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authorPeter Oberparleiter <oberpar@linux.vnet.ibm.com>2017-02-20 14:52:58 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-15 10:02:41 +0800
commitdc31841fcdce435ed88f87489f9ab09b48b43505 (patch)
tree3fba73d0b3527307ab5ea7fbd9c2dd4ed4eadf78
parent91cfcaa6ed46e41c8b44ee09754988b64e075ef2 (diff)
s390/chsc: Add exception handler for CHSC instruction
commit 77759137248f34864a8f7a58bbcebfcf1047504a upstream. Prevent kernel crashes due to unhandled exceptions raised by the CHSC instruction which may for example be triggered by invalid ioctl data. Fixes: 64150adf89df ("s390/cio: Introduce generic synchronous CHSC IOCTL") Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/s390/cio/ioasm.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/s390/cio/ioasm.c b/drivers/s390/cio/ioasm.c
index 8225da619014..4182f60124da 100644
--- a/drivers/s390/cio/ioasm.c
+++ b/drivers/s390/cio/ioasm.c
@@ -165,13 +165,15 @@ int tpi(struct tpi_info *addr)
int chsc(void *chsc_area)
{
typedef struct { char _[4096]; } addr_type;
- int cc;
+ int cc = -EIO;
asm volatile(
" .insn rre,0xb25f0000,%2,0\n"
- " ipm %0\n"
+ "0: ipm %0\n"
" srl %0,28\n"
- : "=d" (cc), "=m" (*(addr_type *) chsc_area)
+ "1:\n"
+ EX_TABLE(0b, 1b)
+ : "+d" (cc), "=m" (*(addr_type *) chsc_area)
: "d" (chsc_area), "m" (*(addr_type *) chsc_area)
: "cc");
trace_s390_cio_chsc(chsc_area, cc);