Re: [Qemu-devel] [PATCH v2 05/39] fdsets: use weak aliases instead of qemu-tool.c/qemu-user.c

[Paolo Bonzini]

Il 15/11/2012 19:01, Stefan Weil ha scritto:
> Hi Paolo,
> 
> this patch breaks QEMU on 32 and 64 bit hosts, native and with Wine.
> It's easy to reproduce the SIGSEGV crash: just add a -snapshot option.
> Obviously the critical code is executed only when this option was used.

I cannot reproduce this, so it must be an assembler or linker bug.

Can you try the alternative code that is used for Mac OS X?

Paolo

> Here is a simple command line using Wine:
> 
> wine i386-softmmu/qemu-system-i386 -L pc-bios -snapshot Makefile
> 
> The disk image does not matter, so I just selected QEMU's Makefile.
> 
> It looks like weak symbols are not really working with MinGW
> (Blue Swirl previously pointed out that only ELF and a.out are
> officially supported).
> 
> I can see in the debugger that QEMU wants to call monitor_fdset_dup_fd_find
> from qemu_close.
> 
> In previous versions, this was just a dummy function returning 0.
> Now, it is the function in monitor.c, but the address does not match
> exactly, so the code addresses lines near the beginning of
> monitor_fdset_dup_fd_find which does not work of course.
> 
> A trivial workaround is calling default_fdset_dup_fd_find which
> restores the old behaviour. I expect that all other weak functions
> would show the same problem if they were used.
> 
> Regards,
> 
> Stefan
> 
>