[ARM] vfp: fix leak of VFP_NAN_FLAG into FPSCR

The VFP code can leak VFP_NAN_FLAG into the FPSCR. It doesn't correspond
to any real FPSCR bit (and overlaps one of the exception flags).

Bug report from Daniel Jacobowitz

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/vfp/vfpdouble.c b/arch/arm/vfp/vfpdouble.c
index febd115..009038c 100644 (file)
--- a/arch/arm/vfp/vfpdouble.c
+++ b/arch/arm/vfp/vfpdouble.c
@@ -197,7 +197,7 @@ u32 vfp_double_normaliseround(int dd, struct vfp_double *vd, u32 fpscr, u32 exce
                         dd, d, exceptions);
                vfp_put_double(dd, d);
        }
-       return exceptions & ~VFP_NAN_FLAG;
+       return exceptions;
 }
 
 /*

diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 22f3da4..37ff814 100644 (file)
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -180,7 +180,7 @@ static u32 vfp_emulate_instruction(u32 inst, u32 fpscr, struct pt_regs *regs)
                 * emulate it.
                 */
        }
-       return exceptions;
+       return exceptions & ~VFP_NAN_FLAG;
 }
 
 /*

diff --git a/arch/arm/vfp/vfpsingle.c b/arch/arm/vfp/vfpsingle.c
index 4ac27f1..dae2c2f 100644 (file)
--- a/arch/arm/vfp/vfpsingle.c
+++ b/arch/arm/vfp/vfpsingle.c
@@ -203,7 +203,7 @@ u32 vfp_single_normaliseround(int sd, struct vfp_single *vs, u32 fpscr, u32 exce
                vfp_put_float(sd, d);
        }
 
-       return exceptions & ~VFP_NAN_FLAG;
+       return exceptions;
 }
 
 /*