gnu". > For bug reporting instructions, please see: > <http://www.gnu.org/software/gdb/bugs/>... > Reading symbols from /home/build/rel-qemu-git/bin/qemu-system-ppc...done. > (gdb) r > Starting program: /home/build/rel-qemu-git/bin/qemu-system-ppc -bios > /home/build/src/openbios/openbios.git/openbios/obj-ppc/openbios-qemu.elf.nostrip > -cdrom /home/build/src/qemu/image/ppc/MacOS921.iso -boot d -m 512 -M mac99 > warning: no loadable sections found in added symbol-file system-supplied > DSO at 0x7ffff7ffa000 > [Thread debugging using libthread_db enabled] > Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". > [New Thread 0x7fffe9eee700 (LWP 29713)] > [New Thread 0x7fffe6bf5700 (LWP 29714)] > [New Thread 0x7fffe63f4700 (LWP 29715)] > Trying to write invalid spr 0 (0x000) at 00f113c0 > Trying to read invalid spr 0 (0x000) at 00f113c8 > Trying to write privileged spr 955 (0x3bb) at 00f164b8 > Trying to write invalid spr 959 (0x3bf) at 00f16520 > Trying to read invalid spr 959 (0x3bf) at 00f16528 > Trying to write privileged spr 955 (0x3bb) at 00f164b8 > Trying to write invalid spr 959 (0x3bf) at 00f16520 > Trying to read invalid spr 959 (0x3bf) at 00f16528 > > Program received signal SIGSEGV, Segmentation fault. > [Switching to Thread 0x7fffe63f4700 (LWP 29715)] > 0x00007ffff7e20010 in ?? () > (gdb) bt > #0 0x00007ffff7e20010 in ?? () > #1 0x0000000000000002 in ?? () > #2 0x0000000068090040 in ?? () > #3 0x0000000000000002 in ?? () > #4 0x6b67829c063b8d00 in ?? () > #5 0x6b67829c063b8d00 in ?? () > #6 0x000000000043986d in tcg_temp_new_internal_i32 > (temp_local=temp_local@entry=0) at > /home/build/src/qemu/git/qemu/tcg/tcg.c:632 > #7 0x00000000004434a5 in tcg_temp_new_i32 () at > /home/build/src/qemu/git/qemu/tcg/tcg.h:807 > #8 tcg_gen_andc_i32 (ret=0xa, arg1=0x7fffe63f3848, arg2=0x3f) at > /home/build/src/qemu/git/qemu/tcg/tcg-op.c:411 > #9 0x00000000005099ad in gen_op_arith_compute_ov (arg0=arg0@entry=0xd7, > arg1=arg1@entry=0x6a, arg2=0xd8, arg2@entry=0xa, sub=sub@entry=0, > ctx=<error reading variable: Unhandled dwarf expression opcode 0xfa>) > at /home/build/src/qemu/git/qemu/target/ppc/translate.c:821 > #10 0x00000000005631b1 in gen_op_arith_add (compute_rc0=true, > compute_ov=true, compute_ca=true, add_ca=false, arg2=0xa, arg1=0x6a, > ret=0x3a, ctx=0x7fffe63f3800) at > /home/build/src/qemu/git/qemu/target/ppc/translate.c:895 > #11 gen_addco (ctx=0x7fffe63f3800) at > /home/build/src/qemu/git/qemu/target/ppc/translate.c:931 > #12 0x00000000005796ba in gen_intermediate_code > (env=env@entry=0x7ffff7e282a0, tb=tb@entry=0x7fffe6db6a80) at > /home/build/src/qemu/git/qemu/target/ppc/translate.c:7287 > #13 0x000000000043381a in tb_gen_code (cpu=cpu@entry=0x7ffff7e20010, > pc=pc@entry=1745420352, cs_base=cs_base@entry=0, flags=16432, > cflags=cflags@entry=0) at /home/build/src/qemu/git/qemu/translate-all.c:1281 > #14 0x0000000000435a32 in tb_find (tb_exit=0, last_tb=0x0, > cpu=0x7ffff7e20010) at /home/build/src/qemu/git/qemu/cpu-exec.c:370 > #15 cpu_exec (cpu=cpu@entry=0x7ffff7e20010) at > /home/build/src/qemu/git/qemu/cpu-exec.c:685 > #16 0x000000000047457e in tcg_cpu_exec (cpu=0x7ffff7e20010) at > /home/build/src/qemu/git/qemu/cpus.c:1251 > #17 0x00000000004748b4 in qemu_tcg_rr_cpu_thread_fn (arg=<optimized > out>) at /home/build/src/qemu/git/qemu/cpus.c:1347 > #18 0x00007ffff2a50b50 in start_thread (arg=<optimized out>) at > pthread_create.c:304 > #19 0x00007ffff279afbd in clone () at > ../sysdeps/unix/sysv/linux/x86_64/clone.S:112 > #20 0x0000000000000000 in ?? () > (gdb) > > git bisect points to the following commit: > > commit dc0ad84449a4e2f28d2cc055998cb10c1a4d89a9 > Author: Nikunj A Dadhania <nik...@linux.vnet.ibm.com> > Date: Mon Feb 27 10:27:57 2017 +0530 > > target/ppc: update overflow flags for add/sub > > * SO and OV reflects overflow of the 64-bit result in 64-bit mode > and overflow of the low-order 32-bit result in 32-bit mode > > * OV32 reflects overflow of the low-order 32-bit independent of > the mode > > Signed-off-by: Nikunj A Dadhania <nik...@linux.vnet.ibm.com> > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > > Interestingly enough if I recompile with CFLAGS="-O0 -g" to try and get > a full backtrace then the segfault goes away which suggests this could > be tickling a compiler bug somewhere - although even in this > configuration, I am seeing video artifacts during OS 9 boot which > suggests something still isn't quite right. Yes, I reviewed the code, looks correct. Should be some optimization related. > > This is on a Debian wheezy x86_64 system with gcc 4.7.2. Will have a detailed look today. Regards Nikunj
