Messages in this thread | | | From | Linus Walleij <> | Date | Mon, 18 Jul 2022 14:53:15 +0200 | Subject | Re: [PATCH v3] ARM: Fix MAX_DMA_ADDRESS overflow |
| |
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>
Yours, Linus Walleij
| |