From: David Laight <David.Laight@ACULAB.COM>
To: "'David Miller'" <davem@davemloft.net>,
"geert@linux-m68k.org" <geert@linux-m68k.org>
Cc: "me@tobin.cc" <me@tobin.cc>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
"torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
"Jason@zx2c4.com" <Jason@zx2c4.com>,
"tytso@mit.edu" <tytso@mit.edu>,
"keescook@chromium.org" <keescook@chromium.org>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"tycho@tycho.ws" <tycho@tycho.ws>,
"william.c.roberts@intel.com" <william.c.roberts@intel.com>,
"tj@kernel.org" <tj@kernel.org>,
"Golden_Miller83@protonmail.ch" <Golden_Miller83@protonmail.ch>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"pmladek@suse.com" <pmladek@suse.com>,
"joe@perches.com" <joe@perches.com>,
"ijc@hellion.org.uk" <ijc@hellion.org.uk>,
"sergey.senozhatsky@gmail.com" <sergey.senozhatsky@gmail.com>,
"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
"wilal.deacon@arm.com" <wilal.deacon@arm.com>,
"rostedt@goodmis.org" <rostedt@goodmis.org>,
"cfries@google.com" <cfries@google.com>,
"olorin@google.com" <olorin@google.com>,
"danielmicay@gmail.com" <danielmicay@gmail.com>,
"tixxdz@gmail.com" <tixxdz@gmail.com>,
"rkrcmar@redhat.com" <rkrcmar@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"sfr@canb.auug.org.au" <sfr@canb.auug.org.au>,
"aryabinin@virtuozzo.com" <aryabinin@virtuozzo.com>,
"glider@google.com" <glider@google.com>,
"dvyukov@google.com" <dvyukov@google.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"sergei.shtylyov@cogentembedded.com"
<sergei.shtylyov@cogentembedded.com>
Subject: RE: [PATCH V11 3/5] printk: hash addresses printed with %p
Date: Wed, 6 Dec 2017 10:31:15 +0000 [thread overview]
Message-ID: <e8dd4332196348df8938a1ad8991dc84@AcuMS.aculab.com> (raw)
In-Reply-To: <20171205.153120.151025775956658954.davem@davemloft.net>
From: David Miller
> Sent: 05 December 2017 20:31
...
> > Would it make sense to keep the 3 lowest bits of the address?
> >
> > Currently printed pointers no longer have any correlation with the actual
> > alignment in memory of the object, which is a typical cause of a class of bugs.
>
> Yeah, this is driving people nuts who wonder why pointers are aligned
> all weird now.
I can also image issues where you want to know whether 2 pointers point
into the same structure (like an skb).
Useful if you suspect that code is using a stale pointer because the
skb got reallocated by some internal function.
I'm not sure such pointers are printed by default though.
I know I have debugged things that required hexdumps of memory areas
referenced by traced pointers.
I won't have done that for anything written with the kernel printf because
getting any more info for a linux kernel oops is actually quite hard.
David
next prev parent reply other threads:[~2017-12-06 10:31 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-29 2:05 [PATCH V11 0/5] " Tobin C. Harding
2017-11-29 2:05 ` [PATCH V11 1/5] docs: correct documentation for %pK Tobin C. Harding
2017-11-29 2:05 ` [PATCH V11 2/5] vsprintf: refactor %pK code out of pointer() Tobin C. Harding
2017-11-29 2:39 ` Steven Rostedt
2017-11-29 4:27 ` Tobin C. Harding
2017-11-29 11:54 ` Steven Rostedt
2017-11-29 2:05 ` [PATCH V11 3/5] printk: hash addresses printed with %p Tobin C. Harding
2017-11-29 23:21 ` Andrew Morton
2017-12-05 20:20 ` Geert Uytterhoeven
2017-12-05 20:31 ` David Miller
2017-12-06 10:31 ` David Laight [this message]
2017-12-06 23:21 ` Kees Cook
2017-12-06 23:28 ` Linus Torvalds
2017-12-05 20:44 ` Tobin C. Harding
2017-12-05 22:57 ` Geert Uytterhoeven
2017-12-05 23:33 ` Linus Torvalds
2017-12-06 8:48 ` Geert Uytterhoeven
2017-11-29 2:05 ` [PATCH V11 4/5] vsprintf: add printk specifier %px Tobin C. Harding
2017-11-29 2:29 ` Linus Torvalds
2017-11-29 4:29 ` Tobin C. Harding
2017-11-29 10:07 ` David Laight
2017-11-29 22:28 ` Kees Cook
2017-11-29 22:36 ` Roberts, William C
2017-11-29 22:47 ` Linus Torvalds
2017-11-30 10:38 ` David Laight
2017-12-05 21:08 ` Randy Dunlap
2017-12-05 21:22 ` Linus Torvalds
2017-12-06 1:36 ` Sergey Senozhatsky
2017-12-06 1:59 ` Linus Torvalds
2017-12-06 2:15 ` Sergey Senozhatsky
2017-12-06 8:32 ` Geert Uytterhoeven
2017-12-06 8:45 ` Sergey Senozhatsky
2017-12-07 5:17 ` Tobin C. Harding
2017-12-07 5:37 ` Sergey Senozhatsky
2017-12-07 5:12 ` Tobin C. Harding
2017-11-29 23:20 ` Andrew Morton
2017-11-29 23:26 ` Tobin C. Harding
2017-11-30 3:58 ` Joe Perches
2017-11-30 4:18 ` Tobin C. Harding
2017-11-30 4:41 ` Joe Perches
2017-11-30 5:00 ` Tobin C. Harding
2017-11-29 2:05 ` [PATCH V11 5/5] kasan: use %px to print addresses instead of %p Tobin C. Harding
2017-11-29 23:20 ` [PATCH V11 0/5] hash addresses printed with %p Andrew Morton
2017-11-29 23:34 ` Tobin C. Harding
2017-11-30 10:23 ` David Laight
2017-11-30 10:26 ` Sergey Senozhatsky
2017-12-01 6:15 ` Sergey Senozhatsky
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=e8dd4332196348df8938a1ad8991dc84@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=Golden_Miller83@protonmail.ch \
--cc=Jason@zx2c4.com \
--cc=akpm@linux-foundation.org \
--cc=aryabinin@virtuozzo.com \
--cc=catalin.marinas@arm.com \
--cc=cfries@google.com \
--cc=danielmicay@gmail.com \
--cc=davem@davemloft.net \
--cc=dvyukov@google.com \
--cc=geert@linux-m68k.org \
--cc=glider@google.com \
--cc=gregkh@linuxfoundation.org \
--cc=ijc@hellion.org.uk \
--cc=joe@perches.com \
--cc=keescook@chromium.org \
--cc=kernel-hardening@lists.openwall.com \
--cc=linux-kernel@vger.kernel.org \
--cc=me@tobin.cc \
--cc=netdev@vger.kernel.org \
--cc=olorin@google.com \
--cc=pbonzini@redhat.com \
--cc=pmladek@suse.com \
--cc=rkrcmar@redhat.com \
--cc=rostedt@goodmis.org \
--cc=sergei.shtylyov@cogentembedded.com \
--cc=sergey.senozhatsky@gmail.com \
--cc=sfr@canb.auug.org.au \
--cc=tixxdz@gmail.com \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=tycho@tycho.ws \
--cc=tytso@mit.edu \
--cc=wilal.deacon@arm.com \
--cc=william.c.roberts@intel.com \
/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
Powered by JetHome