Add a new member to struct pstore_info for passing information about
kmesg dump maximum reason. This allows a finer control of what kmesg
dumps are sent to pstore storage backends.
Those backends that do not explicitly set this field (keeping it equal to
0), get the default behavior: store only Oopses and Panics, or everything
if the printk.always_kmsg_dump boot param is set.
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Link: https://lore.kernel.org/lkml/20200515184434.8470-5-keescook@chromium.org/
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
The pstore subsystem already had a private version of this function.
With the coming addition of the pstore/zone driver, this needs to be
shared. As it really should live with printk, move it there instead.
Link: https://lore.kernel.org/lkml/20200515184434.8470-4-keescook@chromium.org/
Acked-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
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>
In order to more cleanly pass around backend names, make the "name" member
const. This means the module param needs to be dynamic (technically, it
was before, so this actually cleans up a minor memory leak if a backend
was specified and then gets unloaded.)
Link: https://lore.kernel.org/lkml/20200510202436.63222-3-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
The CON_ENABLED flag gets cleared during unregister_console(), so make
sure we already reset the console flags before calling register_console(),
otherwise unloading and reloading a pstore backend will not restart
console logging.
Signed-off-by: Kees Cook <keescook@chromium.org>
If a backend was unloaded without having first removed all its
associated records in pstorefs, subsequent removals would crash while
attempting to call into the now missing backend. Add automatic removal
from the tree in pstore_unregister(), so that no references to the
backend remain.
Reported-by: Luis Henriques <lhenriques@suse.com>
Link: https://lore.kernel.org/lkml/87o8yrmv69.fsf@suse.com
Link: https://lore.kernel.org/lkml/20200506152114.50375-11-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
The pstore.update_ms value was being disabled during pstore_unregister(),
which would cause any prior value to go unnoticed on the next
pstore_register(). Instead, just let del_timer() stop the timer, which
was always sufficient. This additionally refactors the timer reset code
and allows the timer to be enabled if the module parameter is changed
away from the default.
Link: https://lore.kernel.org/lkml/20200506152114.50375-10-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
Nothing was protecting changes to the pstorefs superblock. Add locking
and refactor away is_pstore_mounted(), instead using a helper to add a
way to safely lock the pstorefs root inode during filesystem changes.
Link: https://lore.kernel.org/lkml/20200506152114.50375-9-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
The "unlink" handling should perform list removal (which can also make
sure records don't get double-erased), and the "evict" handling should
be responsible only for memory freeing.
Link: https://lore.kernel.org/lkml/20200506152114.50375-8-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
The pstorefs internal list lock doesn't need to be a spinlock and will
create problems when trying to access the list in the subsequent patch
that will walk the pstorefs records during pstore_unregister(). Change
this to a mutex to avoid may_sleep() warnings when unregistering devices.
Link: https://lore.kernel.org/lkml/20200506152114.50375-6-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
The name "allpstore" doesn't carry much meaning, so rename it to what it
actually is: the list of all records present in the filesystem. The lock
is also renamed accordingly.
Link: https://lore.kernel.org/lkml/20200506152114.50375-5-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
Currently pstore can only have a single backend attached at a time, and it
tracks the active backend via "psinfo", under a lock. The locking for this
does not need to be a spinlock, and in order to avoid may_sleep() issues
during future changes to pstore_unregister(), switch to a mutex instead.
Link: https://lore.kernel.org/lkml/20200506152114.50375-4-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
There is no reason to be doing a module get/put in pstore_register(),
since the module calling pstore_register() cannot be unloaded since it
hasn't finished its initialization. Remove it so there is no confusion
about how registration ordering works.
Link: https://lore.kernel.org/lkml/20200506152114.50375-2-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200309202327.GA8813@embeddedor
Signed-off-by: Kees Cook <keescook@chromium.org>
In Aug 2018 NeilBrown noticed
commit 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code and interface")
"Some ->next functions do not increment *pos when they return NULL...
Note that such ->next functions are buggy and should be fixed.
A simple demonstration is
dd if=/proc/swaps bs=1000 skip=1
Choose any block size larger than the size of /proc/swaps. This will
always show the whole last line of /proc/swaps"
/proc/swaps output was fixed recently, however there are lot of other
affected files, and one of them is related to pstore subsystem.
If .next function does not change position index, following .show function
will repeat output related to current position index.
There are at least 2 related problems:
- read after lseek beyond end of file, described above by NeilBrown
"dd if=<AFFECTED_FILE> bs=1000 skip=1" will generate whole last list
- read after lseek on in middle of last line will output expected rest of
last line but then repeat whole last line once again.
If .show() function generates multy-line output (like
pstore_ftrace_seq_show() does ?) following bash script cycles endlessly
$ q=;while read -r r;do echo "$((++q)) $r";done < AFFECTED_FILE
Unfortunately I'm not familiar enough to pstore subsystem and was unable
to find affected pstore-related file on my test node.
If .next function does not change position index, following .show function
will repeat output related to current position index.
Cc: stable@vger.kernel.org
Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Link: https://lore.kernel.org/r/4e49830d-4c88-0171-ee24-1ee540028dad@virtuozzo.com
[kees: with robustness tweak from Joel Fernandes <joelaf@google.com>]
Signed-off-by: Kees Cook <keescook@chromium.org>
There is a potential mem leak when pstore_init_fs failed,
since the pstore compression maybe unlikey to initialized
successfully. We must clean up the allocation once this
unlikey issue happens.
Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
Link: https://lore.kernel.org/r/1581068800-13817-1-git-send-email-qiwuchen55@gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
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>
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>
The pstore_choose_compression() function is not exported so make it
static to avoid the following sparse warning:
fs/pstore/platform.c:796:13: warning: symbol 'pstore_choose_compression' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Link: https://lore.kernel.org/r/20191016123317.3154-1-ben.dooks@codethink.co.uk
Fixes: cb095afd44 ("pstore: Centralize init/exit routines")
Signed-off-by: Kees Cook <keescook@chromium.org>
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
The pstore_mkfile() function is passed a pointer to a struct
pstore_record. On success it consumes this 'record' pointer and
references it from the created inode.
On failure, however, it may or may not free the record. There are even
two different code paths which return -ENOMEM -- one of which does and
the other doesn't free the record.
Make the behaviour deterministic by never consuming and freeing the
record when returning failure, allowing the caller to do the cleanup
consistently.
Signed-off-by: Norbert Manthey <nmanthey@amazon.de>
Link: https://lore.kernel.org/r/1562331960-26198-1-git-send-email-nmanthey@amazon.de
Fixes: 83f70f0769 ("pstore: Do not duplicate record metadata")
Fixes: 1dfff7dd67 ("pstore: Pass record contents instead of copying")
Cc: stable@vger.kernel.org
[kees: also move "private" allocation location, rename inode cleanup label]
Signed-off-by: Kees Cook <keescook@chromium.org>
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
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>
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
...
- Avoid NULL deref when unloading/reloading ramoops module (Pi-Hsun Shih)
- Run ramoops without crash dump region
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Merge tag 'pstore-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull pstore fixes from Kees Cook:
- Avoid NULL deref when unloading/reloading ramoops module (Pi-Hsun
Shih)
- Run ramoops without crash dump region
* tag 'pstore-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
pstore/ram: Run without kernel crash dump region
pstore: Set tfm to NULL on free_buf_for_compression
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>
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 59 temple place suite 330 boston ma 02111
1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 136 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/20190530000436.384967451@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this software is licensed under the terms of the gnu general public
license version 2 as published by the free software foundation and
may be copied distributed and modified under those terms 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
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 285 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/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Set tfm to NULL on free_buf_for_compression() after crypto_free_comp().
This avoid a use-after-free when allocate_buf_for_compression()
and free_buf_for_compression() are called twice. Although
free_buf_for_compression() freed the tfm, allocate_buf_for_compression()
won't reinitialize the tfm since the tfm pointer is not NULL.
Fixes: 95047b0519 ("pstore: Refactor compression initialization")
Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
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>
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>
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>
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>
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>
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
