On Wed, 19 Aug 2020 10:15:53 -0700 Florian Fainelli <f.fainelli@xxxxxxxxx> wrote: > >> In many cases the difference is not significant, but for example > >> an ARM platform with 1GB of memory and the following memory layout > >> [ 0.000000] cma: Reserved 256 MiB at 0x0000000030000000 > >> [ 0.000000] Zone ranges: > >> [ 0.000000] DMA [mem 0x0000000000000000-0x000000002fffffff] > >> [ 0.000000] Normal empty > >> [ 0.000000] HighMem [mem 0x0000000030000000-0x000000003fffffff] > >> > >> would result in 0 lowmem_reserve for the DMA zone. This would allow > >> userspace to deplete the DMA zone easily. > > > > Sounds fairly serious for thos machines. Was a cc:stable considered? > > Since there is a Fixes: tag, it may have been assumed that the patch > would be picked up and as soon as it reaches Linus' tree it would be > picked up by the stable selection. It doesn't work that way - sometimes a fix isn't considered important enough to backport. It could just fix a typo in a comment!
