<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/pstore, branch v6.3</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'pstore-v6.2-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux</title>
<updated>2022-12-23T19:55:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-23T19:55:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=edb23125fd4a79003012bc619d2c604da922865e'/>
<id>edb23125fd4a79003012bc619d2c604da922865e</id>
<content type='text'>
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
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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
</pre>
</div>
</content>
</entry>
<entry>
<title>pstore: Properly assign mem_type property</title>
<updated>2022-12-23T18:34:25+00:00</updated>
<author>
<name>Luca Stefani</name>
<email>luca@osomprivacy.com</email>
</author>
<published>2022-12-22T13:10:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=beca3e311a49cd3c55a056096531737d7afa4361'/>
<id>beca3e311a49cd3c55a056096531737d7afa4361</id>
<content type='text'>
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: 9d843e8fafc7 ("pstore: Add mem_type property DT parsing support")
Cc: stable@vger.kernel.org
Signed-off-by: Luca Stefani &lt;luca@osomprivacy.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221222131049.286288-1-luca@osomprivacy.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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: 9d843e8fafc7 ("pstore: Add mem_type property DT parsing support")
Cc: stable@vger.kernel.org
Signed-off-by: Luca Stefani &lt;luca@osomprivacy.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221222131049.286288-1-luca@osomprivacy.com
</pre>
</div>
</content>
</entry>
<entry>
<title>pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXES</title>
<updated>2022-12-23T18:33:27+00:00</updated>
<author>
<name>John Stultz</name>
<email>jstultz@google.com</email>
</author>
<published>2022-12-21T05:18:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2f4fec5943407318b9523f01ce1f5d668c028332'/>
<id>2f4fec5943407318b9523f01ce1f5d668c028332</id>
<content type='text'>
In commit 76d62f24db07 ("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 &lt;wvw@google.com&gt;
Cc: Midas Chien&lt;midaschieh@google.com&gt;
Cc: Connor O'Brien &lt;connoro@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Anton Vorontsov &lt;anton@enomsg.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: kernel test robot &lt;lkp@intel.com&gt;
Cc: kernel-team@android.com
Fixes: 76d62f24db07 ("pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: John Stultz &lt;jstultz@google.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221221051855.15761-1-jstultz@google.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In commit 76d62f24db07 ("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 &lt;wvw@google.com&gt;
Cc: Midas Chien&lt;midaschieh@google.com&gt;
Cc: Connor O'Brien &lt;connoro@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Anton Vorontsov &lt;anton@enomsg.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: kernel test robot &lt;lkp@intel.com&gt;
Cc: kernel-team@android.com
Fixes: 76d62f24db07 ("pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: John Stultz &lt;jstultz@google.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221221051855.15761-1-jstultz@google.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'driver-core-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core</title>
<updated>2022-12-16T11:54:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-16T11:54:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=71a7507afbc3f27c346898f13ab9bfd918613c34'/>
<id>71a7507afbc3f27c346898f13ab9bfd918613c34</id>
<content type='text'>
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 *
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 *
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion</title>
<updated>2022-12-15T03:37:42+00:00</updated>
<author>
<name>John Stultz</name>
<email>jstultz@google.com</email>
</author>
<published>2022-12-14T23:18:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=76d62f24db07f22ccf9bc18ca793c27d4ebef721'/>
<id>76d62f24db07f22ccf9bc18ca793c27d4ebef721</id>
<content type='text'>
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 &lt;wvw@google.com&gt;
Cc: Midas Chien&lt;midaschieh@google.com&gt;
Cc: Connor O'Brien &lt;connoro@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Anton Vorontsov &lt;anton@enomsg.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: kernel-team@android.com
Fixes: 9d5438f462ab ("pstore: Add pmsg - user-space accessible pstore object")
Reported-by: Wei Wang &lt;wvw@google.com&gt;
Signed-off-by: John Stultz &lt;jstultz@google.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221214231834.3711880-1-jstultz@google.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;wvw@google.com&gt;
Cc: Midas Chien&lt;midaschieh@google.com&gt;
Cc: Connor O'Brien &lt;connoro@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Anton Vorontsov &lt;anton@enomsg.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: kernel-team@android.com
Fixes: 9d5438f462ab ("pstore: Add pmsg - user-space accessible pstore object")
Reported-by: Wei Wang &lt;wvw@google.com&gt;
Signed-off-by: John Stultz &lt;jstultz@google.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221214231834.3711880-1-jstultz@google.com
</pre>
</div>
</content>
</entry>
<entry>
<title>pstore: Avoid kcore oops by vmap()ing with VM_IOREMAP</title>
<updated>2022-12-06T00:15:09+00:00</updated>
<author>
<name>Stephen Boyd</name>
<email>swboyd@chromium.org</email>
</author>
<published>2022-12-05T23:31:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e6b842741b4f39007215fd7e545cb55aa3d358a2'/>
<id>e6b842741b4f39007215fd7e545cb55aa3d358a2</id>
<content type='text'>
An oops can be induced by running 'cat /proc/kcore &gt; /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 &lt;bgeffon@google.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Fixes: 404a6043385d ("staging: android: persistent_ram: handle reserving and mapping memory")
Signed-off-by: Stephen Boyd &lt;swboyd@chromium.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221205233136.3420802-1-swboyd@chromium.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
An oops can be induced by running 'cat /proc/kcore &gt; /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 &lt;bgeffon@google.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Fixes: 404a6043385d ("staging: android: persistent_ram: handle reserving and mapping memory")
Signed-off-by: Stephen Boyd &lt;swboyd@chromium.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221205233136.3420802-1-swboyd@chromium.org
</pre>
</div>
</content>
</entry>
<entry>
<title>pstore/ram: Fix error return code in ramoops_probe()</title>
<updated>2022-12-02T23:16:59+00:00</updated>
<author>
<name>Wang Yufen</name>
<email>wangyufen@huawei.com</email>
</author>
<published>2022-12-02T08:22:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e1fce564900f8734edf15b87f028c57e14f6e28d'/>
<id>e1fce564900f8734edf15b87f028c57e14f6e28d</id>
<content type='text'>
In the if (dev_of_node(dev) &amp;&amp; !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: 35da60941e44 ("pstore/ram: add Device Tree bindings")
Signed-off-by: Wang Yufen &lt;wangyufen@huawei.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/1669969374-46582-1-git-send-email-wangyufen@huawei.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the if (dev_of_node(dev) &amp;&amp; !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: 35da60941e44 ("pstore/ram: add Device Tree bindings")
Signed-off-by: Wang Yufen &lt;wangyufen@huawei.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/1669969374-46582-1-git-send-email-wangyufen@huawei.com
</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: make struct class.devnode() take a const *</title>
<updated>2022-11-24T16:12:27+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2022-11-23T12:25:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ff62b8e6588fb07bedda7423622c140c4edd66a7'/>
<id>ff62b8e6588fb07bedda7423622c140c4edd66a7</id>
<content type='text'>
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 &lt;fenghua.yu@intel.com&gt;
Cc: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: x86@kernel.org
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: FUJITA Tomonori &lt;fujita.tomonori@lab.ntt.co.jp&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Justin Sanders &lt;justin@coraid.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Sumit Semwal &lt;sumit.semwal@linaro.org&gt;
Cc: Benjamin Gaignard &lt;benjamin.gaignard@collabora.com&gt;
Cc: Liam Mark &lt;lmark@codeaurora.org&gt;
Cc: Laura Abbott &lt;labbott@redhat.com&gt;
Cc: Brian Starkey &lt;Brian.Starkey@arm.com&gt;
Cc: John Stultz &lt;jstultz@google.com&gt;
Cc: "Christian König" &lt;christian.koenig@amd.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Leon Romanovsky &lt;leon@kernel.org&gt;
Cc: Dennis Dalessandro &lt;dennis.dalessandro@cornelisnetworks.com&gt;
Cc: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Cc: Mauro Carvalho Chehab &lt;mchehab@kernel.org&gt;
Cc: Sean Young &lt;sean@mess.org&gt;
Cc: Frank Haverkamp &lt;haver@linux.ibm.com&gt;
Cc: Jiri Slaby &lt;jirislaby@kernel.org&gt;
Cc: "Michael S. Tsirkin" &lt;mst@redhat.com&gt;
Cc: Jason Wang &lt;jasowang@redhat.com&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Cc: Cornelia Huck &lt;cohuck@redhat.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Anton Vorontsov &lt;anton@enomsg.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Jaroslav Kysela &lt;perex@perex.cz&gt;
Cc: Takashi Iwai &lt;tiwai@suse.com&gt;
Cc: Hans Verkuil &lt;hverkuil-cisco@xs4all.nl&gt;
Cc: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Cc: Xie Yongji &lt;xieyongji@bytedance.com&gt;
Cc: Gautam Dawar &lt;gautam.dawar@xilinx.com&gt;
Cc: Dan Carpenter &lt;error27@gmail.com&gt;
Cc: Eli Cohen &lt;elic@nvidia.com&gt;
Cc: Parav Pandit &lt;parav@nvidia.com&gt;
Cc: Maxime Coquelin &lt;maxime.coquelin@redhat.com&gt;
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 &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;fenghua.yu@intel.com&gt;
Cc: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: x86@kernel.org
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: FUJITA Tomonori &lt;fujita.tomonori@lab.ntt.co.jp&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Justin Sanders &lt;justin@coraid.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Sumit Semwal &lt;sumit.semwal@linaro.org&gt;
Cc: Benjamin Gaignard &lt;benjamin.gaignard@collabora.com&gt;
Cc: Liam Mark &lt;lmark@codeaurora.org&gt;
Cc: Laura Abbott &lt;labbott@redhat.com&gt;
Cc: Brian Starkey &lt;Brian.Starkey@arm.com&gt;
Cc: John Stultz &lt;jstultz@google.com&gt;
Cc: "Christian König" &lt;christian.koenig@amd.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Leon Romanovsky &lt;leon@kernel.org&gt;
Cc: Dennis Dalessandro &lt;dennis.dalessandro@cornelisnetworks.com&gt;
Cc: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Cc: Mauro Carvalho Chehab &lt;mchehab@kernel.org&gt;
Cc: Sean Young &lt;sean@mess.org&gt;
Cc: Frank Haverkamp &lt;haver@linux.ibm.com&gt;
Cc: Jiri Slaby &lt;jirislaby@kernel.org&gt;
Cc: "Michael S. Tsirkin" &lt;mst@redhat.com&gt;
Cc: Jason Wang &lt;jasowang@redhat.com&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Cc: Cornelia Huck &lt;cohuck@redhat.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Anton Vorontsov &lt;anton@enomsg.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Jaroslav Kysela &lt;perex@perex.cz&gt;
Cc: Takashi Iwai &lt;tiwai@suse.com&gt;
Cc: Hans Verkuil &lt;hverkuil-cisco@xs4all.nl&gt;
Cc: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Cc: Xie Yongji &lt;xieyongji@bytedance.com&gt;
Cc: Gautam Dawar &lt;gautam.dawar@xilinx.com&gt;
Cc: Dan Carpenter &lt;error27@gmail.com&gt;
Cc: Eli Cohen &lt;elic@nvidia.com&gt;
Cc: Parav Pandit &lt;parav@nvidia.com&gt;
Cc: Maxime Coquelin &lt;maxime.coquelin@redhat.com&gt;
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 &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pstore: Alert on backend write error</title>
<updated>2022-10-19T16:25:39+00:00</updated>
<author>
<name>Guilherme G. Piccoli</name>
<email>gpiccoli@igalia.com</email>
</author>
<published>2022-10-13T21:06:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=38b91847c314f49c80e30062549d4709a3754ea6'/>
<id>38b91847c314f49c80e30062549d4709a3754ea6</id>
<content type='text'>
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 &lt;gpiccoli@igalia.com&gt;
Acked-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221013210648.137452-2-gpiccoli@igalia.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;gpiccoli@igalia.com&gt;
Acked-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20221013210648.137452-2-gpiccoli@igalia.com
</pre>
</div>
</content>
</entry>
<entry>
<title>pstore/ram: Set freed addresses to NULL</title>
<updated>2022-10-19T16:25:39+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2022-10-11T20:01:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=06b4e09aab6c1ae6b3991a729d2fcb31e358e7f3'/>
<id>06b4e09aab6c1ae6b3991a729d2fcb31e358e7f3</id>
<content type='text'>
For good measure, set all the freed addresses to NULL when managing
przs.

Cc: Anton Vorontsov &lt;anton@enomsg.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-and-tested-by: Guilherme G. Piccoli &lt;gpiccoli@igalia.com&gt;
Link: https://lore.kernel.org/r/20221011200112.731334-5-keescook@chromium.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For good measure, set all the freed addresses to NULL when managing
przs.

Cc: Anton Vorontsov &lt;anton@enomsg.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-and-tested-by: Guilherme G. Piccoli &lt;gpiccoli@igalia.com&gt;
Link: https://lore.kernel.org/r/20221011200112.731334-5-keescook@chromium.org
</pre>
</div>
</content>
</entry>
</feed>
