On Thu, 28 Apr 2022, Stephen Zhang wrote: > > Please send me .config causing it and tell me what compiler and version > > you have seen this error with. We rely on things being optimised away > > heavily throughout the Linux kernel, so this is certainly something to > > investigate. I have built such a config just fine, but maybe there's a > > bug somewhere my setup does not trigger. > > Okay. The compiler we used is: > > Compiler gcc > Compiler version 10 > Compiler string mips-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110 > Cross-compile mips-linux-gnu > > the commit id of kernel is c00c5e1d157bec0ef0b0b59aa5482eb8dc7e8e49 > > and the .config file is sent as an attachment. Thanks. The bug is in arch/mips/include/asm/mach-ip27/cpu-feature-overrides.h, which has: #define cpu_has_fpu 1 (and similarly arch/mips/include/asm/mach-ip30/cpu-feature-overrides.h). This is not supported, as noted in arch/mips/include/asm/cpu-features.h: /* Don't override `cpu_has_fpu' to 1 or the "nofpu" option won't work. */ Perhaps we should explicitly undefine `cpu_has_fpu' if set to 1? Maciej
