Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Borislav Petkov <bp@alien8.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	alex@ghiti.fr, aou@eecs.berkeley.edu,
	 Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Arnd Bergmann <arnd@arndb.de>,
	 Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	 Christian Borntraeger <borntraeger@de.ibm.com>,
	Qian Cai <cai@lca.pw>,  Catalin Marinas <catalin.marinas@arm.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	 dave.jiang@intel.com, David Miller <davem@davemloft.net>,
	 Dmitry Vyukov <dvyukov@google.com>,
	Alexander Potapenko <glider@google.com>,
	 Vasily Gorbik <gor@linux.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	 Peter Anvin <hpa@zytor.com>, James Morse <james.morse@arm.com>,
	James Hogan <jhogan@kernel.org>,
	 Kan Liang <kan.liang@linux.intel.com>,
	Linux-MM <linux-mm@kvack.org>,
	 Russell King - ARM Linux <linux@armlinux.org.uk>,
	Andrew Lutomirski <luto@kernel.org>,
	 Mark Rutland <mark.rutland@arm.com>,
	mawilcox@microsoft.com, Ingo Molnar <mingo@elte.hu>,
	 mm-commits@vger.kernel.org,
	Michael Ellerman <mpe@ellerman.id.au>,
	n-horiguchi@ah.jp.nec.com,  Palmer Dabbelt <palmer@sifive.com>,
	Paul Burton <paul.burton@mips.com>,
	 Paul Walmsley <paul.walmsley@sifive.com>,
	Paul Mackerras <paulus@samba.org>,
	 Peter Zijlstra <peterz@infradead.org>,
	ralf@linux-mips.org, shashim@codeaurora.org,
	 Steven Price <steven.price@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	vgupta@synopsys.com,  Will Deacon <will@kernel.org>,
	zong.li@sifive.com
Subject: Re: [patch 064/158] mm: add generic ptdump
Date: Sun, 1 Dec 2019 06:45:23 -0800
Message-ID: <CAHk-=wiaAbELGZCYZHBsAmxSeK9YdZrrp-RX057x8QoWFva4qw@mail.gmail.com> (raw)
In-Reply-To: <20191201090724.GA6629@zn.tnic>

On Sun, Dec 1, 2019 at 1:09 AM Borislav Petkov <bp@alien8.de> wrote:
>
> That generic ptdump stuff is probably causing a splat on 32-bit:
>
> https://lkml.kernel.org/r/20191125144946.GA6628@duo.ucw.cz

Hmm. I'm not sure about code generation, but for me that config gives me

  60:   55                      push   %ebp
  61:   89 e5                   mov    %esp,%ebp
  63:   57                      push   %edi
  64:   8b 4d 08                mov    0x8(%ebp),%ecx
  67:   56                      push   %esi
  68:   53                      push   %ebx
  69:   8b 30                   mov    (%eax),%esi
  6b:   8b 59 10                mov    0x10(%ecx),%ebx

so that "ptdump_pte_entry+9" is the "mov    (%eax),%esi"

And that is "READ_ONCE(*pte)"

So the pte pointer itself is broken. Which sounds really odd.

 Hmm. I've applied the whole series to a local branch, but I'm not
merging it into my master branch yet. Can somebody figure out how the
page walking could get that broken?

             Linus


  reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-01  1:53 akpm
2019-12-01  9:07 ` Borislav Petkov
2019-12-01 14:45   ` Linus Torvalds [this message]
2019-12-01 15:10     ` Borislav Petkov
2019-12-01 15:21       ` Borislav Petkov
2019-12-01 15:45         ` Borislav Petkov
2019-12-02  9:09           ` Steven Price
2019-12-02 15:42             ` Borislav Petkov
2019-12-03 10:47 ` David Hildenbrand
2019-12-03 11:00   ` David Hildenbrand

Reply instructions:

You may reply publically 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='CAHk-=wiaAbELGZCYZHBsAmxSeK9YdZrrp-RX057x8QoWFva4qw@mail.gmail.com' \
    --to=torvalds@linux-foundation.org \
    --cc=akpm@linux-foundation.org \
    --cc=alex@ghiti.fr \
    --cc=aou@eecs.berkeley.edu \
    --cc=ard.biesheuvel@linaro.org \
    --cc=arnd@arndb.de \
    --cc=aryabinin@virtuozzo.com \
    --cc=benh@kernel.crashing.org \
    --cc=borntraeger@de.ibm.com \
    --cc=bp@alien8.de \
    --cc=cai@lca.pw \
    --cc=catalin.marinas@arm.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=dave.jiang@intel.com \
    --cc=davem@davemloft.net \
    --cc=dvyukov@google.com \
    --cc=glider@google.com \
    --cc=gor@linux.ibm.com \
    --cc=heiko.carstens@de.ibm.com \
    --cc=hpa@zytor.com \
    --cc=james.morse@arm.com \
    --cc=jhogan@kernel.org \
    --cc=kan.liang@linux.intel.com \
    --cc=linux-mm@kvack.org \
    --cc=linux@armlinux.org.uk \
    --cc=luto@kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mawilcox@microsoft.com \
    --cc=mingo@elte.hu \
    --cc=mm-commits@vger.kernel.org \
    --cc=mpe@ellerman.id.au \
    --cc=n-horiguchi@ah.jp.nec.com \
    --cc=palmer@sifive.com \
    --cc=paul.burton@mips.com \
    --cc=paul.walmsley@sifive.com \
    --cc=paulus@samba.org \
    --cc=peterz@infradead.org \
    --cc=ralf@linux-mips.org \
    --cc=shashim@codeaurora.org \
    --cc=steven.price@arm.com \
    --cc=tglx@linutronix.de \
    --cc=vgupta@synopsys.com \
    --cc=will@kernel.org \
    --cc=zong.li@sifive.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

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org
	public-inbox-index linux-mm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git