Commit Graph

390 Commits

Author SHA1 Message Date
John Stultz b4f1e0138d pstore: Revert pmsg_lock back to a normal mutex
[ Upstream commit 5239a89b06 ]

This reverts commit 76d62f24db.

So while priority inversion on the pmsg_lock is an occasional
problem that an rt_mutex would help with, in uses where logging
is writing to pmsg heavily from multiple threads, the pmsg_lock
can be heavily contended.

After this change landed, it was reported that cases where the
mutex locking overhead was commonly adding on the order of 10s
of usecs delay had suddenly jumped to ~msec delay with rtmutex.

It seems the slight differences in the locks under this level
of contention causes the normal mutexes to utilize the spinning
optimizations, while the rtmutexes end up in the sleeping
slowpath (which allows additional threads to pile on trying
to take the lock).

In this case, it devolves to a worse case senerio where the lock
acquisition and scheduling overhead dominates, and each thread
is waiting on the order of ~ms to do ~us of work.

Obviously, having tons of threads all contending on a single
lock for logging is non-optimal, so the proper fix is probably
reworking pstore pmsg to have per-cpu buffers so we don't have
contention.

Additionally, Steven Rostedt has provided some furhter
optimizations for rtmutexes that improves the rtmutex spinning
path, but at least in my testing, I still see the test tripping
into the sleeping path on rtmutexes while utilizing the spinning
path with mutexes.

But in the short term, lets revert the change to the rt_mutex
and go back to normal mutexes to avoid a potentially major
performance regression. And we can work on optimizations to both
rtmutexes and finer-grained locking for pstore pmsg in the
future.

Cc: Wei Wang <wvw@google.com>
Cc: Midas Chien<midaschieh@google.com>
Cc: "Chunhui Li (李春辉)" <chunhui.li@mediatek.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: kernel-team@android.com
Fixes: 76d62f24db ("pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion")
Reported-by: "Chunhui Li (李春辉)" <chunhui.li@mediatek.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230308204043.2061631-1-jstultz@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-11 23:11:20 +09:00
Linus Torvalds edb23125fd pstore updates for v6.2-rc1-fixes
- Switch pmsg_lock to an rt_mutex to avoid priority inversion (John Stultz)
 
 - Correctly assign mem_type property (Luca Stefani)
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Merge tag 'pstore-v6.2-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore fixes from Kees Cook:

 - Switch pmsg_lock to an rt_mutex to avoid priority inversion (John
   Stultz)

 - Correctly assign mem_type property (Luca Stefani)

* tag 'pstore-v6.2-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore: Properly assign mem_type property
  pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXES
  pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion
2022-12-23 11:55:54 -08:00
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
John Stultz 2f4fec5943 pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXES
In commit 76d62f24db ("pstore: Switch pmsg_lock to an rt_mutex
to avoid priority inversion") I changed a lock to an rt_mutex.

However, its possible that CONFIG_RT_MUTEXES is not enabled,
which then results in a build failure, as the 0day bot detected:
  https://lore.kernel.org/linux-mm/202212211244.TwzWZD3H-lkp@intel.com/

Thus this patch changes CONFIG_PSTORE_PMSG to select
CONFIG_RT_MUTEXES, which ensures the build will not fail.

Cc: Wei Wang <wvw@google.com>
Cc: Midas Chien<midaschieh@google.com>
Cc: Connor O'Brien <connoro@google.com>
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: kernel test robot <lkp@intel.com>
Cc: kernel-team@android.com
Fixes: 76d62f24db ("pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221221051855.15761-1-jstultz@google.com
2022-12-23 10:33:27 -08:00
Linus Torvalds 71a7507afb Driver Core changes for 6.2-rc1
Here is the set of driver core and kernfs changes for 6.2-rc1.
 
 The "big" change in here is the addition of a new macro,
 container_of_const() that will preserve the "const-ness" of a pointer
 passed into it.
 
 The "problem" of the current container_of() macro is that if you pass in
 a "const *", out of it can comes a non-const pointer unless you
 specifically ask for it.  For many usages, we want to preserve the
 "const" attribute by using the same call.  For a specific example, this
 series changes the kobj_to_dev() macro to use it, allowing it to be used
 no matter what the const value is.  This prevents every subsystem from
 having to declare 2 different individual macros (i.e.
 kobj_const_to_dev() and kobj_to_dev()) and having the compiler enforce
 the const value at build time, which having 2 macros would not do
 either.
 
 The driver for all of this have been discussions with the Rust kernel
 developers as to how to properly mark driver core, and kobject, objects
 as being "non-mutable".  The changes to the kobject and driver core in
 this pull request are the result of that, as there are lots of paths
 where kobjects and device pointers are not modified at all, so marking
 them as "const" allows the compiler to enforce this.
 
 So, a nice side affect of the Rust development effort has been already
 to clean up the driver core code to be more obvious about object rules.
 
 All of this has been bike-shedded in quite a lot of detail on lkml with
 different names and implementations resulting in the tiny version we
 have in here, much better than my original proposal.  Lots of subsystem
 maintainers have acked the changes as well.
 
 Other than this change, included in here are smaller stuff like:
   - kernfs fixes and updates to handle lock contention better
   - vmlinux.lds.h fixes and updates
   - sysfs and debugfs documentation updates
   - device property updates
 
 All of these have been in the linux-next tree for quite a while with no
 problems, OTHER than some merge issues with other trees that should be
 obvious when you hit them (block tree deletes a driver that this tree
 modifies, iommufd tree modifies code that this tree also touches).  If
 there are merge problems with these trees, please let me know.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of driver core and kernfs changes for 6.2-rc1.

  The "big" change in here is the addition of a new macro,
  container_of_const() that will preserve the "const-ness" of a pointer
  passed into it.

  The "problem" of the current container_of() macro is that if you pass
  in a "const *", out of it can comes a non-const pointer unless you
  specifically ask for it. For many usages, we want to preserve the
  "const" attribute by using the same call. For a specific example, this
  series changes the kobj_to_dev() macro to use it, allowing it to be
  used no matter what the const value is. This prevents every subsystem
  from having to declare 2 different individual macros (i.e.
  kobj_const_to_dev() and kobj_to_dev()) and having the compiler enforce
  the const value at build time, which having 2 macros would not do
  either.

  The driver for all of this have been discussions with the Rust kernel
  developers as to how to properly mark driver core, and kobject,
  objects as being "non-mutable". The changes to the kobject and driver
  core in this pull request are the result of that, as there are lots of
  paths where kobjects and device pointers are not modified at all, so
  marking them as "const" allows the compiler to enforce this.

  So, a nice side affect of the Rust development effort has been already
  to clean up the driver core code to be more obvious about object
  rules.

  All of this has been bike-shedded in quite a lot of detail on lkml
  with different names and implementations resulting in the tiny version
  we have in here, much better than my original proposal. Lots of
  subsystem maintainers have acked the changes as well.

  Other than this change, included in here are smaller stuff like:

   - kernfs fixes and updates to handle lock contention better

   - vmlinux.lds.h fixes and updates

   - sysfs and debugfs documentation updates

   - device property updates

  All of these have been in the linux-next tree for quite a while with
  no problems"

* tag 'driver-core-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (58 commits)
  device property: Fix documentation for fwnode_get_next_parent()
  firmware_loader: fix up to_fw_sysfs() to preserve const
  usb.h: take advantage of container_of_const()
  device.h: move kobj_to_dev() to use container_of_const()
  container_of: add container_of_const() that preserves const-ness of the pointer
  driver core: fix up missed drivers/s390/char/hmcdrv_dev.c class.devnode() conversion.
  driver core: fix up missed scsi/cxlflash class.devnode() conversion.
  driver core: fix up some missing class.devnode() conversions.
  driver core: make struct class.devnode() take a const *
  driver core: make struct class.dev_uevent() take a const *
  cacheinfo: Remove of_node_put() for fw_token
  device property: Add a blank line in Kconfig of tests
  device property: Rename goto label to be more precise
  device property: Move PROPERTY_ENTRY_BOOL() a bit down
  device property: Get rid of __PROPERTY_ENTRY_ARRAY_EL*SIZE*()
  kernfs: fix all kernel-doc warnings and multiple typos
  driver core: pass a const * into of_device_uevent()
  kobject: kset_uevent_ops: make name() callback take a const *
  kobject: kset_uevent_ops: make filter() callback take a const *
  kobject: make kobject_namespace take a const *
  ...
2022-12-16 03:54:54 -08:00
John Stultz 76d62f24db pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion
Wei Wang reported seeing priority inversion caused latencies
caused by contention on pmsg_lock, and suggested it be switched
to a rt_mutex.

I was initially hesitant this would help, as the tasks in that
trace all seemed to be SCHED_NORMAL, so the benefit would be
limited to only nice boosting.

However, another similar issue was raised where the priority
inversion was seen did involve a blocked RT task so it is clear
this would be helpful in that case.

Cc: Wei Wang <wvw@google.com>
Cc: Midas Chien<midaschieh@google.com>
Cc: Connor O'Brien <connoro@google.com>
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: kernel-team@android.com
Fixes: 9d5438f462 ("pstore: Add pmsg - user-space accessible pstore object")
Reported-by: Wei Wang <wvw@google.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221214231834.3711880-1-jstultz@google.com
2022-12-14 19:37:42 -08:00
Stephen Boyd e6b842741b pstore: Avoid kcore oops by vmap()ing with VM_IOREMAP
An oops can be induced by running 'cat /proc/kcore > /dev/null' on
devices using pstore with the ram backend because kmap_atomic() assumes
lowmem pages are accessible with __va().

 Unable to handle kernel paging request at virtual address ffffff807ff2b000
 Mem abort info:
 ESR = 0x96000006
 EC = 0x25: DABT (current EL), IL = 32 bits
 SET = 0, FnV = 0
 EA = 0, S1PTW = 0
 FSC = 0x06: level 2 translation fault
 Data abort info:
 ISV = 0, ISS = 0x00000006
 CM = 0, WnR = 0
 swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000081d87000
 [ffffff807ff2b000] pgd=180000017fe18003, p4d=180000017fe18003, pud=180000017fe18003, pmd=0000000000000000
 Internal error: Oops: 96000006 [#1] PREEMPT SMP
 Modules linked in: dm_integrity
 CPU: 7 PID: 21179 Comm: perf Not tainted 5.15.67-10882-ge4eb2eb988cd #1 baa443fb8e8477896a370b31a821eb2009f9bfba
 Hardware name: Google Lazor (rev3 - 8) (DT)
 pstate: a0400009 (NzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : __memcpy+0x110/0x260
 lr : vread+0x194/0x294
 sp : ffffffc013ee39d0
 x29: ffffffc013ee39f0 x28: 0000000000001000 x27: ffffff807ff2b000
 x26: 0000000000001000 x25: ffffffc0085a2000 x24: ffffff802d4b3000
 x23: ffffff80f8a60000 x22: ffffff802d4b3000 x21: ffffffc0085a2000
 x20: ffffff8080b7bc68 x19: 0000000000001000 x18: 0000000000000000
 x17: 0000000000000000 x16: 0000000000000000 x15: ffffffd3073f2e60
 x14: ffffffffad588000 x13: 0000000000000000 x12: 0000000000000001
 x11: 00000000000001a2 x10: 00680000fff2bf0b x9 : 03fffffff807ff2b
 x8 : 0000000000000001 x7 : 0000000000000000 x6 : 0000000000000000
 x5 : ffffff802d4b4000 x4 : ffffff807ff2c000 x3 : ffffffc013ee3a78
 x2 : 0000000000001000 x1 : ffffff807ff2b000 x0 : ffffff802d4b3000
 Call trace:
 __memcpy+0x110/0x260
 read_kcore+0x584/0x778
 proc_reg_read+0xb4/0xe4

During early boot, memblock reserves the pages for the ramoops reserved
memory node in DT that would otherwise be part of the direct lowmem
mapping. Pstore's ram backend reuses those reserved pages to change the
memory type (writeback or non-cached) by passing the pages to vmap()
(see pfn_to_page() usage in persistent_ram_vmap() for more details) with
specific flags. When read_kcore() starts iterating over the vmalloc
region, it runs over the virtual address that vmap() returned for
ramoops. In aligned_vread() the virtual address is passed to
vmalloc_to_page() which returns the page struct for the reserved lowmem
area. That lowmem page is passed to kmap_atomic(), which effectively
calls page_to_virt() that assumes a lowmem page struct must be directly
accessible with __va() and friends. These pages are mapped via vmap()
though, and the lowmem mapping was never made, so accessing them via the
lowmem virtual address oopses like above.

Let's side-step this problem by passing VM_IOREMAP to vmap(). This will
tell vread() to not include the ramoops region in the kcore. Instead the
area will look like a bunch of zeros. The alternative is to teach kmap()
about vmalloc areas that intersect with lowmem. Presumably such a change
isn't a one-liner, and there isn't much interest in inspecting the
ramoops region in kcore files anyway, so the most expedient route is
taken for now.

Cc: Brian Geffon <bgeffon@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 404a604338 ("staging: android: persistent_ram: handle reserving and mapping memory")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221205233136.3420802-1-swboyd@chromium.org
2022-12-05 16:15:09 -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
Greg Kroah-Hartman ff62b8e658 driver core: make struct class.devnode() take a const *
The devnode() in struct class should not be modifying the device that is
passed into it, so mark it as a const * and propagate the function
signature changes out into all relevant subsystems that use this
callback.

Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Justin Sanders <justin@coraid.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: John Stultz <jstultz@google.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Sean Young <sean@mess.org>
Cc: Frank Haverkamp <haver@linux.ibm.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
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: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Xie Yongji <xieyongji@bytedance.com>
Cc: Gautam Dawar <gautam.dawar@xilinx.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Eli Cohen <elic@nvidia.com>
Cc: Parav Pandit <parav@nvidia.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: alsa-devel@alsa-project.org
Cc: dri-devel@lists.freedesktop.org
Cc: kvm@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: linux-block@vger.kernel.org
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20221123122523.1332370-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-24 17:12:27 +01:00
Guilherme G. Piccoli 38b91847c3 pstore: Alert on backend write error
The pstore dump function doesn't alert at all on errors - despite
pstore is usually a last resource and if it fails users won't be
able to read the kernel log, this is not the case for server users
with serial access, for example.

So, let's at least attempt to inform such advanced users on the first
backend writing error detected during the kmsg dump - this is also
very useful for pstore debugging purposes.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221013210648.137452-2-gpiccoli@igalia.com
2022-10-19 09:25:39 -07:00
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
Guilherme G. Piccoli 6a14f1982e pstore: Inform unregistered backend names as well
Currently we only show the registered ones in the kernel
log; users that change backend for some reason require
first to unregister the current one, so let's confirm this
operation with a message in the log.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221006224212.569555-4-gpiccoli@igalia.com
2022-10-17 13:14:10 -07:00
Guilherme G. Piccoli 8f5de3fd38 pstore: Expose kmsg_bytes as a module parameter
Currently this tuning is only exposed as a filesystem option,
but most Linux distros automatically mount pstore, hence changing
this setting requires remounting it. Also, if that mount option
wasn't explicitly set it doesn't show up in mount information,
so users cannot check what is the current value of kmsg_bytes.

Let's then expose it as a module parameter, allowing both user
visibility at all times (even if not manually set) and also the
possibility of setting that as a boot/module parameter.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221006224212.569555-3-gpiccoli@igalia.com
2022-10-17 13:14:10 -07:00
Guilherme G. Piccoli d85644dc5c pstore: Improve error reporting in case of backend overlap
The pstore infrastructure supports one single backend at a time;
trying to load a another backend causes an error and displays a
message, introduced on commit 0d7cd09a3d ("pstore: Improve
register_pstore() error reporting").

Happens that this message is not really clear about the situation,
also the current error returned (-EPERM) isn't accurate, whereas
-EBUSY makes more sense. We have another place in the code that
relies in the -EBUSY return for a similar check.

So, make it consistent here by returning -EBUSY and using a
similar message in both scenarios.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221006224212.569555-2-gpiccoli@igalia.com
2022-10-17 13:14:10 -07:00
Qiujun Huang 99b3b83785 pstore/zone: Use GFP_ATOMIC to allocate zone buffer
There is a case found when triggering a panic_on_oom, pstore fails to dump
kmsg. Because psz_kmsg_write_record can't get the new buffer.

Handle this by using GFP_ATOMIC to allocate a buffer at lower watermark.

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Fixes: 335426c6dc ("pstore/zone: Provide way to skip "broken" zone for MTD devices")
Cc: WeiXiong Liao <gmpy.liaowx@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/CAJRQjofRCF7wjrYmw3D7zd5QZnwHQq+F8U-mJDJ6NZ4bddYdLA@mail.gmail.com
2022-10-17 13:14:10 -07:00
Guilherme G. Piccoli 40158dbf7e Revert "pstore: migrate to crypto acomp interface"
This reverts commit e4f0a7ec58.

When using this new interface, both efi_pstore and ramoops
backends are unable to properly decompress dmesg if using
zstd, lz4 and lzo algorithms (and maybe more). It does succeed
with deflate though.

The message observed in the kernel log is:

[2.328828] pstore: crypto_acomp_decompress failed, ret = -22!

The pstore infrastructure is able to collect the dmesg with
both backends tested, but since decompression fails it's
unreadable. With this revert everything is back to normal.

Fixes: e4f0a7ec58 ("pstore: migrate to crypto acomp interface")
Cc: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220929215515.276486-1-gpiccoli@igalia.com
2022-09-30 08:16:06 -07:00
Linus Torvalds 97a77ab14f EFI updates for v5.20
- Enable mirrored memory for arm64
 - Fix up several abuses of the efivar API
 - Refactor the efivar API in preparation for moving the 'business logic'
   part of it into efivarfs
 - Enable ACPI PRM on arm64
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Merge tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:

 - Enable mirrored memory for arm64

 - Fix up several abuses of the efivar API

 - Refactor the efivar API in preparation for moving the 'business
   logic' part of it into efivarfs

 - Enable ACPI PRM on arm64

* tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits)
  ACPI: Move PRM config option under the main ACPI config
  ACPI: Enable Platform Runtime Mechanism(PRM) support on ARM64
  ACPI: PRM: Change handler_addr type to void pointer
  efi: Simplify arch_efi_call_virt() macro
  drivers: fix typo in firmware/efi/memmap.c
  efi: vars: Drop __efivar_entry_iter() helper which is no longer used
  efi: vars: Use locking version to iterate over efivars linked lists
  efi: pstore: Omit efivars caching EFI varstore access layer
  efi: vars: Add thin wrapper around EFI get/set variable interface
  efi: vars: Don't drop lock in the middle of efivar_init()
  pstore: Add priv field to pstore_record for backend specific use
  Input: applespi - avoid efivars API and invoke EFI services directly
  selftests/kexec: remove broken EFI_VARS secure boot fallback check
  brcmfmac: Switch to appropriate helper to load EFI variable contents
  iwlwifi: Switch to proper EFI variable store interface
  media: atomisp_gmin_platform: stop abusing efivar API
  efi: efibc: avoid efivar API for setting variables
  efi: avoid efivars layer when loading SSDTs from variables
  efi: Correct comment on efi_memmap_alloc
  memblock: Disable mirror feature if kernelcore is not specified
  ...
2022-08-03 14:38:02 -07:00
Ard Biesheuvel 8ca869b245 pstore: Add priv field to pstore_record for backend specific use
The EFI pstore backend will need to store per-record variable name data
when we switch away from the efivars layer. Add a priv field to struct
pstore_record, and document it as holding a backend specific pointer
that is assumed to be a kmalloc()d buffer, and will be kfree()d when the
entire record is freed.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24 20:40:04 +02:00
Dan Carpenter 2c09d1443b pstore/zone: cleanup "rcnt" type
The info->read() function returns ssize_t.  That means that info->read()
either returns either negative error codes or a positive number
representing the bytes read.

The "rcnt" variable should be declared as ssize_t as well.  Most places
do this correctly but psz_kmsg_recover_meta() needed to be fixed.

This code casts the "rcnt" to int.  That is unnecessary when "rcnt"
is already signed.  It's also slightly wrong because if info->read()
returned a very high (more than INT_MAX) number of bytes then this might
treat that as an error.  This bug cannot happen in real life, so it
doesn't affect run time, but static checkers correctly complain that it
is wrong.

fs/pstore/zone.c:366 psz_kmsg_recover_data() warn: casting 'rcnt' truncates high bits

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/YrRtPSFHDVJzV6d+@kili
2022-06-23 08:27:52 -07:00
Ard Biesheuvel e4f0a7ec58 pstore: migrate to crypto acomp interface
The crypto 'compress' interface is deprecated, so before adding new
features, migrate to the acomp interface. Note that we are only using
synchronous implementations of acomp, so we don't have to deal with
asynchronous completion.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-12 09:31:00 -07:00
Jann Horn 8126b1c731 pstore: Don't use semaphores in always-atomic-context code
pstore_dump() is *always* invoked in atomic context (nowadays in an RCU
read-side critical section, before that under a spinlock).
It doesn't make sense to try to use semaphores here.

This is mostly a revert of commit ea84b580b9 ("pstore: Convert buf_lock
to semaphore"), except that two parts aren't restored back exactly as they
were:

 - keep the lock initialization in pstore_register
 - in efi_pstore_write(), always set the "block" flag to false
 - omit "is_locked", that was unnecessary since
   commit 959217c84c ("pstore: Actually give up during locking failure")
 - fix the bailout message

The actual problem that the buggy commit was trying to address may have
been that the use of preemptible() in efi_pstore_write() was wrong - it
only looks at preempt_count() and the state of IRQs, but __rcu_read_lock()
doesn't touch either of those under CONFIG_PREEMPT_RCU.
(Sidenote: CONFIG_PREEMPT_RCU means that the scheduler can preempt tasks in
RCU read-side critical sections, but you're not allowed to actively
block/reschedule.)

Lockdep probably never caught the problem because it's very rare that you
actually hit the contended case, so lockdep always just sees the
down_trylock(), not the down_interruptible(), and so it can't tell that
there's a problem.

Fixes: ea84b580b9 ("pstore: Convert buf_lock to semaphore")
Cc: stable@vger.kernel.org
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220314185953.2068993-1-jannh@google.com
2022-03-15 11:08:23 -07:00
Vincent Whitchurch 023bbde3db pstore: Add prefix to ECC messages
The "No errors detected" message from the ECC code is shown at the end
of the pstore log and can be confusing or misleading, especially since
it usually appears just after a kernel crash log which normally means
quite the opposite of "no errors".  Prefix the message to clarify that
this message is only about ECC-detected errors.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220301144932.89549-1-vincent.whitchurch@axis.com
2022-03-01 10:36:59 -08:00
Linus Torvalds 404dbad382 pstore update for v5.17-rc1
- Add boot param for early ftrace recording in pstore (Uwe Kleine-König)
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Merge tag 'pstore-v5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore update from Kees Cook:

 - Add boot param for early ftrace recording in pstore (Uwe
   Kleine-König)

* tag 'pstore-v5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ftrace: Allow immediate recording
2022-01-10 11:48:37 -08:00
Geert Uytterhoeven 61eb495c83 pstore/blk: Use "%lu" to format unsigned long
On 32-bit:

    fs/pstore/blk.c: In function ‘__best_effort_init’:
    include/linux/kern_levels.h:5:18: warning: format ‘%zu’ expects argument of type ‘size_t’, but argument 3 has type ‘long unsigned int’ [-Wformat=]
	5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
	  |                  ^~~~~~
    include/linux/kern_levels.h:14:19: note: in expansion of macro ‘KERN_SOH’
       14 | #define KERN_INFO KERN_SOH "6" /* informational */
	  |                   ^~~~~~~~
    include/linux/printk.h:373:9: note: in expansion of macro ‘KERN_INFO’
      373 |  printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
	  |         ^~~~~~~~~
    fs/pstore/blk.c:314:3: note: in expansion of macro ‘pr_info’
      314 |   pr_info("attached %s (%zu) (no dedicated panic_write!)\n",
	  |   ^~~~~~~

Cc: stable@vger.kernel.org
Fixes: 7bb9557b48 ("pstore/blk: Use the normal block device I/O path")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210629103700.1935012-1-geert@linux-m68k.org
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-21 09:44:19 -08:00
Uwe Kleine-König a5d05b0796 pstore/ftrace: Allow immediate recording
Without a module param knob there was no way to enable pstore ftrace
recording early enough to debug hangs happening during the boot process
before userspace is up enough to enable it via the regular debugfs
knobs.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210610082134.20636-1-u.kleine-koenig@pengutronix.de
2021-11-18 10:29:52 -08:00
Kees Cook d1faacbf67 Revert "mark pstore-blk as broken"
This reverts commit d07f3b081e.

pstore-blk was fixed to avoid the unwanted APIs in commit 7bb9557b48
("pstore/blk: Use the normal block device I/O path"), which landed in
the same release as the commit adding BROKEN.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211116181559.3975566-1-keescook@chromium.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-16 17:23:42 -07:00
Nick Terrell cf30f6a5f0 lib: zstd: Add kernel-specific API
This patch:
- Moves `include/linux/zstd.h` -> `include/linux/zstd_lib.h`
- Updates modified zstd headers to yearless copyright
- Adds a new API in `include/linux/zstd.h` that is functionally
  equivalent to the in-use subset of the current API. Functions are
  renamed to avoid symbol collisions with zstd, to make it clear it is
  not the upstream zstd API, and to follow the kernel style guide.
- Updates all callers to use the new API.

There are no functional changes in this patch. Since there are no
functional change, I felt it was okay to update all the callers in a
single patch. Once the API is approved, the callers are mechanically
changed.

This patch is preparing for the 3rd patch in this series, which updates
zstd to version 1.4.10. Since the upstream zstd API is no longer exposed
to callers, the update can happen transparently.

Signed-off-by: Nick Terrell <terrelln@fb.com>
Tested By: Paul Jones <paul@pauljones.id.au>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 on x86-64
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
2021-11-08 16:55:21 -08:00
Christoph Hellwig 4646198519 pstore/blk: use bdev_nr_bytes instead of open coding it
Use the proper helper to read the block device size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211018101130.1838532-22-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 14:43:23 -06:00
Linus Torvalds 440462198d for-5.14/drivers-2021-06-29
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Merge tag 'for-5.14/drivers-2021-06-29' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "Pretty calm round, mostly just NVMe and a bit of MD:

   - NVMe updates (via Christoph)
        - improve the APST configuration algorithm (Alexey Bogoslavsky)
        - look for StorageD3Enable on companion ACPI device
          (Mario Limonciello)
        - allow selecting the network interface for TCP connections
          (Martin Belanger)
        - misc cleanups (Amit Engel, Chaitanya Kulkarni, Colin Ian King,
          Christoph)
        - move the ACPI StorageD3 code to drivers/acpi/ and add quirks
          for certain AMD CPUs (Mario Limonciello)
        - zoned device support for nvmet (Chaitanya Kulkarni)
        - fix the rules for changing the serial number in nvmet
          (Noam Gottlieb)
        - various small fixes and cleanups (Dan Carpenter, JK Kim,
          Chaitanya Kulkarni, Hannes Reinecke, Wesley Sheng, Geert
          Uytterhoeven, Daniel Wagner)

   - MD updates (Via Song)
        - iostats rewrite (Guoqing Jiang)
        - raid5 lock contention optimization (Gal Ofri)

   - Fall through warning fix (Gustavo)

   - Misc fixes (Gustavo, Jiapeng)"

* tag 'for-5.14/drivers-2021-06-29' of git://git.kernel.dk/linux-block: (78 commits)
  nvmet: use NVMET_MAX_NAMESPACES to set nn value
  loop: Fix missing discard support when using LOOP_CONFIGURE
  nvme.h: add missing nvme_lba_range_type endianness annotations
  nvme: remove zeroout memset call for struct
  nvme-pci: remove zeroout memset call for struct
  nvmet: remove zeroout memset call for struct
  nvmet: add ZBD over ZNS backend support
  nvmet: add Command Set Identifier support
  nvmet: add nvmet_req_bio put helper for backends
  nvmet: add req cns error complete helper
  block: export blk_next_bio()
  nvmet: remove local variable
  nvmet: use nvme status value directly
  nvmet: use u32 type for the local variable nsid
  nvmet: use u32 for nvmet_subsys max_nsid
  nvmet: use req->cmd directly in file-ns fast path
  nvmet: use req->cmd directly in bdev-ns fast path
  nvmet: make ver stable once connection established
  nvmet: allow mn change if subsys not discovered
  nvmet: make sn stable once connection was established
  ...
2021-06-30 12:21:16 -07:00
Kees Cook 1d1f6cc581 pstore/blk: Include zone in pstore_device_info
Information was redundant between struct pstore_zone_info and struct
pstore_device_info. Use struct pstore_zone_info, with member name "zone".

Additionally untangle the logic for the "best effort" block device
instance.

Signed-off-by: Kees Cook <keescook@chromium.org>
Fixed-by: Pu Lehui <pulehui@huawei.com>
Link: https://lore.kernel.org/lkml/20210617005424.182305-1-pulehui@huawei.com
2021-06-16 21:09:31 -07:00
Kees Cook c811659bb9 pstore/blk: Fix kerndoc and redundancy on blkdev param
Remove redundant details of blkdev and fix up resulting kerndoc.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
2021-06-16 09:27:32 -07:00
Kees Cook 7bb9557b48 pstore/blk: Use the normal block device I/O path
Stop poking into block layer internals and just open the block device
file an use kernel_read and kernel_write on it. Note that this means
the transformation from name_to_dev_t can't be used anymore when
pstore_blk is loaded as a module: a full filesystem device path name
must be used instead. Additionally removes ":internal:" kerndoc link,
since no such documentation remains.

Co-developed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
2021-06-16 09:26:56 -07:00
Kees Cook 2a03ddbde1 pstore/blk: Move verify_size() macro out of function
There's no good reason for the verify_size macro to live inside the
function. Move it up with the check_size() macro and fix indenting.

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>
2021-06-16 08:19:40 -07:00
Kees Cook 6eed261f48 pstore/blk: Improve failure reporting
There was no feedback on bad registration attempts. Add details on the
failure cause.

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>
2021-06-16 08:19:37 -07:00
Christoph Hellwig d07f3b081e mark pstore-blk as broken
pstore-blk just pokes directly into the pagecache for the block
device without going through the file operations for that by faking
up it's own file operations that do not match the block device ones.

As this breaks the control of the block layer of it's page cache,
and even now just works by accident only the best thing is to just
disable this driver.

Fixes: 17639f67c1 ("pstore/blk: Introduce backend for block devices")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210608161327.1537919-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-14 08:26:03 -06:00
Linus Torvalds 7f3d08b255 printk changes for 5.13
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Merge tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Stop synchronizing kernel log buffer readers by logbuf_lock. As a
   result, the access to the buffer is fully lockless now.

   Note that printk() itself still uses locks because it tries to flush
   the messages to the console immediately. Also the per-CPU temporary
   buffers are still there because they prevent infinite recursion and
   serialize backtraces from NMI. All this is going to change in the
   future.

 - kmsg_dump API rework and cleanup as a side effect of the logbuf_lock
   removal.

 - Make bstr_printf() aware that %pf and %pF formats could deference the
   given pointer.

 - Show also page flags by %pGp format.

 - Clarify the documentation for plain pointer printing.

 - Do not show no_hash_pointers warning multiple times.

 - Update Senozhatsky email address.

 - Some clean up.

* tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits)
  lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf()
  printk: clarify the documentation for plain pointer printing
  kernel/printk.c: Fixed mundane typos
  printk: rename vprintk_func to vprintk
  vsprintf: dump full information of page flags in pGp
  mm, slub: don't combine pr_err with INFO
  mm, slub: use pGp to print page flags
  MAINTAINERS: update Senozhatsky email address
  lib/vsprintf: do not show no_hash_pointers message multiple times
  printk: console: remove unnecessary safe buffer usage
  printk: kmsg_dump: remove _nolock() variants
  printk: remove logbuf_lock
  printk: introduce a kmsg_dump iterator
  printk: kmsg_dumper: remove @active field
  printk: add syslog_lock
  printk: use atomic64_t for devkmsg_user.seq
  printk: use seqcount_latch for clear_seq
  printk: introduce CONSOLE_LOG_MAX
  printk: consolidate kmsg_dump_get_buffer/syslog_print_all code
  printk: refactor kmsg_dump_get_buffer()
  ...
2021-04-27 18:09:44 -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
John Ogness f9f3f02db9 printk: introduce a kmsg_dump iterator
Rather than storing the iterator information in the registered
kmsg_dumper structure, create a separate iterator structure. The
kmsg_dump_iter structure can reside on the stack of the caller, thus
allowing lockless use of the kmsg_dump functions.

Update code that accesses the kernel logs using the kmsg_dumper
structure to use the new kmsg_dump_iter structure. For kmsg_dumpers,
this also means adding a call to kmsg_dump_rewind() to initialize
the iterator.

All this is in preparation for removal of @logbuf_lock.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org> # pstore
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
2021-03-08 11:43:27 +01:00
Linus Torvalds 8b24ef4478 pstore fixes for v5.12-rc2
- Rate-limit ECC warnings (Dmitry Osipenko)
 
 - Fix error path check for NULL (Tetsuo Handa)
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Merge tag 'pstore-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore fixes from Kees Cook:

 - Rate-limit ECC warnings (Dmitry Osipenko)

 - Fix error path check for NULL (Tetsuo Handa)

* tag 'pstore-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ram: Rate-limit "uncorrectable error in header" message
  pstore: Fix warning in pstore_kill_sb()
2021-03-05 17:21:25 -08:00
Dmitry Osipenko 7db688e99c pstore/ram: Rate-limit "uncorrectable error in header" message
There is a quite huge "uncorrectable error in header" flood in KMSG
on a clean system boot since there is no pstore buffer saved in RAM.
Let's silence the redundant noisy messages by rate-limiting the printk
message. Now there are maximum 10 messages printed repeatedly instead
of 35+.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210302095850.30894-1-digetx@gmail.com
2021-03-02 11:52:31 -08:00
Tetsuo Handa 9c7d83ae6b pstore: Fix warning in pstore_kill_sb()
syzbot is hitting WARN_ON(pstore_sb != sb) at pstore_kill_sb() [1], for the
assumption that pstore_sb != NULL is wrong because pstore_fill_super() will
not assign pstore_sb = sb when new_inode() for d_make_root() returned NULL
(due to memory allocation fault injection).

Since mount_single() calls pstore_kill_sb() when pstore_fill_super()
failed, pstore_kill_sb() needs to be aware of such failure path.

[1] https://syzkaller.appspot.com/bug?id=6abacb8da5137cb47a416f2bef95719ed60508a0

Reported-by: syzbot <syzbot+d0cf0ad6513e9a1da5df@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210214031307.57903-1-penguin-kernel@I-love.SAKURA.ne.jp
2021-02-23 09:27:20 -08:00
Linus Torvalds 0e63a5c6ba It has been a relatively quiet cycle in docsland.
- As promised, the minimum Sphinx version to build the docs is now 1.7,
    and we have dropped support for Python 2 entirely.  That allowed the
    removal of a bunch of compatibility code.
 
  - A set of treewide warning fixups from Mauro that I applied after it
    became clear nobody else was going to deal with them.
 
  - The automarkup mechanism can now create cross-references from relative
    paths to RST files.
 
  - More translations, typo fixes, and warning fixes.
 
 No conflicts with any other tree as far as I know.
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Merge tag 'docs-5.12' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "It has been a relatively quiet cycle in docsland.

   - As promised, the minimum Sphinx version to build the docs is now
     1.7, and we have dropped support for Python 2 entirely. That
     allowed the removal of a bunch of compatibility code.

   - A set of treewide warning fixups from Mauro that I applied after it
     became clear nobody else was going to deal with them.

   - The automarkup mechanism can now create cross-references from
     relative paths to RST files.

   - More translations, typo fixes, and warning fixes"

* tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits)
  docs: kernel-hacking: be more civil
  docs: Remove the Microsoft rhetoric
  Documentation/admin-guide: kernel-parameters: Update nohlt section
  doc/admin-guide: fix spelling mistake: "perfomance" -> "performance"
  docs: Document cross-referencing using relative path
  docs: Enable usage of relative paths to docs on automarkup
  docs: thermal: fix spelling mistakes
  Documentation: admin-guide: Update kvm/xen config option
  docs: Make syscalls' helpers naming consistent
  coding-style.rst: Avoid comma statements
  Documentation: /proc/loadavg: add 3 more field descriptions
  Documentation/submitting-patches: Add blurb about backtraces in commit messages
  Docs: drop Python 2 support
  Move our minimum Sphinx version to 1.7
  Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams
  scripts/kernel-doc: add internal hyperlink to DOC: sections
  Update Documentation/admin-guide/sysctl/fs.rst
  docs: Update DTB format references
  docs: zh_CN: add iio index.rst translation
  docs/zh_CN: add iio ep93xx_adc.rst translation
  ...
2021-02-22 10:57:46 -08:00
Jiri Bohac 19d8e9149c pstore: Fix typo in compression option name
Both pstore_compress() and decompress_record() use a mistyped config
option name ("PSTORE_COMPRESSION" instead of "PSTORE_COMPRESS"). As
a result compression and decompression of pstore records was always
disabled.

Use the correct config option name.

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Fixes: fd49e03280 ("pstore: Fix linking when crypto API disabled")
Acked-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210218111547.johvp5klpv3xrpnn@dwarf.suse.cz
2021-02-18 12:27:49 -08:00
Mauro Carvalho Chehab 4fd15eaf42 pstore/zone: fix a kernel-doc markup
The documented struct is psz_head and not psz_buffer.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a67ca4d12c3ef277dadb9e0d0df8450158e637cc.1610610937.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-01-21 14:06:00 -07:00
Linus Torvalds 09c0796adf Tracing updates for 5.11
The major update to this release is that there's a new arch config option called:
 CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. Currently, only x86_64 enables it.
 All the ftrace callbacks now take a struct ftrace_regs instead of a struct
 pt_regs. If the architecture has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then
 the ftrace_regs will have enough information to read the arguments of the
 function being traced, as well as access to the stack pointer. This way, if
 a user (like live kernel patching) only cares about the arguments, then it
 can avoid using the heavier weight "regs" callback, that puts in enough
 information in the struct ftrace_regs to simulate a breakpoint exception
 (needed for kprobes).
 
 New config option that audits the timestamps of the ftrace ring buffer at
 most every event recorded.  The "check_buffer()" calls will conflict with
 mainline, because I purposely added the check without including the fix that
 it caught, which is in mainline. Running a kernel built from the commit of
 the added check will trigger it.
 
 Ftrace recursion protection has been cleaned up to move the protection to
 the callback itself (this saves on an extra function call for those
 callbacks).
 
 Perf now handles its own RCU protection and does not depend on ftrace to do
 it for it (saving on that extra function call).
 
 New debug option to add "recursed_functions" file to tracefs that lists all
 the places that triggered the recursion protection of the function tracer.
 This will show where things need to be fixed as recursion slows down the
 function tracer.
 
 The eval enum mapping updates done at boot up are now offloaded to a work
 queue, as it caused a noticeable pause on slow embedded boards.
 
 Various clean ups and last minute fixes.
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Merge tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The major update to this release is that there's a new arch config
  option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS.

  Currently, only x86_64 enables it. All the ftrace callbacks now take a
  struct ftrace_regs instead of a struct pt_regs. If the architecture
  has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will
  have enough information to read the arguments of the function being
  traced, as well as access to the stack pointer.

  This way, if a user (like live kernel patching) only cares about the
  arguments, then it can avoid using the heavier weight "regs" callback,
  that puts in enough information in the struct ftrace_regs to simulate
  a breakpoint exception (needed for kprobes).

  A new config option that audits the timestamps of the ftrace ring
  buffer at most every event recorded.

  Ftrace recursion protection has been cleaned up to move the protection
  to the callback itself (this saves on an extra function call for those
  callbacks).

  Perf now handles its own RCU protection and does not depend on ftrace
  to do it for it (saving on that extra function call).

  New debug option to add "recursed_functions" file to tracefs that
  lists all the places that triggered the recursion protection of the
  function tracer. This will show where things need to be fixed as
  recursion slows down the function tracer.

  The eval enum mapping updates done at boot up are now offloaded to a
  work queue, as it caused a noticeable pause on slow embedded boards.

  Various clean ups and last minute fixes"

* tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  tracing: Offload eval map updates to a work queue
  Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"
  ring-buffer: Add rb_check_bpage in __rb_allocate_pages
  ring-buffer: Fix two typos in comments
  tracing: Drop unneeded assignment in ring_buffer_resize()
  tracing: Disable ftrace selftests when any tracer is running
  seq_buf: Avoid type mismatch for seq_buf_init
  ring-buffer: Fix a typo in function description
  ring-buffer: Remove obsolete rb_event_is_commit()
  ring-buffer: Add test to validate the time stamp deltas
  ftrace/documentation: Fix RST C code blocks
  tracing: Clean up after filter logic rewriting
  tracing: Remove the useless value assignment in test_create_synth_event()
  livepatch: Use the default ftrace_ops instead of REGS when ARGS is available
  ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default
  ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs
  MAINTAINERS: assign ./fs/tracefs to TRACING
  tracing: Fix some typos in comments
  ftrace: Remove unused varible 'ret'
  ring-buffer: Add recording of ring buffer recursion into recursed_functions
  ...
2020-12-17 13:22:17 -08:00
Linus Torvalds ac7ac4618c for-5.11/block-2020-12-14
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Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Another series of killing more code than what is being added, again
  thanks to Christoph's relentless cleanups and tech debt tackling.

  This contains:

   - blk-iocost improvements (Baolin Wang)

   - part0 iostat fix (Jeffle Xu)

   - Disable iopoll for split bios (Jeffle Xu)

   - block tracepoint cleanups (Christoph Hellwig)

   - Merging of struct block_device and hd_struct (Christoph Hellwig)

   - Rework/cleanup of how block device sizes are updated (Christoph
     Hellwig)

   - Simplification of gendisk lookup and removal of block device
     aliasing (Christoph Hellwig)

   - Block device ioctl cleanups (Christoph Hellwig)

   - Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig)

   - Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig)

   - sbitmap improvements (Pavel Begunkov)

   - Hybrid polling fix (Pavel Begunkov)

   - bvec iteration improvements (Pavel Begunkov)

   - Zone revalidation fixes (Damien Le Moal)

   - blk-throttle limit fix (Yu Kuai)

   - Various little fixes"

* tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits)
  blk-mq: fix msec comment from micro to milli seconds
  blk-mq: update arg in comment of blk_mq_map_queue
  blk-mq: add helper allocating tagset->tags
  Revert "block: Fix a lockdep complaint triggered by request queue flushing"
  nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class
  blk-mq: add new API of blk_mq_hctx_set_fq_lock_class
  block: disable iopoll for split bio
  block: Improve blk_revalidate_disk_zones() checks
  sbitmap: simplify wrap check
  sbitmap: replace CAS with atomic and
  sbitmap: remove swap_lock
  sbitmap: optimise sbitmap_deferred_clear()
  blk-mq: skip hybrid polling if iopoll doesn't spin
  blk-iocost: Factor out the base vrate change into a separate function
  blk-iocost: Factor out the active iocgs' state check into a separate function
  blk-iocost: Move the usage ratio calculation to the correct place
  blk-iocost: Remove unnecessary advance declaration
  blk-iocost: Fix some typos in comments
  blktrace: fix up a kerneldoc comment
  block: remove the request_queue to argument request based tracepoints
  ...
2020-12-16 12:57:51 -08:00
Christoph Hellwig a782483cc1 block: remove the nr_sects field in struct hd_struct
Now that the hd_struct always has a block device attached to it, there is
no need for having two size field that just get out of sync.

Additionally the field in hd_struct did not use proper serialization,
possibly allowing for torn writes.  By only using the block_device field
this problem also gets fixed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Coly Li <colyli@suse.de>			[bcache]
Acked-by: Chao Yu <yuchao0@huawei.com>			[f2fs]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00