We need to use alloc_smp_resp() and alloc_smp_req() before call smp_execute_task() as we can't allocate these memories on the stack for calling sg_init_one(). But if we changed smp_execute_task() to memcpy from/to data on the stack, it might make callers simpler. Suggested-by: John Garry <john.g.garry@xxxxxxxxxx> Signed-off-by: Xingui Yang <yangxingui@xxxxxxxxxx> --- drivers/scsi/libsas/sas_expander.c | 32 ++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c index a2204674b680..1eeb69cba8da 100644 --- a/drivers/scsi/libsas/sas_expander.c +++ b/drivers/scsi/libsas/sas_expander.c @@ -120,17 +120,6 @@ static int smp_execute_task_sg(struct domain_device *dev, return res; } -static int smp_execute_task(struct domain_device *dev, void *req, int req_size, - void *resp, int resp_size) -{ - struct scatterlist req_sg; - struct scatterlist resp_sg; - - sg_init_one(&req_sg, req, req_size); - sg_init_one(&resp_sg, resp, resp_size); - return smp_execute_task_sg(dev, &req_sg, &resp_sg); -} - /* ---------- Allocations ---------- */ static inline void *alloc_smp_req(int size) @@ -146,6 +135,27 @@ static inline void *alloc_smp_resp(int size) return kzalloc(size, GFP_KERNEL); } +static int smp_execute_task(struct domain_device *dev, void *req, int req_size, + void *resp, int resp_size) +{ + struct scatterlist req_sg; + struct scatterlist resp_sg; + void *_req = kmemdup(req, req_size, GFP_KERNEL); + void *_resp = alloc_smp_resp(resp_size); + int ret; + + if (!_req || !resp) + return -ENOMEM; + + sg_init_one(&req_sg, _req, req_size); + sg_init_one(&resp_sg, _resp, resp_size); + ret = smp_execute_task_sg(dev, &req_sg, &resp_sg); + memcpy(resp, _resp, resp_size); + kfree(_req); + kfree(_resp); + return ret; +} + static char sas_route_char(struct domain_device *dev, struct ex_phy *phy) { switch (phy->routing_attr) { -- 2.17.1