From: Ramana Radhakrishnan <ramana.radhakrishnan@foss.arm.com>
To: Yao Qi <qiyaoltc@gmail.com>, gdb-patches@sourceware.org
Subject: Re: [PATCH] [AArch64 Linux] Get rid of top byte from tagged address
Date: Thu, 19 Oct 2017 09:51:00 -0000 [thread overview]
Message-ID: <f8e94415-d7f4-333c-41cf-d718665e80dc@foss.arm.com> (raw)
In-Reply-To: <1508400527-20718-1-git-send-email-yao.qi@linaro.org>
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
next prev parent reply other threads:[~2017-10-19 9:51 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-19 8:08 Yao Qi
2017-10-19 9:51 ` Ramana Radhakrishnan [this message]
2017-10-19 10:53 ` Yao Qi
2017-10-19 9:52 ` Pedro Alves
2017-10-19 9:55 ` Ramana Radhakrishnan
2017-10-19 10:51 ` Yao Qi
2017-10-19 11:09 ` Pedro Alves
2017-10-19 13:17 ` Yao Qi
2017-10-19 13:22 ` Pedro Alves
2017-10-19 11:21 ` Pedro Alves
2017-10-19 13:25 ` Yao Qi
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