From: David Daney <ddaney@caviumnetworks.com>
To: Earl Chew <echew@ixiacom.com>
Cc: "linux-mips@linux-mips.org" <linux-mips@linux-mips.org>
Subject: Re: Filling in struct mips64_watch_regs from a 32 bit process
Date: Mon, 31 Jan 2011 17:24:49 -0800 [thread overview]
Message-ID: <4D4760E1.9000400@caviumnetworks.com> (raw)
In-Reply-To: <4D475DFC.1040401@ixiacom.com>
On 01/31/2011 05:12 PM, Earl Chew wrote:
>>> I notice that a 32 bit process running on a 64 bit kernel is expected to
>>> know that it should fill in mips64_watch_regs --- even though it is running
>>> against a 32 bit ABI.
>>>
>>> Is this an oversight, or am I missing something ?
>>
>> It is intentional.
>
> Oh I see ... I have to call PTRACE_SET_WATCH_REGS first in order to figure
> out whether the kernel is expecting me to use pt_watch_style_mips32 or
> pt_watch_style_mips64.
>
That would be PTRACE_GET_WATCH_REGS. It will tell you the width of the
registers as well as how many are available (in the num_valid field) and
the properties of each (in the watch_masks[] fields).
Fill in watchlo[] and watchhi[], write them back with
PTRACE_SET_WATCH_REGS, then sit back and wait for SIGTRAP.
David Daney
next prev parent reply other threads:[~2011-02-01 1:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-01 0:41 Filling in struct mips64_watch_regs from a 32 bit process Earl Chew
2011-02-01 1:03 ` David Daney
2011-02-01 1:12 ` Earl Chew
2011-02-01 1:24 ` David Daney [this message]
2011-02-01 1:26 ` Earl Chew
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4D4760E1.9000400@caviumnetworks.com \
--to=ddaney@caviumnetworks.com \
--cc=echew@ixiacom.com \
--cc=linux-mips@linux-mips.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.