On Fri, 21 Apr 2017, Kees Cook wrote:
The linux-4.2 x86 defconfig could still be built with gcc-4.0, but later kernels have several minor problems with that, and require at least gcc-4.3.
If we are ok with this status quo, we could simply declare gcc-4.3 the absolute minimum version for the kernel, make gcc-4.9 the recommeded minimum version, and remove all workarounds for gcc-4.2 or older.
I think starting with this would be a good first step. I'm not sure the best way to add "recommended minimum" to Documentation/process/changes.rst hmmm
FWIW for some reasons (mainly the ability to avoid NPTL) I have stuck to GCC 4.1.2 with some MIPS configurations and I've had no issues with that compiler up to Linux 4.6.0, which is the last kernel version I have tried with that compiler so far. I could check if anything has regressed since then I suppose.
Maciej