From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Joerg Roedel <joro@8bytes.org>
Cc: Brian Gerst <brgerst@gmail.com>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>,
X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Dave Hansen <dave.hansen@intel.com>,
Juergen Gross <jgross@suse.com>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
David Laight <David.Laight@aculab.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
Eduardo Valentin <eduval@amazon.com>,
Greg KH <gregkh@linuxfoundation.org>,
Will Deacon <will.deacon@arm.com>,
"Liguori, Anthony" <aliguori@amazon.com>,
Daniel Gruss <daniel.gruss@iaik.tugraz.at>,
Hugh Dickins <hughd@google.com>, Kees Cook <keescook@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Waiman Long <llong@redhat.com>, Joerg Roedel <jroedel@suse.de>
Subject: Re: [PATCH 03/16] x86/entry/32: Leave the kernel via the trampoline stack
Date: Wed, 17 Jan 2018 08:45:03 -0600 [thread overview]
Message-ID: <20180117144503.62e47m6e5yyyze3d@treble> (raw)
In-Reply-To: <20180117141418.GS28161@8bytes.org>
On Wed, Jan 17, 2018 at 03:14:18PM +0100, Joerg Roedel wrote:
> On Wed, Jan 17, 2018 at 06:00:07AM -0800, Brian Gerst wrote:
> > On Wed, Jan 17, 2018 at 5:57 AM, Brian Gerst <brgerst@gmail.com> wrote:
> > But then again, you could take a fault on the trampoline stack if you
> > get a bad segment. Perhaps just pushing the new stack pointer onto
> > the process stack before user segment loads will be the right move.
>
> User segment loads pop from the stack, so having anything on-top also
> doesn't work.
>
> Maybe I can leave some space at the bottom of the task-stack at entry
> time and store the pointer there on exit, if that doesn't confuse the
> stack unwinder too much.
If you put it at the end of the stack page, I _think_ all you'd have to
do is just adjust TOP_OF_KERNEL_STACK_PADDING.
--
Josh
WARNING: multiple messages have this Message-ID (diff)
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Joerg Roedel <joro@8bytes.org>
Cc: Brian Gerst <brgerst@gmail.com>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>,
X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Dave Hansen <dave.hansen@intel.com>,
Juergen Gross <jgross@suse.com>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
David Laight <David.Laight@aculab.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
Eduardo Valentin <eduval@amazon.com>,
Greg KH <gregkh@linuxfoundation.org>,
Will Deacon <will.deacon@arm.com>,
"Liguori, Anthony" <aliguori@amazon.com>,
Daniel Gruss <daniel.gruss@iaik.tugraz.at>,
Hugh Dickins <hughd@google.com>, Kees Cook <keescook@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Waiman Long <llong@redhat.com>, Joerg Roedel <jroedel@suse.de>
Subject: Re: [PATCH 03/16] x86/entry/32: Leave the kernel via the trampoline stack
Date: Wed, 17 Jan 2018 08:45:03 -0600 [thread overview]
Message-ID: <20180117144503.62e47m6e5yyyze3d@treble> (raw)
In-Reply-To: <20180117141418.GS28161@8bytes.org>
On Wed, Jan 17, 2018 at 03:14:18PM +0100, Joerg Roedel wrote:
> On Wed, Jan 17, 2018 at 06:00:07AM -0800, Brian Gerst wrote:
> > On Wed, Jan 17, 2018 at 5:57 AM, Brian Gerst <brgerst@gmail.com> wrote:
> > But then again, you could take a fault on the trampoline stack if you
> > get a bad segment. Perhaps just pushing the new stack pointer onto
> > the process stack before user segment loads will be the right move.
>
> User segment loads pop from the stack, so having anything on-top also
> doesn't work.
>
> Maybe I can leave some space at the bottom of the task-stack at entry
> time and store the pointer there on exit, if that doesn't confuse the
> stack unwinder too much.
If you put it at the end of the stack page, I _think_ all you'd have to
do is just adjust TOP_OF_KERNEL_STACK_PADDING.
--
Josh
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2018-01-17 14:45 UTC|newest]
Thread overview: 183+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-16 16:36 [RFC PATCH 00/16] PTI support for x86-32 Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 16:36 ` [PATCH 01/16] x86/entry/32: Rename TSS_sysenter_sp0 to TSS_sysenter_stack Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 18:35 ` Thomas Gleixner
2018-01-16 18:35 ` Thomas Gleixner
2018-01-16 16:36 ` [PATCH 02/16] x86/entry/32: Enter the kernel via trampoline stack Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 20:30 ` Thomas Gleixner
2018-01-16 20:30 ` Thomas Gleixner
2018-01-16 22:37 ` Andy Lutomirski
2018-01-16 22:37 ` Andy Lutomirski
2018-01-16 22:45 ` Andy Lutomirski
2018-01-16 22:45 ` Andy Lutomirski
2018-01-17 9:18 ` Joerg Roedel
2018-01-17 9:18 ` Joerg Roedel
2018-01-17 18:10 ` Andy Lutomirski
2018-01-17 18:10 ` Andy Lutomirski
2018-01-19 9:55 ` Joerg Roedel
2018-01-19 9:55 ` Joerg Roedel
2018-01-19 16:30 ` Andy Lutomirski
2018-01-19 16:30 ` Andy Lutomirski
2018-01-22 10:11 ` Joerg Roedel
2018-01-22 10:11 ` Joerg Roedel
2018-01-22 17:46 ` Andy Lutomirski
2018-01-22 17:46 ` Andy Lutomirski
2018-01-17 2:47 ` Boris Ostrovsky
2018-01-17 2:47 ` Boris Ostrovsky
2018-01-17 9:02 ` Joerg Roedel
2018-01-17 9:02 ` Joerg Roedel
2018-01-17 14:04 ` Andrew Cooper
2018-01-17 14:04 ` Andrew Cooper
2018-01-17 15:22 ` Boris Ostrovsky
2018-01-17 15:22 ` Boris Ostrovsky
2018-01-16 16:36 ` [PATCH 03/16] x86/entry/32: Leave the kernel via the " Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 22:48 ` Andy Lutomirski
2018-01-16 22:48 ` Andy Lutomirski
2018-01-17 9:24 ` Joerg Roedel
2018-01-17 9:24 ` Joerg Roedel
2018-01-17 13:57 ` Brian Gerst
2018-01-17 13:57 ` Brian Gerst
2018-01-17 14:00 ` Brian Gerst
2018-01-17 14:00 ` Brian Gerst
2018-01-17 14:14 ` Joerg Roedel
2018-01-17 14:14 ` Joerg Roedel
2018-01-17 14:45 ` Josh Poimboeuf [this message]
2018-01-17 14:45 ` Josh Poimboeuf
2018-01-17 14:10 ` Joerg Roedel
2018-01-17 14:10 ` Joerg Roedel
2018-01-17 18:12 ` Andy Lutomirski
2018-01-17 18:12 ` Andy Lutomirski
2018-01-19 9:57 ` Joerg Roedel
2018-01-19 9:57 ` Joerg Roedel
2018-01-16 16:36 ` [PATCH 04/16] x86/pti: Define X86_CR3_PTI_PCID_USER_BIT on x86_32 Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 22:46 ` Andy Lutomirski
2018-01-16 22:46 ` Andy Lutomirski
2018-01-17 9:26 ` Joerg Roedel
2018-01-17 9:26 ` Joerg Roedel
2018-01-16 16:36 ` [PATCH 05/16] x86/pgtable: Move pgdp kernel/user conversion functions to pgtable.h Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 16:36 ` [PATCH 06/16] x86/mm/ldt: Reserve high address-space range for the LDT Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 16:52 ` Peter Zijlstra
2018-01-16 16:52 ` Peter Zijlstra
2018-01-16 17:13 ` Joerg Roedel
2018-01-16 17:13 ` Joerg Roedel
2018-01-16 17:31 ` Peter Zijlstra
2018-01-16 17:31 ` Peter Zijlstra
2018-01-16 17:34 ` Waiman Long
2018-01-16 17:34 ` Waiman Long
2018-01-16 22:51 ` Andy Lutomirski
2018-01-16 22:51 ` Andy Lutomirski
2018-01-17 7:59 ` Peter Zijlstra
2018-01-17 7:59 ` Peter Zijlstra
2018-01-16 16:36 ` [PATCH 07/16] x86/mm: Move two more functions from pgtable_64.h to pgtable.h Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 18:03 ` Dave Hansen
2018-01-16 18:03 ` Dave Hansen
2018-01-16 19:11 ` Joerg Roedel
2018-01-16 19:11 ` Joerg Roedel
2018-01-16 19:34 ` Thomas Gleixner
2018-01-16 19:34 ` Thomas Gleixner
2018-01-16 16:36 ` [PATCH 08/16] x86/pgtable/32: Allocate 8k page-tables when PTI is enabled Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-17 23:43 ` Andy Lutomirski
2018-01-17 23:43 ` Andy Lutomirski
2018-01-19 9:57 ` Joerg Roedel
2018-01-19 9:57 ` Joerg Roedel
2018-01-16 16:36 ` [PATCH 09/16] x86/mm/pti: Clone CPU_ENTRY_AREA on PMD level on x86_32 Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 21:03 ` Thomas Gleixner
2018-01-16 21:03 ` Thomas Gleixner
2018-01-16 16:36 ` [PATCH 10/16] x86/mm/pti: Populate valid user pud entries Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 18:06 ` Dave Hansen
2018-01-16 18:06 ` Dave Hansen
2018-01-16 19:41 ` Joerg Roedel
2018-01-16 19:41 ` Joerg Roedel
2018-01-16 21:06 ` Thomas Gleixner
2018-01-16 21:06 ` Thomas Gleixner
2018-01-16 16:36 ` [PATCH 11/16] x86/mm/pgtable: Move pti_set_user_pgd() to pgtable.h Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 16:36 ` [PATCH 12/16] x86/mm/pae: Populate the user page-table with user pgd's Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 18:11 ` Dave Hansen
2018-01-16 18:11 ` Dave Hansen
2018-01-16 19:44 ` Joerg Roedel
2018-01-16 19:44 ` Joerg Roedel
2018-01-16 21:10 ` Thomas Gleixner
2018-01-16 21:10 ` Thomas Gleixner
2018-01-16 21:15 ` Dave Hansen
2018-01-16 21:15 ` Dave Hansen
2018-01-16 16:36 ` [PATCH 13/16] x86/mm/pti: Add an overflow check to pti_clone_pmds() Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 16:36 ` [PATCH 14/16] x86/mm/legacy: Populate the user page-table with user pgd's Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-17 23:41 ` Andy Lutomirski
2018-01-17 23:41 ` Andy Lutomirski
2018-01-16 16:36 ` [PATCH 15/16] x86/entry/32: Switch between kernel and user cr3 on entry/exit Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 16:36 ` [PATCH 16/16] x86/pti: Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32 Joerg Roedel
2018-01-16 16:36 ` Joerg Roedel
2018-01-16 18:14 ` [RFC PATCH 00/16] PTI support for x86-32 Dave Hansen
2018-01-16 18:14 ` Dave Hansen
2018-01-16 19:46 ` Joerg Roedel
2018-01-16 19:46 ` Joerg Roedel
2018-01-16 18:59 ` Linus Torvalds
2018-01-16 18:59 ` Linus Torvalds
2018-01-16 19:02 ` Dave Hansen
2018-01-16 19:02 ` Dave Hansen
2018-01-16 19:21 ` Andrew Cooper
2018-01-16 19:21 ` Andrew Cooper
2018-01-16 19:55 ` Joerg Roedel
2018-01-16 19:55 ` Joerg Roedel
2018-01-16 21:20 ` Thomas Gleixner
2018-01-16 21:20 ` Thomas Gleixner
2018-01-17 9:55 ` Joerg Roedel
2018-01-17 9:55 ` Joerg Roedel
2018-01-16 22:26 ` Andy Lutomirski
2018-01-16 22:26 ` Andy Lutomirski
2018-01-17 9:33 ` Joerg Roedel
2018-01-17 9:33 ` Joerg Roedel
2018-01-19 10:55 ` Pavel Machek
2018-01-19 11:07 ` Joerg Roedel
2018-01-19 11:07 ` Joerg Roedel
2018-01-19 12:58 ` Pavel Machek
2018-01-21 20:13 ` Nadav Amit
2018-01-21 20:13 ` Nadav Amit
2018-01-21 20:44 ` Nadav Amit
2018-01-21 20:44 ` Nadav Amit
2018-01-21 23:46 ` Nadav Amit
2018-01-21 23:46 ` Nadav Amit
2018-01-22 2:11 ` Linus Torvalds
2018-01-22 2:11 ` Linus Torvalds
2018-01-22 2:20 ` hpa
2018-01-22 2:20 ` hpa
2018-01-22 20:14 ` Linus Torvalds
2018-01-22 20:14 ` Linus Torvalds
2018-01-22 21:10 ` H. Peter Anvin
2018-01-22 21:10 ` H. Peter Anvin
2018-01-23 14:38 ` Alan Cox
2018-01-23 14:38 ` Alan Cox
2018-01-22 2:27 ` Nadav Amit
2018-01-22 2:27 ` Nadav Amit
2018-01-22 8:56 ` Joerg Roedel
2018-01-22 8:56 ` Joerg Roedel
2018-01-23 14:57 ` Alan Cox
2018-01-23 14:57 ` Alan Cox
2018-01-25 17:09 ` Alan Cox
2018-01-25 17:09 ` Alan Cox
2018-01-26 12:36 ` Joerg Roedel
2018-01-26 12:36 ` Joerg Roedel
2018-01-22 9:55 ` David Laight
2018-01-22 10:04 ` Joerg Roedel
2018-01-22 10:04 ` Joerg Roedel
2018-01-24 18:58 ` Krzysztof Mazur
2018-01-24 18:58 ` Krzysztof Mazur
2018-01-25 22:09 ` Nadav Amit
2018-01-25 22:09 ` Nadav Amit
2018-01-26 9:28 ` Krzysztof Mazur
2018-01-26 9:28 ` Krzysztof Mazur
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=20180117144503.62e47m6e5yyyze3d@treble \
--to=jpoimboe@redhat.com \
--cc=David.Laight@aculab.com \
--cc=aarcange@redhat.com \
--cc=aliguori@amazon.com \
--cc=boris.ostrovsky@oracle.com \
--cc=bp@alien8.de \
--cc=brgerst@gmail.com \
--cc=daniel.gruss@iaik.tugraz.at \
--cc=dave.hansen@intel.com \
--cc=dvlasenk@redhat.com \
--cc=eduval@amazon.com \
--cc=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=hughd@google.com \
--cc=jgross@suse.com \
--cc=jkosina@suse.cz \
--cc=joro@8bytes.org \
--cc=jroedel@suse.de \
--cc=keescook@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=llong@redhat.com \
--cc=luto@kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=will.deacon@arm.com \
--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 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.