From 77759137248f34864a8f7a58bbcebfcf1047504a Mon Sep 17 00:00:00 2001 From: Peter Oberparleiter Date: Mon, 20 Feb 2017 14:52:58 +0100 Subject: 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: # v3.11+ Signed-off-by: Peter Oberparleiter Reviewed-by: Sebastian Ott Reviewed-by: Cornelia Huck Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/ioasm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers') 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); -- cgit v1.2.3