Re: [Qemu-devel] [PATCH v6 4/8] module: implement module loading function

[Michael Tokarev <mjt@tls.msk.ru>]

12.09.2013 07:02, Fam Zheng wrote.
> On Wed, 09/11 11:46, Richard Henderson wrote:
>> On 09/11/2013 08:48 AM, Daniel P. Berrange wrote:
>>> We know the precise list of valid modules when building QEMU,
>>> so IMHO, this should just explicitly load each known module
>>> name, and *not* readdir. Also it should do something along the
>>> lines suggested their of poisoning exported symbols with a
>>> build hash to guarantee the modules loaded match the original
>>> binary and that the symbols change on every rebuild.
>>
>> We need not mangle the symbols, which could be complicated to
>> actually implement, and irritating to work around within gdb.
>>
> Agree with this, some id or hash check should be enough.

A solution which I proposed at the very beginning -- to export
a "hashed" init function from modules, and call it from the
main executable.  Like, instead of, say, qemu_module_init(),
call qemu_module_init_0xdeadbeaf(), where 0xdeadbeaf is a
hash of some build-dependent value.  This should be enough
to keep it going.

Ofcourse, if a module lacks this function, it should not be
loaded.

Thanks,

/mjt