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 <[email protected]>
Signed-off-by: Xingui Yang <[email protected]>
---
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
Hi Xingui,
kernel test robot noticed the following build warnings:
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Xingui-Yang/scsi-libsas-Allow-smp_execute_task-arguments-to-be-on-the-stack/20240307-174215
base: https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
patch link: https://lore.kernel.org/r/20240307093733.41222-2-yangxingui%40huawei.com
patch subject: [PATCH v3 1/3] scsi: libsas: Allow smp_execute_task() arguments to be on the stack
config: i386-randconfig-141-20240308 (https://download.01.org/0day-ci/archive/20240310/[email protected]/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Reported-by: Dan Carpenter <[email protected]>
| Closes: https://lore.kernel.org/r/[email protected]/
New smatch warnings:
drivers/scsi/libsas/sas_expander.c:148 smp_execute_task() warn: possible memory leak of '_req'
vim +/_req +148 drivers/scsi/libsas/sas_expander.c
adfd2325dfc5cf6 Xingui Yang 2024-03-07 138 static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
adfd2325dfc5cf6 Xingui Yang 2024-03-07 139 void *resp, int resp_size)
adfd2325dfc5cf6 Xingui Yang 2024-03-07 140 {
adfd2325dfc5cf6 Xingui Yang 2024-03-07 141 struct scatterlist req_sg;
adfd2325dfc5cf6 Xingui Yang 2024-03-07 142 struct scatterlist resp_sg;
adfd2325dfc5cf6 Xingui Yang 2024-03-07 143 void *_req = kmemdup(req, req_size, GFP_KERNEL);
adfd2325dfc5cf6 Xingui Yang 2024-03-07 144 void *_resp = alloc_smp_resp(resp_size);
adfd2325dfc5cf6 Xingui Yang 2024-03-07 145 int ret;
adfd2325dfc5cf6 Xingui Yang 2024-03-07 146
adfd2325dfc5cf6 Xingui Yang 2024-03-07 147 if (!_req || !resp)
adfd2325dfc5cf6 Xingui Yang 2024-03-07 @148 return -ENOMEM;
I haven't looked at the callers so I don't know how likely it is for one
of the allocations to fail and the other succeed... But it seems
possible.
adfd2325dfc5cf6 Xingui Yang 2024-03-07 149
adfd2325dfc5cf6 Xingui Yang 2024-03-07 150 sg_init_one(&req_sg, _req, req_size);
adfd2325dfc5cf6 Xingui Yang 2024-03-07 151 sg_init_one(&resp_sg, _resp, resp_size);
adfd2325dfc5cf6 Xingui Yang 2024-03-07 152 ret = smp_execute_task_sg(dev, &req_sg, &resp_sg);
adfd2325dfc5cf6 Xingui Yang 2024-03-07 153 memcpy(resp, _resp, resp_size);
adfd2325dfc5cf6 Xingui Yang 2024-03-07 154 kfree(_req);
adfd2325dfc5cf6 Xingui Yang 2024-03-07 155 kfree(_resp);
adfd2325dfc5cf6 Xingui Yang 2024-03-07 156 return ret;
adfd2325dfc5cf6 Xingui Yang 2024-03-07 157 }
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On 2024/3/11 13:42, Dan Carpenter wrote:
> Hi Xingui,
>
> kernel test robot noticed the following build warnings:
>
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Xingui-Yang/scsi-libsas-Allow-smp_execute_task-arguments-to-be-on-the-stack/20240307-174215
> base: https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
> patch link: https://lore.kernel.org/r/20240307093733.41222-2-yangxingui%40huawei.com
> patch subject: [PATCH v3 1/3] scsi: libsas: Allow smp_execute_task() arguments to be on the stack
> config: i386-randconfig-141-20240308 (https://download.01.org/0day-ci/archive/20240310/[email protected]/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <[email protected]>
> | Reported-by: Dan Carpenter <[email protected]>
> | Closes: https://lore.kernel.org/r/[email protected]/
>
> New smatch warnings:
> drivers/scsi/libsas/sas_expander.c:148 smp_execute_task() warn: possible memory leak of '_req'
>
> vim +/_req +148 drivers/scsi/libsas/sas_expander.c
>
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 138 static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 139 void *resp, int resp_size)
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 140 {
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 141 struct scatterlist req_sg;
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 142 struct scatterlist resp_sg;
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 143 void *_req = kmemdup(req, req_size, GFP_KERNEL);
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 144 void *_resp = alloc_smp_resp(resp_size);
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 145 int ret;
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 146
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 147 if (!_req || !resp)
> adfd2325dfc5cf6 Xingui Yang 2024-03-07 @148 return -ENOMEM;
>
> I haven't looked at the callers so I don't know how likely it is for one
> of the allocations to fail and the other succeed... But it seems
> possible.
Yes, it's possible. This patch has been canceled in v4. Based on John's
suggestion, if there are plans to resubmit modifications , we will pay
attention to this, thank you.
Thanks,
Xingui