All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Will Deacon <will@kernel.org>
Cc: rjw@rjwysocki.net, oleg@redhat.com, mingo@kernel.org,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, mgorman@suse.de,
	linux-kernel@vger.kernel.org, tj@kernel.org,
	linux-pm@vger.kernel.org
Subject: Re: [PATCH v3 3/6] ptrace: Order and comment PT_flags
Date: Thu, 14 Oct 2021 16:27:55 +0200	[thread overview]
Message-ID: <YWg+a6PPD5Mpr4c/@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20211014093121.GA8239@willie-the-truck>

On Thu, Oct 14, 2021 at 10:31:22AM +0100, Will Deacon wrote:
> On Sat, Oct 09, 2021 at 12:07:57PM +0200, Peter Zijlstra wrote:
> > Add a comment to the PT_flags to indicate their actual value, this
> > makes it easier to see what bits are used and where there might be a
> > possible hole to use.
> > 
> > Notable PT_SEIZED was placed wrong, also PT_EVENT_FLAG() space seems
> > ill defined, as written is seems to be meant to cover the entire
> > PTRACE_O_ range offset by 3 bits, which would then be 3+[0..21],
> > however PT_SEIZED is in the middle of that.
> 
> Why do you think PT_EVENT_FLAG() should cover all the PTRACE_O_* options?
> Just going by the name and current callers, I'd only expect it to cover
> the PTRACE_EVENT_* flags, no?

Because PT_EXITKILL and PT_SUSPEND_SECCOMP are also exposed in that same
mapping.

Ideally we'd change PT_OPT_FLAG_SHIFT to 8 or something and have the
high 24 bits for OPT and then use the low 8 bits for SEIZED and the new
flags.

  reply	other threads:[~2021-10-14 14:28 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-09 10:07 [PATCH v3 0/6] Freezer rewrite Peter Zijlstra
2021-10-09 10:07 ` [PATCH v3 1/6] freezer: Have {,un}lock_system_sleep() save/restore flags Peter Zijlstra
2021-10-14  8:58   ` Will Deacon
2021-10-09 10:07 ` [PATCH v3 2/6] freezer,umh: Clean up freezer/initrd interaction Peter Zijlstra
2021-10-14  9:13   ` Will Deacon
2021-10-09 10:07 ` [PATCH v3 3/6] ptrace: Order and comment PT_flags Peter Zijlstra
2021-10-14  9:31   ` Will Deacon
2021-10-14 14:27     ` Peter Zijlstra [this message]
2021-10-09 10:07 ` [PATCH v3 4/6] ptrace: Track __TASK_TRACED state in p->ptrace Peter Zijlstra
2021-10-09 10:07 ` [PATCH v3 5/6] sched,ptrace: Avoid relying on __TASK_TRACED | __TASK_STOPPED Peter Zijlstra
2021-10-09 10:08 ` [PATCH v3 6/6] freezer,sched: Rewrite core freezer logic Peter Zijlstra
2021-10-18 13:36   ` Peter Zijlstra

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=YWg+a6PPD5Mpr4c/@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=dietmar.eggemann@arm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mgorman@suse.de \
    --cc=mingo@kernel.org \
    --cc=oleg@redhat.com \
    --cc=rjw@rjwysocki.net \
    --cc=rostedt@goodmis.org \
    --cc=tj@kernel.org \
    --cc=vincent.guittot@linaro.org \
    --cc=will@kernel.org \
    --subject='Re: [PATCH v3 3/6] ptrace: Order and comment PT_flags' \
    /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

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.