Commit Graph

130 Commits

Author SHA1 Message Date
Yuxiao Zhang
104fd0b5e9 pstore: Support record sizes larger than kmalloc() limit
Currently pstore record buffers are allocated using kmalloc() which has
a maximum size based on page size. If a large "pmsg-size" module
parameter is specified, pmsg will fail to copy the contents since
memdup_user() is limited to kmalloc() allocation sizes.

Since we don't need physically contiguous memory for any of the pstore
record buffers, use kvzalloc() to avoid such limitations in the core of
pstore and in the ram backend, and explicitly read from userspace using
vmemdup_user(). This also means that any other backends that want to
(or do already) support larger record sizes will Just Work now.

Signed-off-by: Yuxiao Zhang <yuxiaozhang@google.com>
Link: https://lore.kernel.org/r/20230627202540.881909-2-yuxiaozhang@google.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-08-17 15:18:24 -07:00
Uwe Kleine-König
48f2c681df pstore/ram: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230401120000.2487153-1-u.kleine-koenig@pengutronix.de
2023-05-10 14:06:00 -07:00
Luca Stefani
beca3e311a pstore: Properly assign mem_type property
If mem-type is specified in the device tree
it would end up overriding the record_size
field instead of populating mem_type.

As record_size is currently parsed after the
improper assignment with default size 0 it
continued to work as expected regardless of the
value found in the device tree.

Simply changing the target field of the struct
is enough to get mem-type working as expected.

Fixes: 9d843e8faf ("pstore: Add mem_type property DT parsing support")
Cc: stable@vger.kernel.org
Signed-off-by: Luca Stefani <luca@osomprivacy.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221222131049.286288-1-luca@osomprivacy.com
2022-12-23 10:34:25 -08:00
Wang Yufen
e1fce56490 pstore/ram: Fix error return code in ramoops_probe()
In the if (dev_of_node(dev) && !pdata) path, the "err" may be assigned a
value of 0, so the error return code -EINVAL may be incorrectly set
to 0. To fix set valid return code before calling to goto.

Fixes: 35da60941e ("pstore/ram: add Device Tree bindings")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/1669969374-46582-1-git-send-email-wangyufen@huawei.com
2022-12-02 15:16:59 -08:00
Kees Cook
06b4e09aab pstore/ram: Set freed addresses to NULL
For good measure, set all the freed addresses to NULL when managing
przs.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-and-tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-5-keescook@chromium.org
2022-10-19 09:25:39 -07:00
Kees Cook
8bd4da0f06 pstore/ram: Move internal definitions out of kernel-wide include
Most of the details of the ram backend are entirely internal to the
backend itself. Leave only what is needed to instantiate a ram backend
in the kernel-wide header.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-and-tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-4-keescook@chromium.org
2022-10-17 13:14:32 -07:00
Kees Cook
6daf4e82bd pstore/ram: Move pmsg init earlier
Since the ftrace area can vary in size based on CPU count, move pmsg
initialization earlier so it will have a stable location.

Suggested-by: Paramjit Oberoi <pso@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-3-keescook@chromium.org
2022-10-17 13:14:32 -07:00
Kees Cook
3219122b8c pstore/ram: Consolidate kfree() paths
There's no reason to keep separate kfree() paths: either all allocations
succeeded, or not. Everything is torn down in the case of failure, so
adjust the callers to reflect this.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-and-tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-2-keescook@chromium.org
2022-10-17 13:14:32 -07:00
Mukesh Ojha
9d843e8faf pstore: Add mem_type property DT parsing support
There could be a scenario where we define some region
in normal memory and use them store to logs which is later
retrieved by bootloader during warm reset.

In this scenario, we wanted to treat this memory as normal
cacheable memory instead of default behaviour which
is an overhead. Making it cacheable could improve
performance.

This commit gives control to change mem_type from Device
tree, and also documents the value for normal memory.

Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/1616438537-13719-1-git-send-email-mojha@codeaurora.org
2021-03-31 10:06:23 -07:00
Kees Cook
791205e3ec pstore/ram: Introduce max_reason and convert dump_oops
Now that pstore_register() can correctly pass max_reason to the kmesg
dump facility, introduce a new "max_reason" module parameter and
"max-reason" Device Tree field.

The "dump_oops" module parameter and "dump-oops" Device
Tree field are now considered deprecated, but are now automatically
converted to their corresponding max_reason values when present, though
the new max_reason setting has precedence.

For struct ramoops_platform_data, the "dump_oops" member is entirely
replaced by a new "max_reason" member, with the only existing user
updated in place.

Additionally remove the "reason" filter logic from ramoops_pstore_write(),
as that is not specifically needed anymore, though technically
this is a change in behavior for any ramoops users also setting the
printk.always_kmsg_dump boot param, which will cause ramoops to behave as
if max_reason was set to KMSG_DUMP_MAX.

Co-developed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Link: https://lore.kernel.org/lkml/20200515184434.8470-6-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:03 -07:00
Kees Cook
16a583079e pstore/ftrace: Provide ftrace log merging routine
Move the ftrace log merging logic out of pstore/ram into pstore/ftrace
so other backends can use it, like pstore/zone.

Link: https://lore.kernel.org/lkml/20200510202436.63222-7-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:02 -07:00
Kees Cook
df9bf19d88 pstore/ram: Refactor ftrace buffer merging
This changes the ftrace record merging code to be agnostic of
pstore/ram, as the first step to making it available as a generic
routine for other backends to use, such as pstore/zone.

Link: https://lore.kernel.org/lkml/20200510202436.63222-6-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:02 -07:00
Kees Cook
26961d76ff pstore/ram: Refactor DT size parsing
Refactor device tree size parsing routines to be able to pass a non-zero
default value for providing a configurable default for the coming
"max_reason" field. Also rename the helpers, since we're not always
parsing a size -- we're parsing a u32 and making sure it's not greater
than INT_MAX.

Link: https://lore.kernel.org/lkml/20200506211523.15077-4-keescook@chromium.org/
Link: https://lore.kernel.org/lkml/20200521205223.175957-1-tyhicks@linux.microsoft.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:02 -07:00
Kees Cook
f858b57f7d pstore/ram: Adjust module param permissions to reflect reality
A couple module parameters had 0600 permissions, but changing them would
have no impact on ramoops, so switch these to 0400 to reflect reality.

Link: https://lore.kernel.org/lkml/20200506211523.15077-7-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:02 -07:00
chenqiwu
e030b80ff4 pstore/ram: remove unnecessary ramoops_unregister_dummy()
Remove unnecessary ramoops_unregister_dummy() if ramoops
platform device register failed.

Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
Link: https://lore.kernel.org/r/1581068800-13817-2-git-send-email-qiwuchen55@gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-02-25 11:15:53 -08:00
Kees Cook
e163fdb3f7 pstore/ram: Regularize prz label allocation lifetime
In my attempt to fix a memory leak, I introduced a double-free in the
pstore error path. Instead of trying to manage the allocation lifetime
between persistent_ram_new() and its callers, adjust the logic so
persistent_ram_new() always takes a kstrdup() copy, and leaves the
caller's allocation lifetime up to the caller. Therefore callers are
_always_ responsible for freeing their label. Before, it only needed
freeing when the prz itself failed to allocate, and not in any of the
other prz failure cases, which callers would have no visibility into,
which is the root design problem that lead to both the leak and now
double-free bugs.

Reported-by: Cengiz Can <cengiz@kernel.wtf>
Link: https://lore.kernel.org/lkml/d4ec59002ede4aaf9928c7f7526da87c@kernel.wtf
Fixes: 8df955a32a ("pstore/ram: Fix error-path memory leak in persistent_ram_new() callers")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-01-08 17:05:45 -08:00
Aleksandr Yashkin
9e5f1c1980 pstore/ram: Write new dumps to start of recycled zones
The ram_core.c routines treat przs as circular buffers. When writing a
new crash dump, the old buffer needs to be cleared so that the new dump
doesn't end up in the wrong place (i.e. at the end).

The solution to this problem is to reset the circular buffer state before
writing a new Oops dump.

Signed-off-by: Aleksandr Yashkin <a.yashkin@inango-systems.com>
Signed-off-by: Nikolay Merinov <n.merinov@inango-systems.com>
Signed-off-by: Ariel Gilman <a.gilman@inango-systems.com>
Link: https://lore.kernel.org/r/20191223133816.28155-1-n.merinov@inango-systems.com
Fixes: 896fc1f0c4 ("pstore/ram: Switch to persistent_ram routines")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-01-02 12:30:50 -08:00
Kees Cook
8df955a32a pstore/ram: Fix error-path memory leak in persistent_ram_new() callers
For callers that allocated a label for persistent_ram_new(), if the call
fails, they must clean up the allocation.

Suggested-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Fixes: 1227daa43b ("pstore/ram: Clarify resource reservation labels")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20191211191353.14385-1-navid.emamdoost@gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-01-02 12:30:39 -08:00
Deepa Dinamani
83b8a3fbe3 pstore: fs superblock limits
Leaving granularity at 1ns because it is dependent on the specific
attached backing pstore module. ramoops has microsecond resolution.

Fix the readback of ramoops fractional timestamp microseconds,
which has incorrectly been reporting the value as nanoseconds.

Fixes: 3f8f80f0cf ("pstore/ram: Read and write to the 'compressed' flag of pstore").

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Jeff Layton <jlayton@kernel.org>
Cc: anton@enomsg.org
Cc: ccross@android.com
Cc: keescook@chromium.org
Cc: tony.luck@intel.com
2019-08-30 08:11:25 -07:00
Douglas Anderson
1614e92179 pstore/ram: Improve backward compatibility with older Chromebooks
When you try to run an upstream kernel on an old ARM-based Chromebook
you'll find that console-ramoops doesn't work.

Old ARM-based Chromebooks, before <https://crrev.com/c/439792>
("ramoops: support upstream {console,pmsg,ftrace}-size properties")
used to create a "ramoops" node at the top level that looked like:

/ {
  ramoops {
    compatible = "ramoops";
    reg = <...>;
    record-size = <...>;
    dump-oops;
  };
};

...and these Chromebooks assumed that the downstream kernel would make
console_size / pmsg_size match the record size.  The above ramoops
node was added by the firmware so it's not easy to make any changes.

Let's match the expected behavior, but only for those using the old
backward-compatible way of working where ramoops is right under the
root node.

NOTE: if there are some out-of-tree devices that had ramoops at the
top level, left everything but the record size as 0, and somehow
doesn't want this behavior, we can try to add more conditions here.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-07-08 21:04:42 -07:00
Linus Torvalds
9331b6740f SPDX update for 5.2-rc4
Another round of SPDX header file fixes for 5.2-rc4
 
 These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being
 added, based on the text in the files.  We are slowly chipping away at
 the 700+ different ways people tried to write the license text.  All of
 these were reviewed on the spdx mailing list by a number of different
 people.
 
 We now have over 60% of the kernel files covered with SPDX tags:
 	$ ./scripts/spdxcheck.py -v 2>&1 | grep Files
 	Files checked:            64533
 	Files with SPDX:          40392
 	Files with errors:            0
 
 I think the majority of the "easy" fixups are now done, it's now the
 start of the longer-tail of crazy variants to wade through.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull yet more SPDX updates from Greg KH:
 "Another round of SPDX header file fixes for 5.2-rc4

  These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being
  added, based on the text in the files. We are slowly chipping away at
  the 700+ different ways people tried to write the license text. All of
  these were reviewed on the spdx mailing list by a number of different
  people.

  We now have over 60% of the kernel files covered with SPDX tags:
	$ ./scripts/spdxcheck.py -v 2>&1 | grep Files
	Files checked:            64533
	Files with SPDX:          40392
	Files with errors:            0

  I think the majority of the "easy" fixups are now done, it's now the
  start of the longer-tail of crazy variants to wade through"

* tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (159 commits)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 450
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 449
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 448
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 446
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 445
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 444
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 443
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 442
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 436
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 435
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 434
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 433
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 432
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 431
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 430
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 429
  ...
2019-06-08 12:52:42 -07:00
Thomas Gleixner
2b27bdcc20 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 51 franklin st fifth floor boston ma 02110
  1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 246 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.674189849@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:07 +02:00
Kees Cook
8880fa32c5 pstore/ram: Run without kernel crash dump region
The ram pstore backend has always had the crash dumper frontend enabled
unconditionally. However, it was possible to effectively disable it
by setting a record_size=0. All the machinery would run (storing dumps
to the temporary crash buffer), but 0 bytes would ultimately get stored
due to there being no przs allocated for dumps. Commit 89d328f637
("pstore/ram: Correctly calculate usable PRZ bytes"), however, assumed
that there would always be at least one allocated dprz for calculating
the size of the temporary crash buffer. This was, of course, not the
case when record_size=0, and would lead to a NULL deref trying to find
the dprz buffer size:

BUG: unable to handle kernel NULL pointer dereference at (null)
...
IP: ramoops_probe+0x285/0x37e (fs/pstore/ram.c:808)

        cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;

Instead, we need to only enable the frontends based on the success of the
prz initialization and only take the needed actions when those zones are
available. (This also fixes a possible error in detecting if the ftrace
frontend should be enabled.)

Reported-and-tested-by: Yaro Slav <yaro330@gmail.com>
Fixes: 89d328f637 ("pstore/ram: Correctly calculate usable PRZ bytes")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-05-31 01:19:06 -07:00
Kees Cook
93ee4b7d9f pstore/ram: Avoid needless alloc during header write
Since the header is a fixed small maximum size, just use a stack variable
to avoid memory allocation in the write path.

Signed-off-by: Kees Cook <keescook@chromium.org>
2019-02-12 13:45:53 -08:00
Yue Hu
47afd7ae65 pstore/ram: Add kmsg hlen zero check to ramoops_pstore_write()
If zero-length header happened in ramoops_write_kmsg_hdr(), that means
we will not be able to read back dmesg record later, since it will be
treated as invalid header in ramoops_pstore_read(). So we should not
execute the following code but return the error.

Signed-off-by: Yue Hu <huyue2@yulong.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-02-12 12:38:54 -08:00
Yue Hu
1e0f67a96a pstore/ram: Move initialization earlier
Since only one single ramoops area allowed at a time, other probes
(like device tree) are meaningless, as it will waste CPU resources.
So let's check for being already initialized first.

Signed-off-by: Yue Hu <huyue2@yulong.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-02-12 12:10:43 -08:00
Yue Hu
4c6c4d3453 pstore: Avoid writing records with zero size
Sometimes pstore_console_write() will write records with zero size
to persistent ram zone, which is unnecessary. It will only increase
resource consumption. Also adjust ramoops_write_kmsg_hdr() to have
same logic if memory allocation fails.

Signed-off-by: Yue Hu <huyue2@yulong.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-02-12 12:09:49 -08:00
Yue Hu
182ca6e0ae pstore/ram: Replace dummy_data heap memory with stack memory
In ramoops_register_dummy() dummy_data is allocated via kzalloc()
then it will always occupy the heap space after register platform
device via platform_device_register_data(), but it will not be
used any more. So let's free it for system usage, replace it with
stack memory is better due to small size.

Signed-off-by: Yue Hu <huyue2@yulong.com>
[kees: add required memset and adjust sizeof() argument]
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-21 19:32:17 -08:00
Kees Cook
5631e8576a pstore/ram: Avoid allocation and leak of platform data
Yue Hu noticed that when parsing device tree the allocated platform data
was never freed. Since it's not used beyond the function scope, this
switches to using a stack variable instead.

Reported-by: Yue Hu <huyue2@yulong.com>
Fixes: 35da60941e ("pstore/ram: add Device Tree bindings")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-20 14:44:52 -08:00
Sai Prakash Ranjan
6a4c9ab13f pstore/ram: Fix console ramoops to show the previous boot logs
commit b05c950698 ("pstore/ram: Simplify ramoops_get_next_prz()
arguments") changed update assignment in getting next persistent ram zone
by adding a check for record type. But the check always returns true since
the record type is assigned 0. And this breaks console ramoops by showing
current console log instead of previous log on warm reset and hard reset
(actually hard reset should not be showing any logs).

Fix this by having persistent ram zone type check instead of record type
check. Tested this on SDM845 MTP and dragonboard 410c.

Reproducing this issue is simple as below:

1. Trigger hard reset and mount pstore. Will see console-ramoops
   record in the mounted location which is the current log.

2. Trigger warm reset and mount pstore. Will see the current
   console-ramoops record instead of previous record.

Fixes: b05c950698 ("pstore/ram: Simplify ramoops_get_next_prz() arguments")
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[kees: dropped local variable usage]
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-17 09:14:06 -08:00
Kees Cook
8665569e97 pstore/ram: Avoid NULL deref in ftrace merging failure path
Given corruption in the ftrace records, it might be possible to allocate
tmp_prz without assigning prz to it, but still marking it as needing to
be freed, which would cause at least a NULL dereference.

smatch warnings:
fs/pstore/ram.c:340 ramoops_pstore_read() error: we previously assumed 'prz' could be null (see line 255)

https://lists.01.org/pipermail/kbuild-all/2018-December/055528.html

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 2fbea82bbb ("pstore: Merge per-CPU ftrace records into one")
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-03 17:11:02 -08:00
Kees Cook
ea84b580b9 pstore: Convert buf_lock to semaphore
Instead of running with interrupts disabled, use a semaphore. This should
make it easier for backends that may need to sleep (e.g. EFI) when
performing a write:

|BUG: sleeping function called from invalid context at kernel/sched/completion.c:99
|in_atomic(): 1, irqs_disabled(): 1, pid: 2236, name: sig-xstate-bum
|Preemption disabled at:
|[<ffffffff99d60512>] pstore_dump+0x72/0x330
|CPU: 26 PID: 2236 Comm: sig-xstate-bum Tainted: G      D           4.20.0-rc3 #45
|Call Trace:
| dump_stack+0x4f/0x6a
| ___might_sleep.cold.91+0xd3/0xe4
| __might_sleep+0x50/0x90
| wait_for_completion+0x32/0x130
| virt_efi_query_variable_info+0x14e/0x160
| efi_query_variable_store+0x51/0x1a0
| efivar_entry_set_safe+0xa3/0x1b0
| efi_pstore_write+0x109/0x140
| pstore_dump+0x11c/0x330
| kmsg_dump+0xa4/0xd0
| oops_exit+0x22/0x30
...

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Fixes: 21b3ddd39f ("efi: Don't use spinlocks for efi vars")
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-03 17:11:02 -08:00
Joel Fernandes (Google)
b05c950698 pstore/ram: Simplify ramoops_get_next_prz() arguments
(1) remove type argument from ramoops_get_next_prz()

Since we store the type of the prz when we initialize it, we no longer
need to pass it again in ramoops_get_next_prz() since we can just use
that to setup the pstore record. So lets remove it from the argument list.

(2) remove max argument from ramoops_get_next_prz()

Looking at the code flow, the 'max' checks are already being done on
the prz passed to ramoops_get_next_prz(). Lets remove it to simplify
this function and reduce its arguments.

(3) further reduce ramoops_get_next_prz() arguments by passing record

Both the id and type fields of a pstore_record are set by
ramoops_get_next_prz(). So we can just pass a pointer to the pstore_record
instead of passing individual elements. This results in cleaner more
readable code and fewer lines.

In addition lets also remove the 'update' argument since we can detect
that. Changes are squashed into a single patch to reduce fixup conflicts.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-03 16:52:35 -08:00
Joel Fernandes (Google)
f0f23e5469 pstore: Map PSTORE_TYPE_* to strings
In later patches we will need to map types to names, so create a
constant table for that which can also be used in different parts of
old and new code. This saves the type in the PRZ which will be useful
in later patches.

Instead of having an explicit PSTORE_TYPE_UNKNOWN, just use ..._MAX.

This includes removing the now redundant filename templates which can use
a single format string. Also, there's no reason to limit the "is it still
compressed?" test to only PSTORE_TYPE_DMESG when building the pstorefs
filename. Records are zero-initialized, so a backend would need to have
explicitly set compressed=1.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-03 16:52:35 -08:00
Kees Cook
dc80b1ea4c pstore/ram: Report backend assignments with finer granularity
In order to more easily perform automated regression testing, this
adds pr_debug() calls to report each prz allocation which can then be
verified against persistent storage. Specifically, seeing the dividing
line between header, data, any ECC bytes. (And the general assignment
output is updated to remove the bogus ECC blocksize which isn't actually
recorded outside the prz instance.)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-03 16:52:35 -08:00
Peng Wang
7684bd334d pstore: Avoid duplicate call of persistent_ram_zap()
When initialing a prz, if invalid data is found (no PERSISTENT_RAM_SIG),
the function call path looks like this:

ramoops_init_prz ->
    persistent_ram_new -> persistent_ram_post_init -> persistent_ram_zap
    persistent_ram_zap

As we can see, persistent_ram_zap() is called twice.
We can avoid this by adding an option to persistent_ram_new(), and
only call persistent_ram_zap() when it is needed.

Signed-off-by: Peng Wang <wangpeng15@xiaomi.com>
[kees: minor tweak to exit path and commit log]
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-03 16:52:35 -08:00
Kees Cook
971f66d8a7 Merge branch 'for-linus/pstore' into for-next/pstore 2018-12-03 16:52:02 -08:00
Kees Cook
89d328f637 pstore/ram: Correctly calculate usable PRZ bytes
The actual number of bytes stored in a PRZ is smaller than the
bytes requested by platform data, since there is a header on each
PRZ. Additionally, if ECC is enabled, there are trailing bytes used
as well. Normally this mismatch doesn't matter since PRZs are circular
buffers and the leading "overflow" bytes are just thrown away. However, in
the case of a compressed record, this rather badly corrupts the results.

This corruption was visible with "ramoops.mem_size=204800 ramoops.ecc=1".
Any stored crashes would not be uncompressable (producing a pstorefs
"dmesg-*.enc.z" file), and triggering errors at boot:

  [    2.790759] pstore: crypto_comp_decompress failed, ret = -22!

Backporting this depends on commit 70ad35db33 ("pstore: Convert console
write to use ->write_buf")

Reported-by: Joel Fernandes <joel@joelfernandes.org>
Fixes: b0aad7a99c ("pstore: Add compression support to pstore")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
2018-11-29 13:46:43 -08:00
Linus Torvalds
08ffb584d9 pstore improvements:
- refactor init to happen as early as possible again (Joel Fernandes)
 - improve resource reservation names
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Merge tag 'pstore-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore updates from Kees Cook:
 "pstore improvements:

   - refactor init to happen as early as possible again (Joel Fernandes)

   - improve resource reservation names"

* tag 'pstore-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ram: Clarify resource reservation labels
  pstore: Refactor compression initialization
  pstore: Allocate compression during late_initcall()
  pstore: Centralize init/exit routines
2018-10-24 14:42:02 +01:00
Kees Cook
1227daa43b pstore/ram: Clarify resource reservation labels
When ramoops reserved a memory region in the kernel, it had an unhelpful
label of "persistent_memory". When reading /proc/iomem, it would be
repeated many times, did not hint that it was ramoops in particular,
and didn't clarify very much about what each was used for:

400000000-407ffffff : Persistent Memory (legacy)
  400000000-400000fff : persistent_memory
  400001000-400001fff : persistent_memory
...
  4000ff000-4000fffff : persistent_memory

Instead, this adds meaningful labels for how the various regions are
being used:

400000000-407ffffff : Persistent Memory (legacy)
  400000000-400000fff : ramoops:dump(0/252)
  400001000-400001fff : ramoops:dump(1/252)
...
  4000fc000-4000fcfff : ramoops:dump(252/252)
  4000fd000-4000fdfff : ramoops:console
  4000fe000-4000fe3ff : ramoops:ftrace(0/3)
  4000fe400-4000fe7ff : ramoops:ftrace(1/3)
  4000fe800-4000febff : ramoops:ftrace(2/3)
  4000fec00-4000fefff : ramoops:ftrace(3/3)
  4000ff000-4000fffff : ramoops:pmsg

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Tested-by: Guenter Roeck <groeck@chromium.org>
2018-10-22 07:11:58 -07:00
Joel Fernandes (Google)
416031653e pstore: Allocate compression during late_initcall()
ramoops's call of pstore_register() was recently moved to run during
late_initcall() because the crypto backend may not have been ready during
postcore_initcall(). This meant early-boot crash dumps were not getting
caught by pstore any more.

Instead, lets allow calls to pstore_register() earlier, and once crypto
is ready we can initialize the compression.

Reported-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Fixes: cb3bee0369 ("pstore: Use crypto compress API")
[kees: trivial rebase]
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Guenter Roeck <groeck@chromium.org>
2018-10-22 07:11:58 -07:00
Kees Cook
bac6f6cda2 pstore/ram: Fix failure-path memory leak in ramoops_init
As reported by nixiaoming, with some minor clarifications:

1) memory leak in ramoops_register_dummy():
   dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
   but no kfree() if platform_device_register_data() fails.

2) memory leak in ramoops_init():
   Missing platform_device_unregister(dummy) and kfree(dummy_data)
   if platform_driver_register(&ramoops_driver) fails.

I've clarified the purpose of ramoops_register_dummy(), and added a
common cleanup routine for all three failure paths to call.

Reported-by: nixiaoming <nixiaoming@huawei.com>
Cc: stable@vger.kernel.org
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-09-30 10:15:41 -07:00
Arnd Bergmann
e264abeaf9 pstore: Remove bogus format string definition
The pstore conversion to timespec64 introduces its own method of passing
seconds into sscanf() and sprintf() type functions to work around the
timespec64 definition on 64-bit systems that redefine it to 'timespec'.

That hack is now finally getting removed, but that means we get a (harmless)
warning once both patches are merged:

fs/pstore/ram.c: In function 'ramoops_read_kmsg_hdr':
fs/pstore/ram.c:39:29: error: format '%ld' expects argument of type 'long int *', but argument 3 has type 'time64_t *' {aka 'long long int *'} [-Werror=format=]
 #define RAMOOPS_KERNMSG_HDR "===="
                             ^~~~~~
fs/pstore/ram.c:167:21: note: in expansion of macro 'RAMOOPS_KERNMSG_HDR'

This removes the pstore specific workaround and uses the same method that
we have in place for all other functions that print a timespec64.

Related to this, I found that the kasprintf() output contains an incorrect
nanosecond values for any number starting with zeroes, and I adapt the
format string accordingly.

Link: https://lkml.org/lkml/2018/5/19/115
Link: https://lkml.org/lkml/2018/5/16/1080
Fixes: 0f0d83b99ef7 ("pstore: Convert internal records to timespec64")
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-06-14 14:57:24 +02:00
Kees Cook
7aaa822ed0 pstore: Convert internal records to timespec64
This prepares pstore for converting the VFS layer to timespec64.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
2018-06-05 16:57:31 -07:00
Geliang Tang
cb3bee0369 pstore: Use crypto compress API
In the pstore compression part, we use zlib/lzo/lz4/lz4hc/842
compression algorithm API to implement pstore compression backends. But
there are many repeat codes in these implementations. This patch uses
crypto compress API to simplify these codes.

1) rewrite allocate_buf_for_compression, free_buf_for_compression,
pstore_compress, pstore_decompress functions using crypto compress API.
2) drop compress, decompress, allocate, free functions in pstore_zbackend,
and add zbufsize function to get each different compress buffer size.
3) use late_initcall to call ramoops_init later, to make sure the crypto
subsystem has already initialized.
4) use 'unsigned int' type instead of 'size_t' in pstore_compress,
pstore_decompress functions' length arguments.
5) rename 'zlib' to 'deflate' to follow the crypto API's name convention.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
[kees: tweaked error messages on allocation failures and Kconfig help]
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-03-09 14:16:29 -08:00
Kees Cook
c7f3c595f6 pstore: Populate pstore record->time field
The current time will be initially available in the record->time field
for all pstore_read() and pstore_write() calls. Backends can either
update the field during read(), or use the field during write() instead
of fetching time themselves.

Signed-off-by: Kees Cook <keescook@chromium.org>
2017-05-31 10:13:44 -07:00
Linus Torvalds
291b38a756 Annotation of module parameters that specify device settings
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Merge tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull hw lockdown support from David Howells:
 "Annotation of module parameters that configure hardware resources
  including ioports, iomem addresses, irq lines and dma channels.

  This allows a future patch to prohibit the use of such module
  parameters to prevent that hardware from being abused to gain access
  to the running kernel image as part of locking the kernel down under
  UEFI secure boot conditions.

  Annotations are made by changing:

        module_param(n, t, p)
        module_param_named(n, v, t, p)
        module_param_array(n, t, m, p)

  to:

        module_param_hw(n, t, hwtype, p)
        module_param_hw_named(n, v, t, hwtype, p)
        module_param_hw_array(n, t, hwtype, m, p)

  where the module parameter refers to a hardware setting

  hwtype specifies the type of the resource being configured. This can
  be one of:

        ioport          Module parameter configures an I/O port
        iomem           Module parameter configures an I/O mem address
        ioport_or_iomem Module parameter could be either (runtime set)
        irq             Module parameter configures an I/O port
        dma             Module parameter configures a DMA channel
        dma_addr        Module parameter configures a DMA buffer address
        other           Module parameter configures some other value

  Note that the hwtype is compile checked, but not currently stored (the
  lockdown code probably won't require it). It is, however, there for
  future use.

  A bonus is that the hwtype can also be used for grepping.

  The intention is for the kernel to ignore or reject attempts to set
  annotated module parameters if lockdown is enabled. This applies to
  options passed on the boot command line, passed to insmod/modprobe or
  direct twiddling in /sys/module/ parameter files.

  The module initialisation then needs to handle the parameter not being
  set, by (1) giving an error, (2) probing for a value or (3) using a
  reasonable default.

  What I can't do is just reject a module out of hand because it may
  take a hardware setting in the module parameters. Some important
  modules, some ipmi stuff for instance, both probe for hardware and
  allow hardware to be manually specified; if the driver is aborts with
  any error, you don't get any ipmi hardware.

  Further, trying to do this entirely in the module initialisation code
  doesn't protect against sysfs twiddling.

  [!] Note that in and of itself, this series of patches should have no
      effect on the the size of the kernel or code execution - that is
      left to a patch in the next series to effect. It does mark
      annotated kernel parameters with a KERNEL_PARAM_FL_HWPARAM flag in
      an already existing field"

* tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (38 commits)
  Annotate hardware config module parameters in sound/pci/
  Annotate hardware config module parameters in sound/oss/
  Annotate hardware config module parameters in sound/isa/
  Annotate hardware config module parameters in sound/drivers/
  Annotate hardware config module parameters in fs/pstore/
  Annotate hardware config module parameters in drivers/watchdog/
  Annotate hardware config module parameters in drivers/video/
  Annotate hardware config module parameters in drivers/tty/
  Annotate hardware config module parameters in drivers/staging/vme/
  Annotate hardware config module parameters in drivers/staging/speakup/
  Annotate hardware config module parameters in drivers/staging/media/
  Annotate hardware config module parameters in drivers/scsi/
  Annotate hardware config module parameters in drivers/pcmcia/
  Annotate hardware config module parameters in drivers/pci/hotplug/
  Annotate hardware config module parameters in drivers/parport/
  Annotate hardware config module parameters in drivers/net/wireless/
  Annotate hardware config module parameters in drivers/net/wan/
  Annotate hardware config module parameters in drivers/net/irda/
  Annotate hardware config module parameters in drivers/net/hamradio/
  Annotate hardware config module parameters in drivers/net/ethernet/
  ...
2017-05-10 19:13:03 -07:00
David Howells
b90fe0c4e0 Annotate hardware config module parameters in fs/pstore/
When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image.  Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.

To this end, annotate module_param* statements that refer to hardware
configuration and indicate for future reference what type of parameter they
specify.  The parameter parser in the core sees this information and can
skip such parameters with an error message if the kernel is locked down.
The module initialisation then runs as normal, but just sees whatever the
default values for those parameters is.

Note that we do still need to do the module initialisation because some
drivers have viable defaults set in case parameters aren't specified and
some drivers support automatic configuration (e.g. PNP or PCI) in addition
to manually coded parameters.

This patch annotates drivers in fs/pstore/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
cc: Anton Vorontsov <anton@enomsg.org>
cc: Colin Cross <ccross@android.com>
cc: Tony Luck <tony.luck@intel.com>
2017-04-20 12:02:32 +01:00
Kees Cook
4c9ec21976 pstore: Remove write_buf() callback
Now that write() and write_buf() are functionally identical, this removes
write_buf(), and renames write_buf_user() to write_user(). Additionally
adds sanity-checks for pstore_info's declared functions and flags at
registration time.

Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07 14:01:02 -08:00
Kees Cook
fdd0311863 pstore: Replace arguments for write_buf_user() API
Removes argument list in favor of pstore record, though the user buffer
remains passed separately since it must carry the __user annotation.

Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07 14:01:01 -08:00