Re: [PATCH v3 05/16] fuzz: Declare DMA Read callback function

[Paolo Bonzini]

On 11/10/20 17:45, Alexander Bulekov wrote:
> On 201008 0939, Paolo Bonzini wrote:
>> On 21/09/20 04:24, Alexander Bulekov wrote:
>>> This patch declares the fuzz_dma_read_cb function and uses the
>>> preprocessor and linker(weak symbols) to handle these cases:
>>>
>>> When we build softmmu/all with --enable-fuzzing, there should be no
>>> strong symbol defined for fuzz_dma_read_cb, and we link against a weak
>>> stub function.
>>>
>>> When we build softmmu/fuzz with --enable-fuzzing, we link against the
>>> strong symbol in general_fuzz.c
>>>
>>> When we build softmmu/all without --enable-fuzzing, fuzz_dma_read_cb is
>>> an empty, inlined function. As long as we don't call any other functions
>>> when building the arguments, there should be no overhead.
>>
>> Can you move the weak function somewhere in tests/qtest/fuzz instead?
>> Then you don't need an #ifdef because you can add it to specific_fuzz_ss.
> 
> If I understand correctly, specific_fuzz_ss is only used to build
> qemu-fuzz targets. The goal here was to support building qemu-system
> with --enable-fuzzing (ie CONFIG_FUZZ=y), where specific_fuzz isn't
> used. If its too ugly, we could make a stub file under tests/qtest/fuzz
> and add it to specific_ss when: 'CONFIG_FUZZ'.

You're right.

Paolo