When a 32-bit kernel is configured to support MIPS64r6 (CPU_MIPS64_R6),
MIPS_O32_FP64_SUPPORT won't be selected as it should be because
MIPS32_O32 is disabled (o32 is already the default ABI available on
32-bit kernels).
This results in userland FP breakage as CP0_Status.FR is read-only 1
since r6 (when an FPU is present) but CP0_Config5.FRE won't be set to
emulate FR=0.
Force o32 fp64 support in this case by also selecting
MIPS_O32_FP64_SUPPORT from CPU_MIPS64_R6 if 32BIT.
Fixes: 4e9d324d4288 ("MIPS: Require O32 FP64 support for MIPS64 with O32 compat")
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # 4.0.x-
---
arch/mips/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b969522feb97..e2890002d6d1 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1531,7 +1531,7 @@ config CPU_MIPS64_R6
select CPU_SUPPORTS_HIGHMEM
select CPU_SUPPORTS_MSA
select GENERIC_CSUM
- select MIPS_O32_FP64_SUPPORT if MIPS32_O32
+ select MIPS_O32_FP64_SUPPORT if 32BIT || MIPS32_O32
select HAVE_KVM
help
Choose this option to build a kernel for release 6 or later of the
--
git-series 0.8.10