From: Niklas Schnelle Date: Wed, 12 Mar 2025 10:32:18 +0000 (+0100) Subject: s390/pci: Fix dev.dma_range_map missing sentinel element X-Git-Tag: v6.15-rc1~15^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=807c2743035446cf0484772a76e1c35ce27fd8e3;p=thirdparty%2Fkernel%2Flinux.git s390/pci: Fix dev.dma_range_map missing sentinel element The fixed commit sets up dev.dma_range_map but missed that this is supposed to be an array of struct bus_dma_region with a sentinel element with the size field set to 0 at the end. This would lead to overruns in e.g. dma_range_map_min(). It could also result in wrong translations instead of DMA_MAPPING_ERROR in translate_phys_to_dma() if the paddr were to not fit in the aperture. Fix this by using the dma_direct_set_offset() helper which creates a sentinel for us. Fixes: d236843a6964 ("s390/pci: store DMA offset in bus_dma_region") Reviewed-by: Matthew Rosato Signed-off-by: Niklas Schnelle Link: https://lore.kernel.org/r/20250312-fix_dma_map_alloc-v2-1-530108d9de21@linux.ibm.com Signed-off-by: Vasily Gorbik --- diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c index 4d45edb026f2c..81bdb54ad5e38 100644 --- a/arch/s390/pci/pci_bus.c +++ b/arch/s390/pci/pci_bus.c @@ -287,23 +287,21 @@ static struct zpci_bus *zpci_bus_alloc(int topo, bool topo_is_tid) static void pci_dma_range_setup(struct pci_dev *pdev) { struct zpci_dev *zdev = to_zpci(pdev); - struct bus_dma_region *map; - u64 aligned_end; + u64 aligned_end, size; + dma_addr_t dma_start; + int ret; - map = kzalloc(sizeof(*map), GFP_KERNEL); - if (!map) - return; - - map->cpu_start = 0; - map->dma_start = PAGE_ALIGN(zdev->start_dma); + dma_start = PAGE_ALIGN(zdev->start_dma); aligned_end = PAGE_ALIGN_DOWN(zdev->end_dma + 1); - if (aligned_end >= map->dma_start) - map->size = aligned_end - map->dma_start; + if (aligned_end >= dma_start) + size = aligned_end - dma_start; else - map->size = 0; - WARN_ON_ONCE(map->size == 0); + size = 0; + WARN_ON_ONCE(size == 0); - pdev->dev.dma_range_map = map; + ret = dma_direct_set_offset(&pdev->dev, 0, dma_start, size); + if (ret) + pr_err("Failed to allocate DMA range map for %s\n", pci_name(pdev)); } void pcibios_bus_add_device(struct pci_dev *pdev)