Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

lab04: exercises: fixed access variable reset #535

Closed
wants to merge 76 commits into from
Closed

lab04: exercises: fixed access variable reset #535

wants to merge 76 commits into from

Conversation

crmares
Copy link

@crmares crmares commented Mar 18, 2018

atomic_inc will not reset the access variable, and so, the resource will be busy at any second call. To solve, atomic_dec, or simply, atomic_set to 0, as implied in the TODO.

tavip and others added 30 commits July 1, 2017 16:35
@tavip
labs: add lab infrastructure and documentation
f232ff9 
The Linux kernel labs documentation is a collection of "labs" for
various device driver topics. For each topic there are two parts: a
walk-through which explain the basic concepts and a hands-on part which
contains a few exercises.

This commit also adds the labs infrastructure which allows us to build
and test kernel modules in a qemu environment.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip
labs: add kernel modules lab
cc3525c 
Add the documentation and templates for the kernel modules lab which
focuses on: creating simple modules; describing the process of kernel
module compilation; presenting how a module can be used with a kernel;
simple kernel debugging methods

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip
labs: add kernel api lab
e80133f 
Add the documentation and templates for the kernel modules lab which
focuses on: familiarizing with the basic Linux kernel API, describing
memory allocation and locking mechanism.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip
labs: add device drivers lab
a9e47bc 
Add documentation and templates for the device drivers labs which
focuses on: understanding the concepts behind character device drivers;
understading the various operations that can be performed on character
device drivers; working with waiting queues.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip
labs: add I/O access and interrupts lab
9983afd 
Add documentation and templates for the I/O access and interrupts lab
which focuses on: communication with pheripheral devices; implementing
interrupt handlers; synchronizing interrupts with process context.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip
labs: add deferred work lab
e4a004e 
Add documentation and templates for the deffered work lab which focuses
on: understanding deffered work; implementation of common tasks that use
deferred work; understanding the peculiarities of synchronization for
deferred work.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip
labs: add memory mapping lab
86d4a8f 
Add documentation and templates for the memory mapping lab which focuses
on: understanding the address space mapping mechanism; learn about the
most important structures related to memory mapping.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip
labs: add device model lab
f08b9e4 
Add documentationa and templates for the Linux device module lab which
focuses on understanding the main Linux abstraction that deals with
devices: devices, buses, drivers, subsystems and classes.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip @dbaluta
labs: add lab infrastructure and documentation
605d223 
The Linux kernel labs documentation is a collection of "labs" for
various device driver topics. For each topic there are two parts: a
walk-through which explain the basic concepts and a hands-on part which
contains a few exercises.

This commit also adds the labs infrastructure which allows us to build
and test kernel modules in a qemu environment.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip @dbaluta
labs: add kernel modules lab
cda9ea5 
Add the documentation and templates for the kernel modules lab which
focuses on: creating simple modules; describing the process of kernel
module compilation; presenting how a module can be used with a kernel;
simple kernel debugging methods

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip @dbaluta
labs: add kernel api lab
6c98f7c 
Add the documentation and templates for the kernel modules lab which
focuses on: familiarizing with the basic Linux kernel API, describing
memory allocation and locking mechanism.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip @dbaluta
labs: add device drivers lab
c8f2815 
Add documentation and templates for the device drivers labs which
focuses on: understanding the concepts behind character device drivers;
understading the various operations that can be performed on character
device drivers; working with waiting queues.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip @dbaluta
labs: add I/O access and interrupts lab
ce41d39 
Add documentation and templates for the I/O access and interrupts lab
which focuses on: communication with pheripheral devices; implementing
interrupt handlers; synchronizing interrupts with process context.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip @dbaluta
labs: add deferred work lab
e59056d 
Add documentation and templates for the deffered work lab which focuses
on: understanding deffered work; implementation of common tasks that use
deferred work; understanding the peculiarities of synchronization for
deferred work.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip @dbaluta
labs: add memory mapping lab
4c5580e 
Add documentation and templates for the memory mapping lab which focuses
on: understanding the address space mapping mechanism; learn about the
most important structures related to memory mapping.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@tavip @dbaluta
labs: add device model lab
dd1229f 
Add documentationa and templates for the Linux device module lab which
focuses on understanding the main Linux abstraction that deals with
devices: devices, buses, drivers, subsystems and classes.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@dbaluta
Merge pull request #4 from dbaluta/kernel-labs-v4.15
bdc7674 
Kernel labs v4.15
@tavip
Documentation: move from labs to teaching/labs
ac75ef3 
Since we are going to add lectures change the top level directory name
from labs to teaching/labs.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
@tavip
Documentation: add support for slides
fbfab0e 
Enable hieroglyph extension if it is installed on the host and add a
slides documentation target.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
@tavip
tools: labs: build slides
0f59b21 
Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
@tavip
Documentation: add ditaa sphinx directive
58e2976 
This is based on the psphinxcontrib.ditaa pip package and we add it
localy since we need some fixes to properly render images in
hieroglpyh slides.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
@tavip
Documentation: sphinx: ditaa: fix relative image names
5f89d7b 
Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
@tavip
tools: labs: add requirements.txt
8002421 
Add reqirements.txt and run pip in the doc target to make sure we have
all required sphinx dependencies.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
@tavip
Documentation: teaching: add intro lecture
ca5465b 
This is split into two parts: one the is specific to cs.pub.ro and
another one that is generic.

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
@tavip
Merge pull request #5 from tavip/lklabs-lectures-intro
414c483 
Lklabs lectures intro
@tavip
.circleci: add initial build configuration
10cf683 
Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
@tavip
Merge pull request #6 from tavip/lktp-ci
3cb002d 
Add docs building and publishing support via Circle CI
@tavip
Documentation: fix common substitutions
77def8f 
The conf.py needs to be at the top of the namespace directory so move
it where it belongs.

And since we now have multiple subdirectories and includes are
relative to current file directory, the common substitution will not
longer work for all files. To fix this, just move the contents of
subst.hrst directly to rst_epilog in conf.py.

Fixes the following errors:

deferred_work.rst:721: ERROR: Undefined substitution referenced: "LXR".
deferred_work.rst:721: ERROR: Unknown target name: "lxr".
interrupts.rst:688: ERROR: Undefined substitution referenced: "LXR".
interrupts.rst:688: ERROR: Unknown target name: "lxr".
kernel_api.rst:739: ERROR: Unexpected indentation.
kernel_api.rst:582: ERROR: Undefined substitution referenced: "LXR".
kernel_api.rst:582: ERROR: Unknown target name: "lxr".
kernel_modules.rst:810: ERROR: Undefined substitution referenced: "LXR".
kernel_modules.rst:939: ERROR: Undefined substitution referenced: "LXR".
kernel_modules.rst:810: ERROR: Unknown target name: "lxr".
kernel_modules.rst:939: ERROR: Unknown target name: "lxr".

Signed-off-by: Octavian Purdila <tavi@cs.pub.ro>
@tavip
Merge pull request #8 from tavip/lktp-3
24cfdef 
Documentation: move teaching/labs/conf.py to teaching/
@andanicolae
labs: add introduction lab
77180a9 
Introduction lab presents few ways to navigate the kernel source code
(LXR and cscope) and how to perform static and dynamic kernel analysis
using gdb, vmlinux and /proc/kcore.
ramele1907 and others added 11 commits March 6, 2018 14:26
@ramele1907
Merge branch 'master' of https://github.com/ramele1907/linux
6d1bf51
@andanicolae
lab03: kernel_api: update exercises requirements
babf653 
* update links to point to 4.15.7 kernel API
* use c constructs (:c:type:``, :c:macro:`` etc)
  to highlight structures, macros etc

Signed-off-by: Anda Nicolae <nicolae.anda@gmail.com>
@dbaluta
Merge pull request #26 from ramele1907/master
b00025c 
teaching: labs: introduction: Fix typos
@andanicolae
lab03: kernel_api: fixes
70d5636 
* removed links to lxr kernel API
* used :c:type:``, :c:data:``, :c:func:``, etc
  in all lab, when appropriate
* reformulated documentation when needed
* added missing list evolution image

Signed-off-by: Anda Nicolae <nicolae.anda@gmail.com>
@dbaluta
Merge pull request #28 from andanicolae/lab03-update-exercises
bd169a7 
lab03: kernel_api: update exercises requirements
@dbaluta
Documentation: lectures: Add draft 'Interrupts' lecture
cfffb16 
Signed-off-by: Daniel Baluta <daniel.baluta@gmail.com>
@dbaluta
Merge pull request #30 from dbaluta/master
ed8e26a 
Documentation: lectures: Add draft 'Interrupts' lecture
@valighita
lab04: exercises: Fix TODO numbers.
7568811
@dbaluta
Merge pull request #33 from valx90/lab04-fix-wrong-todo-numbers
ed00a31 
lab04: exercises: Fix TODO numbers.
@alexandrasandulescu
tracer_assignment: add checker and tracer skel
2e95ab8
@dbaluta
Merge pull request #34 from alexandrasandulescu/tracer-assignment
0865b29 
Add tracer assignment
@KernelPRBot
Copy link

Hi @crmares!

Thanks for your contribution to the Linux kernel!

Linux kernel development happens on mailing lists, rather than on GitHub - this GitHub repository is a read-only mirror that isn't used for accepting contributions. So that your change can become part of Linux, please email it to us as a patch.

Sending patches isn't quite as simple as sending a pull request, but fortunately it is a well documented process.

Here's what to do:

  • Format your contribution according to kernel requirements
  • Decide who to send your contribution to
  • Set up your system to send your contribution as an email
  • Send your contribution and wait for feedback

How do I format my contribution?

The Linux kernel community is notoriously picky about how contributions are formatted and sent. Fortunately, they have documented their expectations.

Firstly, all contributions need to be formatted as patches. A patch is a plain text document showing the change you want to make to the code, and documenting why it is a good idea.

You can create patches with git format-patch.

Secondly, patches need 'commit messages', which is the human-friendly documentation explaining what the change is and why it's necessary.

Thirdly, changes have some technical requirements. There is a Linux kernel coding style, and there are licensing requirements you need to comply with.

Both of these are documented in the Submitting Patches documentation that is part of the kernel.

Note that you will almost certainly have to modify your existing git commits to satisfy these requirements. Don't worry: there are many guides on the internet for doing this.

Who do I send my contribution to?

The Linux kernel is composed of a number of subsystems. These subsystems are maintained by different people, and have different mailing lists where they discuss proposed changes.

If you don't already know what subsystem your change belongs to, the get_maintainer.pl script in the kernel source can help you.

get_maintainer.pl will take the patch or patches you created in the previous step, and tell you who is responsible for them, and what mailing lists are used. You can also take a look at the MAINTAINERS file by hand.

Make sure that your list of recipients includes a mailing list. If you can't find a more specific mailing list, then LKML - the Linux Kernel Mailing List - is the place to send your patches.

It's not usually necessary to subscribe to the mailing list before you send the patches, but if you're interested in kernel development, subscribing to a subsystem mailing list is a good idea. (At this point, you probably don't need to subscribe to LKML - it is a very high traffic list with about a thousand messages per day, which is often not useful for beginners.)

How do I send my contribution?

Use git send-email, which will ensure that your patches are formatted in the standard manner. In order to use git send-email, you'll need to configure git to use your SMTP email server.

For more information about using git send-email, look at the Git documentation or type git help send-email. There are a number of useful guides and tutorials about git send-email that can be found on the internet.

How do I get help if I'm stuck?

Firstly, don't get discouraged! There are an enormous number of resources on the internet, and many kernel developers who would like to see you succeed.

Many issues - especially about how to use certain tools - can be resolved by using your favourite internet search engine.

If you can't find an answer, there are a few places you can turn:

If you get really, really stuck, you could try the owners of this bot, @daxtens and @ajdlinux. Please be aware that we do have full-time jobs, so we are almost certainly the slowest way to get answers!

I sent my patch - now what?

You wait.

You can check that your email has been received by checking the mailing list archives for the mailing list you sent your patch to. Messages may not be received instantly, so be patient. Kernel developers are generally very busy people, so it may take a few weeks before your patch is looked at.

Then, you keep waiting. Three things may happen:

  • You might get a response to your email. Often these will be comments, which may require you to make changes to your patch, or explain why your way is the best way. You should respond to these comments, and you may need to submit another revision of your patch to address the issues raised.
  • Your patch might be merged into the subsystem tree. Code that becomes part of Linux isn't merged into the main repository straight away - it first goes into the subsystem tree, which is managed by the subsystem maintainer. It is then batched up with a number of other changes sent to Linus for inclusion. (This process is described in some detail in the kernel development process guide).
  • Your patch might be ignored completely. This happens sometimes - don't take it personally. Here's what to do:
    • Wait a bit more - patches often take several weeks to get a response; more if they were sent at a busy time.
    • Kernel developers often silently ignore patches that break the rules. Check for obvious violations of the Submitting Patches guidelines, the style guidelines, and any other documentation you can find about your subsystem. Check that you're sending your patch to the right place.
    • Try again later. When you resend it, don't add angry commentary, as that will get your patch ignored. It might also get you silently blacklisted.

Further information

Happy hacking!

This message was posted by a bot - if you have any questions or suggestions, please talk to my owners, @ajdlinux and @daxtens, or raise an issue at https://github.com/ajdlinux/KernelPRBot.

@crmares crmares closed this Mar 18, 2018
rgushchin pushed a commit to rgushchin/linux that referenced this pull request Dec 19, 2018
@yhuang-intel @hnaz
swap: fix general protection fault when swapoff
287411e 
When VMA based swap readahead is used, which is default if all swap
devices are SSD, swapoff will trigger general protection fault as follow,
because vmf->pmd isn't initialized when calling swapin_readahead().  This
fix could be folded into the patch: mm, swap: rid swapoff of quadratic
complexity in -mm patchset.

general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
CPU: 3 PID: 352 Comm: swapoff Not tainted 4.20.0-rc5-mm1-kvm+ torvalds#535
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-1.fc28 04/01/2014
RIP: 0010:swapin_readahead+0xb7/0x39b
Code: ff 01 00 00 40 f6 c7 80 49 0f 45 d0 48 21 d7 48 ba 00 00 00 00 80 88 ff ff 48 8d 14 f2 48 01 d7 48 ba ff ff ff ff ff ff ff ef <48> 39 17 0f 87 5d 01 00 00 49 8b 95 b0 00 00 00 48 85 d2 75 05 ba
RSP: 0018:ffffc900004c3ca0 EFLAGS: 00010207
RAX: 000055de5d252000 RBX: 000000055de5d252 RCX: 0000000000000003
RDX: efffffffffffffff RSI: 0000000000000052 RDI: 000f0bc11c600290
RBP: ffffc900004c3d30 R08: 000fffffffe00000 R09: ffffc900004c3ea0
R10: ffffc900004c3d50 R11: 0000000000000002 R12: ffffc900004c3da8
R13: ffff88803b71d780 R14: 0000000000000001 R15: ffff88803b71d780
FS:  00007f87c20e02c0(0000) GS:ffff88803e800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a439825398 CR3: 000000003b49a004 CR4: 0000000000360ea0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ? list_add_tail_rcu+0x19/0x31
 ? __lock_acquire+0xd61/0xe1c
 ? find_held_lock+0x2b/0x6e
 ? unuse_pte_range+0xe9/0x429
 unuse_pte_range+0xe9/0x429
 ? find_held_lock+0x2b/0x6e
 ? __lock_is_held+0x40/0x71
 try_to_unuse+0x311/0x54b
 __do_sys_swapoff+0x254/0x625
 ? lockdep_hardirqs_off+0x29/0x86
 ? do_syscall_64+0x12/0x65
 do_syscall_64+0x57/0x65
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Link: http://lkml.kernel.org/r/20181211084609.19553-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Vineeth Remanan Pillai <vpillai@digitalocean.com>
Cc: Kelley Nielsen <kelleynnn@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Dec 20, 2018
@yhuang-intel @sfrothwell
swap: fix general protection fault when swapoff
11f8087 
When VMA based swap readahead is used, which is default if all swap
devices are SSD, swapoff will trigger general protection fault as follow,
because vmf->pmd isn't initialized when calling swapin_readahead().  This
fix could be folded into the patch: mm, swap: rid swapoff of quadratic
complexity in -mm patchset.

general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
CPU: 3 PID: 352 Comm: swapoff Not tainted 4.20.0-rc5-mm1-kvm+ torvalds#535
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-1.fc28 04/01/2014
RIP: 0010:swapin_readahead+0xb7/0x39b
Code: ff 01 00 00 40 f6 c7 80 49 0f 45 d0 48 21 d7 48 ba 00 00 00 00 80 88 ff ff 48 8d 14 f2 48 01 d7 48 ba ff ff ff ff ff ff ff ef <48> 39 17 0f 87 5d 01 00 00 49 8b 95 b0 00 00 00 48 85 d2 75 05 ba
RSP: 0018:ffffc900004c3ca0 EFLAGS: 00010207
RAX: 000055de5d252000 RBX: 000000055de5d252 RCX: 0000000000000003
RDX: efffffffffffffff RSI: 0000000000000052 RDI: 000f0bc11c600290
RBP: ffffc900004c3d30 R08: 000fffffffe00000 R09: ffffc900004c3ea0
R10: ffffc900004c3d50 R11: 0000000000000002 R12: ffffc900004c3da8
R13: ffff88803b71d780 R14: 0000000000000001 R15: ffff88803b71d780
FS:  00007f87c20e02c0(0000) GS:ffff88803e800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a439825398 CR3: 000000003b49a004 CR4: 0000000000360ea0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ? list_add_tail_rcu+0x19/0x31
 ? __lock_acquire+0xd61/0xe1c
 ? find_held_lock+0x2b/0x6e
 ? unuse_pte_range+0xe9/0x429
 unuse_pte_range+0xe9/0x429
 ? find_held_lock+0x2b/0x6e
 ? __lock_is_held+0x40/0x71
 try_to_unuse+0x311/0x54b
 __do_sys_swapoff+0x254/0x625
 ? lockdep_hardirqs_off+0x29/0x86
 ? do_syscall_64+0x12/0x65
 do_syscall_64+0x57/0x65
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Link: http://lkml.kernel.org/r/20181211084609.19553-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Vineeth Remanan Pillai <vpillai@digitalocean.com>
Cc: Kelley Nielsen <kelleynnn@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Dec 25, 2018
@yhuang-intel @sfrothwell
swap: fix general protection fault when swapoff
7942f79 
When VMA based swap readahead is used, which is default if all swap
devices are SSD, swapoff will trigger general protection fault as follow,
because vmf->pmd isn't initialized when calling swapin_readahead().  This
fix could be folded into the patch: mm, swap: rid swapoff of quadratic
complexity in -mm patchset.

general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
CPU: 3 PID: 352 Comm: swapoff Not tainted 4.20.0-rc5-mm1-kvm+ torvalds#535
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-1.fc28 04/01/2014
RIP: 0010:swapin_readahead+0xb7/0x39b
Code: ff 01 00 00 40 f6 c7 80 49 0f 45 d0 48 21 d7 48 ba 00 00 00 00 80 88 ff ff 48 8d 14 f2 48 01 d7 48 ba ff ff ff ff ff ff ff ef <48> 39 17 0f 87 5d 01 00 00 49 8b 95 b0 00 00 00 48 85 d2 75 05 ba
RSP: 0018:ffffc900004c3ca0 EFLAGS: 00010207
RAX: 000055de5d252000 RBX: 000000055de5d252 RCX: 0000000000000003
RDX: efffffffffffffff RSI: 0000000000000052 RDI: 000f0bc11c600290
RBP: ffffc900004c3d30 R08: 000fffffffe00000 R09: ffffc900004c3ea0
R10: ffffc900004c3d50 R11: 0000000000000002 R12: ffffc900004c3da8
R13: ffff88803b71d780 R14: 0000000000000001 R15: ffff88803b71d780
FS:  00007f87c20e02c0(0000) GS:ffff88803e800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a439825398 CR3: 000000003b49a004 CR4: 0000000000360ea0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ? list_add_tail_rcu+0x19/0x31
 ? __lock_acquire+0xd61/0xe1c
 ? find_held_lock+0x2b/0x6e
 ? unuse_pte_range+0xe9/0x429
 unuse_pte_range+0xe9/0x429
 ? find_held_lock+0x2b/0x6e
 ? __lock_is_held+0x40/0x71
 try_to_unuse+0x311/0x54b
 __do_sys_swapoff+0x254/0x625
 ? lockdep_hardirqs_off+0x29/0x86
 ? do_syscall_64+0x12/0x65
 do_syscall_64+0x57/0x65
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Link: http://lkml.kernel.org/r/20181211084609.19553-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Vineeth Remanan Pillai <vpillai@digitalocean.com>
Cc: Kelley Nielsen <kelleynnn@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Aug 11, 2020
@osctobe @intel-lab-lkp
regulator: push allocations in create_regulator() outside of lock
22693d8 
Move all allocations outside of the regulator_lock()ed section.

======================================================
WARNING: possible circular locking dependency detected
5.7.13+ torvalds#535 Not tainted
------------------------------------------------------
f2fs_discard-179:7/702 is trying to acquire lock:
c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0

but task is already holding lock:
cb95b080 (&dcc->cmd_lock){+.+.}-{3:3}, at: __issue_discard_cmd+0xec/0x5f8

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

[...]

-> #3 (fs_reclaim){+.+.}-{0:0}:
       fs_reclaim_acquire.part.11+0x40/0x50
       fs_reclaim_acquire+0x24/0x28
       __kmalloc_track_caller+0x54/0x218
       kstrdup+0x40/0x5c
       create_regulator+0xf4/0x368
       regulator_resolve_supply+0x1a0/0x200
       regulator_register+0x9c8/0x163c

[...]

other info that might help us debug this:

Chain exists of:
  regulator_list_mutex --> &sit_i->sentry_lock --> &dcc->cmd_lock

[...]

Cc: stable@vger.kernel.org
Fixes: f8702f9 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Aug 12, 2020
@osctobe @intel-lab-lkp
regulator: push allocations in create_regulator() outside of lock
8b8c061 
Move all allocations outside of the regulator_lock()ed section.

======================================================
WARNING: possible circular locking dependency detected
5.7.13+ torvalds#535 Not tainted
------------------------------------------------------
f2fs_discard-179:7/702 is trying to acquire lock:
c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0

but task is already holding lock:
cb95b080 (&dcc->cmd_lock){+.+.}-{3:3}, at: __issue_discard_cmd+0xec/0x5f8

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

[...]

-> #3 (fs_reclaim){+.+.}-{0:0}:
       fs_reclaim_acquire.part.11+0x40/0x50
       fs_reclaim_acquire+0x24/0x28
       __kmalloc_track_caller+0x54/0x218
       kstrdup+0x40/0x5c
       create_regulator+0xf4/0x368
       regulator_resolve_supply+0x1a0/0x200
       regulator_register+0x9c8/0x163c

[...]

other info that might help us debug this:

Chain exists of:
  regulator_list_mutex --> &sit_i->sentry_lock --> &dcc->cmd_lock

[...]

Cc: stable@vger.kernel.org
Fixes: f8702f9 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
ruscur pushed a commit to ruscur/linux that referenced this pull request Aug 18, 2020
@osctobe @broonie
regulator: push allocations in create_regulator() outside of lock
87fe29b 
Move all allocations outside of the regulator_lock()ed section.

======================================================
WARNING: possible circular locking dependency detected
5.7.13+ torvalds#535 Not tainted
------------------------------------------------------
f2fs_discard-179:7/702 is trying to acquire lock:
c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0

but task is already holding lock:
cb95b080 (&dcc->cmd_lock){+.+.}-{3:3}, at: __issue_discard_cmd+0xec/0x5f8

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

[...]

-> #3 (fs_reclaim){+.+.}-{0:0}:
       fs_reclaim_acquire.part.11+0x40/0x50
       fs_reclaim_acquire+0x24/0x28
       __kmalloc_track_caller+0x54/0x218
       kstrdup+0x40/0x5c
       create_regulator+0xf4/0x368
       regulator_resolve_supply+0x1a0/0x200
       regulator_register+0x9c8/0x163c

[...]

other info that might help us debug this:

Chain exists of:
  regulator_list_mutex --> &sit_i->sentry_lock --> &dcc->cmd_lock

[...]

Fixes: f8702f9 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/6eebc99b2474f4ffaa0405b15178ece0e7e4f608.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Noltari pushed a commit to Noltari/linux that referenced this pull request Sep 17, 2020
@osctobe @gregkh
regulator: push allocations in create_regulator() outside of lock
31d8965 
commit 87fe29b upstream.

Move all allocations outside of the regulator_lock()ed section.

======================================================
WARNING: possible circular locking dependency detected
5.7.13+ torvalds#535 Not tainted
------------------------------------------------------
f2fs_discard-179:7/702 is trying to acquire lock:
c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0

but task is already holding lock:
cb95b080 (&dcc->cmd_lock){+.+.}-{3:3}, at: __issue_discard_cmd+0xec/0x5f8

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

[...]

-> #3 (fs_reclaim){+.+.}-{0:0}:
       fs_reclaim_acquire.part.11+0x40/0x50
       fs_reclaim_acquire+0x24/0x28
       __kmalloc_track_caller+0x54/0x218
       kstrdup+0x40/0x5c
       create_regulator+0xf4/0x368
       regulator_resolve_supply+0x1a0/0x200
       regulator_register+0x9c8/0x163c

[...]

other info that might help us debug this:

Chain exists of:
  regulator_list_mutex --> &sit_i->sentry_lock --> &dcc->cmd_lock

[...]

Fixes: f8702f9 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/6eebc99b2474f4ffaa0405b15178ece0e7e4f608.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jackpot51 pushed a commit to pop-os/linux that referenced this pull request Oct 19, 2020
@osctobe @piso77
regulator: push allocations in create_regulator() outside of lock
5d6888b 
BugLink: https://bugs.launchpad.net/bugs/1896078

commit 87fe29b upstream.

Move all allocations outside of the regulator_lock()ed section.

======================================================
WARNING: possible circular locking dependency detected
5.7.13+ torvalds#535 Not tainted
------------------------------------------------------
f2fs_discard-179:7/702 is trying to acquire lock:
c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0

but task is already holding lock:
cb95b080 (&dcc->cmd_lock){+.+.}-{3:3}, at: __issue_discard_cmd+0xec/0x5f8

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

[...]

-> #3 (fs_reclaim){+.+.}-{0:0}:
       fs_reclaim_acquire.part.11+0x40/0x50
       fs_reclaim_acquire+0x24/0x28
       __kmalloc_track_caller+0x54/0x218
       kstrdup+0x40/0x5c
       create_regulator+0xf4/0x368
       regulator_resolve_supply+0x1a0/0x200
       regulator_register+0x9c8/0x163c

[...]

other info that might help us debug this:

Chain exists of:
  regulator_list_mutex --> &sit_i->sentry_lock --> &dcc->cmd_lock

[...]

Fixes: f8702f9 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/6eebc99b2474f4ffaa0405b15178ece0e7e4f608.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Mar 15, 2021
@intel-lab-lkp
Staging: rtl8723bs: fix spaces in HalBtcOutSrc.h
8a2ad08 
This commit fixes the following checkpatch.pl errors:

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#535: FILE: ./hal/HalBtcOutSrc.h:535:
    +void EXhalbtcoutsrc_PowerOnSetting(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#536: FILE: ./hal/HalBtcOutSrc.h:536:
    +void EXhalbtcoutsrc_InitHwConfig(struct BTC_COEXIST * pBtCoexist, u8 bWifiOnly);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#537: FILE: ./hal/HalBtcOutSrc.h:537:
    +void EXhalbtcoutsrc_InitCoexDm(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#538: FILE: ./hal/HalBtcOutSrc.h:538:
    +void EXhalbtcoutsrc_IpsNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#539: FILE: ./hal/HalBtcOutSrc.h:539:
    +void EXhalbtcoutsrc_LpsNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#540: FILE: ./hal/HalBtcOutSrc.h:540:
    +void EXhalbtcoutsrc_ScanNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#541: FILE: ./hal/HalBtcOutSrc.h:541:
    +void EXhalbtcoutsrc_ConnectNotify(struct BTC_COEXIST * pBtCoexist, u8 action);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#543: FILE: ./hal/HalBtcOutSrc.h:543:
    +	struct BTC_COEXIST * pBtCoexist, enum RT_MEDIA_STATUS mediaStatus

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#545: FILE: ./hal/HalBtcOutSrc.h:545:
    +void EXhalbtcoutsrc_SpecialPacketNotify(struct BTC_COEXIST * pBtCoexist, u8 pktType);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#547: FILE: ./hal/HalBtcOutSrc.h:547:
    +	struct BTC_COEXIST * pBtCoexist, u8 *tmpBuf, u8 length

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#549: FILE: ./hal/HalBtcOutSrc.h:549:
    +void EXhalbtcoutsrc_HaltNotify(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#550: FILE: ./hal/HalBtcOutSrc.h:550:
    +void EXhalbtcoutsrc_PnpNotify(struct BTC_COEXIST * pBtCoexist, u8 pnpState);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#551: FILE: ./hal/HalBtcOutSrc.h:551:
    +void EXhalbtcoutsrc_Periodical(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#555: FILE: ./hal/HalBtcOutSrc.h:555:
    +void EXhalbtcoutsrc_DisplayBtCoexInfo(struct BTC_COEXIST * pBtCoexist);

Signed-off-by: Marco Cesati <marcocesati@gmail.com>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Mar 16, 2021
@gregkh
Staging: rtl8723bs: fix spaces in HalBtcOutSrc.h
044e893 
This commit fixes the following checkpatch.pl errors:

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#535: FILE: ./hal/HalBtcOutSrc.h:535:
    +void EXhalbtcoutsrc_PowerOnSetting(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#536: FILE: ./hal/HalBtcOutSrc.h:536:
    +void EXhalbtcoutsrc_InitHwConfig(struct BTC_COEXIST * pBtCoexist, u8 bWifiOnly);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#537: FILE: ./hal/HalBtcOutSrc.h:537:
    +void EXhalbtcoutsrc_InitCoexDm(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#538: FILE: ./hal/HalBtcOutSrc.h:538:
    +void EXhalbtcoutsrc_IpsNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#539: FILE: ./hal/HalBtcOutSrc.h:539:
    +void EXhalbtcoutsrc_LpsNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#540: FILE: ./hal/HalBtcOutSrc.h:540:
    +void EXhalbtcoutsrc_ScanNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#541: FILE: ./hal/HalBtcOutSrc.h:541:
    +void EXhalbtcoutsrc_ConnectNotify(struct BTC_COEXIST * pBtCoexist, u8 action);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#543: FILE: ./hal/HalBtcOutSrc.h:543:
    +	struct BTC_COEXIST * pBtCoexist, enum RT_MEDIA_STATUS mediaStatus

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#545: FILE: ./hal/HalBtcOutSrc.h:545:
    +void EXhalbtcoutsrc_SpecialPacketNotify(struct BTC_COEXIST * pBtCoexist, u8 pktType);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#547: FILE: ./hal/HalBtcOutSrc.h:547:
    +	struct BTC_COEXIST * pBtCoexist, u8 *tmpBuf, u8 length

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#549: FILE: ./hal/HalBtcOutSrc.h:549:
    +void EXhalbtcoutsrc_HaltNotify(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#550: FILE: ./hal/HalBtcOutSrc.h:550:
    +void EXhalbtcoutsrc_PnpNotify(struct BTC_COEXIST * pBtCoexist, u8 pnpState);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#551: FILE: ./hal/HalBtcOutSrc.h:551:
    +void EXhalbtcoutsrc_Periodical(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#555: FILE: ./hal/HalBtcOutSrc.h:555:
    +void EXhalbtcoutsrc_DisplayBtCoexInfo(struct BTC_COEXIST * pBtCoexist);

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marco Cesati <marcocesati@gmail.com>
Link: https://lore.kernel.org/r/20210315170618.2566-7-marcocesati@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
yestyle pushed a commit to yestyle/linux that referenced this pull request Jun 26, 2022
@ojeda
Merge pull request torvalds#535 from ojeda/sync
0c07aeb 
Sync with v5.15-rc7
gatieme pushed a commit to gatieme/linux that referenced this pull request Nov 24, 2022
ipv6: use jhash2() in rt6_exception_hash()
1305f1d 
ANBZ: torvalds#535

commit b6b556a ("ipv6: use jhash2() in rt6_exception_hash()")

Faster jhash2() can be used instead of jhash(), since
IPv6 addresses have the needed alignment requirement.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Dust Li <dust.li@linux.alibaba.com>
gatieme pushed a commit to gatieme/linux that referenced this pull request Nov 24, 2022
ipv6: use siphash in rt6_exception_hash()
a3dc114 
ANBZ: torvalds#535

commit 4785305 ("ipv6: use siphash in rt6_exception_hash()")

A group of security researchers brought to our attention
the weakness of hash function used in rt6_exception_hash()

Lets use siphash instead of Jenkins Hash, to considerably
reduce security risks.

Following patch deals with IPv4.

Fixes: 35732d0 ("ipv6: introduce a hash table to store dst cache")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Wei Wang <weiwan@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Dust Li <dust.li@linux.alibaba.com>
gatieme pushed a commit to gatieme/linux that referenced this pull request Nov 24, 2022
ipv6: make exception cache less predictible
bf044eb 
ANBZ: torvalds#535

commit a00df2c ("ipv6: make exception cache less predictible")

Even after commit 4785305 ("ipv6: use siphash in rt6_exception_hash()"),
an attacker can still use brute force to learn some secrets from a victim
linux host.

One way to defeat these attacks is to make the max depth of the hash
table bucket a random value.

Before this patch, each bucket of the hash table used to store exceptions
could contain 6 items under attack.

After the patch, each bucket would contains a random number of items,
between 6 and 10. The attacker can no longer infer secrets.

This is slightly increasing memory size used by the hash table,
we do not expect this to be a problem.

Following patch is dealing with the same issue in IPv4.

Fixes: 35732d0 ("ipv6: introduce a hash table to store dst cache")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Wei Wang <weiwan@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
[Xuan Zhuo: fix minor conflict]
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Dust Li <dust.li@linux.alibaba.com>
gatieme pushed a commit to gatieme/linux that referenced this pull request Nov 24, 2022
@MiaoheLin
net: clean up codestyle
0b19032 
ANBZ: torvalds#535

commit 5af6889 ("net: clean up codestyle")

This is a pure codestyle cleanup patch. No functional change intended.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Dust Li <dust.li@linux.alibaba.com>
gatieme pushed a commit to gatieme/linux that referenced this pull request Nov 24, 2022
ipv4: use siphash instead of Jenkins in fnhe_hashfun()
e87fd0f 
ANBZ: torvalds#535

commit 6457378 ("ipv4: use siphash instead of Jenkins in fnhe_hashfun()")

A group of security researchers brought to our attention
the weakness of hash function used in fnhe_hashfun().

Lets use siphash instead of Jenkins Hash, to considerably
reduce security risks.

Also remove the inline keyword, this really is distracting.

Fixes: d546c62 ("ipv4: harden fnhe_hashfun()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Dust Li <dust.li@linux.alibaba.com>
gatieme pushed a commit to gatieme/linux that referenced this pull request Nov 24, 2022
ipv4: make exception cache less predictible
6ca2386 
ANBZ: torvalds#535

commit 67d6d68 ("ipv4: make exception cache less predictible")

Even after commit 6457378 ("ipv4: use siphash instead of Jenkins in
fnhe_hashfun()"), an attacker can still use brute force to learn
some secrets from a victim linux host.

One way to defeat these attacks is to make the max depth of the hash
table bucket a random value.

Before this patch, each bucket of the hash table used to store exceptions
could contain 6 items under attack.

After the patch, each bucket would contains a random number of items,
between 6 and 10. The attacker can no longer infer secrets.

This is slightly increasing memory size used by the hash table,
by 50% in average, we do not expect this to be a problem.

This patch is more complex than the prior one (IPv6 equivalent),
because IPv4 was reusing the oldest entry.
Since we need to be able to evict more than one entry per
update_or_create_fnhe() call, I had to replace
fnhe_oldest() with fnhe_remove_oldest().

Also note that we will queue extra kfree_rcu() calls under stress,
which hopefully wont be a too big issue.

Fixes: 4895c77 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: David Ahern <dsahern@kernel.org>
Tested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Dust Li <dust.li@linux.alibaba.com>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers
No reviews
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.