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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2013-10-15 16:08:34 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-10-24 17:17:11 +0200
commit4725c86055f5bbdcdfe47199c0715881893a2c79 (patch)
treee201bd8d8a11e58117e9ecf360f3fab43c6267e9 /arch/s390/math-emu
parent01a7cfa24afd8e18ce691d3c2f1e1f093cf3a900 (diff)
s390: fix save and restore of the floating-point-control register
The FPC_VALID_MASK has been used to check the validity of the value to be loaded into the floating-point-control register. With the introduction of the floating-point extension facility and the decimal-floating-point additional bits have been defined which need to be checked in a non straight forward way. So far these bits have been ignored which can cause an incorrect results for decimal- floating-point operations, e.g. an incorrect rounding mode to be set after signal return. The static check with the FPC_VALID_MASK is replaced with a trial load of the floating-point-control value, see test_fp_ctl. In addition an information leak with the padding word between the floating-point-control word and the floating-point registers in the s390_fp_regs is fixed. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/math-emu')
-rw-r--r--arch/s390/math-emu/math.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/math-emu/math.c b/arch/s390/math-emu/math.c
index 58bff541fde9..a6ba0d724335 100644
--- a/arch/s390/math-emu/math.c
+++ b/arch/s390/math-emu/math.c
@@ -19,6 +19,8 @@
#include <math-emu/double.h>
#include <math-emu/quad.h>
+#define FPC_VALID_MASK 0xF8F8FF03
+
/*
* I miss a macro to round a floating point number to the
* nearest integer in the same floating point format.