From: Paul Burton <paul.burton@mips.com>
Date: Wed, 7 Nov 2018 23:14:09 +0000 (+0000)
Subject: MIPS: Avoid FCSR sanitization when CONFIG_MIPS_FP_SUPPORT=n
X-Git-Tag: v5.4-rc1~1858^2~80
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=36a498035bd2e5169bbceed1e3b0c8bb0ce5a7b4;p=platform%2Fkernel%2Flinux-rpi.git

MIPS: Avoid FCSR sanitization when CONFIG_MIPS_FP_SUPPORT=n

When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so we
don't need to worry about floating point exceptions pending in the
Floating point Control & Status Register (FCSR) during switch_to(). Stub
out the __sanitize_fcr31() macro in this case.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21010/
Cc: linux-mips@linux-mips.org
---

diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h
index e610473..0f813bb 100644
--- a/arch/mips/include/asm/switch_to.h
+++ b/arch/mips/include/asm/switch_to.h
@@ -84,7 +84,8 @@ do {									\
  * Check FCSR for any unmasked exceptions pending set with `ptrace',
  * clear them and send a signal.
  */
-#define __sanitize_fcr31(next)						\
+#ifdef CONFIG_MIPS_FP_SUPPORT
+# define __sanitize_fcr31(next)						\
 do {									\
 	unsigned long fcr31 = mask_fcr31_x(next->thread.fpu.fcr31);	\
 	void __user *pc;						\
@@ -95,6 +96,9 @@ do {									\
 		force_fcr31_sig(fcr31, pc, next);			\
 	}								\
 } while (0)
+#else
+# define __sanitize_fcr31(next)
+#endif
 
 /*
  * For newly created kernel threads switch_to() will return to