| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.10 11/75] s390/chsc: Add exception handler for CHSC instruction | Date | Mon, 13 Mar 2017 16:43:20 +0800 |
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4.10-stable review patch. If anyone has any objections, please let me know.
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From: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
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>
--- drivers/s390/cio/ioasm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
--- 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);
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