linux-toradex.git/kernel/crash_core.c, branch v6.9-rc4

crash: split crash dumping code out from kexec_core.c

2024-02-24T01:48:22+00:00

Currently, KEXEC_CORE select CRASH_CORE automatically because crash codes
need be built in to avoid compiling error when building kexec code even
though the crash dumping functionality is not enabled. E.g
--------------------
CONFIG_CRASH_CORE=y
CONFIG_KEXEC_CORE=y
CONFIG_KEXEC=y
CONFIG_KEXEC_FILE=y
---------------------

After splitting out crashkernel reservation code and vmcoreinfo exporting
code, there's only crash related code left in kernel/crash_core.c. Now
move crash related codes from kexec_core.c to crash_core.c and only build it
in when CONFIG_CRASH_DUMP=y.

And also wrap up crash codes inside CONFIG_CRASH_DUMP ifdeffery scope,
or replace inappropriate CONFIG_KEXEC_CORE ifdef with CONFIG_CRASH_DUMP
ifdef in generic kernel files.

With these changes, crash_core codes are abstracted from kexec codes and
can be disabled at all if only kexec reboot feature is wanted.

Link: https://lkml.kernel.org/r/20240124051254.67105-5-bhe@redhat.com
Signed-off-by: Baoquan He 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Hari Bathini 
Cc: Pingfan Liu 
Cc: Klara Modin 
Cc: Michael Kelley 
Cc: Nathan Chancellor 
Cc: Stephen Rothwell 
Cc: Yang Li 
Signed-off-by: Andrew Morton

crash: split vmcoreinfo exporting code out from crash_core.c

2024-02-24T01:48:22+00:00

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
 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.

[yang.lee@linux.alibaba.com: remove duplicated include in vmcore_info.c]
  Link: https://lkml.kernel.org/r/20240126005744.16561-1-yang.lee@linux.alibaba.com
Link: https://lkml.kernel.org/r/20240124051254.67105-3-bhe@redhat.com
Signed-off-by: Baoquan He 
Signed-off-by: Yang Li 
Acked-by: Hari Bathini 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Pingfan Liu 
Cc: Klara Modin 
Cc: Michael Kelley 
Cc: Nathan Chancellor 
Cc: Stephen Rothwell 
Cc: Yang Li 
Signed-off-by: Andrew Morton

kexec: split crashkernel reservation code out from crash_core.c

2024-02-24T01:48:21+00:00

Patch series "Split crash out from kexec and clean up related config
items", v3.

Motivation:
=============
Previously, LKP reported a building error. When investigating, it can't
be resolved reasonablly with the present messy kdump config items.

 https://lore.kernel.org/oe-kbuild-all/202312182200.Ka7MzifQ-lkp@intel.com/

The kdump (crash dumping) related config items could causes confusions:

Firstly,

CRASH_CORE enables codes including
 - crashkernel reservation;
 - elfcorehdr updating;
 - vmcoreinfo exporting;
 - crash hotplug handling;

Now fadump of powerpc, kcore dynamic debugging and kdump all selects
CRASH_CORE, while fadump
 - fadump needs crashkernel parsing, vmcoreinfo exporting, and accessing
   global variable 'elfcorehdr_addr';
 - kcore only needs vmcoreinfo exporting;
 - kdump needs all of the current kernel/crash_core.c.

So only enabling PROC_CORE or FA_DUMP will enable CRASH_CORE, this
mislead people that we enable crash dumping, actual it's not.

Secondly,

It's not reasonable to allow KEXEC_CORE select CRASH_CORE.

Because KEXEC_CORE enables codes which allocate control pages, copy
kexec/kdump segments, and prepare for switching. These codes are
shared by both kexec reboot and kdump. We could want kexec reboot,
but disable kdump. In that case, CRASH_CORE should not be selected.

 --------------------
 CONFIG_CRASH_CORE=y
 CONFIG_KEXEC_CORE=y
 CONFIG_KEXEC=y
 CONFIG_KEXEC_FILE=y
 ---------------------

Thirdly,

It's not reasonable to allow CRASH_DUMP select KEXEC_CORE.

That could make KEXEC_CORE, CRASH_DUMP are enabled independently from
KEXEC or KEXEC_FILE. However, w/o KEXEC or KEXEC_FILE, the KEXEC_CORE
code built in doesn't make any sense because no kernel loading or
switching will happen to utilize the KEXEC_CORE code.
 ---------------------
 CONFIG_CRASH_CORE=y
 CONFIG_KEXEC_CORE=y
 CONFIG_CRASH_DUMP=y
 ---------------------

In this case, what is worse, on arch sh and arm, KEXEC relies on MMU,
while CRASH_DUMP can still be enabled when !MMU, then compiling error is
seen as the lkp test robot reported in above link.

 ------arch/sh/Kconfig------
 config ARCH_SUPPORTS_KEXEC
         def_bool MMU

 config ARCH_SUPPORTS_CRASH_DUMP
         def_bool BROKEN_ON_SMP
 ---------------------------

Changes:
===========
1, split out crash_reserve.c from crash_core.c;
2, split out vmcore_infoc. from crash_core.c;
3, move crash related codes in kexec_core.c into crash_core.c;
4, remove dependency of FA_DUMP on CRASH_DUMP;
5, clean up kdump related config items;
6, wrap up crash codes in crash related ifdefs on all 8 arch-es
   which support crash dumping, except of ppc;

Achievement:
===========
With above changes, I can rearrange the config item logic as below (the right
item depends on or is selected by the left item):

    PROC_KCORE -----------> VMCORE_INFO

               |----------> VMCORE_INFO
    FA_DUMP----|
               |----------> CRASH_RESERVE

                                                    ---->VMCORE_INFO
                                                   /
                                                   |---->CRASH_RESERVE
    KEXEC      --|                                /|
                 |--> KEXEC_CORE--> CRASH_DUMP-->/-|---->PROC_VMCORE
    KEXEC_FILE --|                               \ |
                                                   \---->CRASH_HOTPLUG


    KEXEC      --|
                 |--> KEXEC_CORE (for kexec reboot only)
    KEXEC_FILE --|

Test
========
On all 8 architectures, including x86_64, arm64, s390x, sh, arm, mips,
riscv, loongarch, I did below three cases of config item setting and
building all passed. Take configs on x86_64 as exampmle here:

(1) Both CONFIG_KEXEC and KEXEC_FILE is unset, then all kexec/kdump
items are unset automatically:
# Kexec and crash features
# CONFIG_KEXEC is not set
# CONFIG_KEXEC_FILE is not set
# end of Kexec and crash features

(2) set CONFIG_KEXEC_FILE and 'make olddefconfig':
---------------
# Kexec and crash features
CONFIG_CRASH_RESERVE=y
CONFIG_VMCORE_INFO=y
CONFIG_KEXEC_CORE=y
CONFIG_KEXEC_FILE=y
CONFIG_CRASH_DUMP=y
CONFIG_CRASH_HOTPLUG=y
CONFIG_CRASH_MAX_MEMORY_RANGES=8192
# end of Kexec and crash features
---------------

(3) unset CONFIG_CRASH_DUMP in case 2 and execute 'make olddefconfig':
------------------------
# Kexec and crash features
CONFIG_KEXEC_CORE=y
CONFIG_KEXEC_FILE=y
# end of Kexec and crash features
------------------------

Note:
For ppc, it needs investigation to make clear how to split out crash
code in arch folder. Hope Hari and Pingfan can help have a look, see if
it's doable. Now, I make it either have both kexec and crash enabled, or
disable both of them altogether.


This patch (of 14):

Both kdump and fa_dump of ppc rely on crashkernel reservation.  Move the
relevant codes into separate files: crash_reserve.c,
include/linux/crash_reserve.h.

And also add config item CRASH_RESERVE to control its enabling of the
codes.  And update config items which has relationship with crashkernel
reservation.

And also change ifdeffery from CONFIG_CRASH_CORE to CONFIG_CRASH_RESERVE
when those scopes are only crashkernel reservation related.

And also rename arch/XXX/include/asm/{crash_core.h => crash_reserve.h} on
arm64, x86 and risc-v because those architectures' crash_core.h is only
related to crashkernel reservation.

[akpm@linux-foundation.org: s/CRASH_RESEERVE/CRASH_RESERVE/, per Klara Modin]
Link: https://lkml.kernel.org/r/20240124051254.67105-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20240124051254.67105-2-bhe@redhat.com
Signed-off-by: Baoquan He 
Acked-by: Hari Bathini 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Pingfan Liu 
Cc: Klara Modin 
Cc: Michael Kelley 
Cc: Nathan Chancellor 
Cc: Stephen Rothwell 
Cc: Yang Li 
Signed-off-by: Andrew Morton

mm/vmalloc: remove vmap_area_list

2024-02-24T01:48:19+00:00

Earlier, vmap_area_list is exported to vmcoreinfo so that makedumpfile get
the base address of vmalloc area.  Now, vmap_area_list is empty, so export
VMALLOC_START to vmcoreinfo instead, and remove vmap_area_list.

[urezki@gmail.com: fix a warning in the crash_save_vmcoreinfo_init()]
  Link: https://lkml.kernel.org/r/20240111192329.449189-1-urezki@gmail.com
Link: https://lkml.kernel.org/r/20240102184633.748113-6-urezki@gmail.com
Signed-off-by: Baoquan He 
Signed-off-by: Uladzislau Rezki (Sony) 
Acked-by: Lorenzo Stoakes 
Cc: Christoph Hellwig 
Cc: Dave Chinner 
Cc: Joel Fernandes (Google) 
Cc: Kazuhito Hagio 
Cc: Liam R. Howlett 
Cc: Matthew Wilcox (Oracle) 
Cc: Oleksiy Avramchenko 
Cc: Paul E. McKenney 
Signed-off-by: Andrew Morton

kernel/crash_core.c: make __crash_hotplug_lock static

2024-01-12T23:20:47+00:00

sparse warnings:
kernel/crash_core.c:749:1: sparse: sparse: symbol '__crash_hotplug_lock' was not declared. Should it be static?

Fixes: e2a8f20dd8e9 ("Crash: add lock to serialize crash hotplug handling")
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202401080654.IjjU5oK7-lkp@intel.com/
Cc: Baoquan He 
Signed-off-by: Andrew Morton

kdump: defer the insertion of crashkernel resources

2024-01-12T23:20:45+00:00

In /proc/iomem, sub-regions should be inserted after their parent,
otherwise the insertion of parent resource fails.  But after generic
crashkernel reservation applied, in both RISC-V and ARM64 (LoongArch will
also use generic reservation later on), crashkernel resources are inserted
before their parent, which causes the parent disappear in /proc/iomem.  So
we defer the insertion of crashkernel resources to an early_initcall().

1, Without 'crashkernel' parameter:

 100d0100-100d01ff : LOON0001:00
   100d0100-100d01ff : LOON0001:00 LOON0001:00
 100e0000-100e0bff : LOON0002:00
   100e0000-100e0bff : LOON0002:00 LOON0002:00
 1fe001e0-1fe001e7 : serial
 90400000-fa17ffff : System RAM
   f6220000-f622ffff : Reserved
   f9ee0000-f9ee3fff : Reserved
   fa120000-fa17ffff : Reserved
 fa190000-fe0bffff : System RAM
   fa190000-fa1bffff : Reserved
 fe4e0000-47fffffff : System RAM
   43c000000-441ffffff : Reserved
   47ff98000-47ffa3fff : Reserved
   47ffa4000-47ffa7fff : Reserved
   47ffa8000-47ffabfff : Reserved
   47ffac000-47ffaffff : Reserved
   47ffb0000-47ffb3fff : Reserved

2, With 'crashkernel' parameter, before this patch:

 100d0100-100d01ff : LOON0001:00
   100d0100-100d01ff : LOON0001:00 LOON0001:00
 100e0000-100e0bff : LOON0002:00
   100e0000-100e0bff : LOON0002:00 LOON0002:00
 1fe001e0-1fe001e7 : serial
 e6200000-f61fffff : Crash kernel
 fa190000-fe0bffff : System RAM
   fa190000-fa1bffff : Reserved
 fe4e0000-47fffffff : System RAM
   43c000000-441ffffff : Reserved
   47ff98000-47ffa3fff : Reserved
   47ffa4000-47ffa7fff : Reserved
   47ffa8000-47ffabfff : Reserved
   47ffac000-47ffaffff : Reserved
   47ffb0000-47ffb3fff : Reserved

3, With 'crashkernel' parameter, after this patch:

 100d0100-100d01ff : LOON0001:00
   100d0100-100d01ff : LOON0001:00 LOON0001:00
 100e0000-100e0bff : LOON0002:00
   100e0000-100e0bff : LOON0002:00 LOON0002:00
 1fe001e0-1fe001e7 : serial
 90400000-fa17ffff : System RAM
   e6200000-f61fffff : Crash kernel
   f6220000-f622ffff : Reserved
   f9ee0000-f9ee3fff : Reserved
   fa120000-fa17ffff : Reserved
 fa190000-fe0bffff : System RAM
   fa190000-fa1bffff : Reserved
 fe4e0000-47fffffff : System RAM
   43c000000-441ffffff : Reserved
   47ff98000-47ffa3fff : Reserved
   47ffa4000-47ffa7fff : Reserved
   47ffa8000-47ffabfff : Reserved
   47ffac000-47ffaffff : Reserved
   47ffb0000-47ffb3fff : Reserved

Link: https://lkml.kernel.org/r/20231229080213.2622204-1-chenhuacai@loongson.cn
Signed-off-by: Huacai Chen 
Fixes: 0ab97169aa05 ("crash_core: add generic function to do reservation")
Cc: Baoquan He 
Cc: Zhen Lei 
Cc: 	[6.6+]
Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-01-09T19:46:20+00:00

Pull non-MM updates from Andrew Morton:
 "Quite a lot of kexec work this time around. Many singleton patches in
  many places. The notable patch series are:

   - nilfs2 folio conversion from Matthew Wilcox in 'nilfs2: Folio
     conversions for file paths'.

   - Additional nilfs2 folio conversion from Ryusuke Konishi in 'nilfs2:
     Folio conversions for directory paths'.

   - IA64 remnant removal in Heiko Carstens's 'Remove unused code after
     IA-64 removal'.

   - Arnd Bergmann has enabled the -Wmissing-prototypes warning
     everywhere in 'Treewide: enable -Wmissing-prototypes'. This had
     some followup fixes:

      - Nathan Chancellor has cleaned up the hexagon build in the series
        'hexagon: Fix up instances of -Wmissing-prototypes'.

      - Nathan also addressed some s390 warnings in 's390: A couple of
        fixes for -Wmissing-prototypes'.

      - Arnd Bergmann addresses the same warnings for MIPS in his series
        'mips: address -Wmissing-prototypes warnings'.

   - Baoquan He has made kexec_file operate in a top-down-fitting manner
     similar to kexec_load in the series 'kexec_file: Load kernel at top
     of system RAM if required'

   - Baoquan He has also added the self-explanatory 'kexec_file: print
     out debugging message if required'.

   - Some checkstack maintenance work from Tiezhu Yang in the series
     'Modify some code about checkstack'.

   - Douglas Anderson has disentangled the watchdog code's logging when
     multiple reports are occurring simultaneously. The series is
     'watchdog: Better handling of concurrent lockups'.

   - Yuntao Wang has contributed some maintenance work on the crash code
     in 'crash: Some cleanups and fixes'"

* tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (157 commits)
  crash_core: fix and simplify the logic of crash_exclude_mem_range()
  x86/crash: use SZ_1M macro instead of hardcoded value
  x86/crash: remove the unused image parameter from prepare_elf_headers()
  kdump: remove redundant DEFAULT_CRASH_KERNEL_LOW_SIZE
  scripts/decode_stacktrace.sh: strip unexpected CR from lines
  watchdog: if panicking and we dumped everything, don't re-enable dumping
  watchdog/hardlockup: use printk_cpu_sync_get_irqsave() to serialize reporting
  watchdog/softlockup: use printk_cpu_sync_get_irqsave() to serialize reporting
  watchdog/hardlockup: adopt softlockup logic avoiding double-dumps
  kexec_core: fix the assignment to kimage->control_page
  x86/kexec: fix incorrect end address passed to kernel_ident_mapping_init()
  lib/trace_readwrite.c:: replace asm-generic/io with linux/io
  nilfs2: cpfile: fix some kernel-doc warnings
  stacktrace: fix kernel-doc typo
  scripts/checkstack.pl: fix no space expression between sp and offset
  x86/kexec: fix incorrect argument passed to kexec_dprintk()
  x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs
  nilfs2: add missing set_freezable() for freezable kthread
  kernel: relay: remove relay_file_splice_read dead code, doesn't work
  docs: submit-checklist: remove all of "make namespacecheck"
  ...

mm, treewide: introduce NR_PAGE_ORDERS

2024-01-08T23:27:15+00:00

NR_PAGE_ORDERS defines the number of page orders supported by the page
allocator, ranging from 0 to MAX_ORDER, MAX_ORDER + 1 in total.

NR_PAGE_ORDERS assists in defining arrays of page orders and allows for
more natural iteration over them.

[kirill.shutemov@linux.intel.com: fixup for kerneldoc warning]
  Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box
Link: https://lkml.kernel.org/r/20231228144704.14033-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov 
Reviewed-by: Zi Yan 
Cc: Linus Torvalds 
Signed-off-by: Andrew Morton

crash_core: fix and simplify the logic of crash_exclude_mem_range()

2024-01-05T18:45:25+00:00

The purpose of crash_exclude_mem_range() is to remove all memory ranges
that overlap with [mstart-mend].  However, the current logic only removes
the first overlapping memory range.

Commit a2e9a95d2190 ("kexec: Improve & fix crash_exclude_mem_range() to
handle overlapping ranges") attempted to address this issue, but it did
not fix all error cases.

Let's fix and simplify the logic of crash_exclude_mem_range().

Link: https://lkml.kernel.org/r/20240102144905.110047-4-ytcoode@gmail.com
Signed-off-by: Yuntao Wang 
Acked-by: Baoquan He 
Cc: Borislav Petkov (AMD) 
Cc: Dave Hansen 
Cc: Dave Young 
Cc: Hari Bathini 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Sourabh Jain 
Cc: Takashi Iwai 
Cc: Thomas Gleixner 
Cc: Vivek Goyal 
Signed-off-by: Andrew Morton

crash_core: remove duplicated including of kexec.h

2023-12-20T23:02:58+00:00

Remove second include of linux/kexec.h

Link: https://lkml.kernel.org/r/202312151654+0800-wangjinchao@xfusion.com
Signed-off-by: Wang Jinchao 
Acked-by: Baoquan He 
Cc: Dave Young 
Cc: Vivek Goyal 
Signed-off-by: Andrew Morton