* [PATCH] iommu/msm: add a check for the return of kzalloc()
@ 2022-03-25 2:08 xkernel.wang
2022-04-28 8:03 ` Joerg Roedel
2022-04-28 14:51 ` Jeffrey Hugo
0 siblings, 2 replies; 3+ messages in thread
From: xkernel.wang @ 2022-03-25 2:08 UTC (permalink / raw)
To: agross, bjorn.andersson, joro, will
Cc: linux-arm-msm, iommu, linux-kernel, Xiaoke Wang
From: Xiaoke Wang <xkernel.wang@foxmail.com>
kzalloc() is a memory allocation function which can return NULL when
some internal memory errors happen. So it is better to check it to
prevent potential wrong memory access.
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
---
drivers/iommu/msm_iommu.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
index 3a38352..697ad63 100644
--- a/drivers/iommu/msm_iommu.c
+++ b/drivers/iommu/msm_iommu.c
@@ -597,6 +597,10 @@ static void insert_iommu_master(struct device *dev,
if (list_empty(&(*iommu)->ctx_list)) {
master = kzalloc(sizeof(*master), GFP_ATOMIC);
+ if (!master) {
+ dev_err(dev, "Failed to allocate iommu_master\n");
+ return;
+ }
master->of_node = dev->of_node;
list_add(&master->list, &(*iommu)->ctx_list);
dev_iommu_priv_set(dev, master);
--
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] iommu/msm: add a check for the return of kzalloc()
2022-03-25 2:08 [PATCH] iommu/msm: add a check for the return of kzalloc() xkernel.wang
@ 2022-04-28 8:03 ` Joerg Roedel
2022-04-28 14:51 ` Jeffrey Hugo
1 sibling, 0 replies; 3+ messages in thread
From: Joerg Roedel @ 2022-04-28 8:03 UTC (permalink / raw)
To: xkernel.wang
Cc: agross, bjorn.andersson, will, linux-arm-msm, iommu, linux-kernel
On Fri, Mar 25, 2022 at 10:08:01AM +0800, xkernel.wang@foxmail.com wrote:
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
>
> kzalloc() is a memory allocation function which can return NULL when
> some internal memory errors happen. So it is better to check it to
> prevent potential wrong memory access.
>
> Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
> ---
> drivers/iommu/msm_iommu.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index 3a38352..697ad63 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -597,6 +597,10 @@ static void insert_iommu_master(struct device *dev,
>
> if (list_empty(&(*iommu)->ctx_list)) {
> master = kzalloc(sizeof(*master), GFP_ATOMIC);
> + if (!master) {
> + dev_err(dev, "Failed to allocate iommu_master\n");
> + return;
> + }
This is not enough, if the error happens it also need to be propagated
to the caller.
Regards,
Joerg
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] iommu/msm: add a check for the return of kzalloc()
2022-03-25 2:08 [PATCH] iommu/msm: add a check for the return of kzalloc() xkernel.wang
2022-04-28 8:03 ` Joerg Roedel
@ 2022-04-28 14:51 ` Jeffrey Hugo
1 sibling, 0 replies; 3+ messages in thread
From: Jeffrey Hugo @ 2022-04-28 14:51 UTC (permalink / raw)
To: xkernel.wang
Cc: Andy Gross, Bjorn Andersson, Joerg Roedel, Will Deacon, MSM,
iommu, lkml
On Fri, Mar 25, 2022 at 2:13 PM <xkernel.wang@foxmail.com> wrote:
>
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
>
> kzalloc() is a memory allocation function which can return NULL when
> some internal memory errors happen. So it is better to check it to
> prevent potential wrong memory access.
>
> Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
> ---
> drivers/iommu/msm_iommu.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index 3a38352..697ad63 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -597,6 +597,10 @@ static void insert_iommu_master(struct device *dev,
>
> if (list_empty(&(*iommu)->ctx_list)) {
> master = kzalloc(sizeof(*master), GFP_ATOMIC);
> + if (!master) {
> + dev_err(dev, "Failed to allocate iommu_master\n");
How do you reconcile this with chapter 14 of the coding style document?
"These generic allocation functions all emit a stack dump on failure when used
without __GFP_NOWARN so there is no use in emitting an additional failure
message when NULL is returned."
> + return;
> + }
> master->of_node = dev->of_node;
> list_add(&master->list, &(*iommu)->ctx_list);
> dev_iommu_priv_set(dev, master);
> --
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-03-25 2:08 [PATCH] iommu/msm: add a check for the return of kzalloc() xkernel.wang
2022-04-28 8:03 ` Joerg Roedel
2022-04-28 14:51 ` Jeffrey Hugo
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