Messages in this thread | | | Date | Wed, 13 Jul 2022 16:28:11 -0700 | Subject | Re: [PATCH v3] ARM: Fix MAX_DMA_ADDRESS overflow | From | Florian Fainelli <> |
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On 7/6/22 13:33, Florian Fainelli wrote: > Commit 26f09e9b3a06 ("mm/memblock: add memblock memory allocation apis") > added a check to determine whether arm_dma_zone_size is exceeding the > amount of kernel virtual address space available between the upper 4GB > virtual address limit and PAGE_OFFSET in order to provide a suitable > definition of MAX_DMA_ADDRESS that should fit within the 32-bit virtual > address space. The quantity used for comparison was off by a missing > trailing 0, leading to MAX_DMA_ADDRESS to be overflowing a 32-bit > quantity. > > This was caught thanks to CONFIG_DEBUG_VIRTUAL on the bcm2711 platform > where we define a dma_zone_size of 1GB and we have a PAGE_OFFSET value > of 0xc000_0000 (CONFIG_VMSPLIT_3G) leading to MAX_DMA_ADDRESS being > 0x1_0000_0000 which overflows the unsigned long type used throughout > __pa() and then __virt_addr_valid(). Because the virtual address passed > to __virt_addr_valid() would now be 0, the function would loudly warn > and flood the kernel log, thus making the platform unable to boot > properly. > > Fixes: 26f09e9b3a06 ("mm/memblock: add memblock memory allocation apis") > Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Shall I send this to RMK's patch system? -- Florian
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