* [PATCH 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation
@ 2022-02-05 17:10 Christophe JAILLET
2022-02-05 17:11 ` [PATCH 2/2] iommu/arm-smmu-v3: Simplify " Christophe JAILLET
2022-02-07 10:26 ` [PATCH 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in " Robin Murphy
0 siblings, 2 replies; 4+ messages in thread
From: Christophe JAILLET @ 2022-02-05 17:10 UTC (permalink / raw)
To: Will Deacon, Robin Murphy, Joerg Roedel
Cc: linux-kernel, kernel-janitors, Christophe JAILLET,
linux-arm-kernel, iommu
kmalloc_array()/kcalloc() should be used to avoid potential overflow when
a multiplication is needed to compute the size of the requested memory.
So turn a devm_kzalloc()+explicit size computation into an equivalent
devm_kcalloc().
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
This is NOT compile tested.
I don't have the needed cross compiling tools.
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 6dc6d8b6b368..14d06aad0726 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2981,10 +2981,10 @@ static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
{
unsigned int i;
struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
- size_t size = sizeof(*cfg->l1_desc) * cfg->num_l1_ents;
void *strtab = smmu->strtab_cfg.strtab;
- cfg->l1_desc = devm_kzalloc(smmu->dev, size, GFP_KERNEL);
+ cfg->l1_desc = devm_kcalloc(smmu->dev, cfg->num_l1_ents,
+ sizeof(*cfg->l1_desc), GFP_KERNEL);
if (!cfg->l1_desc)
return -ENOMEM;
--
2.32.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] iommu/arm-smmu-v3: Simplify memory allocation
2022-02-05 17:10 [PATCH 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation Christophe JAILLET
@ 2022-02-05 17:11 ` Christophe JAILLET
2022-02-07 10:56 ` Robin Murphy
2022-02-07 10:26 ` [PATCH 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in " Robin Murphy
1 sibling, 1 reply; 4+ messages in thread
From: Christophe JAILLET @ 2022-02-05 17:11 UTC (permalink / raw)
To: Will Deacon, Robin Murphy, Joerg Roedel
Cc: linux-kernel, kernel-janitors, Christophe JAILLET,
linux-arm-kernel, iommu
Use devm_bitmap_zalloc() instead of hand writing it.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
This is NOT compile tested.
I don't have the needed cross compiling tools.
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 14d06aad0726..ba0e7f1f7dbf 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2911,12 +2911,6 @@ static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
return 0;
}
-static void arm_smmu_cmdq_free_bitmap(void *data)
-{
- unsigned long *bitmap = data;
- bitmap_free(bitmap);
-}
-
static int arm_smmu_cmdq_init(struct arm_smmu_device *smmu)
{
int ret = 0;
@@ -2927,13 +2921,13 @@ static int arm_smmu_cmdq_init(struct arm_smmu_device *smmu)
atomic_set(&cmdq->owner_prod, 0);
atomic_set(&cmdq->lock, 0);
- bitmap = (atomic_long_t *)bitmap_zalloc(nents, GFP_KERNEL);
+ bitmap = (atomic_long_t *)devm_bitmap_zalloc(smmu->dev, nents,
+ GFP_KERNEL);
if (!bitmap) {
dev_err(smmu->dev, "failed to allocate cmdq bitmap\n");
ret = -ENOMEM;
} else {
cmdq->valid_map = bitmap;
- devm_add_action(smmu->dev, arm_smmu_cmdq_free_bitmap, bitmap);
}
return ret;
--
2.32.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation
2022-02-05 17:10 [PATCH 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation Christophe JAILLET
2022-02-05 17:11 ` [PATCH 2/2] iommu/arm-smmu-v3: Simplify " Christophe JAILLET
@ 2022-02-07 10:26 ` Robin Murphy
1 sibling, 0 replies; 4+ messages in thread
From: Robin Murphy @ 2022-02-07 10:26 UTC (permalink / raw)
To: Christophe JAILLET, Will Deacon, Joerg Roedel
Cc: linux-kernel, kernel-janitors, linux-arm-kernel, iommu
On 2022-02-05 17:10, Christophe JAILLET wrote:
> kmalloc_array()/kcalloc() should be used to avoid potential overflow when
> a multiplication is needed to compute the size of the requested memory.
>
> So turn a devm_kzalloc()+explicit size computation into an equivalent
> devm_kcalloc().
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> This is NOT compile tested.
> I don't have the needed cross compiling tools.
FYI, https://cdn.kernel.org/pub/tools/crosstool/
Either way, the patch looks reasonable, thanks!
Acked-by: Robin Murphy <robin.murphy@arm.com>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 6dc6d8b6b368..14d06aad0726 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2981,10 +2981,10 @@ static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
> {
> unsigned int i;
> struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
> - size_t size = sizeof(*cfg->l1_desc) * cfg->num_l1_ents;
> void *strtab = smmu->strtab_cfg.strtab;
>
> - cfg->l1_desc = devm_kzalloc(smmu->dev, size, GFP_KERNEL);
> + cfg->l1_desc = devm_kcalloc(smmu->dev, cfg->num_l1_ents,
> + sizeof(*cfg->l1_desc), GFP_KERNEL);
> if (!cfg->l1_desc)
> return -ENOMEM;
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] iommu/arm-smmu-v3: Simplify memory allocation
2022-02-05 17:11 ` [PATCH 2/2] iommu/arm-smmu-v3: Simplify " Christophe JAILLET
@ 2022-02-07 10:56 ` Robin Murphy
0 siblings, 0 replies; 4+ messages in thread
From: Robin Murphy @ 2022-02-07 10:56 UTC (permalink / raw)
To: Christophe JAILLET, Will Deacon, Joerg Roedel
Cc: linux-kernel, kernel-janitors, linux-arm-kernel, iommu
On 2022-02-05 17:11, Christophe JAILLET wrote:
> Use devm_bitmap_zalloc() instead of hand writing it.
Heh, that reminds me that I have more or less the same patch sat locally
somewhere, except IIRC I took it further and removed the unhelpful error
message and pruned the local variables as well - I think that would
still be my preference here (or I could dig out my patch and post it if
you like).
Cheers,
Robin.
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> This is NOT compile tested.
> I don't have the needed cross compiling tools.
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 10 ++--------
> 1 file changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 14d06aad0726..ba0e7f1f7dbf 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2911,12 +2911,6 @@ static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
> return 0;
> }
>
> -static void arm_smmu_cmdq_free_bitmap(void *data)
> -{
> - unsigned long *bitmap = data;
> - bitmap_free(bitmap);
> -}
> -
> static int arm_smmu_cmdq_init(struct arm_smmu_device *smmu)
> {
> int ret = 0;
> @@ -2927,13 +2921,13 @@ static int arm_smmu_cmdq_init(struct arm_smmu_device *smmu)
> atomic_set(&cmdq->owner_prod, 0);
> atomic_set(&cmdq->lock, 0);
>
> - bitmap = (atomic_long_t *)bitmap_zalloc(nents, GFP_KERNEL);
> + bitmap = (atomic_long_t *)devm_bitmap_zalloc(smmu->dev, nents,
> + GFP_KERNEL);
> if (!bitmap) {
> dev_err(smmu->dev, "failed to allocate cmdq bitmap\n");
> ret = -ENOMEM;
> } else {
> cmdq->valid_map = bitmap;
> - devm_add_action(smmu->dev, arm_smmu_cmdq_free_bitmap, bitmap);
> }
>
> return ret;
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-02-05 17:10 [PATCH 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation Christophe JAILLET
2022-02-05 17:11 ` [PATCH 2/2] iommu/arm-smmu-v3: Simplify " Christophe JAILLET
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2022-02-07 10:26 ` [PATCH 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in " Robin Murphy
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