Linux-Kernel Archive: Re: [PATCH] arch/mips/kernel/traps: add CONFIG_MIPS_FP_SUPPORT when using handle_fpe Re: [PATCH] arch/mips/kernel/traps: add CONFIG_MIPS_FP_SUPPORT when using handle_fpe From: Maciej W. Rozycki Date: Thu Apr 28 2022 - 05:00:28 EST Next message: Sebastian Andrzej Siewior: "Re: [PATCH v3 4/4] Documentation/vm: Rework "Temporary Virtual Mappings" section" Previous message: Yongqiang Niu: "[PATCH v4, 1/1] drm/mediatek: add lut diff flag for new gamma hardware support" In reply to: Stephen Zhang: "Re: [PATCH] arch/mips/kernel/traps: add CONFIG_MIPS_FP_SUPPORT when using handle_fpe" Next in thread: Stephen Zhang: "Re: [PATCH] arch/mips/kernel/traps: add CONFIG_MIPS_FP_SUPPORT when using handle_fpe" Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] 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 Next message: Sebastian Andrzej Siewior: "Re: [PATCH v3 4/4] Documentation/vm: Rework "Temporary Virtual Mappings" section" Previous message: Yongqiang Niu: "[PATCH v4, 1/1] drm/mediatek: add lut diff flag for new gamma hardware support" In reply to: Stephen Zhang: "Re: [PATCH] arch/mips/kernel/traps: add CONFIG_MIPS_FP_SUPPORT when using handle_fpe" Next in thread: Stephen Zhang: "Re: [PATCH] arch/mips/kernel/traps: add CONFIG_MIPS_FP_SUPPORT when using handle_fpe" Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
