3.16.44-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Peter Oberparleiter <[email protected]> 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 <[email protected]> Reviewed-by: Sebastian Ott <[email protected]> Reviewed-by: Cornelia Huck <[email protected]> Signed-off-by: Martin Schwidefsky <[email protected]> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <[email protected]> --- drivers/s390/cio/ioasm.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/s390/cio/ioasm.h +++ b/drivers/s390/cio/ioasm.h @@ -138,13 +138,15 @@ static inline int tpi(struct tpi_info *a static inline 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"); return cc;
