3.16.43-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Paul Burton <paul.burton@xxxxxxxxxx> commit 33c771ba5c5d067f85a5a6c4b11047219b5b8f4e upstream. The kernel depends upon MSA never being enabled when the FPU is not, a condition which is currently violated in a few places (whilst saving sigcontext, following mips_cpu_save). Catch all the problem cases by disabling MSA in lose_fpu, after saving context if necessary. Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Patchwork: https://patchwork.linux-mips.org/patch/7302/ Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> --- arch/mips/include/asm/fpu.h | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) --- a/arch/mips/include/asm/fpu.h +++ b/arch/mips/include/asm/fpu.h @@ -21,6 +21,7 @@ #include <asm/hazards.h> #include <asm/processor.h> #include <asm/current.h> +#include <asm/msa.h> #ifdef CONFIG_MIPS_MT_FPAFF #include <asm/mips_mt.h> @@ -141,13 +142,21 @@ static inline int own_fpu(int restore) static inline void lose_fpu(int save) { preempt_disable(); - if (is_fpu_owner()) { + if (is_msa_enabled()) { + if (save) { + save_msa(current); + asm volatile("cfc1 %0, $31" + : "=r"(current->thread.fpu.fcr31)); + } + disable_msa(); + clear_thread_flag(TIF_USEDMSA); + } else if (is_fpu_owner()) { if (save) _save_fp(current); - KSTK_STATUS(current) &= ~ST0_CU1; - clear_thread_flag(TIF_USEDFPU); __disable_fpu(); } + KSTK_STATUS(current) &= ~ST0_CU1; + clear_thread_flag(TIF_USEDFPU); preempt_enable(); }