path: root/arch
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authorFlorian Fainelli <f.fainelli@gmail.com>2022-07-19 17:33:21 +0100
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2022-07-27 17:55:01 +0100
commitfb0fd3469ead5b937293c213daa1f589b4b7ce46 (patch)
tree92382cedc981a203680589e7d5d69c18a5315ce3 /arch
parent29589ca09a74cfc0c50ad002e298bf4b8e69e0bd (diff)
ARM: 9216/1: Fix MAX_DMA_ADDRESS overflow
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> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch')
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/include/asm/dma.h b/arch/arm/include/asm/dma.h
index a81dda65c576..45180a2cc47c 100644
--- a/arch/arm/include/asm/dma.h
+++ b/arch/arm/include/asm/dma.h
@@ -10,7 +10,7 @@
#define MAX_DMA_ADDRESS ({ \
extern phys_addr_t arm_dma_zone_size; \
- arm_dma_zone_size && arm_dma_zone_size < (0x10000000 - PAGE_OFFSET) ? \
+ arm_dma_zone_size && arm_dma_zone_size < (0x100000000ULL - PAGE_OFFSET) ? \
(PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; })

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