kernel/linux.git/include/linux/swiotlb.h, branch v5.15.209

swiotlb: Support aligned swiotlb buffers

2022-04-08T12:24:17+00:00

commit e81e99bacc9f9347bda7808a949c1ce9fcc2bbf4 upstream. Add an argument to swiotlb_tbl_map_single that specifies the desired alignment of the allocated buffer. This is used by dma-iommu to ensure the buffer is aligned to the iova granule size when using swiotlb with untrusted sub-granule mappings. This addresses an issue where adjacent slots could be exposed to the untrusted device if IO_TLB_SIZE < iova granule < PAGE_SIZE. Signed-off-by: David Stevens Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210929023300.335969-7-stevensd@google.com Signed-off-by: Joerg Roedel Cc: Mario Limonciello Signed-off-by: Greg Kroah-Hartman

swiotlb: Convert io_default_tlb_mem to static allocation

2021-07-24T00:14:43+00:00

Since commit 69031f500865 ("swiotlb: Set dev->dma_io_tlb_mem to the swiotlb pool used"), 'struct device' may hold a copy of the global 'io_default_tlb_mem' pointer if the device is using swiotlb for DMA. A subsequent call to swiotlb_exit() will therefore leave dangling pointers behind in these device structures, resulting in KASAN splats such as: | BUG: KASAN: use-after-free in __iommu_dma_unmap_swiotlb+0x64/0xb0 | Read of size 8 at addr ffff8881d7830000 by task swapper/0/0 | | CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc3-debug #1 | Hardware name: HP HP Desktop M01-F1xxx/87D6, BIOS F.12 12/17/2020 | Call Trace: | | dump_stack+0x9c/0xcf | print_address_description.constprop.0+0x18/0x130 | kasan_report.cold+0x7f/0x111 | __iommu_dma_unmap_swiotlb+0x64/0xb0 | nvme_pci_complete_rq+0x73/0x130 | blk_complete_reqs+0x6f/0x80 | __do_softirq+0xfc/0x3be Convert 'io_default_tlb_mem' to a static structure, so that the per-device pointers remain valid after swiotlb_exit() has been invoked. All users are updated to reference the static structure directly, using the 'nslabs' field to determine whether swiotlb has been initialised. The 'slots' array is still allocated dynamically and referenced via a pointer rather than a flexible array member. Cc: Claire Chang Cc: Christoph Hellwig Cc: Robin Murphy Cc: Konrad Rzeszutek Wilk Fixes: 69031f500865 ("swiotlb: Set dev->dma_io_tlb_mem to the swiotlb pool used") Reported-by: Nathan Chancellor Tested-by: Nathan Chancellor Tested-by: Claire Chang Reviewed-by: Christoph Hellwig Signed-off-by: Will Deacon Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Add restricted DMA pool initialization

2021-07-14T00:04:50+00:00

Add the initialization function to create restricted DMA pools from matching reserved-memory nodes. Regardless of swiotlb setting, the restricted DMA pool is preferred if available. The restricted DMA pools provide a basic level of protection against the DMA overwriting buffer contents at unexpected times. However, to protect against general data leakage and system memory corruption, the system needs to provide a way to lock down the memory access, e.g., MPU. Signed-off-by: Claire Chang Reviewed-by: Christoph Hellwig Tested-by: Stefano Stabellini Tested-by: Will Deacon Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Add restricted DMA alloc/free support

2021-07-14T00:04:48+00:00

Add the functions, swiotlb_{alloc,free} and is_swiotlb_for_alloc to support the memory allocation from restricted DMA pool. The restricted DMA pool is preferred if available. Note that since coherent allocation needs remapping, one must set up another device coherent pool by shared-dma-pool and use dma_alloc_from_dev_coherent instead for atomic coherent allocation. Signed-off-by: Claire Chang Reviewed-by: Christoph Hellwig Tested-by: Stefano Stabellini Tested-by: Will Deacon Acked-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-07-14T00:04:43+00:00

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 Reviewed-by: Christoph Hellwig Tested-by: Stefano Stabellini Tested-by: Will Deacon Acked-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk [v2: Includes Will's fix]

swiotlb: Update is_swiotlb_active to add a struct device argument

2021-07-14T00:04:41+00:00

Update is_swiotlb_active to add a struct device argument. This will be useful later to allow for different pools. Signed-off-by: Claire Chang Reviewed-by: Christoph Hellwig Tested-by: Stefano Stabellini Tested-by: Will Deacon Acked-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Update is_swiotlb_buffer to add a struct device argument

2021-07-14T00:04:38+00:00

Update is_swiotlb_buffer to add a struct device argument. This will be useful later to allow for different pools. Signed-off-by: Claire Chang Reviewed-by: Christoph Hellwig Tested-by: Stefano Stabellini Tested-by: Will Deacon Acked-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: remove swiotlb_nr_tbl

2021-03-19T04:58:25+00:00

All callers just use it to check if swiotlb is active at all, for which they can just use is_swiotlb_active. In the longer run drivers need to stop using is_swiotlb_active as well, but let's do the simple step first. Signed-off-by: Christoph Hellwig Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: dynamically allocate io_tlb_default_mem

2021-03-19T04:58:25+00:00

Instead of allocating ->list and ->orig_addr separately just do one dynamic allocation for the actual io_tlb_mem structure. This simplifies a lot of the initialization code, and also allows to just check io_tlb_default_mem to see if swiotlb is in use. Signed-off-by: Christoph Hellwig Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: move global variables into a new io_tlb_mem structure

2021-03-19T04:58:25+00:00

Added a new struct, io_tlb_mem, as the IO TLB memory pool descriptor and moved relevant global variables into that struct. This will be useful later to allow for restricted DMA pool. Signed-off-by: Claire Chang [hch: rebased] Signed-off-by: Christoph Hellwig Signed-off-by: Konrad Rzeszutek Wilk