Please re-send with
Robin Murphy <[email protected]>
in Cc.
On Mon, May 30, 2022 at 08:07:45PM +0800, [email protected] wrote:
> From: Yunfei Wang <[email protected]>
>
> When many devices share the same iova domain, iommu_dma_init_domain()
> may be called at the same time. The checking of iovad->start_pfn will
> all get false in iommu_dma_init_domain() and both enter init_iova_domain()
> to do iovad initialization.
>
> Fix this by protecting init_iova_domain() with iommu_dma_cookie->mutex.
>
> Exception backtrace:
> rb_insert_color(param1=0xFFFFFF80CD2BDB40, param3=1) + 64
> init_iova_domain() + 180
> iommu_setup_dma_ops() + 260
> arch_setup_dma_ops() + 132
> of_dma_configure_id() + 468
> platform_dma_configure() + 32
> really_probe() + 1168
> driver_probe_device() + 268
> __device_attach_driver() + 524
> __device_attach() + 524
> bus_probe_device() + 64
> deferred_probe_work_func() + 260
> process_one_work() + 580
> worker_thread() + 1076
> kthread() + 332
> ret_from_fork() + 16
>
> Signed-off-by: Ning Li <[email protected]>
> Signed-off-by: Yunfei Wang <[email protected]>
> ---
> drivers/iommu/dma-iommu.c | 17 +++++++++++++----
> 1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 09f6e1c0f9c0..b38c5041eeab 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -63,6 +63,7 @@ struct iommu_dma_cookie {
>
> /* Domain for flush queue callback; NULL if flush queue not in use */
> struct iommu_domain *fq_domain;
> + struct mutex mutex;
> };
>
> static DEFINE_STATIC_KEY_FALSE(iommu_deferred_attach_enabled);
> @@ -309,6 +310,7 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
> if (!domain->iova_cookie)
> return -ENOMEM;
>
> + mutex_init(&domain->iova_cookie->mutex);
> return 0;
> }
>
> @@ -549,26 +551,33 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
> }
>
> /* start_pfn is always nonzero for an already-initialised domain */
> + mutex_lock(&cookie->mutex);
> if (iovad->start_pfn) {
> if (1UL << order != iovad->granule ||
> base_pfn != iovad->start_pfn) {
> pr_warn("Incompatible range for DMA domain\n");
> - return -EFAULT;
> + ret = -EFAULT;
> + goto done_unlock;
> }
>
> - return 0;
> + ret = 0;
> + goto done_unlock;
> }
>
> init_iova_domain(iovad, 1UL << order, base_pfn);
> ret = iova_domain_init_rcaches(iovad);
> if (ret)
> - return ret;
> + goto done_unlock;
>
> /* If the FQ fails we can simply fall back to strict mode */
> if (domain->type == IOMMU_DOMAIN_DMA_FQ && iommu_dma_init_fq(domain))
> domain->type = IOMMU_DOMAIN_DMA;
>
> - return iova_reserve_iommu_regions(dev, domain);
> + ret = iova_reserve_iommu_regions(dev, domain);
> +
> +done_unlock:
> + mutex_unlock(&cookie->mutex);
> + return ret;
> }
>
> /**
> --
> 2.18.0
On 2022-06-22 13:46, Joerg Roedel wrote:
> Please re-send with
>
> Robin Murphy <[email protected]>
>
> in Cc.
Apologies, I did spot this before, I've just been tied up with other
things and dropping everything non-critical on the floor, so didn't get
round to replying before it slipped my mind again.
In summary, I hate it, but mostly because the whole situation of calling
iommu_probe_device off the back of driver probe is fundamentally broken.
I'm still a few steps away from fixing that properly, at which point I
can just as well rip all these little bodges out again. If it really
does need mitigating in the meantime (i.e. this is real-world async
probe, not just some contrived testcase), then I can't easily think of
any cleaner hack, so,
Acked-by: Robin Murphy <[email protected]>
(somewhat reluctantly)
Cheers,
Robin.
> On Mon, May 30, 2022 at 08:07:45PM +0800, [email protected] wrote:
>> From: Yunfei Wang <[email protected]>
>>
>> When many devices share the same iova domain, iommu_dma_init_domain()
>> may be called at the same time. The checking of iovad->start_pfn will
>> all get false in iommu_dma_init_domain() and both enter init_iova_domain()
>> to do iovad initialization.
>>
>> Fix this by protecting init_iova_domain() with iommu_dma_cookie->mutex.
>>
>> Exception backtrace:
>> rb_insert_color(param1=0xFFFFFF80CD2BDB40, param3=1) + 64
>> init_iova_domain() + 180
>> iommu_setup_dma_ops() + 260
>> arch_setup_dma_ops() + 132
>> of_dma_configure_id() + 468
>> platform_dma_configure() + 32
>> really_probe() + 1168
>> driver_probe_device() + 268
>> __device_attach_driver() + 524
>> __device_attach() + 524
>> bus_probe_device() + 64
>> deferred_probe_work_func() + 260
>> process_one_work() + 580
>> worker_thread() + 1076
>> kthread() + 332
>> ret_from_fork() + 16
>>
>> Signed-off-by: Ning Li <[email protected]>
>> Signed-off-by: Yunfei Wang <[email protected]>
>> ---
>> drivers/iommu/dma-iommu.c | 17 +++++++++++++----
>> 1 file changed, 13 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>> index 09f6e1c0f9c0..b38c5041eeab 100644
>> --- a/drivers/iommu/dma-iommu.c
>> +++ b/drivers/iommu/dma-iommu.c
>> @@ -63,6 +63,7 @@ struct iommu_dma_cookie {
>>
>> /* Domain for flush queue callback; NULL if flush queue not in use */
>> struct iommu_domain *fq_domain;
>> + struct mutex mutex;
>> };
>>
>> static DEFINE_STATIC_KEY_FALSE(iommu_deferred_attach_enabled);
>> @@ -309,6 +310,7 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
>> if (!domain->iova_cookie)
>> return -ENOMEM;
>>
>> + mutex_init(&domain->iova_cookie->mutex);
>> return 0;
>> }
>>
>> @@ -549,26 +551,33 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
>> }
>>
>> /* start_pfn is always nonzero for an already-initialised domain */
>> + mutex_lock(&cookie->mutex);
>> if (iovad->start_pfn) {
>> if (1UL << order != iovad->granule ||
>> base_pfn != iovad->start_pfn) {
>> pr_warn("Incompatible range for DMA domain\n");
>> - return -EFAULT;
>> + ret = -EFAULT;
>> + goto done_unlock;
>> }
>>
>> - return 0;
>> + ret = 0;
>> + goto done_unlock;
>> }
>>
>> init_iova_domain(iovad, 1UL << order, base_pfn);
>> ret = iova_domain_init_rcaches(iovad);
>> if (ret)
>> - return ret;
>> + goto done_unlock;
>>
>> /* If the FQ fails we can simply fall back to strict mode */
>> if (domain->type == IOMMU_DOMAIN_DMA_FQ && iommu_dma_init_fq(domain))
>> domain->type = IOMMU_DOMAIN_DMA;
>>
>> - return iova_reserve_iommu_regions(dev, domain);
>> + ret = iova_reserve_iommu_regions(dev, domain);
>> +
>> +done_unlock:
>> + mutex_unlock(&cookie->mutex);
>> + return ret;
>> }
>>
>> /**
>> --
>> 2.18.0
> _______________________________________________
> iommu mailing list
> [email protected]
> https://lists.linuxfoundation.org/mailman/listinfo/iommu
On Wed, Jun 22, 2022 at 02:27:57PM +0100, Robin Murphy wrote:
> Apologies, I did spot this before, I've just been tied up with other things
> and dropping everything non-critical on the floor, so didn't get round to
> replying before it slipped my mind again.
>
> In summary, I hate it, but mostly because the whole situation of calling
> iommu_probe_device off the back of driver probe is fundamentally broken. I'm
> still a few steps away from fixing that properly, at which point I can just
> as well rip all these little bodges out again. If it really does need
> mitigating in the meantime (i.e. this is real-world async probe, not just
> some contrived testcase), then I can't easily think of any cleaner hack, so,
>
> Acked-by: Robin Murphy <[email protected]>
Alright, applied this now.