* [PATCH] iommu/vt-d: Unlock on error paths
@ 2020-03-12 11:37 Dan Carpenter
2020-03-12 12:02 ` Lu Baolu
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2020-03-12 11:37 UTC (permalink / raw)
To: David Woodhouse, Megha Dey; +Cc: kernel-janitors, iommu
There were a couple places where we need to unlock before returning.
Fixes: 91391b919e19 ("iommu/vt-d: Populate debugfs if IOMMUs are detected")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/iommu/intel-iommu-debugfs.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/intel-iommu-debugfs.c b/drivers/iommu/intel-iommu-debugfs.c
index 8d24c4d85cc2..6a495b103972 100644
--- a/drivers/iommu/intel-iommu-debugfs.c
+++ b/drivers/iommu/intel-iommu-debugfs.c
@@ -289,11 +289,12 @@ static int dmar_translation_struct_show(struct seq_file *m, void *unused)
sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
if (!(sts & DMA_GSTS_TES)) {
seq_puts(m, "DMA Remapping is not enabled\n");
- return 0;
+ goto unlock;
}
root_tbl_walk(m, iommu);
seq_putc(m, '\n');
}
+unlock:
rcu_read_unlock();
return 0;
@@ -444,7 +445,7 @@ static int ir_translation_struct_show(struct seq_file *m, void *unused)
sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
if (!(sts & DMA_GSTS_IRES)) {
seq_puts(m, "Interrupt Remapping is not enabled\n");
- return 0;
+ goto unlock;
}
if (iommu->ir_table) {
@@ -475,6 +476,7 @@ static int ir_translation_struct_show(struct seq_file *m, void *unused)
}
seq_putc(m, '\n');
}
+unlock:
rcu_read_unlock();
return 0;
--
2.20.1
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^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] iommu/vt-d: Unlock on error paths
2020-03-12 11:37 [PATCH] iommu/vt-d: Unlock on error paths Dan Carpenter
@ 2020-03-12 12:02 ` Lu Baolu
2020-03-12 12:55 ` Dan Carpenter
0 siblings, 1 reply; 3+ messages in thread
From: Lu Baolu @ 2020-03-12 12:02 UTC (permalink / raw)
To: Dan Carpenter, David Woodhouse, Megha Dey; +Cc: kernel-janitors, iommu
On 2020/3/12 19:37, Dan Carpenter wrote:
> There were a couple places where we need to unlock before returning.
>
> Fixes: 91391b919e19 ("iommu/vt-d: Populate debugfs if IOMMUs are detected")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> drivers/iommu/intel-iommu-debugfs.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/intel-iommu-debugfs.c b/drivers/iommu/intel-iommu-debugfs.c
> index 8d24c4d85cc2..6a495b103972 100644
> --- a/drivers/iommu/intel-iommu-debugfs.c
> +++ b/drivers/iommu/intel-iommu-debugfs.c
> @@ -289,11 +289,12 @@ static int dmar_translation_struct_show(struct seq_file *m, void *unused)
> sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
> if (!(sts & DMA_GSTS_TES)) {
> seq_puts(m, "DMA Remapping is not enabled\n");
> - return 0;
> + goto unlock;
> }
> root_tbl_walk(m, iommu);
> seq_putc(m, '\n');
> }
> +unlock:
> rcu_read_unlock();
>
> return 0;
> @@ -444,7 +445,7 @@ static int ir_translation_struct_show(struct seq_file *m, void *unused)
> sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
> if (!(sts & DMA_GSTS_IRES)) {
> seq_puts(m, "Interrupt Remapping is not enabled\n");
> - return 0;
> + goto unlock;
> }
>
> if (iommu->ir_table) {
> @@ -475,6 +476,7 @@ static int ir_translation_struct_show(struct seq_file *m, void *unused)
> }
> seq_putc(m, '\n');
> }
> +unlock:
> rcu_read_unlock();
>
> return 0;
>
Thanks a lot for the catch. I think it could be further cleanup. How
about below changes?
index 8d24c4d85cc2..2583a6743dd0 100644
--- a/drivers/iommu/intel-iommu-debugfs.c
+++ b/drivers/iommu/intel-iommu-debugfs.c
@@ -288,8 +288,9 @@ static int dmar_translation_struct_show(struct
seq_file *m, void *unused)
for_each_active_iommu(iommu, drhd) {
sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
if (!(sts & DMA_GSTS_TES)) {
- seq_puts(m, "DMA Remapping is not enabled\n");
- return 0;
+ seq_printf(m, "DMA Remapping is not enabled on
%s\n",
+ iommu->name);
+ continue;
}
root_tbl_walk(m, iommu);
seq_putc(m, '\n');
@@ -431,7 +432,6 @@ static int ir_translation_struct_show(struct
seq_file *m, void *unused)
struct dmar_drhd_unit *drhd;
struct intel_iommu *iommu;
u64 irta;
- u32 sts;
rcu_read_lock();
for_each_active_iommu(iommu, drhd) {
@@ -441,12 +441,6 @@ static int ir_translation_struct_show(struct
seq_file *m, void *unused)
seq_printf(m, "Remapped Interrupt supported on IOMMU:
%s\n",
iommu->name);
- sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
- if (!(sts & DMA_GSTS_IRES)) {
- seq_puts(m, "Interrupt Remapping is not enabled\n");
- return 0;
- }
-
if (iommu->ir_table) {
irta = virt_to_phys(iommu->ir_table->base);
seq_printf(m, " IR table address:%llx\n", irta);
Best regards,
baolu
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^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] iommu/vt-d: Unlock on error paths
2020-03-12 12:02 ` Lu Baolu
@ 2020-03-12 12:55 ` Dan Carpenter
0 siblings, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2020-03-12 12:55 UTC (permalink / raw)
To: Lu Baolu; +Cc: kernel-janitors, Megha Dey, David Woodhouse, iommu
On Thu, Mar 12, 2020 at 08:02:41PM +0800, Lu Baolu wrote:
> On 2020/3/12 19:37, Dan Carpenter wrote:
> > There were a couple places where we need to unlock before returning.
> >
> > Fixes: 91391b919e19 ("iommu/vt-d: Populate debugfs if IOMMUs are detected")
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> > drivers/iommu/intel-iommu-debugfs.c | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/iommu/intel-iommu-debugfs.c b/drivers/iommu/intel-iommu-debugfs.c
> > index 8d24c4d85cc2..6a495b103972 100644
> > --- a/drivers/iommu/intel-iommu-debugfs.c
> > +++ b/drivers/iommu/intel-iommu-debugfs.c
> > @@ -289,11 +289,12 @@ static int dmar_translation_struct_show(struct seq_file *m, void *unused)
> > sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
> > if (!(sts & DMA_GSTS_TES)) {
> > seq_puts(m, "DMA Remapping is not enabled\n");
> > - return 0;
> > + goto unlock;
> > }
> > root_tbl_walk(m, iommu);
> > seq_putc(m, '\n');
> > }
> > +unlock:
> > rcu_read_unlock();
> > return 0;
> > @@ -444,7 +445,7 @@ static int ir_translation_struct_show(struct seq_file *m, void *unused)
> > sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
> > if (!(sts & DMA_GSTS_IRES)) {
> > seq_puts(m, "Interrupt Remapping is not enabled\n");
> > - return 0;
> > + goto unlock;
> > }
> > if (iommu->ir_table) {
> > @@ -475,6 +476,7 @@ static int ir_translation_struct_show(struct seq_file *m, void *unused)
> > }
> > seq_putc(m, '\n');
> > }
> > +unlock:
> > rcu_read_unlock();
> > return 0;
> >
>
> Thanks a lot for the catch. I think it could be further cleanup. How
> about below changes?
Obviously that solves the issues with forgetting to drop the lock but
I'm not qualified to comment on the rest. (And I can't really review
it anyway because the patch was damaged in sending the email).
regards,
dan carepnter
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-03-12 12:02 ` Lu Baolu
2020-03-12 12:55 ` Dan Carpenter
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