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Florian Fainelli
fb0fd3469e
Commit26f09e9b3a("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:26f09e9b3a("mm/memblock: add memblock memory allocation apis") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.