| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <alpine.DEB.2.21.2106161711030.24906@sstabellini-ThinkPad-T480s>
Date: Wed, 16 Jun 2021 17:47:07 -0700 (PDT)
From: Stefano Stabellini <sstabellini@...nel.org>
To: Claire Chang <tientzu@...omium.org>
cc: Rob Herring <robh+dt@...nel.org>, mpe@...erman.id.au,
Joerg Roedel <joro@...tes.org>, Will Deacon <will@...nel.org>,
Frank Rowand <frowand.list@...il.com>,
Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
boris.ostrovsky@...cle.com, jgross@...e.com,
Christoph Hellwig <hch@....de>,
Marek Szyprowski <m.szyprowski@...sung.com>,
benh@...nel.crashing.org, paulus@...ba.org,
"list@....net:IOMMU DRIVERS" <iommu@...ts.linux-foundation.org>,
sstabellini@...nel.org, Robin Murphy <robin.murphy@....com>,
grant.likely@....com, xypron.glpk@....de,
Thierry Reding <treding@...dia.com>, mingo@...nel.org,
bauerman@...ux.ibm.com, peterz@...radead.org,
Greg KH <gregkh@...uxfoundation.org>,
Saravana Kannan <saravanak@...gle.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
heikki.krogerus@...ux.intel.com,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Randy Dunlap <rdunlap@...radead.org>,
Dan Williams <dan.j.williams@...el.com>,
Bartosz Golaszewski <bgolaszewski@...libre.com>,
linux-devicetree <devicetree@...r.kernel.org>,
lkml <linux-kernel@...r.kernel.org>,
linuxppc-dev@...ts.ozlabs.org, xen-devel@...ts.xenproject.org,
Nicolas Boichat <drinkcat@...omium.org>,
Jim Quinlan <james.quinlan@...adcom.com>, tfiga@...omium.org,
bskeggs@...hat.com, bhelgaas@...gle.com, chris@...is-wilson.co.uk,
daniel@...ll.ch, airlied@...ux.ie, dri-devel@...ts.freedesktop.org,
intel-gfx@...ts.freedesktop.org, jani.nikula@...ux.intel.com,
jxgao@...gle.com, joonas.lahtinen@...ux.intel.com,
linux-pci@...r.kernel.org, maarten.lankhorst@...ux.intel.com,
matthew.auld@...el.com, rodrigo.vivi@...el.com,
thomas.hellstrom@...ux.intel.com
Subject: Re: [PATCH v12 06/12] swiotlb: Use is_swiotlb_force_bounce for
swiotlb data bouncing
On Wed, 16 Jun 2021, Claire Chang wrote:
> Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and
> use it to determine whether to bounce the data or not. This will be
> useful later to allow for different pools.
>
> Signed-off-by: Claire Chang <tientzu@...omium.org>
> ---
> include/linux/swiotlb.h | 11 +++++++++++
> kernel/dma/direct.c | 2 +-
> kernel/dma/direct.h | 2 +-
> kernel/dma/swiotlb.c | 4 ++++
> 4 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
> index dd1c30a83058..8d8855c77d9a 100644
> --- a/include/linux/swiotlb.h
> +++ b/include/linux/swiotlb.h
> @@ -84,6 +84,7 @@ extern enum swiotlb_force swiotlb_force;
> * unmap calls.
> * @debugfs: The dentry to debugfs.
> * @late_alloc: %true if allocated using the page allocator
> + * @force_bounce: %true if swiotlb bouncing is forced
> */
> struct io_tlb_mem {
> phys_addr_t start;
> @@ -94,6 +95,7 @@ struct io_tlb_mem {
> spinlock_t lock;
> struct dentry *debugfs;
> bool late_alloc;
> + bool force_bounce;
> struct io_tlb_slot {
> phys_addr_t orig_addr;
> size_t alloc_size;
> @@ -109,6 +111,11 @@ static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
> return mem && paddr >= mem->start && paddr < mem->end;
> }
>
> +static inline bool is_swiotlb_force_bounce(struct device *dev)
> +{
> + return dev->dma_io_tlb_mem->force_bounce;
> +}
> void __init swiotlb_exit(void);
> unsigned int swiotlb_max_segment(void);
> size_t swiotlb_max_mapping_size(struct device *dev);
> @@ -120,6 +127,10 @@ static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
> {
> return false;
> }
> +static inline bool is_swiotlb_force_bounce(struct device *dev)
> +{
> + return false;
> +}
> static inline void swiotlb_exit(void)
> {
> }
> diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
> index 7a88c34d0867..a92465b4eb12 100644
> --- a/kernel/dma/direct.c
> +++ b/kernel/dma/direct.c
> @@ -496,7 +496,7 @@ size_t dma_direct_max_mapping_size(struct device *dev)
> {
> /* If SWIOTLB is active, use its maximum mapping size */
> if (is_swiotlb_active(dev) &&
> - (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE))
> + (dma_addressing_limited(dev) || is_swiotlb_force_bounce(dev)))
> return swiotlb_max_mapping_size(dev);
> return SIZE_MAX;
> }
> diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
> index 13e9e7158d94..4632b0f4f72e 100644
> --- a/kernel/dma/direct.h
> +++ b/kernel/dma/direct.h
> @@ -87,7 +87,7 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
> phys_addr_t phys = page_to_phys(page) + offset;
> dma_addr_t dma_addr = phys_to_dma(dev, phys);
>
> - if (unlikely(swiotlb_force == SWIOTLB_FORCE))
> + if (is_swiotlb_force_bounce(dev))
> return swiotlb_map(dev, phys, size, dir, attrs);
>
> if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
Should we also make the same change in
drivers/xen/swiotlb-xen.c:xen_swiotlb_map_page ?
If I make that change, I can see that everything is working as
expected for a restricted-dma device with Linux running as dom0 on Xen.
However, is_swiotlb_force_bounce returns non-zero even for normal
non-restricted-dma devices. That shouldn't happen, right?
It looks like struct io_tlb_slot is not zeroed on allocation.
Adding memset(mem, 0x0, struct_size) in swiotlb_late_init_with_tbl
solves the issue.
With those two changes, the series passes my tests and you can add my
tested-by.
Powered by blists - more mailing lists