drivers/iommu/dma-iommu.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)
From: Yunfei Wang <yf.wang@mediatek.com>
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 <ning.li@mediatek.com>
Signed-off-by: Yunfei Wang <yf.wang@mediatek.com>
---
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
Please re-send with Robin Murphy <robin.murphy@arm.com> in Cc. On Mon, May 30, 2022 at 08:07:45PM +0800, yf.wang@mediatek.com wrote: > From: Yunfei Wang <yf.wang@mediatek.com> > > 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 <ning.li@mediatek.com> > Signed-off-by: Yunfei Wang <yf.wang@mediatek.com> > --- > 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 <robin.murphy@arm.com> > > 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 <robin.murphy@arm.com> (somewhat reluctantly) Cheers, Robin. > On Mon, May 30, 2022 at 08:07:45PM +0800, yf.wang@mediatek.com wrote: >> From: Yunfei Wang <yf.wang@mediatek.com> >> >> 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 <ning.li@mediatek.com> >> Signed-off-by: Yunfei Wang <yf.wang@mediatek.com> >> --- >> 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 > iommu@lists.linux-foundation.org > 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 <robin.murphy@arm.com> Alright, applied this now.
Hi YF, >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. After reading this patch. It means that we use iovad->start_pfn as a key to tell if an iovad is already initialized, but we do not protect iovad->start_pfn from concurrent access. So what's happening is like: cpu0 cpu1 of_dma_configure_id() of_dma_configure_id() arch_setup_dma_ops() arch_setup_dma_ops() iommu_setup_dma_ops() iommu_setup_dma_ops() init_iova_domain() init_iova_domain() if (iovad->start_pfn) { if (iovad->start_pfn) { } } init_iova_domain() init_iova_domain() init_iova_domain() is called at the same time. >Fix this by protecting init_iova_domain() with iommu_dma_cookie->mutex. Reviewed-by: Miles Chen <miles.chen@mediatek.com> >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 <ning.li@mediatek.com> >Signed-off-by: Yunfei Wang <yf.wang@mediatek.com> >--- > 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 > > >_______________________________________________ >Linux-mediatek mailing list >Linux-mediatek@lists.infradead.org >http://lists.infradead.org/mailman/listinfo/linux-mediatek >
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