From: Aaron Tomlin <atomlin@redhat.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: peterz@infradead.org, mingo@redhat.com, dzickus@redhat.com,
bmr@redhat.com, jcastillo@redhat.com, pzijlstr@redhat.com,
riel@redhat.com, linux-kernel@vger.kernel.org,
tglx@linutronix.de, x86@kernel.org, rostedt@goodmis.org,
hannes@cmpxchg.org, aneesh.kumar@linux.vnet.ibm.com,
akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org,
minchan@kernel.org
Subject: Re: [PATCH 1/2] sched: Add helper for task stack page overrun checking
Date: Thu, 4 Sep 2014 16:52:00 +0100 [thread overview]
Message-ID: <20140904155200.GC1436@atomlin.usersys.redhat.com> (raw)
In-Reply-To: <20140904150234.GA6480@redhat.com>
On Thu, Sep 04, 2014 at 05:02:34PM +0200, Oleg Nesterov wrote:
> On 09/04, Aaron Tomlin wrote:
> >
> > +#define task_stack_end_corrupted(task) \
> > + (*(end_of_stack(task)) != STACK_END_MAGIC)
>
> and it is always used along with "tsk != init_task".
>
> But why we exclude swapper/0? Can't we add
>
> end_of_stack(current) = STACK_END_MAGIC;
>
> somewhere at the start of start_kernel() ?
Good point. I can look into it.
> If not, perhaps this new helper should check "task != &init_task"
> itself so that we can simplify its users?
>
> Oleg.
>
> >
> > static inline int object_is_on_stack(void *obj)
> > {
> > diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
> > index 8a4e5cb..06c7390 100644
> > --- a/kernel/trace/trace_stack.c
> > +++ b/kernel/trace/trace_stack.c
> > @@ -13,7 +13,6 @@
> > #include <linux/sysctl.h>
> > #include <linux/init.h>
> > #include <linux/fs.h>
> > -#include <linux/magic.h>
> >
> > #include <asm/setup.h>
> >
> > @@ -171,8 +170,8 @@ check_stack(unsigned long ip, unsigned long *stack)
> > i++;
> > }
> >
> > - if ((current != &init_task &&
> > - *(end_of_stack(current)) != STACK_END_MAGIC)) {
> > + if (current != &init_task &&
> > + task_stack_end_corrupted(current)) {
> > print_max_stack();
> > BUG();
> > }
> > --
> > 1.9.3
> >
>
--
Aaron Tomlin
next prev parent reply other threads:[~2014-09-04 15:54 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-04 14:50 [PATCH 0/2] sched: Always check the integrity of the canary Aaron Tomlin
2014-09-04 14:50 ` [PATCH 1/2] sched: Add helper for task stack page overrun checking Aaron Tomlin
2014-09-04 15:02 ` Oleg Nesterov
2014-09-04 15:52 ` Aaron Tomlin [this message]
2014-09-04 15:30 ` Peter Zijlstra
2014-09-04 14:50 ` [PATCH 2/2] sched: BUG when stack end location is over written Aaron Tomlin
2014-09-04 15:32 ` Peter Zijlstra
2014-09-04 16:11 ` Aaron Tomlin
2014-09-08 19:23 ` [PATCH v2 0/3] sched: Always check the integrity of the canary Aaron Tomlin
2014-09-08 19:23 ` [PATCH 1/3] init/main.c: Give init_task a canary Aaron Tomlin
2014-09-08 19:23 ` [PATCH 2/3] sched: Add helper for task stack page overrun checking Aaron Tomlin
2014-09-08 19:23 ` [PATCH 3/3] sched: BUG when stack end location is over written Aaron Tomlin
2014-09-09 9:42 ` [PATCH v2 0/3] sched: Always check the integrity of the canary Aaron Tomlin
2014-09-09 9:42 ` [PATCH v2 1/3] init/main.c: Give init_task a canary Aaron Tomlin
2014-09-10 7:26 ` Chuck Ebbert
2014-09-10 13:29 ` Aaron Tomlin
2014-09-11 12:23 ` Chuck Ebbert
2014-09-11 14:47 ` Aaron Tomlin
2014-09-09 9:42 ` [PATCH v2 2/3] sched: Add helper for task stack page overrun checking Aaron Tomlin
2014-09-09 9:42 ` [PATCH v2 3/3] sched: BUG when stack end location is over written Aaron Tomlin
2014-09-11 15:41 ` [PATCH v3 0/3] sched: Always check the integrity of the canary Aaron Tomlin
2014-09-11 15:41 ` [PATCH v3 1/3] init/main.c: Give init_task a canary Aaron Tomlin
2014-09-12 7:28 ` Michael Ellerman
2014-09-11 15:41 ` [PATCH v3 2/3] sched: Add helper for task stack page overrun checking Aaron Tomlin
2014-09-11 15:41 ` [PATCH v3 3/3] sched: BUG when stack end location is over written Aaron Tomlin
2014-09-12 4:06 ` Michael Ellerman
2014-09-12 9:44 ` Aaron Tomlin
2014-09-12 10:58 ` Mike Galbraith
2014-09-15 2:39 ` Michael Ellerman
2014-09-12 6:04 ` Michael Ellerman
2014-09-12 9:50 ` Aaron Tomlin
2014-09-11 15:53 ` [PATCH v3 0/3] sched: Always check the integrity of the canary Peter Zijlstra
2014-09-11 15:59 ` Aaron Tomlin
2014-09-11 16:02 ` David Laight
2014-09-11 17:26 ` Chuck Ebbert
2014-09-12 8:43 ` David Laight
2014-09-11 17:44 ` Aaron Tomlin
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=20140904155200.GC1436@atomlin.usersys.redhat.com \
--to=atomlin@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=bmr@redhat.com \
--cc=dzickus@redhat.com \
--cc=hannes@cmpxchg.org \
--cc=jcastillo@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=minchan@kernel.org \
--cc=mingo@redhat.com \
--cc=oleg@redhat.com \
--cc=peterz@infradead.org \
--cc=pzijlstr@redhat.com \
--cc=riel@redhat.com \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).