* [PATCH] iommu/dma: Fix MSI reservation allocation
@ 2020-03-03 11:51 ` Marc Zyngier
0 siblings, 0 replies; 8+ messages in thread
From: Marc Zyngier @ 2020-03-03 11:51 UTC (permalink / raw)
To: linux-arm-kernel, linux-kernel
Cc: Robin Murphy, Joerg Roedel, Eric Auger, Will Deacon, stable
The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page
structures doesn't match the way iommu_put_dma_cookie() frees them.
The former performs a single allocation of all the required structures,
while the latter tries to free them one at a time. It doesn't quite
work for the main use case (the GICv3 ITS where the range is 64kB)
when the base ganule size is 4kB.
This leads to a nice slab corruption on teardown, which is easily
observable by simply creating a VF on a SRIOV-capable device, and
tearing it down immediately (no need to even make use of it).
Fix it by allocating iommu_dma_msi_page structures one at a time.
Fixes: 7c1b058c8b5a3 ("iommu/dma: Handle IOMMU API reserved regions")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: stable@vger.kernel.org
---
drivers/iommu/dma-iommu.c | 36 ++++++++++++++++++++++++------------
1 file changed, 24 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index a2e96a5fd9a7..01fa64856c12 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -171,25 +171,37 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
phys_addr_t start, phys_addr_t end)
{
struct iova_domain *iovad = &cookie->iovad;
- struct iommu_dma_msi_page *msi_page;
- int i, num_pages;
+ struct iommu_dma_msi_page *msi_page, *tmp;
+ int i, num_pages, ret = 0;
+ phys_addr_t base;
- start -= iova_offset(iovad, start);
+ base = start -= iova_offset(iovad, start);
num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
- msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL);
- if (!msi_page)
- return -ENOMEM;
-
for (i = 0; i < num_pages; i++) {
- msi_page[i].phys = start;
- msi_page[i].iova = start;
- INIT_LIST_HEAD(&msi_page[i].list);
- list_add(&msi_page[i].list, &cookie->msi_page_list);
+ msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL);
+ if (!msi_page) {
+ ret = -ENOMEM;
+ break;
+ }
+ msi_page->phys = start;
+ msi_page->iova = start;
+ INIT_LIST_HEAD(&msi_page->list);
+ list_add(&msi_page->list, &cookie->msi_page_list);
start += iovad->granule;
}
- return 0;
+ if (ret) {
+ list_for_each_entry_safe(msi_page, tmp,
+ &cookie->msi_page_list, list) {
+ if (msi_page->phys >= base && msi_page->phys < start) {
+ list_del(&msi_page->list);
+ kfree(msi_page);
+ }
+ }
+ }
+
+ return ret;
}
static int iova_reserve_pci_windows(struct pci_dev *dev,
--
2.20.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH] iommu/dma: Fix MSI reservation allocation
@ 2020-03-03 11:51 ` Marc Zyngier
0 siblings, 0 replies; 8+ messages in thread
From: Marc Zyngier @ 2020-03-03 11:51 UTC (permalink / raw)
To: linux-arm-kernel, linux-kernel
Cc: Eric Auger, Joerg Roedel, Robin Murphy, stable, Will Deacon
The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page
structures doesn't match the way iommu_put_dma_cookie() frees them.
The former performs a single allocation of all the required structures,
while the latter tries to free them one at a time. It doesn't quite
work for the main use case (the GICv3 ITS where the range is 64kB)
when the base ganule size is 4kB.
This leads to a nice slab corruption on teardown, which is easily
observable by simply creating a VF on a SRIOV-capable device, and
tearing it down immediately (no need to even make use of it).
Fix it by allocating iommu_dma_msi_page structures one at a time.
Fixes: 7c1b058c8b5a3 ("iommu/dma: Handle IOMMU API reserved regions")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: stable@vger.kernel.org
---
drivers/iommu/dma-iommu.c | 36 ++++++++++++++++++++++++------------
1 file changed, 24 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index a2e96a5fd9a7..01fa64856c12 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -171,25 +171,37 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
phys_addr_t start, phys_addr_t end)
{
struct iova_domain *iovad = &cookie->iovad;
- struct iommu_dma_msi_page *msi_page;
- int i, num_pages;
+ struct iommu_dma_msi_page *msi_page, *tmp;
+ int i, num_pages, ret = 0;
+ phys_addr_t base;
- start -= iova_offset(iovad, start);
+ base = start -= iova_offset(iovad, start);
num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
- msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL);
- if (!msi_page)
- return -ENOMEM;
-
for (i = 0; i < num_pages; i++) {
- msi_page[i].phys = start;
- msi_page[i].iova = start;
- INIT_LIST_HEAD(&msi_page[i].list);
- list_add(&msi_page[i].list, &cookie->msi_page_list);
+ msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL);
+ if (!msi_page) {
+ ret = -ENOMEM;
+ break;
+ }
+ msi_page->phys = start;
+ msi_page->iova = start;
+ INIT_LIST_HEAD(&msi_page->list);
+ list_add(&msi_page->list, &cookie->msi_page_list);
start += iovad->granule;
}
- return 0;
+ if (ret) {
+ list_for_each_entry_safe(msi_page, tmp,
+ &cookie->msi_page_list, list) {
+ if (msi_page->phys >= base && msi_page->phys < start) {
+ list_del(&msi_page->list);
+ kfree(msi_page);
+ }
+ }
+ }
+
+ return ret;
}
static int iova_reserve_pci_windows(struct pci_dev *dev,
--
2.20.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] iommu/dma: Fix MSI reservation allocation
2020-03-03 11:51 ` Marc Zyngier
@ 2020-03-03 12:56 ` Auger Eric
-1 siblings, 0 replies; 8+ messages in thread
From: Auger Eric @ 2020-03-03 12:56 UTC (permalink / raw)
To: Marc Zyngier, linux-arm-kernel, linux-kernel
Cc: Joerg Roedel, Robin Murphy, stable, Will Deacon
Hi Marc,
On 3/3/20 12:51 PM, Marc Zyngier wrote:
> The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page
> structures doesn't match the way iommu_put_dma_cookie() frees them.
>
> The former performs a single allocation of all the required structures,
> while the latter tries to free them one at a time. It doesn't quite
> work for the main use case (the GICv3 ITS where the range is 64kB)
> when the base ganule size is 4kB.
>
> This leads to a nice slab corruption on teardown, which is easily
> observable by simply creating a VF on a SRIOV-capable device, and
> tearing it down immediately (no need to even make use of it).
>
> Fix it by allocating iommu_dma_msi_page structures one at a time.
>
> Fixes: 7c1b058c8b5a3 ("iommu/dma: Handle IOMMU API reserved regions")
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Thanks
Eric
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Joerg Roedel <jroedel@suse.de>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: stable@vger.kernel.org
> ---
> drivers/iommu/dma-iommu.c | 36 ++++++++++++++++++++++++------------
> 1 file changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index a2e96a5fd9a7..01fa64856c12 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -171,25 +171,37 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
> phys_addr_t start, phys_addr_t end)
> {
> struct iova_domain *iovad = &cookie->iovad;
> - struct iommu_dma_msi_page *msi_page;
> - int i, num_pages;
> + struct iommu_dma_msi_page *msi_page, *tmp;
> + int i, num_pages, ret = 0;
> + phys_addr_t base;
>
> - start -= iova_offset(iovad, start);
> + base = start -= iova_offset(iovad, start);
> num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
>
> - msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL);
> - if (!msi_page)
> - return -ENOMEM;
> -
> for (i = 0; i < num_pages; i++) {
> - msi_page[i].phys = start;
> - msi_page[i].iova = start;
> - INIT_LIST_HEAD(&msi_page[i].list);
> - list_add(&msi_page[i].list, &cookie->msi_page_list);
> + msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL);
> + if (!msi_page) {
> + ret = -ENOMEM;
> + break;
> + }
> + msi_page->phys = start;
> + msi_page->iova = start;
> + INIT_LIST_HEAD(&msi_page->list);
> + list_add(&msi_page->list, &cookie->msi_page_list);
> start += iovad->granule;
> }
>
> - return 0;
> + if (ret) {
> + list_for_each_entry_safe(msi_page, tmp,
> + &cookie->msi_page_list, list) {
> + if (msi_page->phys >= base && msi_page->phys < start) {
> + list_del(&msi_page->list);
> + kfree(msi_page);
> + }
> + }
> + }
> +
> + return ret;
> }
>
> static int iova_reserve_pci_windows(struct pci_dev *dev,
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] iommu/dma: Fix MSI reservation allocation
@ 2020-03-03 12:56 ` Auger Eric
0 siblings, 0 replies; 8+ messages in thread
From: Auger Eric @ 2020-03-03 12:56 UTC (permalink / raw)
To: Marc Zyngier, linux-arm-kernel, linux-kernel
Cc: Will Deacon, Joerg Roedel, Robin Murphy, stable
Hi Marc,
On 3/3/20 12:51 PM, Marc Zyngier wrote:
> The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page
> structures doesn't match the way iommu_put_dma_cookie() frees them.
>
> The former performs a single allocation of all the required structures,
> while the latter tries to free them one at a time. It doesn't quite
> work for the main use case (the GICv3 ITS where the range is 64kB)
> when the base ganule size is 4kB.
>
> This leads to a nice slab corruption on teardown, which is easily
> observable by simply creating a VF on a SRIOV-capable device, and
> tearing it down immediately (no need to even make use of it).
>
> Fix it by allocating iommu_dma_msi_page structures one at a time.
>
> Fixes: 7c1b058c8b5a3 ("iommu/dma: Handle IOMMU API reserved regions")
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Thanks
Eric
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Joerg Roedel <jroedel@suse.de>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: stable@vger.kernel.org
> ---
> drivers/iommu/dma-iommu.c | 36 ++++++++++++++++++++++++------------
> 1 file changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index a2e96a5fd9a7..01fa64856c12 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -171,25 +171,37 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
> phys_addr_t start, phys_addr_t end)
> {
> struct iova_domain *iovad = &cookie->iovad;
> - struct iommu_dma_msi_page *msi_page;
> - int i, num_pages;
> + struct iommu_dma_msi_page *msi_page, *tmp;
> + int i, num_pages, ret = 0;
> + phys_addr_t base;
>
> - start -= iova_offset(iovad, start);
> + base = start -= iova_offset(iovad, start);
> num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
>
> - msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL);
> - if (!msi_page)
> - return -ENOMEM;
> -
> for (i = 0; i < num_pages; i++) {
> - msi_page[i].phys = start;
> - msi_page[i].iova = start;
> - INIT_LIST_HEAD(&msi_page[i].list);
> - list_add(&msi_page[i].list, &cookie->msi_page_list);
> + msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL);
> + if (!msi_page) {
> + ret = -ENOMEM;
> + break;
> + }
> + msi_page->phys = start;
> + msi_page->iova = start;
> + INIT_LIST_HEAD(&msi_page->list);
> + list_add(&msi_page->list, &cookie->msi_page_list);
> start += iovad->granule;
> }
>
> - return 0;
> + if (ret) {
> + list_for_each_entry_safe(msi_page, tmp,
> + &cookie->msi_page_list, list) {
> + if (msi_page->phys >= base && msi_page->phys < start) {
> + list_del(&msi_page->list);
> + kfree(msi_page);
> + }
> + }
> + }
> +
> + return ret;
> }
>
> static int iova_reserve_pci_windows(struct pci_dev *dev,
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] iommu/dma: Fix MSI reservation allocation
2020-03-03 11:51 ` Marc Zyngier
@ 2020-03-03 17:23 ` Robin Murphy
-1 siblings, 0 replies; 8+ messages in thread
From: Robin Murphy @ 2020-03-03 17:23 UTC (permalink / raw)
To: Marc Zyngier, linux-arm-kernel, linux-kernel
Cc: Joerg Roedel, Eric Auger, Will Deacon, stable
On 03/03/2020 11:51 am, Marc Zyngier wrote:
> The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page
> structures doesn't match the way iommu_put_dma_cookie() frees them.
>
> The former performs a single allocation of all the required structures,
> while the latter tries to free them one at a time. It doesn't quite
> work for the main use case (the GICv3 ITS where the range is 64kB)
> when the base ganule size is 4kB.
>
> This leads to a nice slab corruption on teardown, which is easily
> observable by simply creating a VF on a SRIOV-capable device, and
> tearing it down immediately (no need to even make use of it).
>
> Fix it by allocating iommu_dma_msi_page structures one at a time.
Bleh, you know you're supposed to be using 64K pages on those things,
right? :P
> Fixes: 7c1b058c8b5a3 ("iommu/dma: Handle IOMMU API reserved regions")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Joerg Roedel <jroedel@suse.de>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: stable@vger.kernel.org
> ---
> drivers/iommu/dma-iommu.c | 36 ++++++++++++++++++++++++------------
> 1 file changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index a2e96a5fd9a7..01fa64856c12 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -171,25 +171,37 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
> phys_addr_t start, phys_addr_t end)
> {
> struct iova_domain *iovad = &cookie->iovad;
> - struct iommu_dma_msi_page *msi_page;
> - int i, num_pages;
> + struct iommu_dma_msi_page *msi_page, *tmp;
> + int i, num_pages, ret = 0;
> + phys_addr_t base;
>
> - start -= iova_offset(iovad, start);
> + base = start -= iova_offset(iovad, start);
> num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
>
> - msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL);
> - if (!msi_page)
> - return -ENOMEM;
> -
> for (i = 0; i < num_pages; i++) {
> - msi_page[i].phys = start;
> - msi_page[i].iova = start;
> - INIT_LIST_HEAD(&msi_page[i].list);
> - list_add(&msi_page[i].list, &cookie->msi_page_list);
> + msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL);
> + if (!msi_page) {
> + ret = -ENOMEM;
I think we can just return here and skip the cleanup below - by the time
we get here the cookie itself has already been allocated and
initialised, so even if iommu_dma_init_domain() fails someone else has
already accepted the responsibility of calling iommu_put_dma_cookie() at
some point later, which will clean up properly.
Cheers,
Robin.
> + break;
> + }
> + msi_page->phys = start;
> + msi_page->iova = start;
> + INIT_LIST_HEAD(&msi_page->list);
> + list_add(&msi_page->list, &cookie->msi_page_list);
> start += iovad->granule;
> }
>
> - return 0;
> + if (ret) {
> + list_for_each_entry_safe(msi_page, tmp,
> + &cookie->msi_page_list, list) {
> + if (msi_page->phys >= base && msi_page->phys < start) {
> + list_del(&msi_page->list);
> + kfree(msi_page);
> + }
> + }
> + }
> +
> + return ret;
> }
>
> static int iova_reserve_pci_windows(struct pci_dev *dev,
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] iommu/dma: Fix MSI reservation allocation
@ 2020-03-03 17:23 ` Robin Murphy
0 siblings, 0 replies; 8+ messages in thread
From: Robin Murphy @ 2020-03-03 17:23 UTC (permalink / raw)
To: Marc Zyngier, linux-arm-kernel, linux-kernel
Cc: Eric Auger, Joerg Roedel, Will Deacon, stable
On 03/03/2020 11:51 am, Marc Zyngier wrote:
> The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page
> structures doesn't match the way iommu_put_dma_cookie() frees them.
>
> The former performs a single allocation of all the required structures,
> while the latter tries to free them one at a time. It doesn't quite
> work for the main use case (the GICv3 ITS where the range is 64kB)
> when the base ganule size is 4kB.
>
> This leads to a nice slab corruption on teardown, which is easily
> observable by simply creating a VF on a SRIOV-capable device, and
> tearing it down immediately (no need to even make use of it).
>
> Fix it by allocating iommu_dma_msi_page structures one at a time.
Bleh, you know you're supposed to be using 64K pages on those things,
right? :P
> Fixes: 7c1b058c8b5a3 ("iommu/dma: Handle IOMMU API reserved regions")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Joerg Roedel <jroedel@suse.de>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: stable@vger.kernel.org
> ---
> drivers/iommu/dma-iommu.c | 36 ++++++++++++++++++++++++------------
> 1 file changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index a2e96a5fd9a7..01fa64856c12 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -171,25 +171,37 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
> phys_addr_t start, phys_addr_t end)
> {
> struct iova_domain *iovad = &cookie->iovad;
> - struct iommu_dma_msi_page *msi_page;
> - int i, num_pages;
> + struct iommu_dma_msi_page *msi_page, *tmp;
> + int i, num_pages, ret = 0;
> + phys_addr_t base;
>
> - start -= iova_offset(iovad, start);
> + base = start -= iova_offset(iovad, start);
> num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
>
> - msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL);
> - if (!msi_page)
> - return -ENOMEM;
> -
> for (i = 0; i < num_pages; i++) {
> - msi_page[i].phys = start;
> - msi_page[i].iova = start;
> - INIT_LIST_HEAD(&msi_page[i].list);
> - list_add(&msi_page[i].list, &cookie->msi_page_list);
> + msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL);
> + if (!msi_page) {
> + ret = -ENOMEM;
I think we can just return here and skip the cleanup below - by the time
we get here the cookie itself has already been allocated and
initialised, so even if iommu_dma_init_domain() fails someone else has
already accepted the responsibility of calling iommu_put_dma_cookie() at
some point later, which will clean up properly.
Cheers,
Robin.
> + break;
> + }
> + msi_page->phys = start;
> + msi_page->iova = start;
> + INIT_LIST_HEAD(&msi_page->list);
> + list_add(&msi_page->list, &cookie->msi_page_list);
> start += iovad->granule;
> }
>
> - return 0;
> + if (ret) {
> + list_for_each_entry_safe(msi_page, tmp,
> + &cookie->msi_page_list, list) {
> + if (msi_page->phys >= base && msi_page->phys < start) {
> + list_del(&msi_page->list);
> + kfree(msi_page);
> + }
> + }
> + }
> +
> + return ret;
> }
>
> static int iova_reserve_pci_windows(struct pci_dev *dev,
>
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] iommu/dma: Fix MSI reservation allocation
2020-03-03 17:23 ` Robin Murphy
@ 2020-03-03 17:33 ` Marc Zyngier
-1 siblings, 0 replies; 8+ messages in thread
From: Marc Zyngier @ 2020-03-03 17:33 UTC (permalink / raw)
To: Robin Murphy
Cc: linux-arm-kernel, linux-kernel, Joerg Roedel, Eric Auger,
Will Deacon, stable
On 2020-03-03 17:23, Robin Murphy wrote:
> On 03/03/2020 11:51 am, Marc Zyngier wrote:
>> The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page
>> structures doesn't match the way iommu_put_dma_cookie() frees them.
>>
>> The former performs a single allocation of all the required
>> structures,
>> while the latter tries to free them one at a time. It doesn't quite
>> work for the main use case (the GICv3 ITS where the range is 64kB)
>> when the base ganule size is 4kB.
>>
>> This leads to a nice slab corruption on teardown, which is easily
>> observable by simply creating a VF on a SRIOV-capable device, and
>> tearing it down immediately (no need to even make use of it).
>>
>> Fix it by allocating iommu_dma_msi_page structures one at a time.
>
> Bleh, you know you're supposed to be using 64K pages on those things,
> right? :P
lalalala... ;-)
[...]
>> + if (!msi_page) {
>> + ret = -ENOMEM;
>
> I think we can just return here and skip the cleanup below - by the
> time we get here the cookie itself has already been allocated and
> initialised, so even if iommu_dma_init_domain() fails someone else has
> already accepted the responsibility of calling iommu_put_dma_cookie()
> at some point later, which will clean up properly.
Ah, that's a very good point. I'll refresh the patch with a simplified
error handling.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] iommu/dma: Fix MSI reservation allocation
@ 2020-03-03 17:33 ` Marc Zyngier
0 siblings, 0 replies; 8+ messages in thread
From: Marc Zyngier @ 2020-03-03 17:33 UTC (permalink / raw)
To: Robin Murphy
Cc: Joerg Roedel, linux-kernel, stable, Eric Auger, Will Deacon,
linux-arm-kernel
On 2020-03-03 17:23, Robin Murphy wrote:
> On 03/03/2020 11:51 am, Marc Zyngier wrote:
>> The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page
>> structures doesn't match the way iommu_put_dma_cookie() frees them.
>>
>> The former performs a single allocation of all the required
>> structures,
>> while the latter tries to free them one at a time. It doesn't quite
>> work for the main use case (the GICv3 ITS where the range is 64kB)
>> when the base ganule size is 4kB.
>>
>> This leads to a nice slab corruption on teardown, which is easily
>> observable by simply creating a VF on a SRIOV-capable device, and
>> tearing it down immediately (no need to even make use of it).
>>
>> Fix it by allocating iommu_dma_msi_page structures one at a time.
>
> Bleh, you know you're supposed to be using 64K pages on those things,
> right? :P
lalalala... ;-)
[...]
>> + if (!msi_page) {
>> + ret = -ENOMEM;
>
> I think we can just return here and skip the cleanup below - by the
> time we get here the cookie itself has already been allocated and
> initialised, so even if iommu_dma_init_domain() fails someone else has
> already accepted the responsibility of calling iommu_put_dma_cookie()
> at some point later, which will clean up properly.
Ah, that's a very good point. I'll refresh the patch with a simplified
error handling.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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linux-arm-kernel@lists.infradead.org
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^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-03-03 17:34 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-03 11:51 [PATCH] iommu/dma: Fix MSI reservation allocation Marc Zyngier
2020-03-03 11:51 ` Marc Zyngier
2020-03-03 12:56 ` Auger Eric
2020-03-03 12:56 ` Auger Eric
2020-03-03 17:23 ` Robin Murphy
2020-03-03 17:23 ` Robin Murphy
2020-03-03 17:33 ` Marc Zyngier
2020-03-03 17:33 ` Marc Zyngier
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