[PATCH 4.0 28/72] MIPS: asm: elf: Set O32 default FPU flags

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.0-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Markos Chandras <markos.chandras@imgtec.com>

Commit 48f8eaee3f59848809644507fc47363b37e54450 upstream.

Set good default FPU flags (FR0) for O32 binaries similar to what the
kernel does for the N64/N32 ones. This also fixes a regression
introduced in commit 46490b572544 ("MIPS: kernel: elf: Improve the
overall ABI and FPU mode checks") when MIPS_O32_FP64_SUPPORT is
disabled. In that case, the mips_set_personality_fp() did not set the
FPU mode at all because it assumed that the FPU mode was already set
properly. That led to O32 userland problems.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reported-by: Mans Rullgard <mans@mansr.com>
Fixes: 46490b572544 ("MIPS: kernel: elf: Improve the overall ABI and FPU mode checks")
Tested-by: Mans Rullgard <mans@mansr.com>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/9344/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/mips/include/asm/elf.h |    5 +++++
 1 file changed, 5 insertions(+)

--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -294,6 +294,9 @@ do {									\
 	if (personality(current->personality) != PER_LINUX)		\
 		set_personality(PER_LINUX);				\
 									\
+	clear_thread_flag(TIF_HYBRID_FPREGS);				\
+	set_thread_flag(TIF_32BIT_FPREGS);				\
+									\
 	mips_set_personality_fp(state);					\
 									\
 	current->thread.abi = &mips_abi;				\
@@ -319,6 +322,8 @@ do {									\
 	do {								\
 		set_thread_flag(TIF_32BIT_REGS);			\
 		set_thread_flag(TIF_32BIT_ADDR);			\
+		clear_thread_flag(TIF_HYBRID_FPREGS);			\
+		set_thread_flag(TIF_32BIT_FPREGS);			\
 									\
 		mips_set_personality_fp(state);				\
 									\