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authorPeter Oberparleiter <oberpar@linux.vnet.ibm.com>2017-02-20 14:52:58 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2017-02-23 10:06:38 +0100
commit77759137248f34864a8f7a58bbcebfcf1047504a (patch)
treefd5022c36a6d18ee5fa437c1e4cddb4c309f7683
parents390: opt into HAVE_COPY_THREAD_TLS (diff)
downloadlinux-dev-77759137248f34864a8f7a58bbcebfcf1047504a.tar.xz
linux-dev-77759137248f34864a8f7a58bbcebfcf1047504a.zip
s390/chsc: Add exception handler for CHSC instruction
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") Cc: <stable@vger.kernel.org> # v3.11+ 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>
-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);