[Qemu-devel] Documentation/tools on debuging dyngen code?

[Bruce Beare (bbeare)]

I'm working on a 2.6.24 Linux port built for ARCH=powerpc and configured
for the PReP machine. I have the port booting using an unmodified 0.9.1
version (actually, head from the SVN repo) of qemu-system-ppc but
sometimes find that QEMU "hangs". Analysis of the hang reveals:

  o C-A C-X does not respond
  o QEMU is sucking up 100% cpu time of one processor
  o GDB to the kernel debug port (qemu option -s -p 1234) is non
responsive
  o ltrace, strace show no system or library calls in progress
  o GDB on QEMU shows that it is executing apparently valid code in the
0x4xxxxxxx
    range.

My conclusion is that QEMU is looping while executing the dynamically
generated code. I'd like to debug this further... and am looking for
some pointers on how to do so. Is there a built-in debugger? Is there a
particular probe point that I should set a GDB breakpoint on? What is
the general procedure for doing this level of debug?

Thanks for any help...
Bruce


address@hidden:/nobackup/bbeare/ppcroot$ pstack 21406
#0  0x0000000041c1bc23 in ?? ()
#1  0x0000000000000007 in ?? ()
#2  0x0000000000000000 in ?? ()
address@hidden:/nobackup/bbeare/ppcroot$ pstack 21406
#0  0x0000000041c1bc81 in ?? ()
#1  0x0000000000000000 in ?? ()
address@hidden:/nobackup/bbeare/ppcroot$ pstack 21406
#0  0x0000000041c1bc23 in ?? ()
#1  0x0000000000000007 in ?? ()
#2  0x0000000000000000 in ?? ()
address@hidden:/nobackup/bbeare/ppcroot$ pstack 21406
#0  0x0000000041c1bc30 in ?? ()
#1  0x0000000000000000 in ?? ()
address@hidden:/nobackup/bbeare/ppcroot$ pstack 21406
#0  0x0000000041c1bb6f in ?? ()
#1  0x0000000000000000 in ?? ()
address@hidden:/nobackup/bbeare/ppcroot$ pstack 21406
#0  0x0000000041c1bb71 in ?? ()
#1  0x0000000000000000 in ?? ()
address@hidden:/nobackup/bbeare/ppcroot$ pstack 21406
#0  0x0000000041c1bbf2 in ?? ()
#1  0x0000000000000007 in ?? ()
#2  0x0000000000000000 in ?? ()
address@hidden:/nobackup/bbeare/ppcroot$ pstack 21406
#0  0x0000000041c1bb53 in ?? ()
#1  0x0000000000000000 in ?? ()