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Commit 77759137 authored by Peter Oberparleiter's avatar Peter Oberparleiter Committed by Martin Schwidefsky
Browse files

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: 64150adf ("s390/cio: Introduce generic synchronous CHSC IOCTL")
Cc: <stable@vger.kernel.org> # v3.11+
Signed-off-by: default avatarPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent f50c0e63

drivers/s390/cio/ioasm.c

+5 −3
Original line number Diff line number Diff line
@@ -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);