Re: [PATCH] [AArch64 Linux] Get rid of top byte from tagged address

Ramana Radhakrishnan
2017-10-19T09:51:15Z

On 10/19/17 9:08 AM, Yao Qi wrote:
> ARMv8 supports tagged address, that is, the top one byte in address
> is ignored. It is always enabled on aarch64-linux. The patch clear
> the top byte of the virtual address, at the point before GDB/GDBserver
> pass the address to /proc or ptrace syscall. The top byte of address is
> still retained in the rest of GDB, because these bits can be used by
> different applications in different ways. That is reason I didn't
> implement gdbarch method addr_bits_remove to get rid of them.

I think you also want to point people at ...

https://www.kernel.org/doc/Documentation/arm64/tagged-pointers.txt

regards
Ramana