Re: block: DMA alignment of IO buffer allocated from slab

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, 24 Sep 2018, Bart Van Assche wrote:

> That means that two buffers allocated with kmalloc() may share a cache line on
> x86-64. Since it is allowed to use a buffer allocated by kmalloc() for DMA, can
> this lead to data corruption, e.g. if the CPU writes into one buffer allocated
> with kmalloc() and a device performs a DMA write to another kmalloc() buffer and
> both write operations affect the same cache line?

The devices writes to the cacheline through the processor which serializes
access appropriately.

The DMA device cannot write directly to memory after all on current Intel
processors. Other architectures have bus protocols that prevent situations
like that.






[Index of Archives]     [Linux RAID]     [Linux SCSI]     [Linux ATA RAID]     [IDE]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Device Mapper]

  Powered by Linux