Messages in this thread | | | Date | Tue, 19 Jul 2022 09:34:12 -0700 | Subject | Re: [PATCH v3] ARM: Fix MAX_DMA_ADDRESS overflow | From | Florian Fainelli <> |
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On 7/18/2022 5:53 AM, Linus Walleij wrote: > On Thu, Jul 14, 2022 at 1:28 AM Florian Fainelli <f.fainelli@gmail.com> wrote: >> 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? > > I think so! > Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Thanks:
https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=9216/1 -- Florian
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