virtio-mem: support CONFIG_PROC_VMCORE_DEVICE_RAM

Let's implement the get_device_ram() vmcore callback, so
architectures that select NEED_PROC_VMCORE_NEED_DEVICE_RAM, like s390
soon, can include tha

virtio-mem: support CONFIG_PROC_VMCORE_DEVICE_RAM

Let's implement the get_device_ram() vmcore callback, so
architectures that select NEED_PROC_VMCORE_NEED_DEVICE_RAM, like s390
soon, can include that memory in a crash dump.

Merge ranges, and process ranges that might contain a mixture of plugged
and unplugged, to reduce the total number of ranges.

Signed-off-by: David Hildenbrand <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

show more ...

fs/proc/vmcore: introduce PROC_VMCORE_DEVICE_RAM to detect device RAM ranges in 2nd kernel

s390 allocates+prepares the elfcore hdr in the dump (2nd) kernel, not in
the crashed kernel.

RAM provided

fs/proc/vmcore: introduce PROC_VMCORE_DEVICE_RAM to detect device RAM ranges in 2nd kernel

s390 allocates+prepares the elfcore hdr in the dump (2nd) kernel, not in
the crashed kernel.

RAM provided by memory devices such as virtio-mem can only be detected
using the device driver; when vmcore_init() is called, these device
drivers are usually not loaded yet, or the devices did not get probed
yet. Consequently, on s390 these RAM ranges will not be included in
the crash dump, which makes the dump partially corrupt and is
unfortunate.

Instead of deferring the vmcore_init() call, to an (unclear?) later point,
let's reuse the vmcore_cb infrastructure to obtain device RAM ranges as
the device drivers probe the device and get access to this information.

Then, we'll add these ranges to the vmcore, adding more PT_LOAD
entries and updating the offsets+vmcore size.

Use a separate Kconfig option to be set by an architecture to include this
code only if the arch really needs it. Further, we'll make the config
depend on the relevant drivers (i.e., virtio_mem) once they implement
support (next). The alternative of having a PROVIDE_PROC_VMCORE_DEVICE_RAM
config option was dropped for now for simplicity.

The current target use case is s390, which only creates an elf64
elfcore, so focusing on elf64 is sufficient.

Signed-off-by: David Hildenbrand <[email protected]>
Message-Id: <[email protected]>
Acked-by: Andrew Morton <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

show more ...

crash: split vmcoreinfo exporting code out from crash_core.c

Now move the relevant codes into separate files:
kernel/crash_reserve.c, include/linux/crash_reserve.h.

And add config item CRASH_RESERV

crash: split vmcoreinfo exporting code out from crash_core.c

Now move the relevant codes into separate files:
kernel/crash_reserve.c, include/linux/crash_reserve.h.

And add config item CRASH_RESERVE to control its enabling.

And also update the old ifdeffery of CONFIG_CRASH_CORE, including of
<linux/crash_core.h> and config item dependency on CRASH_CORE
accordingly.

And also do renaming as follows:
- arch/xxx/kernel/{crash_core.c => vmcore_info.c}
because they are only related to vmcoreinfo exporting on x86, arm64,
riscv.

And also Remove config item CRASH_CORE, and rely on CONFIG_KEXEC_CORE to
decide if build in crash_core.c.

[[email protected]: remove duplicated include in vmcore_info.c]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Baoquan He <[email protected]>
Signed-off-by: Yang Li <[email protected]>
Acked-by: Hari Bathini <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Pingfan Liu <[email protected]>
Cc: Klara Modin <[email protected]>
Cc: Michael Kelley <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Yang Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

proc: make config PROC_CHILDREN depend on PROC_FS

Commit 2e13ba54a268 ("fs, proc: introduce CONFIG_PROC_CHILDREN")
introduces the config PROC_CHILDREN to configure kernels to provide the
/proc/<pid>

proc: make config PROC_CHILDREN depend on PROC_FS

Commit 2e13ba54a268 ("fs, proc: introduce CONFIG_PROC_CHILDREN")
introduces the config PROC_CHILDREN to configure kernels to provide the
/proc/<pid>/task/<tid>/children file.

When one deselects PROC_FS for kernel builds without /proc/, the config
PROC_CHILDREN has no effect anymore, but is still visible in menuconfig.

Add the dependency on PROC_FS to make the PROC_CHILDREN option disappear
for kernel builds without /proc/.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 2e13ba54a268 ("fs, proc: introduce CONFIG_PROC_CHILDREN")
Signed-off-by: Lukas Bulwahn <[email protected]>

Cc: Iago López Galeiras <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasi

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <[email protected]>

show more ...

docs: filesystems: fix renamed references

Some filesystem references got broken by a previous patch
series I submitted. Address those.

Signed-off-by: Mauro Carvalho Chehab <[email protected]

docs: filesystems: fix renamed references

Some filesystem references got broken by a previous patch
series I submitted. Address those.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Acked-by: David Sterba <[email protected]> # fs/affs/Kconfig
Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <[email protected]>

show more ...

x86/resctrl: Add task resctrl information display

Monitoring tools that want to find out which resctrl control and monitor
groups a task belongs to must currently read the "tasks" file in every
grou

x86/resctrl: Add task resctrl information display

Monitoring tools that want to find out which resctrl control and monitor
groups a task belongs to must currently read the "tasks" file in every
group until they locate the process ID.

Add an additional file /proc/{pid}/cpu_resctrl_groups to provide this
information:

1) res:
mon:

resctrl is not available.

2) res:/
mon:

Task is part of the root resctrl control group, and it is not associated
to any monitor group.

3) res:/
mon:mon0

Task is part of the root resctrl control group and monitor group mon0.

4) res:group0
mon:

Task is part of resctrl control group group0, and it is not associated
to any monitor group.

5) res:group0
mon:mon1

Task is part of resctrl control group group0 and monitor group mon1.

Signed-off-by: Chen Yu <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Tested-by: Jinshi Chen <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

show more ...

fs/proc/Kconfig: fix indentation

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ / /' -i */Kconfig

[[email protected]

fs/proc/Kconfig: fix indentation

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ / /' -i */Kconfig

[[email protected]: add two spaces where necessary]
Link: http://lkml.kernel.org/r/20191124133936.GA5655@avx2
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

vmcore: add a kernel parameter novmcoredd

Since commit 2724273e8fd0 ("vmcore: add API to collect hardware dump in
second kernel"), drivers are allowed to add device related dump data to
vmcore as th

vmcore: add a kernel parameter novmcoredd

Since commit 2724273e8fd0 ("vmcore: add API to collect hardware dump in
second kernel"), drivers are allowed to add device related dump data to
vmcore as they want by using the device dump API. This has a potential
issue, the data is stored in memory, drivers may append too much data
and use too much memory. The vmcore is typically used in a kdump kernel
which runs in a pre-reserved small chunk of memory. So as a result it
will make kdump unusable at all due to OOM issues.

So introduce new 'novmcoredd' command line option. User can disable
device dump to reduce memory usage. This is helpful if device dump is
using too much memory, disabling device dump could make sure a regular
vmcore without device dump data is still available.

[[email protected]: tweak documentation]
[[email protected]: vmcore.c needs moduleparam.h]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Kairui Song <[email protected]>
Acked-by: Dave Young <[email protected]>
Reviewed-by: Bhupesh Sharma <[email protected]>
Cc: Rahul Lakkireddy <[email protected]>
Cc: "David S . Miller" <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Baoquan He <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

docs: admin-guide: move sysctl directory to it

The stuff under sysctl describes /sys interface from userspace
point of view. So, add it to the admin-guide and remove the
:orphan: from its index file

docs: admin-guide: move sysctl directory to it

The stuff under sysctl describes /sys interface from userspace
point of view. So, add it to the admin-guide and remove the
:orphan: from its index file.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>

show more ...

proc: Add /proc/<pid>/arch_status

Exposing architecture specific per process information is useful for
various reasons. An example is the AVX512 usage on x86 which is important
for task placement fo

proc: Add /proc/<pid>/arch_status

Exposing architecture specific per process information is useful for
various reasons. An example is the AVX512 usage on x86 which is important
for task placement for power/performance optimizations.

Adding this information to the existing /prcc/pid/status file would be the
obvious choise, but it has been agreed on that a explicit arch_status file
is better in separating the generic and architecture specific information.

[ tglx: Massage changelog ]

Signed-off-by: Aubrey Li <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Andrew Morton <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Andy Lutomirski <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Arjan van de Ven <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Linux API <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

show more ...

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

proc/kcore: add vmcoreinfo note to /proc/kcore

The vmcoreinfo information is useful for runtime debugging tools, not just
for crash dumps. A lot of this information can be determined by other
means

proc/kcore: add vmcoreinfo note to /proc/kcore

The vmcoreinfo information is useful for runtime debugging tools, not just
for crash dumps. A lot of this information can be determined by other
means, but this is much more convenient, and it only adds a page at most
to the file.

Link: http://lkml.kernel.org/r/fddbcd08eed76344863303878b12de1c1e2a04b6.1531953780.git.osandov@fb.com
Signed-off-by: Omar Sandoval <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Bhupesh Sharma <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: James Morse <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

vmcore: add API to collect hardware dump in second kernel

The sequence of actions done by device drivers to append their device
specific hardware/firmware logs to /proc/vmcore are as follows:

1. Du

vmcore: add API to collect hardware dump in second kernel

The sequence of actions done by device drivers to append their device
specific hardware/firmware logs to /proc/vmcore are as follows:

1. During probe (before hardware is initialized), device drivers
register to the vmcore module (via vmcore_add_device_dump()), with
callback function, along with buffer size and log name needed for
firmware/hardware log collection.

2. vmcore module allocates the buffer with requested size. It adds
an Elf note and invokes the device driver's registered callback
function.

3. Device driver collects all hardware/firmware logs into the buffer
and returns control back to vmcore module.

Ensure that the device dump buffer size is always aligned to page size
so that it can be mmaped.

Also, rename alloc_elfnotes_buf() to vmcore_alloc_buf() to make it more
generic and reserve NT_VMCOREDD note type to indicate vmcore device
dump.

Suggested-by: Eric Biederman <[email protected]>.
Signed-off-by: Rahul Lakkireddy <[email protected]>
Signed-off-by: Ganesh Goudar <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

fs, proc: add help for CONFIG_PROC_CHILDREN

The purpose of the option was documented in
Documentation/filesystems/proc.txt but the help text was missing.

Add small help text that also points to the

fs, proc: add help for CONFIG_PROC_CHILDREN

The purpose of the option was documented in
Documentation/filesystems/proc.txt but the help text was missing.

Add small help text that also points to the documentation.

Signed-off-by: Iago López Galeiras <[email protected]>
Reviewed-by: Jean Delvare <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

fs, proc: introduce CONFIG_PROC_CHILDREN

Commit 818411616baf ("fs, proc: introduce /proc/<pid>/task/<tid>/children
entry") introduced the children entry for checkpoint restore and the
file is only a

fs, proc: introduce CONFIG_PROC_CHILDREN

Commit 818411616baf ("fs, proc: introduce /proc/<pid>/task/<tid>/children
entry") introduced the children entry for checkpoint restore and the
file is only available on kernels configured with CONFIG_EXPERT and
CONFIG_CHECKPOINT_RESTORE.

This is available in most distributions (Fedora, Debian, Ubuntu, CoreOS)
because they usually enable CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE.
But Arch does not enable CONFIG_EXPERT or CONFIG_CHECKPOINT_RESTORE.

However, the children proc file is useful outside of checkpoint restore.
I would like to use it in rkt. The rkt process exec() another program
it does not control, and that other program will fork()+exec() a child
process. I would like to find the pid of the child process from an
external tool without iterating in /proc over all processes to find
which one has a parent pid equal to rkt.

This commit introduces CONFIG_PROC_CHILDREN and makes
CONFIG_CHECKPOINT_RESTORE select it. This allows enabling
/proc/<pid>/task/<tid>/children without needing to enable
CONFIG_CHECKPOINT_RESTORE and CONFIG_EXPERT.

Alban tested that /proc/<pid>/task/<tid>/children is present when the
kernel is configured with CONFIG_PROC_CHILDREN=y but without
CONFIG_CHECKPOINT_RESTORE

Signed-off-by: Iago López Galeiras <[email protected]>
Tested-by: Alban Crequy <[email protected]>
Reviewed-by: Cyrill Gorcunov <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Djalal Harouni <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

kcore: add Kconfig help text

Under Pseudo filesystems, /proc/kcore support has no help.

Fixes a portion of kernel bugzilla #52671:
https://bugzilla.kernel.org/show_bug.cgi?id=52671

Thanks for Da

kcore: add Kconfig help text

Under Pseudo filesystems, /proc/kcore support has no help.

Fixes a portion of kernel bugzilla #52671:
https://bugzilla.kernel.org/show_bug.cgi?id=52671

Thanks for David Howells for the help text.

Signed-off-by: Randy Dunlap <[email protected]>
Reported-by: <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT

The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
o

kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT

The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.

This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel. A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).

Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.

Reviewed-by: Ingo Molnar <[email protected]>
Acked-by: David Woodhouse <[email protected]>
Signed-off-by: David Rientjes <[email protected]>
Cc: Greg KH <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Robin Holt <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

vmcore: it is not experimental any more

We use vmcore in our production kernel for a long time, it is pretty
stable now. So I don't think we need to mark it as experimental any more.

Signed-off-by

vmcore: it is not experimental any more

We use vmcore in our production kernel for a long time, it is pretty
stable now. So I don't think we need to mark it as experimental any more.

Signed-off-by: WANG Cong <[email protected]>
Acked-by: Neil Horman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

proc: move PROC_PAGE_MONITOR to fs/proc/Kconfig

Signed-off-by: Alexey Dobriyan <[email protected]>

proc: move Kconfig to fs/proc/Kconfig

Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <torvalds@linux-foun

proc: move Kconfig to fs/proc/Kconfig

Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...