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[Crash-utility,V3,0/9] Support RISCV64 arch and common commands

Message ID 20220813031753.3097720-1-xianting.tian@linux.alibaba.com (mailing list archive)
Headers show
Series Support RISCV64 arch and common commands | expand

Message

Xianting Tian Aug. 13, 2022, 3:17 a.m. UTC
This series of patches are for Crash-utility tool, it make crash tool support
RISCV64 arch and the common commands(*, bt, p, rd, mod, log, set, struct, task,
dis, help -r, help -m, and so on).

To make the crash tool work normally for RISCV64 arch, we need a Linux kernel
patch, which exports the kernel virtual memory layout, va_bits, phys_ram_base
to vmcoreinfo, it can simplify the development of crash tool.

The Linux kernel patch set:
https://lore.kernel.org/linux-riscv/20220811074150.3020189-1-xianting.tian@linux.alibaba.com/
[ Patch 1 ~ 4 already merged to Linux for-next branch, targeted for 5.20;
  Patch 5, 6 already merged to Palmer's riscv-crash branch:
  https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-crash ]
 
This series of patches are tested on QEMU RISCV64 env and SoC platform of
T-head Xuantie 910 RISCV64 CPU.

====================================
  Some test examples list as below
====================================
... ...
      KERNEL: vmlinux
    DUMPFILE: vmcore
        CPUS: 1
        DATE: Fri Jul 15 10:24:25 CST 2022
      UPTIME: 00:00:33
LOAD AVERAGE: 0.05, 0.01, 0.00
       TASKS: 41
    NODENAME: buildroot
     RELEASE: 5.18.9
     VERSION: #30 SMP Fri Jul 15 09:47:03 CST 2022
     MACHINE: riscv64  (unknown Mhz)
      MEMORY: 1 GB
       PANIC: "Kernel panic - not syncing: sysrq triggered crash"
         PID: 113
     COMMAND: "sh"
        TASK: ff60000002269600  [THREAD_INFO: ff60000002269600]
         CPU: 0
       STATE: TASK_RUNNING (PANIC)

carsh>

crash> p mem_map
mem_map = $1 = (struct page *) 0xff6000003effbf00

crash> p /x *(struct page *) 0xff6000003effbf00
$5 = {
  flags = 0x1000,
  {
    {
      {
        lru = {
          next = 0xff6000003effbf08,
          prev = 0xff6000003effbf08
        },
        {
          __filler = 0xff6000003effbf08,
          mlock_count = 0x3effbf08
        }
      },
      mapping = 0x0,
      index = 0x0,
      private = 0x0
    },
  ... ...

crash> mod
     MODULE       NAME             BASE         SIZE  OBJECT FILE
ffffffff0113e740  nvme_core  ffffffff01133000  98304  (not loaded)  [CONFIG_KALLSYMS]
ffffffff011542c0  nvme       ffffffff0114c000  61440  (not loaded)  [CONFIG_KALLSYMS]

crash> rd ffffffff0113e740 8
ffffffff0113e740:  0000000000000000 ffffffff810874f8   .........t......
ffffffff0113e750:  ffffffff011542c8 726f635f656d766e   .B......nvme_cor
ffffffff0113e760:  0000000000000065 0000000000000000   e...............
ffffffff0113e770:  0000000000000000 0000000000000000   ................

crash> vtop ffffffff0113e740
VIRTUAL           PHYSICAL
ffffffff0113e740  8254d740

   PGD: ffffffff810e9ff8 => 2ffff001
  P4D: 0000000000000000 => 000000002fffec01
  PUD: 00005605c2957470 => 0000000020949801
  PMD: 00007fff7f1750c0 => 0000000020947401
   PTE: 0 => 209534e7
 PAGE: 000000008254d000

  PTE     PHYSICAL  FLAGS
209534e7  8254d000  (PRESENT|READ|WRITE|GLOBAL|ACCESSED|DIRTY)

      PAGE       PHYSICAL      MAPPING       INDEX CNT FLAGS
ff6000003f0777d8 8254d000                0        0  1 0

crash> bt
PID: 113      TASK: ff6000000226c200  CPU: 0    COMMAND: "sh"
 #0 [ff20000010333b90] riscv_crash_save_regs at ffffffff800078f8
 #1 [ff20000010333cf0] panic at ffffffff806578c6
 #2 [ff20000010333d50] sysrq_reset_seq_param_set at ffffffff8038c03c
 #3 [ff20000010333da0] __handle_sysrq at ffffffff8038c604
 #4 [ff20000010333e00] write_sysrq_trigger at ffffffff8038cae4
 #5 [ff20000010333e20] proc_reg_write at ffffffff801b7ee8
 #6 [ff20000010333e40] vfs_write at ffffffff80152bb2
 #7 [ff20000010333e80] ksys_write at ffffffff80152eda
 #8 [ff20000010333ed0] sys_write at ffffffff80152f52

-------
Changes V1 -> V2:
 1, Do the below fixes based on HAGIO KAZUHITO's comments: 
    Fix build warnings,
    Use MACRO for Linux version,
    Add description of x86_64 binary for riscv64 in README,
    Fix build error for the "sticky" target for build on x86_64,
    Fix the mixed indent.
 2, Add 'help -m/M' support patch to this patch set.
 3, Support native compiling approach, which means the host OS distro
    is also a riscv64 (lp64d) Linux, based on Yixun Lan's comments.
 4, Use __riscv and __riscv_xlen instead of __riscv64__ based on Yixun Lan's comments.
Changes V2 -> V3:
 1, Fix coding style, avoid including the header twice, move free() to right place,
    introduce VM_FLAGS and so on based on Li Jiang's comments.
 2, Adjust the implementation of riscv64_verify_symbol(refer to the logic of x86_64_verify_symbol)
    as KSYMS_START isn't set when verify symbol in some case. 


Xianting Tian (9):
  Add RISCV64 framework code support
  RISCV64: Make crash tool enter command line and support some commands
  RISCV64: Add 'dis' command support
  RISCV64: Add 'irq' command support
  RISCV64: Add 'bt' command support
  RISCV64: Add 'help -r' command support
  RISCV64: Add 'help -m/M' command support
  RISCV64: Add 'mach' command support
  RISCV64: Add the implementation of symbol verify

 Makefile            |    7 +-
 README              |    4 +-
 configure.c         |   43 +-
 defs.h              |  252 +++++++-
 diskdump.c          |   21 +-
 help.c              |    2 +-
 lkcd_vmdump_v1.h    |    8 +-
 lkcd_vmdump_v2_v3.h |    8 +-
 netdump.c           |   22 +-
 ramdump.c           |    2 +
 riscv64.c           | 1491 +++++++++++++++++++++++++++++++++++++++++++
 symbols.c           |   10 +
 12 files changed, 1848 insertions(+), 22 deletions(-)
 create mode 100644 riscv64.c

Comments

Yixun Lan Aug. 22, 2022, 7:28 a.m. UTC | #1
Hi lijiang

On Mon, Aug 22, 2022 at 3:56 AM lijiang <lijiang@redhat.com> wrote:
>
> Hi, Xianting
> Thank you for the update.
> On Sat, Aug 13, 2022 at 11:18 AM Xianting Tian <xianting.tian@linux.alibaba.com> wrote:
>>
>> This series of patches are for Crash-utility tool, it make crash tool support
>> RISCV64 arch and the common commands(*, bt, p, rd, mod, log, set, struct, task,
>> dis, help -r, help -m, and so on).
>>
>> To make the crash tool work normally for RISCV64 arch, we need a Linux kernel
>> patch, which exports the kernel virtual memory layout, va_bits, phys_ram_base
>> to vmcoreinfo, it can simplify the development of crash tool.
>>
>> The Linux kernel patch set:
>> https://lore.kernel.org/linux-riscv/20220811074150.3020189-1-xianting.tian@linux.alibaba.com/
>> [ Patch 1 ~ 4 already merged to Linux for-next branch, targeted for 5.20;
>>   Patch 5, 6 already merged to Palmer's riscv-crash branch:
>>   https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-crash ]
>>
>
> Can you also help to share the patch link for kexec-tools? Or share your loading steps and generate a vmcore in riscv64 system?
>
> I tried it with kexec-tools and got the following error:
>
> [root@fedora-riscv kexec-tools]# ./configure
> checking for gcc... gcc
> checking whether the C compiler works... yes
> checking for C compiler default output file name... a.out
> checking for suffix of executables...
> checking whether we are cross compiling... no
> checking for suffix of object files... o
> checking whether we are using the GNU C compiler... yes
> checking whether gcc accepts -g... yes
> checking for gcc option to accept ISO C89... none needed
> checking build system type... riscv64-unknown-linux-gnu
> checking host system type... riscv64-unknown-linux-gnu
> checking target system type... riscv64-unknown-linux-gnu
> configure: error: unsupported architecture riscv64
>
> Thanks.
> Lianbo
>
>> This series of patches are tested on QEMU RISCV64 env and SoC platform of
>> T-head Xuantie 910 RISCV64 CPU.
>>
>> ====================================
>>   Some test examples list as below
>> ====================================
>> ... ...
>>       KERNEL: vmlinux
>>     DUMPFILE: vmcore
>>         CPUS: 1
>>         DATE: Fri Jul 15 10:24:25 CST 2022
>>       UPTIME: 00:00:33
>> LOAD AVERAGE: 0.05, 0.01, 0.00
>>        TASKS: 41
>>     NODENAME: buildroot
>>      RELEASE: 5.18.9
>>      VERSION: #30 SMP Fri Jul 15 09:47:03 CST 2022
>>      MACHINE: riscv64  (unknown Mhz)
>>       MEMORY: 1 GB
>>        PANIC: "Kernel panic - not syncing: sysrq triggered crash"
>>          PID: 113
>>      COMMAND: "sh"
>>         TASK: ff60000002269600  [THREAD_INFO: ff60000002269600]
>>          CPU: 0
>>        STATE: TASK_RUNNING (PANIC)
>>
>> carsh>
>>
>> crash> p mem_map
>> mem_map = $1 = (struct page *) 0xff6000003effbf00
>>
>> crash> p /x *(struct page *) 0xff6000003effbf00
>> $5 = {
>>   flags = 0x1000,
>>   {
>>     {
>>       {
>>         lru = {
>>           next = 0xff6000003effbf08,
>>           prev = 0xff6000003effbf08
>>         },
>>         {
>>           __filler = 0xff6000003effbf08,
>>           mlock_count = 0x3effbf08
>>         }
>>       },
>>       mapping = 0x0,
>>       index = 0x0,
>>       private = 0x0
>>     },
>>   ... ...
>>
>> crash> mod
>>      MODULE       NAME             BASE         SIZE  OBJECT FILE
>> ffffffff0113e740  nvme_core  ffffffff01133000  98304  (not loaded)  [CONFIG_KALLSYMS]
>> ffffffff011542c0  nvme       ffffffff0114c000  61440  (not loaded)  [CONFIG_KALLSYMS]
>>
>> crash> rd ffffffff0113e740 8
>> ffffffff0113e740:  0000000000000000 ffffffff810874f8   .........t......
>> ffffffff0113e750:  ffffffff011542c8 726f635f656d766e   .B......nvme_cor
>> ffffffff0113e760:  0000000000000065 0000000000000000   e...............
>> ffffffff0113e770:  0000000000000000 0000000000000000   ................
>>
>> crash> vtop ffffffff0113e740
>> VIRTUAL           PHYSICAL
>> ffffffff0113e740  8254d740
>>
>>    PGD: ffffffff810e9ff8 => 2ffff001
>>   P4D: 0000000000000000 => 000000002fffec01
>>   PUD: 00005605c2957470 => 0000000020949801
>>   PMD: 00007fff7f1750c0 => 0000000020947401
>>    PTE: 0 => 209534e7
>>  PAGE: 000000008254d000
>>
>>   PTE     PHYSICAL  FLAGS
>> 209534e7  8254d000  (PRESENT|READ|WRITE|GLOBAL|ACCESSED|DIRTY)
>>
>>       PAGE       PHYSICAL      MAPPING       INDEX CNT FLAGS
>> ff6000003f0777d8 8254d000                0        0  1 0
>>
>> crash> bt
>> PID: 113      TASK: ff6000000226c200  CPU: 0    COMMAND: "sh"
>>  #0 [ff20000010333b90] riscv_crash_save_regs at ffffffff800078f8
>>  #1 [ff20000010333cf0] panic at ffffffff806578c6
>>  #2 [ff20000010333d50] sysrq_reset_seq_param_set at ffffffff8038c03c
>>  #3 [ff20000010333da0] __handle_sysrq at ffffffff8038c604
>>  #4 [ff20000010333e00] write_sysrq_trigger at ffffffff8038cae4
>>  #5 [ff20000010333e20] proc_reg_write at ffffffff801b7ee8
>>  #6 [ff20000010333e40] vfs_write at ffffffff80152bb2
>>  #7 [ff20000010333e80] ksys_write at ffffffff80152eda
>>  #8 [ff20000010333ed0] sys_write at ffffffff80152f52
>>
>> -------
>> Changes V1 -> V2:
>>  1, Do the below fixes based on HAGIO KAZUHITO's comments:
>>     Fix build warnings,
>>     Use MACRO for Linux version,
>>     Add description of x86_64 binary for riscv64 in README,
>>     Fix build error for the "sticky" target for build on x86_64,
>>     Fix the mixed indent.
>>  2, Add 'help -m/M' support patch to this patch set.
>>  3, Support native compiling approach, which means the host OS distro
>>     is also a riscv64 (lp64d) Linux, based on Yixun Lan's comments.
>>  4, Use __riscv and __riscv_xlen instead of __riscv64__ based on Yixun Lan's comments.
>> Changes V2 -> V3:
>>  1, Fix coding style, avoid including the header twice, move free() to right place,
>>     introduce VM_FLAGS and so on based on Li Jiang's comments.
>>  2, Adjust the implementation of riscv64_verify_symbol(refer to the logic of x86_64_verify_symbol)
>>     as KSYMS_START isn't set when verify symbol in some case.
>>
>>
>> Xianting Tian (9):
>>   Add RISCV64 framework code support
>>   RISCV64: Make crash tool enter command line and support some commands
>>   RISCV64: Add 'dis' command support
>>   RISCV64: Add 'irq' command support
>>   RISCV64: Add 'bt' command support
>>   RISCV64: Add 'help -r' command support
>>   RISCV64: Add 'help -m/M' command support
>>   RISCV64: Add 'mach' command support
>>   RISCV64: Add the implementation of symbol verify
>>
>>  Makefile            |    7 +-
>>  README              |    4 +-
>>  configure.c         |   43 +-
>>  defs.h              |  252 +++++++-
>>  diskdump.c          |   21 +-
>>  help.c              |    2 +-
>>  lkcd_vmdump_v1.h    |    8 +-
>>  lkcd_vmdump_v2_v3.h |    8 +-
>>  netdump.c           |   22 +-
>>  ramdump.c           |    2 +
>>  riscv64.c           | 1491 +++++++++++++++++++++++++++++++++++++++++++
>>  symbols.c           |   10 +
>>  12 files changed, 1848 insertions(+), 22 deletions(-)
>>  create mode 100644 riscv64.c
>>
>> --
>> 2.17.1
>>

FYI, take a look at
lists.infradead.org/pipermail/linux-riscv/2021-October/008773.html

also need this extra fix
lists.infradead.org/pipermail/linux-riscv/2022-August/018398.html

and just follow normal scheme to use kexec + crash, there is nothing different

Yixun
Xianting Tian Aug. 24, 2022, 8:57 a.m. UTC | #2
在 2022/8/22 下午3:28, Yixun Lan 写道:
> Hi lijiang
>
> On Mon, Aug 22, 2022 at 3:56 AM lijiang <lijiang@redhat.com> wrote:
>> Hi, Xianting
>> Thank you for the update.
>> On Sat, Aug 13, 2022 at 11:18 AM Xianting Tian <xianting.tian@linux.alibaba.com> wrote:
>>> This series of patches are for Crash-utility tool, it make crash tool support
>>> RISCV64 arch and the common commands(*, bt, p, rd, mod, log, set, struct, task,
>>> dis, help -r, help -m, and so on).
>>>
>>> To make the crash tool work normally for RISCV64 arch, we need a Linux kernel
>>> patch, which exports the kernel virtual memory layout, va_bits, phys_ram_base
>>> to vmcoreinfo, it can simplify the development of crash tool.
>>>
>>> The Linux kernel patch set:
>>> https://lore.kernel.org/linux-riscv/20220811074150.3020189-1-xianting.tian@linux.alibaba.com/
>>> [ Patch 1 ~ 4 already merged to Linux for-next branch, targeted for 5.20;
>>>    Patch 5, 6 already merged to Palmer's riscv-crash branch:
>>>    https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-crash ]
>>>
>> Can you also help to share the patch link for kexec-tools? Or share your loading steps and generate a vmcore in riscv64 system?
>>
>> I tried it with kexec-tools and got the following error:
>>
>> [root@fedora-riscv kexec-tools]# ./configure
>> checking for gcc... gcc
>> checking whether the C compiler works... yes
>> checking for C compiler default output file name... a.out
>> checking for suffix of executables...
>> checking whether we are cross compiling... no
>> checking for suffix of object files... o
>> checking whether we are using the GNU C compiler... yes
>> checking whether gcc accepts -g... yes
>> checking for gcc option to accept ISO C89... none needed
>> checking build system type... riscv64-unknown-linux-gnu
>> checking host system type... riscv64-unknown-linux-gnu
>> checking target system type... riscv64-unknown-linux-gnu
>> configure: error: unsupported architecture riscv64
>>
>> Thanks.
>> Lianbo
>>
>>> This series of patches are tested on QEMU RISCV64 env and SoC platform of
>>> T-head Xuantie 910 RISCV64 CPU.
>>>
>>> ====================================
>>>    Some test examples list as below
>>> ====================================
>>> ... ...
>>>        KERNEL: vmlinux
>>>      DUMPFILE: vmcore
>>>          CPUS: 1
>>>          DATE: Fri Jul 15 10:24:25 CST 2022
>>>        UPTIME: 00:00:33
>>> LOAD AVERAGE: 0.05, 0.01, 0.00
>>>         TASKS: 41
>>>      NODENAME: buildroot
>>>       RELEASE: 5.18.9
>>>       VERSION: #30 SMP Fri Jul 15 09:47:03 CST 2022
>>>       MACHINE: riscv64  (unknown Mhz)
>>>        MEMORY: 1 GB
>>>         PANIC: "Kernel panic - not syncing: sysrq triggered crash"
>>>           PID: 113
>>>       COMMAND: "sh"
>>>          TASK: ff60000002269600  [THREAD_INFO: ff60000002269600]
>>>           CPU: 0
>>>         STATE: TASK_RUNNING (PANIC)
>>>
>>> carsh>
>>>
>>> crash> p mem_map
>>> mem_map = $1 = (struct page *) 0xff6000003effbf00
>>>
>>> crash> p /x *(struct page *) 0xff6000003effbf00
>>> $5 = {
>>>    flags = 0x1000,
>>>    {
>>>      {
>>>        {
>>>          lru = {
>>>            next = 0xff6000003effbf08,
>>>            prev = 0xff6000003effbf08
>>>          },
>>>          {
>>>            __filler = 0xff6000003effbf08,
>>>            mlock_count = 0x3effbf08
>>>          }
>>>        },
>>>        mapping = 0x0,
>>>        index = 0x0,
>>>        private = 0x0
>>>      },
>>>    ... ...
>>>
>>> crash> mod
>>>       MODULE       NAME             BASE         SIZE  OBJECT FILE
>>> ffffffff0113e740  nvme_core  ffffffff01133000  98304  (not loaded)  [CONFIG_KALLSYMS]
>>> ffffffff011542c0  nvme       ffffffff0114c000  61440  (not loaded)  [CONFIG_KALLSYMS]
>>>
>>> crash> rd ffffffff0113e740 8
>>> ffffffff0113e740:  0000000000000000 ffffffff810874f8   .........t......
>>> ffffffff0113e750:  ffffffff011542c8 726f635f656d766e   .B......nvme_cor
>>> ffffffff0113e760:  0000000000000065 0000000000000000   e...............
>>> ffffffff0113e770:  0000000000000000 0000000000000000   ................
>>>
>>> crash> vtop ffffffff0113e740
>>> VIRTUAL           PHYSICAL
>>> ffffffff0113e740  8254d740
>>>
>>>     PGD: ffffffff810e9ff8 => 2ffff001
>>>    P4D: 0000000000000000 => 000000002fffec01
>>>    PUD: 00005605c2957470 => 0000000020949801
>>>    PMD: 00007fff7f1750c0 => 0000000020947401
>>>     PTE: 0 => 209534e7
>>>   PAGE: 000000008254d000
>>>
>>>    PTE     PHYSICAL  FLAGS
>>> 209534e7  8254d000  (PRESENT|READ|WRITE|GLOBAL|ACCESSED|DIRTY)
>>>
>>>        PAGE       PHYSICAL      MAPPING       INDEX CNT FLAGS
>>> ff6000003f0777d8 8254d000                0        0  1 0
>>>
>>> crash> bt
>>> PID: 113      TASK: ff6000000226c200  CPU: 0    COMMAND: "sh"
>>>   #0 [ff20000010333b90] riscv_crash_save_regs at ffffffff800078f8
>>>   #1 [ff20000010333cf0] panic at ffffffff806578c6
>>>   #2 [ff20000010333d50] sysrq_reset_seq_param_set at ffffffff8038c03c
>>>   #3 [ff20000010333da0] __handle_sysrq at ffffffff8038c604
>>>   #4 [ff20000010333e00] write_sysrq_trigger at ffffffff8038cae4
>>>   #5 [ff20000010333e20] proc_reg_write at ffffffff801b7ee8
>>>   #6 [ff20000010333e40] vfs_write at ffffffff80152bb2
>>>   #7 [ff20000010333e80] ksys_write at ffffffff80152eda
>>>   #8 [ff20000010333ed0] sys_write at ffffffff80152f52
>>>
>>> -------
>>> Changes V1 -> V2:
>>>   1, Do the below fixes based on HAGIO KAZUHITO's comments:
>>>      Fix build warnings,
>>>      Use MACRO for Linux version,
>>>      Add description of x86_64 binary for riscv64 in README,
>>>      Fix build error for the "sticky" target for build on x86_64,
>>>      Fix the mixed indent.
>>>   2, Add 'help -m/M' support patch to this patch set.
>>>   3, Support native compiling approach, which means the host OS distro
>>>      is also a riscv64 (lp64d) Linux, based on Yixun Lan's comments.
>>>   4, Use __riscv and __riscv_xlen instead of __riscv64__ based on Yixun Lan's comments.
>>> Changes V2 -> V3:
>>>   1, Fix coding style, avoid including the header twice, move free() to right place,
>>>      introduce VM_FLAGS and so on based on Li Jiang's comments.
>>>   2, Adjust the implementation of riscv64_verify_symbol(refer to the logic of x86_64_verify_symbol)
>>>      as KSYMS_START isn't set when verify symbol in some case.
>>>
>>>
>>> Xianting Tian (9):
>>>    Add RISCV64 framework code support
>>>    RISCV64: Make crash tool enter command line and support some commands
>>>    RISCV64: Add 'dis' command support
>>>    RISCV64: Add 'irq' command support
>>>    RISCV64: Add 'bt' command support
>>>    RISCV64: Add 'help -r' command support
>>>    RISCV64: Add 'help -m/M' command support
>>>    RISCV64: Add 'mach' command support
>>>    RISCV64: Add the implementation of symbol verify
>>>
>>>   Makefile            |    7 +-
>>>   README              |    4 +-
>>>   configure.c         |   43 +-
>>>   defs.h              |  252 +++++++-
>>>   diskdump.c          |   21 +-
>>>   help.c              |    2 +-
>>>   lkcd_vmdump_v1.h    |    8 +-
>>>   lkcd_vmdump_v2_v3.h |    8 +-
>>>   netdump.c           |   22 +-
>>>   ramdump.c           |    2 +
>>>   riscv64.c           | 1491 +++++++++++++++++++++++++++++++++++++++++++
>>>   symbols.c           |   10 +
>>>   12 files changed, 1848 insertions(+), 22 deletions(-)
>>>   create mode 100644 riscv64.c
>>>
>>> --
>>> 2.17.1
>>>
> FYI, take a look at
> lists.infradead.org/pipermail/linux-riscv/2021-October/008773.html
>
> also need this extra fix
> lists.infradead.org/pipermail/linux-riscv/2022-August/018398.html
>
> and just follow normal scheme to use kexec + crash, there is nothing different

Hi Li Jiang

I just saw this reply from Yixun,

there is some bug for kexec when use initrd, I used a temporary solution 
to fix the issue. And recently, Yixun fixed the issue, it is a better 
fix, you can use it to test on QEMU.

Fot the test on Xuantie 910 RISC-V SoC platform, I didn't use initrd, 
the kexec command I used as below:
         cmdline=$(cat /proc/cmdline)
         kexec -p vmlinux --append="$cmdline"

And with the additional patches:

diff --git a/kexec/arch/riscv/crashdump-riscv.c 
b/kexec/arch/riscv/crashdump-riscv.c
index 4f3ecd6..be73e34 100644
--- a/kexec/arch/riscv/crashdump-riscv.c
+++ b/kexec/arch/riscv/crashdump-riscv.c
@@ -84,7 +84,7 @@ int load_elfcorehdr(struct kexec_info *info)
         for (i = 0; i < info->memory_ranges; i++) {
                 ret = mem_regions_alloc_and_add(&crash_mem_ranges,
                                                 ranges[i].start,
-                                               ranges[i].end - 
ranges[i].start,
+                                               ranges[i].end - 
ranges[i].start + 1,
                                                 ranges[i].type);
                 if (ret ) {
                         fprintf(stderr, "Could not create 
crash_mem_ranges\n");
diff --git a/kexec/arch/riscv/kexec-riscv.c b/kexec/arch/riscv/kexec-riscv.c
index c7bbe5f..1a047de 100644
--- a/kexec/arch/riscv/kexec-riscv.c
+++ b/kexec/arch/riscv/kexec-riscv.c
@@ -455,10 +455,13 @@ static int add_memory_region(struct memory_ranges 
*mem_ranges,
         entry_size = (addr_cells + size_cells) * sizeof(uint32_t);
         reg = fdt_getprop(fdt->buf, node_offset, "reg", &prop_size);
         if (!reg) {
-               fprintf(stderr, "Warning: Malformed memory region with no "
-                               "reg property (%s) !\n",
-                               fdt_get_name(fdt->buf, node_offset, NULL));
-               return -EINVAL;
+               reg = fdt_getprop(fdt->buf, node_offset, "alloc-ranges", 
&prop_size);
+               if (!reg) {
+                       fprintf(stderr, "Warning: Malformed memory 
region with no "
+                                       "reg property (%s) !\n",
+                                       fdt_get_name(fdt->buf, 
node_offset, NULL));
+                       return -EINVAL;
+               }
         }

         num_entries = prop_size / entry_size;
diff --git a/kexec/mem_regions.c b/kexec/mem_regions.c
index ad7d3f1..f650bcd 100644
--- a/kexec/mem_regions.c
+++ b/kexec/mem_regions.c
@@ -126,7 +126,7 @@ int mem_regions_exclude(struct memory_ranges *ranges,
         return 0;
  }

-#define KEXEC_MEMORY_RANGES 16
+#define KEXEC_MEMORY_RANGES 32



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