Overview:
=========
The commit a85ee18c7900 ("kexec_file: print out debugging message
if required") has added general code printing in kexec_file_load(),
but not in kexec_load().
    
Since kexec_load and kexec_file_load are not triggered simultaneously,
we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
    
Next, we need to do some things in this patchset:
    
1. rename kexec_file_dbg_print to kexec_dbg_print
2. Add KEXEC_DEBUG
3. Initialize kexec_dbg_print for kexec
4. Fix uninitialized struct kimage *image pointer 
5. Set the reset of kexec_dbg_print to kimage_free

Testing:
=========
I did testing on x86_64, arm64 and loongarch. On x86_64, the printed messages
look like below:

unset CONFIG_KEXEC_FILE:
[   81.502374] kexec: kexec_load: type:0, start:0x23fff7700 head:0x10a4b9002 flags:0x3e0010

set CONFIG_KEXEC_FILE
[   36.774228] kexec_file: kernel: 0000000066c386c8 kernel_size: 0xd78400
[   36.821814] kexec-bzImage64: Loaded purgatory at 0x23fffb000
[   36.821826] kexec-bzImage64: Loaded boot_param, command line and misc at 0x23fff9000 bufsz=0x12d0 memsz=0x2000
[   36.821829] kexec-bzImage64: Loaded 64bit kernel at 0x23d400000 bufsz=0xd73400 memsz=0x2ab7000
[   36.821918] kexec-bzImage64: Loaded initrd at 0x23bd0b000 bufsz=0x16f40a8 memsz=0x16f40a8
[   36.821920] kexec-bzImage64: Final command line is: root=/dev/mapper/test-root crashkernel=auto rd.lvm.lv=test/root
[   36.821925] kexec-bzImage64: E820 memmap:
[   36.821926] kexec-bzImage64: 0000000000000000-000000000009ffff (1)
[   36.821928] kexec-bzImage64: 0000000000100000-0000000000811fff (1)
[   36.821930] kexec-bzImage64: 0000000000812000-0000000000812fff (2)
[   36.821931] kexec-bzImage64: 0000000000813000-00000000bee38fff (1)
[   36.821933] kexec-bzImage64: 00000000bee39000-00000000beec2fff (2)
[   36.821934] kexec-bzImage64: 00000000beec3000-00000000bf8ecfff (1)
[   36.821935] kexec-bzImage64: 00000000bf8ed000-00000000bfb6cfff (2)
[   36.821936] kexec-bzImage64: 00000000bfb6d000-00000000bfb7efff (3)
[   36.821937] kexec-bzImage64: 00000000bfb7f000-00000000bfbfefff (4)
[   36.821938] kexec-bzImage64: 00000000bfbff000-00000000bff7bfff (1)
[   36.821939] kexec-bzImage64: 00000000bff7c000-00000000bfffffff (2)
[   36.821940] kexec-bzImage64: 00000000feffc000-00000000feffffff (2)
[   36.821941] kexec-bzImage64: 00000000ffc00000-00000000ffffffff (2)
[   36.821942] kexec-bzImage64: 0000000100000000-000000023fffffff (1)
[   36.872348] kexec_file: nr_segments = 4
[   36.872356] kexec_file: segment[0]: buf=0x000000005314ece7 bufsz=0x4000 mem=0x23fffb000 memsz=0x5000
[   36.872370] kexec_file: segment[1]: buf=0x000000006e59b143 bufsz=0x12d0 mem=0x23fff9000 memsz=0x2000
[   36.872374] kexec_file: segment[2]: buf=0x00000000eb7b1fc3 bufsz=0xd73400 mem=0x23d400000 memsz=0x2ab7000
[   36.882172] kexec_file: segment[3]: buf=0x000000006af76441 bufsz=0x16f40a8 mem=0x23bd0b000 memsz=0x16f5000
[   36.889113] kexec_file: kexec_file_load: type:0, start:0x23fffb150 head:0x101a2e002 flags:0x8

Changes in v3:
==========
- Rename kexec_core_dbg_print to kexec_dbg_print
- Remove unnecessary segments prints
- Remove patch "kexec_file: Fix the issue of mismatch between loop variable types"

Qiang Ma (3):
  kexec: Fix uninitialized struct kimage *image pointer
  kexec: add kexec flag to control debug printing
  kexec: print out debugging message if required for kexec_load

 include/linux/kexec.h      | 9 +++++----
 include/uapi/linux/kexec.h | 1 +
 kernel/kexec.c             | 8 +++++++-
 kernel/kexec_core.c        | 4 +++-
 kernel/kexec_file.c        | 4 +---
 5 files changed, 17 insertions(+), 9 deletions(-)

-- 
2.20.1

Hello All,

I read this patch series, including the older versions, and this is what I
think about the changes.

There are two main reasons I see for why this patch series is proposed
(these were not mentioned in the cover letter or commit messages):

1. Commit eb7622d908a09 ("kexec_file, riscv: print out debugging message
    if required") and commit 6f8c1da071a4 ("kexec_file, arm64: print out
    debugging message if required") moved some kexec-related debug prints to
    kexec_dprintk instead of pr_debug or pr_notice.

    These commits made it easier to control the updated debug prints using
    the -d option of kexec tool for kexec_file_load system call. But since
    kexec_dprintk is not available for the kexec_load system call, those 
prints
    are no longer available for kexec_load at all. So patch series try 
to bring
    those logs for kexec_load system call.

2. Patch 03/03 prints additional logs about the kexec image type, start,
     head, and flags via kexec_dprintk for the kexec_load system call.

This is done by enabling the kexec_dprintk for kexec_load, so that logs
from point 1 and the new logs from point 2 can be printed for kexec_load
system call.

However, the patch series does not explain why these additional debug logs
are needed for kexec_load. Since most of the work involved in loading
kexec images through kexec_load happens in the kexec userspace tool, and
the tool already provides enough logs to debug issues, the need for these
extra kernel logs is not clear.

So adding the need for the additional debug logs in the cover letter or
commit message is needed to decide whether it is worth adding the code
change proposed in this patch series Also, I found it hard to map the 
commit message to the changes introduced in the commits. And finally If 
I review the patches only based on the code changes: 01/03 The commit 
message refers to kexec_dbg_print as kexec_core_dbg_print. 02/03 I think 
kexec_dbg_print should be set to false at the end of kimage_free, not at 
the start. 03/03 There is duplication of debug logs for architectures 
that already print the same information. For example, arm64. - Sourabh Jain
On 26/11/25 14:14, Qiang Ma wrote:
> Overview:
> =========
> The commit a85ee18c7900 ("kexec_file: print out debugging message
> if required") has added general code printing in kexec_file_load(),
> but not in kexec_load().
>      
> Since kexec_load and kexec_file_load are not triggered simultaneously,
> we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
>      
> Next, we need to do some things in this patchset:
>      
> 1. rename kexec_file_dbg_print to kexec_dbg_print
> 2. Add KEXEC_DEBUG
> 3. Initialize kexec_dbg_print for kexec
> 4. Fix uninitialized struct kimage *image pointer
> 5. Set the reset of kexec_dbg_print to kimage_free
>
> Testing:
> =========
> I did testing on x86_64, arm64 and loongarch. On x86_64, the printed messages
> look like below:
>
> unset CONFIG_KEXEC_FILE:
> [   81.502374] kexec: kexec_load: type:0, start:0x23fff7700 head:0x10a4b9002 flags:0x3e0010
>
> set CONFIG_KEXEC_FILE
> [   36.774228] kexec_file: kernel: 0000000066c386c8 kernel_size: 0xd78400
> [   36.821814] kexec-bzImage64: Loaded purgatory at 0x23fffb000
> [   36.821826] kexec-bzImage64: Loaded boot_param, command line and misc at 0x23fff9000 bufsz=0x12d0 memsz=0x2000
> [   36.821829] kexec-bzImage64: Loaded 64bit kernel at 0x23d400000 bufsz=0xd73400 memsz=0x2ab7000
> [   36.821918] kexec-bzImage64: Loaded initrd at 0x23bd0b000 bufsz=0x16f40a8 memsz=0x16f40a8
> [   36.821920] kexec-bzImage64: Final command line is: root=/dev/mapper/test-root crashkernel=auto rd.lvm.lv=test/root
> [   36.821925] kexec-bzImage64: E820 memmap:
> [   36.821926] kexec-bzImage64: 0000000000000000-000000000009ffff (1)
> [   36.821928] kexec-bzImage64: 0000000000100000-0000000000811fff (1)
> [   36.821930] kexec-bzImage64: 0000000000812000-0000000000812fff (2)
> [   36.821931] kexec-bzImage64: 0000000000813000-00000000bee38fff (1)
> [   36.821933] kexec-bzImage64: 00000000bee39000-00000000beec2fff (2)
> [   36.821934] kexec-bzImage64: 00000000beec3000-00000000bf8ecfff (1)
> [   36.821935] kexec-bzImage64: 00000000bf8ed000-00000000bfb6cfff (2)
> [   36.821936] kexec-bzImage64: 00000000bfb6d000-00000000bfb7efff (3)
> [   36.821937] kexec-bzImage64: 00000000bfb7f000-00000000bfbfefff (4)
> [   36.821938] kexec-bzImage64: 00000000bfbff000-00000000bff7bfff (1)
> [   36.821939] kexec-bzImage64: 00000000bff7c000-00000000bfffffff (2)
> [   36.821940] kexec-bzImage64: 00000000feffc000-00000000feffffff (2)
> [   36.821941] kexec-bzImage64: 00000000ffc00000-00000000ffffffff (2)
> [   36.821942] kexec-bzImage64: 0000000100000000-000000023fffffff (1)
> [   36.872348] kexec_file: nr_segments = 4
> [   36.872356] kexec_file: segment[0]: buf=0x000000005314ece7 bufsz=0x4000 mem=0x23fffb000 memsz=0x5000
> [   36.872370] kexec_file: segment[1]: buf=0x000000006e59b143 bufsz=0x12d0 mem=0x23fff9000 memsz=0x2000
> [   36.872374] kexec_file: segment[2]: buf=0x00000000eb7b1fc3 bufsz=0xd73400 mem=0x23d400000 memsz=0x2ab7000
> [   36.882172] kexec_file: segment[3]: buf=0x000000006af76441 bufsz=0x16f40a8 mem=0x23bd0b000 memsz=0x16f5000
> [   36.889113] kexec_file: kexec_file_load: type:0, start:0x23fffb150 head:0x101a2e002 flags:0x8
>
> Changes in v3:
> ==========
> - Rename kexec_core_dbg_print to kexec_dbg_print
> - Remove unnecessary segments prints
> - Remove patch "kexec_file: Fix the issue of mismatch between loop variable types"
>
> Qiang Ma (3):
>    kexec: Fix uninitialized struct kimage *image pointer
>    kexec: add kexec flag to control debug printing
>    kexec: print out debugging message if required for kexec_load
>
>   include/linux/kexec.h      | 9 +++++----
>   include/uapi/linux/kexec.h | 1 +
>   kernel/kexec.c             | 8 +++++++-
>   kernel/kexec_core.c        | 4 +++-
>   kernel/kexec_file.c        | 4 +---
>   5 files changed, 17 insertions(+), 9 deletions(-)
>

On 12/04/25 at 05:48pm, Sourabh Jain wrote:
> Hello All,
> 
> I read this patch series, including the older versions, and this is what I
> think about the changes.
> 
> There are two main reasons I see for why this patch series is proposed
> (these were not mentioned in the cover letter or commit messages):
> 
> 1. Commit eb7622d908a09 ("kexec_file, riscv: print out debugging message
>    if required") and commit 6f8c1da071a4 ("kexec_file, arm64: print out
>    debugging message if required") moved some kexec-related debug prints to
>    kexec_dprintk instead of pr_debug or pr_notice.
> 
>    These commits made it easier to control the updated debug prints using
>    the -d option of kexec tool for kexec_file_load system call. But since
>    kexec_dprintk is not available for the kexec_load system call, those
> prints
>    are no longer available for kexec_load at all. So patch series try to
> bring
>    those logs for kexec_load system call.
> 
> 2. Patch 03/03 prints additional logs about the kexec image type, start,
>     head, and flags via kexec_dprintk for the kexec_load system call.
> 
> This is done by enabling the kexec_dprintk for kexec_load, so that logs
> from point 1 and the new logs from point 2 can be printed for kexec_load
> system call.

Thanks a lot for checking these, Soubarh

I thought Qiang had found some missing information and he needed them
when debugging kexec_load interface until I noticed he printed the
segments too in kernel. The segments has been printed in userspace
kexec-tools. After talking, Qiang said he doesn't encounter missing
information when debugging kexec_load interface, he added the segment
printing antoher time in kernel for comparing them with the segments
printed out in userspace kexec-tools.

Basically, when I use 'kexec -d' to debug kexec_load loading, no extra
information is needed. Adding printing in kernel will make them shown in
console, but not in term which is not in the same place.

Anyway, the patch 2 and 3 adding more debug printing to kexec_load
interface in kernel is gilding the lily, drawing legs on a snake.

Qiang,

If you stick to add it, please post patch 1 separately because it's a
code fixing patch which is great. And split patch 2 and 3 to another
patchset and post separately and seek people's ACK.

> 
> However, the patch series does not explain why these additional debug logs
> are needed for kexec_load. Since most of the work involved in loading
> kexec images through kexec_load happens in the kexec userspace tool, and
> the tool already provides enough logs to debug issues, the need for these
> extra kernel logs is not clear.
> 
> So adding the need for the additional debug logs in the cover letter or
> commit message is needed to decide whether it is worth adding the code
> change proposed in this patch series Also, I found it hard to map the commit
> message to the changes introduced in the commits. And finally If I review
> the patches only based on the code changes: 01/03 The commit message refers
> to kexec_dbg_print as kexec_core_dbg_print. 02/03 I think kexec_dbg_print
> should be set to false at the end of kimage_free, not at the start. 03/03
> There is duplication of debug logs for architectures that already print the
> same information. For example, arm64. - Sourabh Jain
> On 26/11/25 14:14, Qiang Ma wrote:
> > Overview:
> > =========
> > The commit a85ee18c7900 ("kexec_file: print out debugging message
> > if required") has added general code printing in kexec_file_load(),
> > but not in kexec_load().
> > Since kexec_load and kexec_file_load are not triggered simultaneously,
> > we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
> > Next, we need to do some things in this patchset:
> > 1. rename kexec_file_dbg_print to kexec_dbg_print
> > 2. Add KEXEC_DEBUG
> > 3. Initialize kexec_dbg_print for kexec
> > 4. Fix uninitialized struct kimage *image pointer
> > 5. Set the reset of kexec_dbg_print to kimage_free
> > 
> > Testing:
> > =========
> > I did testing on x86_64, arm64 and loongarch. On x86_64, the printed messages
> > look like below:
> > 
> > unset CONFIG_KEXEC_FILE:
> > [   81.502374] kexec: kexec_load: type:0, start:0x23fff7700 head:0x10a4b9002 flags:0x3e0010
> > 
> > set CONFIG_KEXEC_FILE
> > [   36.774228] kexec_file: kernel: 0000000066c386c8 kernel_size: 0xd78400
> > [   36.821814] kexec-bzImage64: Loaded purgatory at 0x23fffb000
> > [   36.821826] kexec-bzImage64: Loaded boot_param, command line and misc at 0x23fff9000 bufsz=0x12d0 memsz=0x2000
> > [   36.821829] kexec-bzImage64: Loaded 64bit kernel at 0x23d400000 bufsz=0xd73400 memsz=0x2ab7000
> > [   36.821918] kexec-bzImage64: Loaded initrd at 0x23bd0b000 bufsz=0x16f40a8 memsz=0x16f40a8
> > [   36.821920] kexec-bzImage64: Final command line is: root=/dev/mapper/test-root crashkernel=auto rd.lvm.lv=test/root
> > [   36.821925] kexec-bzImage64: E820 memmap:
> > [   36.821926] kexec-bzImage64: 0000000000000000-000000000009ffff (1)
> > [   36.821928] kexec-bzImage64: 0000000000100000-0000000000811fff (1)
> > [   36.821930] kexec-bzImage64: 0000000000812000-0000000000812fff (2)
> > [   36.821931] kexec-bzImage64: 0000000000813000-00000000bee38fff (1)
> > [   36.821933] kexec-bzImage64: 00000000bee39000-00000000beec2fff (2)
> > [   36.821934] kexec-bzImage64: 00000000beec3000-00000000bf8ecfff (1)
> > [   36.821935] kexec-bzImage64: 00000000bf8ed000-00000000bfb6cfff (2)
> > [   36.821936] kexec-bzImage64: 00000000bfb6d000-00000000bfb7efff (3)
> > [   36.821937] kexec-bzImage64: 00000000bfb7f000-00000000bfbfefff (4)
> > [   36.821938] kexec-bzImage64: 00000000bfbff000-00000000bff7bfff (1)
> > [   36.821939] kexec-bzImage64: 00000000bff7c000-00000000bfffffff (2)
> > [   36.821940] kexec-bzImage64: 00000000feffc000-00000000feffffff (2)
> > [   36.821941] kexec-bzImage64: 00000000ffc00000-00000000ffffffff (2)
> > [   36.821942] kexec-bzImage64: 0000000100000000-000000023fffffff (1)
> > [   36.872348] kexec_file: nr_segments = 4
> > [   36.872356] kexec_file: segment[0]: buf=0x000000005314ece7 bufsz=0x4000 mem=0x23fffb000 memsz=0x5000
> > [   36.872370] kexec_file: segment[1]: buf=0x000000006e59b143 bufsz=0x12d0 mem=0x23fff9000 memsz=0x2000
> > [   36.872374] kexec_file: segment[2]: buf=0x00000000eb7b1fc3 bufsz=0xd73400 mem=0x23d400000 memsz=0x2ab7000
> > [   36.882172] kexec_file: segment[3]: buf=0x000000006af76441 bufsz=0x16f40a8 mem=0x23bd0b000 memsz=0x16f5000
> > [   36.889113] kexec_file: kexec_file_load: type:0, start:0x23fffb150 head:0x101a2e002 flags:0x8
> > 
> > Changes in v3:
> > ==========
> > - Rename kexec_core_dbg_print to kexec_dbg_print
> > - Remove unnecessary segments prints
> > - Remove patch "kexec_file: Fix the issue of mismatch between loop variable types"
> > 
> > Qiang Ma (3):
> >    kexec: Fix uninitialized struct kimage *image pointer
> >    kexec: add kexec flag to control debug printing
> >    kexec: print out debugging message if required for kexec_load
> > 
> >   include/linux/kexec.h      | 9 +++++----
> >   include/uapi/linux/kexec.h | 1 +
> >   kernel/kexec.c             | 8 +++++++-
> >   kernel/kexec_core.c        | 4 +++-
> >   kernel/kexec_file.c        | 4 +---
> >   5 files changed, 17 insertions(+), 9 deletions(-)
> > 
> 

在 2025/12/4 20:18, Sourabh Jain 写道:
> Hello All,
>
> I read this patch series, including the older versions, and this is 
> what I
> think about the changes.
>
> There are two main reasons I see for why this patch series is proposed
> (these were not mentioned in the cover letter or commit messages):
>
> 1. Commit eb7622d908a09 ("kexec_file, riscv: print out debugging message
>    if required") and commit 6f8c1da071a4 ("kexec_file, arm64: print out
>    debugging message if required") moved some kexec-related debug 
> prints to
>    kexec_dprintk instead of pr_debug or pr_notice.
>
>    These commits made it easier to control the updated debug prints using
>    the -d option of kexec tool for kexec_file_load system call. But since
>    kexec_dprintk is not available for the kexec_load system call, 
> those prints
>    are no longer available for kexec_load at all. So patch series try 
> to bring
>    those logs for kexec_load system call.
>
> 2. Patch 03/03 prints additional logs about the kexec image type, start,
>     head, and flags via kexec_dprintk for the kexec_load system call.
>
> This is done by enabling the kexec_dprintk for kexec_load, so that logs
> from point 1 and the new logs from point 2 can be printed for kexec_load
> system call.
>
> However, the patch series does not explain why these additional debug 
> logs
> are needed for kexec_load. Since most of the work involved in loading
> kexec images through kexec_load happens in the kexec userspace tool, and
> the tool already provides enough logs to debug issues, the need for these
> extra kernel logs is not clear.
As pointed out in the point 1, these two commits not only move some
kexec-related debug prints to kexec_dprintk instead of pr_debug or 
pr_notice,
but also respectively remove and delete the debug print in kexec_image_info.
These debug print initially existed for both kexec_load and 
kexec_file_load in kernel space.
Just commit cbc2fe9d9cb2 ("kexec_file: The "add kexec_file flag to 
control debug printing")
series of patches removed or deleted some parts, but this series of 
patches only added them
to the generic code under the kexec_file_load path, not to the 
kexec_load path.
Therefore, the reason for adding this part of the debug print is to add 
this deleted debug print
to the kexec_load generic code. Regarding duplicate prints related to 
architecture, as mentioned
in previous posts[1], I want remove the print(type/head of kimage) in 
arm64, and then add it
to the general code.

[1]: 
https://lore.kernel.org/lkml/4D709A5E16BE5DEC+04521049-61de-411f-85c1-cfc049ff04c5@uniontech.com/

If commit cbc2fe9d9cb2 ("kexec_file: The "add kexec_file flag to control 
debug printing" series of patches
is indeed intended to remove those kexec_image_info in kexec_load, not 
to lose them.
I think patch 3 can be removed, but patch 1, 2 are still required.
As Sourabh Jain mentioned in the point 1, the debugging print that uses 
kexec_dprintk
in the kexec_load path currently existing under arm64 is equivalent to 
being unavailable.
>
> So adding the need for the additional debug logs in the cover letter or
> commit message is needed to decide whether it is worth adding the code
> change proposed in this patch series Also, I found it hard to map the 
> commit message to the changes introduced in the commits. And finally 
> If I review the patches only based on the code changes: 01/03 The 
> commit message refers to kexec_dbg_print 
There is an error in the patch description. It should be 
kexec_file_dbg_print. I will fix it.
> as kexec_core_dbg_print. 02/03 I think kexec_dbg_print should be set 
> to false at the end of kimage_free, not at the start. 03/03 There is 
> duplication of debug logs for architectures that already print the 
> same information. For example, arm64. - 
In the kimage_file_alloc_init()/kimage_alloc_init(), if there is an 
abnormal exit before executing *rimage = image,
the image is empty, but kexec_dbg_print has been initialized.
In this case, It needs to be placed at the beginning of kimage_free to 
reset it.
> Sourabh Jain
> On 26/11/25 14:14, Qiang Ma wrote:
>> Overview:
>> =========
>> The commit a85ee18c7900 ("kexec_file: print out debugging message
>> if required") has added general code printing in kexec_file_load(),
>> but not in kexec_load().
>>      Since kexec_load and kexec_file_load are not triggered 
>> simultaneously,
>> we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
>>      Next, we need to do some things in this patchset:
>>      1. rename kexec_file_dbg_print to kexec_dbg_print
>> 2. Add KEXEC_DEBUG
>> 3. Initialize kexec_dbg_print for kexec
>> 4. Fix uninitialized struct kimage *image pointer
>> 5. Set the reset of kexec_dbg_print to kimage_free
>>
>> Testing:
>> =========
>> I did testing on x86_64, arm64 and loongarch. On x86_64, the printed 
>> messages
>> look like below:
>>
>> unset CONFIG_KEXEC_FILE:
>> [   81.502374] kexec: kexec_load: type:0, start:0x23fff7700 
>> head:0x10a4b9002 flags:0x3e0010
>>
>> set CONFIG_KEXEC_FILE
>> [   36.774228] kexec_file: kernel: 0000000066c386c8 kernel_size: 
>> 0xd78400
>> [   36.821814] kexec-bzImage64: Loaded purgatory at 0x23fffb000
>> [   36.821826] kexec-bzImage64: Loaded boot_param, command line and 
>> misc at 0x23fff9000 bufsz=0x12d0 memsz=0x2000
>> [   36.821829] kexec-bzImage64: Loaded 64bit kernel at 0x23d400000 
>> bufsz=0xd73400 memsz=0x2ab7000
>> [   36.821918] kexec-bzImage64: Loaded initrd at 0x23bd0b000 
>> bufsz=0x16f40a8 memsz=0x16f40a8
>> [   36.821920] kexec-bzImage64: Final command line is: 
>> root=/dev/mapper/test-root crashkernel=auto rd.lvm.lv=test/root
>> [   36.821925] kexec-bzImage64: E820 memmap:
>> [   36.821926] kexec-bzImage64: 0000000000000000-000000000009ffff (1)
>> [   36.821928] kexec-bzImage64: 0000000000100000-0000000000811fff (1)
>> [   36.821930] kexec-bzImage64: 0000000000812000-0000000000812fff (2)
>> [   36.821931] kexec-bzImage64: 0000000000813000-00000000bee38fff (1)
>> [   36.821933] kexec-bzImage64: 00000000bee39000-00000000beec2fff (2)
>> [   36.821934] kexec-bzImage64: 00000000beec3000-00000000bf8ecfff (1)
>> [   36.821935] kexec-bzImage64: 00000000bf8ed000-00000000bfb6cfff (2)
>> [   36.821936] kexec-bzImage64: 00000000bfb6d000-00000000bfb7efff (3)
>> [   36.821937] kexec-bzImage64: 00000000bfb7f000-00000000bfbfefff (4)
>> [   36.821938] kexec-bzImage64: 00000000bfbff000-00000000bff7bfff (1)
>> [   36.821939] kexec-bzImage64: 00000000bff7c000-00000000bfffffff (2)
>> [   36.821940] kexec-bzImage64: 00000000feffc000-00000000feffffff (2)
>> [   36.821941] kexec-bzImage64: 00000000ffc00000-00000000ffffffff (2)
>> [   36.821942] kexec-bzImage64: 0000000100000000-000000023fffffff (1)
>> [   36.872348] kexec_file: nr_segments = 4
>> [   36.872356] kexec_file: segment[0]: buf=0x000000005314ece7 
>> bufsz=0x4000 mem=0x23fffb000 memsz=0x5000
>> [   36.872370] kexec_file: segment[1]: buf=0x000000006e59b143 
>> bufsz=0x12d0 mem=0x23fff9000 memsz=0x2000
>> [   36.872374] kexec_file: segment[2]: buf=0x00000000eb7b1fc3 
>> bufsz=0xd73400 mem=0x23d400000 memsz=0x2ab7000
>> [   36.882172] kexec_file: segment[3]: buf=0x000000006af76441 
>> bufsz=0x16f40a8 mem=0x23bd0b000 memsz=0x16f5000
>> [   36.889113] kexec_file: kexec_file_load: type:0, start:0x23fffb150 
>> head:0x101a2e002 flags:0x8
>>
>> Changes in v3:
>> ==========
>> - Rename kexec_core_dbg_print to kexec_dbg_print
>> - Remove unnecessary segments prints
>> - Remove patch "kexec_file: Fix the issue of mismatch between loop 
>> variable types"
>>
>> Qiang Ma (3):
>>    kexec: Fix uninitialized struct kimage *image pointer
>>    kexec: add kexec flag to control debug printing
>>    kexec: print out debugging message if required for kexec_load
>>
>>   include/linux/kexec.h      | 9 +++++----
>>   include/uapi/linux/kexec.h | 1 +
>>   kernel/kexec.c             | 8 +++++++-
>>   kernel/kexec_core.c        | 4 +++-
>>   kernel/kexec_file.c        | 4 +---
>>   5 files changed, 17 insertions(+), 9 deletions(-)
>>
>
>

Hello All,

Do we have plan to support KEXEC_DEBUG flag?

Because upstream kexec-tools already added support for KEXEC_DEBUG flag
and that breaks the kexec_load with -d option.

- kexec: add kexec flag to support debug printing
   https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/commit/?id=71d6fd99af7e


Thanks,
Sourabh Jain


On 26/11/25 14:14, Qiang Ma wrote:
> Overview:
> =========
> The commit a85ee18c7900 ("kexec_file: print out debugging message
> if required") has added general code printing in kexec_file_load(),
> but not in kexec_load().
>      
> Since kexec_load and kexec_file_load are not triggered simultaneously,
> we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
>      
> Next, we need to do some things in this patchset:
>      
> 1. rename kexec_file_dbg_print to kexec_dbg_print
> 2. Add KEXEC_DEBUG
> 3. Initialize kexec_dbg_print for kexec
> 4. Fix uninitialized struct kimage *image pointer
> 5. Set the reset of kexec_dbg_print to kimage_free
>
> Testing:
> =========
> I did testing on x86_64, arm64 and loongarch. On x86_64, the printed messages
> look like below:
>
> unset CONFIG_KEXEC_FILE:
> [   81.502374] kexec: kexec_load: type:0, start:0x23fff7700 head:0x10a4b9002 flags:0x3e0010
>
> set CONFIG_KEXEC_FILE
> [   36.774228] kexec_file: kernel: 0000000066c386c8 kernel_size: 0xd78400
> [   36.821814] kexec-bzImage64: Loaded purgatory at 0x23fffb000
> [   36.821826] kexec-bzImage64: Loaded boot_param, command line and misc at 0x23fff9000 bufsz=0x12d0 memsz=0x2000
> [   36.821829] kexec-bzImage64: Loaded 64bit kernel at 0x23d400000 bufsz=0xd73400 memsz=0x2ab7000
> [   36.821918] kexec-bzImage64: Loaded initrd at 0x23bd0b000 bufsz=0x16f40a8 memsz=0x16f40a8
> [   36.821920] kexec-bzImage64: Final command line is: root=/dev/mapper/test-root crashkernel=auto rd.lvm.lv=test/root
> [   36.821925] kexec-bzImage64: E820 memmap:
> [   36.821926] kexec-bzImage64: 0000000000000000-000000000009ffff (1)
> [   36.821928] kexec-bzImage64: 0000000000100000-0000000000811fff (1)
> [   36.821930] kexec-bzImage64: 0000000000812000-0000000000812fff (2)
> [   36.821931] kexec-bzImage64: 0000000000813000-00000000bee38fff (1)
> [   36.821933] kexec-bzImage64: 00000000bee39000-00000000beec2fff (2)
> [   36.821934] kexec-bzImage64: 00000000beec3000-00000000bf8ecfff (1)
> [   36.821935] kexec-bzImage64: 00000000bf8ed000-00000000bfb6cfff (2)
> [   36.821936] kexec-bzImage64: 00000000bfb6d000-00000000bfb7efff (3)
> [   36.821937] kexec-bzImage64: 00000000bfb7f000-00000000bfbfefff (4)
> [   36.821938] kexec-bzImage64: 00000000bfbff000-00000000bff7bfff (1)
> [   36.821939] kexec-bzImage64: 00000000bff7c000-00000000bfffffff (2)
> [   36.821940] kexec-bzImage64: 00000000feffc000-00000000feffffff (2)
> [   36.821941] kexec-bzImage64: 00000000ffc00000-00000000ffffffff (2)
> [   36.821942] kexec-bzImage64: 0000000100000000-000000023fffffff (1)
> [   36.872348] kexec_file: nr_segments = 4
> [   36.872356] kexec_file: segment[0]: buf=0x000000005314ece7 bufsz=0x4000 mem=0x23fffb000 memsz=0x5000
> [   36.872370] kexec_file: segment[1]: buf=0x000000006e59b143 bufsz=0x12d0 mem=0x23fff9000 memsz=0x2000
> [   36.872374] kexec_file: segment[2]: buf=0x00000000eb7b1fc3 bufsz=0xd73400 mem=0x23d400000 memsz=0x2ab7000
> [   36.882172] kexec_file: segment[3]: buf=0x000000006af76441 bufsz=0x16f40a8 mem=0x23bd0b000 memsz=0x16f5000
> [   36.889113] kexec_file: kexec_file_load: type:0, start:0x23fffb150 head:0x101a2e002 flags:0x8
>
> Changes in v3:
> ==========
> - Rename kexec_core_dbg_print to kexec_dbg_print
> - Remove unnecessary segments prints
> - Remove patch "kexec_file: Fix the issue of mismatch between loop variable types"
>
> Qiang Ma (3):
>    kexec: Fix uninitialized struct kimage *image pointer
>    kexec: add kexec flag to control debug printing
>    kexec: print out debugging message if required for kexec_load
>
>   include/linux/kexec.h      | 9 +++++----
>   include/uapi/linux/kexec.h | 1 +
>   kernel/kexec.c             | 8 +++++++-
>   kernel/kexec_core.c        | 4 +++-
>   kernel/kexec_file.c        | 4 +---
>   5 files changed, 17 insertions(+), 9 deletions(-)
>

On 11/27/25 at 05:31pm, Sourabh Jain wrote:
> Hello All,
> 
> Do we have plan to support KEXEC_DEBUG flag?
> 
> Because upstream kexec-tools already added support for KEXEC_DEBUG flag
> and that breaks the kexec_load with -d option.
> 
> - kexec: add kexec flag to support debug printing
>   https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/commit/?id=71d6fd99af7e

I think we should revert that kexec-tools commit. This whole patchset is
non-sense. Because of my carelessness, that userspace patch was merged.

Hi Sourabh,

Could you go through this patchset and help check if they are really
needed? I can't find anything to convince myself. Thanks.

Hello Baoquan,

On 27/11/25 21:00, Baoquan He wrote:
> On 11/27/25 at 05:31pm, Sourabh Jain wrote:
>> Hello All,
>>
>> Do we have plan to support KEXEC_DEBUG flag?
>>
>> Because upstream kexec-tools already added support for KEXEC_DEBUG flag
>> and that breaks the kexec_load with -d option.
>>
>> - kexec: add kexec flag to support debug printing
>>    https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/commit/?id=71d6fd99af7e
> I think we should revert that kexec-tools commit.

Yeah, userspace changes shouldn't go in until the kernel patches are
finalized. It seems that there are disagreements regarding the approach
and usefulness of this patch series, so reverting the kexec-tools patch
might be the right thing to avoid breaking anything for now.

I have one question: should the kernel advertise KEXEC_DEBUG so that
backward compatibility can be maintained between the kernel and
kexec-tools? Or is that too much for a debugging flag? How was backward
compatibility handled when we added the KEXEC_FILE_DEBUG flag?

> This whole patchset is
> non-sense. Because of my carelessness, that userspace patch was merged.
>
> Hi Sourabh,
>
> Could you go through this patchset and help check if they are really
> needed? I can't find anything to convince myself. Thanks.

Sure I will review this patch series.

Thanks,
Sourabh Jain

On 11/28/25 at 03:11pm, Sourabh Jain wrote:
> Hello Baoquan,
> 
> On 27/11/25 21:00, Baoquan He wrote:
> > On 11/27/25 at 05:31pm, Sourabh Jain wrote:
> > > Hello All,
> > > 
> > > Do we have plan to support KEXEC_DEBUG flag?
> > > 
> > > Because upstream kexec-tools already added support for KEXEC_DEBUG flag
> > > and that breaks the kexec_load with -d option.
> > > 
> > > - kexec: add kexec flag to support debug printing
> > >    https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/commit/?id=71d6fd99af7e
> > I think we should revert that kexec-tools commit.
> 
> Yeah, userspace changes shouldn't go in until the kernel patches are
> finalized. It seems that there are disagreements regarding the approach
> and usefulness of this patch series, so reverting the kexec-tools patch
> might be the right thing to avoid breaking anything for now.

The patch 1 is issue fixing, that is a good one. While patch 2, 3 are
trying to add debugging printing for kexec_load interface which I think
is not needed. I added debugging printing for kexec_file_load because I
has been using 'kexec -d' to debug for kexec_load while kexec_file_load
didn't have. So I mimicked kexec_load's debugging printing to add one
for kexec_file_load. Now patch 2,3's adding doesn't make sense as he
said he is doing for future need.

> 
> I have one question: should the kernel advertise KEXEC_DEBUG so that
> backward compatibility can be maintained between the kernel and
> kexec-tools? Or is that too much for a debugging flag? How was backward
> compatibility handled when we added the KEXEC_FILE_DEBUG flag?

When I added KEXEC_FILE_DEBUG, I didn't consider backward compatibility.
That is making the then latest kernel match the then latest kexec-tools.

> 
> > This whole patchset is
> > non-sense. Because of my carelessness, that userspace patch was merged.
> > 
> > Hi Sourabh,
> > 
> > Could you go through this patchset and help check if they are really
> > needed? I can't find anything to convince myself. Thanks.
> 
> Sure I will review this patch series.

Thanks. Please check patch 2,3 to see if we really need the debugging
printing for kexec_load, or its adding really brings benefit even if
it's a little bit compared with the mess it brings; and if my objecting
is too subjective.

Thanks
Baoquan

Hi,

On 11/26/25 at 04:44pm, Qiang Ma wrote:
> Overview:
> =========
> The commit a85ee18c7900 ("kexec_file: print out debugging message
> if required") has added general code printing in kexec_file_load(),
> but not in kexec_load().
>     
> Since kexec_load and kexec_file_load are not triggered simultaneously,
> we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.

As I said in your last post, this is not needed at all, you just add a
not needed thing to kernel.

So NACK this patchset, unless you have reason to justify it. Sorry about
it.

Thanks
Baoquan

>     
> Next, we need to do some things in this patchset:
>     
> 1. rename kexec_file_dbg_print to kexec_dbg_print
> 2. Add KEXEC_DEBUG
> 3. Initialize kexec_dbg_print for kexec
> 4. Fix uninitialized struct kimage *image pointer 
> 5. Set the reset of kexec_dbg_print to kimage_free
> 
> Testing:
> =========
> I did testing on x86_64, arm64 and loongarch. On x86_64, the printed messages
> look like below:
> 
> unset CONFIG_KEXEC_FILE:
> [   81.502374] kexec: kexec_load: type:0, start:0x23fff7700 head:0x10a4b9002 flags:0x3e0010
> 
> set CONFIG_KEXEC_FILE
> [   36.774228] kexec_file: kernel: 0000000066c386c8 kernel_size: 0xd78400
> [   36.821814] kexec-bzImage64: Loaded purgatory at 0x23fffb000
> [   36.821826] kexec-bzImage64: Loaded boot_param, command line and misc at 0x23fff9000 bufsz=0x12d0 memsz=0x2000
> [   36.821829] kexec-bzImage64: Loaded 64bit kernel at 0x23d400000 bufsz=0xd73400 memsz=0x2ab7000
> [   36.821918] kexec-bzImage64: Loaded initrd at 0x23bd0b000 bufsz=0x16f40a8 memsz=0x16f40a8
> [   36.821920] kexec-bzImage64: Final command line is: root=/dev/mapper/test-root crashkernel=auto rd.lvm.lv=test/root
> [   36.821925] kexec-bzImage64: E820 memmap:
> [   36.821926] kexec-bzImage64: 0000000000000000-000000000009ffff (1)
> [   36.821928] kexec-bzImage64: 0000000000100000-0000000000811fff (1)
> [   36.821930] kexec-bzImage64: 0000000000812000-0000000000812fff (2)
> [   36.821931] kexec-bzImage64: 0000000000813000-00000000bee38fff (1)
> [   36.821933] kexec-bzImage64: 00000000bee39000-00000000beec2fff (2)
> [   36.821934] kexec-bzImage64: 00000000beec3000-00000000bf8ecfff (1)
> [   36.821935] kexec-bzImage64: 00000000bf8ed000-00000000bfb6cfff (2)
> [   36.821936] kexec-bzImage64: 00000000bfb6d000-00000000bfb7efff (3)
> [   36.821937] kexec-bzImage64: 00000000bfb7f000-00000000bfbfefff (4)
> [   36.821938] kexec-bzImage64: 00000000bfbff000-00000000bff7bfff (1)
> [   36.821939] kexec-bzImage64: 00000000bff7c000-00000000bfffffff (2)
> [   36.821940] kexec-bzImage64: 00000000feffc000-00000000feffffff (2)
> [   36.821941] kexec-bzImage64: 00000000ffc00000-00000000ffffffff (2)
> [   36.821942] kexec-bzImage64: 0000000100000000-000000023fffffff (1)
> [   36.872348] kexec_file: nr_segments = 4
> [   36.872356] kexec_file: segment[0]: buf=0x000000005314ece7 bufsz=0x4000 mem=0x23fffb000 memsz=0x5000
> [   36.872370] kexec_file: segment[1]: buf=0x000000006e59b143 bufsz=0x12d0 mem=0x23fff9000 memsz=0x2000
> [   36.872374] kexec_file: segment[2]: buf=0x00000000eb7b1fc3 bufsz=0xd73400 mem=0x23d400000 memsz=0x2ab7000
> [   36.882172] kexec_file: segment[3]: buf=0x000000006af76441 bufsz=0x16f40a8 mem=0x23bd0b000 memsz=0x16f5000
> [   36.889113] kexec_file: kexec_file_load: type:0, start:0x23fffb150 head:0x101a2e002 flags:0x8
> 
> Changes in v3:
> ==========
> - Rename kexec_core_dbg_print to kexec_dbg_print
> - Remove unnecessary segments prints
> - Remove patch "kexec_file: Fix the issue of mismatch between loop variable types"
> 
> Qiang Ma (3):
>   kexec: Fix uninitialized struct kimage *image pointer
>   kexec: add kexec flag to control debug printing
>   kexec: print out debugging message if required for kexec_load
> 
>  include/linux/kexec.h      | 9 +++++----
>  include/uapi/linux/kexec.h | 1 +
>  kernel/kexec.c             | 8 +++++++-
>  kernel/kexec_core.c        | 4 +++-
>  kernel/kexec_file.c        | 4 +---
>  5 files changed, 17 insertions(+), 9 deletions(-)
> 
> -- 
> 2.20.1
>

在 2025/11/27 09:47, Baoquan He 写道:
> Hi,
>
> On 11/26/25 at 04:44pm, Qiang Ma wrote:
>> Overview:
>> =========
>> The commit a85ee18c7900 ("kexec_file: print out debugging message
>> if required") has added general code printing in kexec_file_load(),
>> but not in kexec_load().
>>      
>> Since kexec_load and kexec_file_load are not triggered simultaneously,
>> we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
> As I said in your last post, this is not needed at all, you just add a
> not needed thing to kernel.
>
> So NACK this patchset, unless you have reason to justify it. Sorry about
> it.
The segment prints discussed in the last post,

this patchset has been removed, leaving only type/start/head of kimage 
and flags.


I think the current patchset is still necessary.
For example, renaming kexec_file_dbg_print is still necessary, but not 
for kexec_file.


> Thanks
> Baoquan
>
>>      
>> Next, we need to do some things in this patchset:
>>      
>> 1. rename kexec_file_dbg_print to kexec_dbg_print
>> 2. Add KEXEC_DEBUG
>> 3. Initialize kexec_dbg_print for kexec
>> 4. Fix uninitialized struct kimage *image pointer
>> 5. Set the reset of kexec_dbg_print to kimage_free
>>
>> Testing:
>> =========
>> I did testing on x86_64, arm64 and loongarch. On x86_64, the printed messages
>> look like below:
>>
>> unset CONFIG_KEXEC_FILE:
>> [   81.502374] kexec: kexec_load: type:0, start:0x23fff7700 head:0x10a4b9002 flags:0x3e0010
>>
>> set CONFIG_KEXEC_FILE
>> [   36.774228] kexec_file: kernel: 0000000066c386c8 kernel_size: 0xd78400
>> [   36.821814] kexec-bzImage64: Loaded purgatory at 0x23fffb000
>> [   36.821826] kexec-bzImage64: Loaded boot_param, command line and misc at 0x23fff9000 bufsz=0x12d0 memsz=0x2000
>> [   36.821829] kexec-bzImage64: Loaded 64bit kernel at 0x23d400000 bufsz=0xd73400 memsz=0x2ab7000
>> [   36.821918] kexec-bzImage64: Loaded initrd at 0x23bd0b000 bufsz=0x16f40a8 memsz=0x16f40a8
>> [   36.821920] kexec-bzImage64: Final command line is: root=/dev/mapper/test-root crashkernel=auto rd.lvm.lv=test/root
>> [   36.821925] kexec-bzImage64: E820 memmap:
>> [   36.821926] kexec-bzImage64: 0000000000000000-000000000009ffff (1)
>> [   36.821928] kexec-bzImage64: 0000000000100000-0000000000811fff (1)
>> [   36.821930] kexec-bzImage64: 0000000000812000-0000000000812fff (2)
>> [   36.821931] kexec-bzImage64: 0000000000813000-00000000bee38fff (1)
>> [   36.821933] kexec-bzImage64: 00000000bee39000-00000000beec2fff (2)
>> [   36.821934] kexec-bzImage64: 00000000beec3000-00000000bf8ecfff (1)
>> [   36.821935] kexec-bzImage64: 00000000bf8ed000-00000000bfb6cfff (2)
>> [   36.821936] kexec-bzImage64: 00000000bfb6d000-00000000bfb7efff (3)
>> [   36.821937] kexec-bzImage64: 00000000bfb7f000-00000000bfbfefff (4)
>> [   36.821938] kexec-bzImage64: 00000000bfbff000-00000000bff7bfff (1)
>> [   36.821939] kexec-bzImage64: 00000000bff7c000-00000000bfffffff (2)
>> [   36.821940] kexec-bzImage64: 00000000feffc000-00000000feffffff (2)
>> [   36.821941] kexec-bzImage64: 00000000ffc00000-00000000ffffffff (2)
>> [   36.821942] kexec-bzImage64: 0000000100000000-000000023fffffff (1)
>> [   36.872348] kexec_file: nr_segments = 4
>> [   36.872356] kexec_file: segment[0]: buf=0x000000005314ece7 bufsz=0x4000 mem=0x23fffb000 memsz=0x5000
>> [   36.872370] kexec_file: segment[1]: buf=0x000000006e59b143 bufsz=0x12d0 mem=0x23fff9000 memsz=0x2000
>> [   36.872374] kexec_file: segment[2]: buf=0x00000000eb7b1fc3 bufsz=0xd73400 mem=0x23d400000 memsz=0x2ab7000
>> [   36.882172] kexec_file: segment[3]: buf=0x000000006af76441 bufsz=0x16f40a8 mem=0x23bd0b000 memsz=0x16f5000
>> [   36.889113] kexec_file: kexec_file_load: type:0, start:0x23fffb150 head:0x101a2e002 flags:0x8
>>
>> Changes in v3:
>> ==========
>> - Rename kexec_core_dbg_print to kexec_dbg_print
>> - Remove unnecessary segments prints
>> - Remove patch "kexec_file: Fix the issue of mismatch between loop variable types"
>>
>> Qiang Ma (3):
>>    kexec: Fix uninitialized struct kimage *image pointer
>>    kexec: add kexec flag to control debug printing
>>    kexec: print out debugging message if required for kexec_load
>>
>>   include/linux/kexec.h      | 9 +++++----
>>   include/uapi/linux/kexec.h | 1 +
>>   kernel/kexec.c             | 8 +++++++-
>>   kernel/kexec_core.c        | 4 +++-
>>   kernel/kexec_file.c        | 4 +---
>>   5 files changed, 17 insertions(+), 9 deletions(-)
>>
>> -- 
>> 2.20.1
>>
>

On 11/27/25 at 10:04am, Qiang Ma wrote:
> 
> 在 2025/11/27 09:47, Baoquan He 写道:
> > Hi,
> > 
> > On 11/26/25 at 04:44pm, Qiang Ma wrote:
> > > Overview:
> > > =========
> > > The commit a85ee18c7900 ("kexec_file: print out debugging message
> > > if required") has added general code printing in kexec_file_load(),
> > > but not in kexec_load().
> > > Since kexec_load and kexec_file_load are not triggered simultaneously,
> > > we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
> > As I said in your last post, this is not needed at all, you just add a
> > not needed thing to kernel.
> > 
> > So NACK this patchset, unless you have reason to justify it. Sorry about
> > it.
> The segment prints discussed in the last post,
> 
> this patchset has been removed, leaving only type/start/head of kimage and
> flags.
> 
> 
> I think the current patchset is still necessary.
> For example, renaming kexec_file_dbg_print is still necessary, but not for
> kexec_file.

How come renaming kexec_file_dbg_print is a justification in this case.

No, kexec_file_dbg_print is named because it's only for kexec_file
debugging printing. Because we have had enough debugging printing for
kexec_load interface. Do you have difficulty on debugging printing of
kexec_load? 

在 2025/11/27 10:36, Baoquan He 写道:
> On 11/27/25 at 10:04am, Qiang Ma wrote:
>> 在 2025/11/27 09:47, Baoquan He 写道:
>>> Hi,
>>>
>>> On 11/26/25 at 04:44pm, Qiang Ma wrote:
>>>> Overview:
>>>> =========
>>>> The commit a85ee18c7900 ("kexec_file: print out debugging message
>>>> if required") has added general code printing in kexec_file_load(),
>>>> but not in kexec_load().
>>>> Since kexec_load and kexec_file_load are not triggered simultaneously,
>>>> we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
>>> As I said in your last post, this is not needed at all, you just add a
>>> not needed thing to kernel.
>>>
>>> So NACK this patchset, unless you have reason to justify it. Sorry about
>>> it.
>> The segment prints discussed in the last post,
>>
>> this patchset has been removed, leaving only type/start/head of kimage and
>> flags.
>>
>>
>> I think the current patchset is still necessary.
>> For example, renaming kexec_file_dbg_print is still necessary, but not for
>> kexec_file.
> How come renaming kexec_file_dbg_print is a justification in this case.
>
> No, kexec_file_dbg_print is named because it's only for kexec_file
> debugging printing. Because we have had enough debugging printing for
> kexec_load interface. Do you have difficulty on debugging printing of
> kexec_load?
It's sufficient now, but there might be a need in the future.
Also, there's kexec_dprintk. Judging from its name, it seems like a 
universal kexec print.
Looking at the code, it feels like not only the kexec_file interface 
path uses it for printing.

So, would it be better to rename kexec_file_dbg_print to kexec_dbg_print.


>
>

On 11/27/25 at 11:00am, Qiang Ma wrote:
> 
> 在 2025/11/27 10:36, Baoquan He 写道:
> > On 11/27/25 at 10:04am, Qiang Ma wrote:
> > > 在 2025/11/27 09:47, Baoquan He 写道:
> > > > Hi,
> > > > 
> > > > On 11/26/25 at 04:44pm, Qiang Ma wrote:
> > > > > Overview:
> > > > > =========
> > > > > The commit a85ee18c7900 ("kexec_file: print out debugging message
> > > > > if required") has added general code printing in kexec_file_load(),
> > > > > but not in kexec_load().
> > > > > Since kexec_load and kexec_file_load are not triggered simultaneously,
> > > > > we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
> > > > As I said in your last post, this is not needed at all, you just add a
> > > > not needed thing to kernel.
> > > > 
> > > > So NACK this patchset, unless you have reason to justify it. Sorry about
> > > > it.
> > > The segment prints discussed in the last post,
> > > 
> > > this patchset has been removed, leaving only type/start/head of kimage and
> > > flags.
> > > 
> > > 
> > > I think the current patchset is still necessary.
> > > For example, renaming kexec_file_dbg_print is still necessary, but not for
> > > kexec_file.
> > How come renaming kexec_file_dbg_print is a justification in this case.
> > 
> > No, kexec_file_dbg_print is named because it's only for kexec_file
> > debugging printing. Because we have had enough debugging printing for
> > kexec_load interface. Do you have difficulty on debugging printing of
> > kexec_load?
> It's sufficient now, but there might be a need in the future.
> Also, there's kexec_dprintk. Judging from its name, it seems like a

Hmm, as I ever said in earlier discussion, kexec sometime means generic
handling including kexec_load and kexec_file_load interfaces. Both possible
future need and kexec_dprintk which seems a little ambiguous to you are
not justified. We do not suggest adding these meaningless code to
kernel. Please do't continue spending effort on this, that is not good.

I welcome cleanup/refactoring/fix for kexec/kdump to improve code, but
adding non-reasonable code is not included.

> universal kexec print.
> Looking at the code, it feels like not only the kexec_file interface path
> uses it for printing.
> 
> So, would it be better to rename kexec_file_dbg_print to kexec_dbg_print.
> 
> 
> > 
> > 
> 

在 2025/11/27 11:55, Baoquan He 写道:
> On 11/27/25 at 11:00am, Qiang Ma wrote:
>> 在 2025/11/27 10:36, Baoquan He 写道:
>>> On 11/27/25 at 10:04am, Qiang Ma wrote:
>>>> 在 2025/11/27 09:47, Baoquan He 写道:
>>>>> Hi,
>>>>>
>>>>> On 11/26/25 at 04:44pm, Qiang Ma wrote:
>>>>>> Overview:
>>>>>> =========
>>>>>> The commit a85ee18c7900 ("kexec_file: print out debugging message
>>>>>> if required") has added general code printing in kexec_file_load(),
>>>>>> but not in kexec_load().
>>>>>> Since kexec_load and kexec_file_load are not triggered simultaneously,
>>>>>> we can unify the debug flag of kexec and kexec_file as kexec_dbg_print.
>>>>> As I said in your last post, this is not needed at all, you just add a
>>>>> not needed thing to kernel.
>>>>>
>>>>> So NACK this patchset, unless you have reason to justify it. Sorry about
>>>>> it.
>>>> The segment prints discussed in the last post,
>>>>
>>>> this patchset has been removed, leaving only type/start/head of kimage and
>>>> flags.
>>>>
>>>>
>>>> I think the current patchset is still necessary.
>>>> For example, renaming kexec_file_dbg_print is still necessary, but not for
>>>> kexec_file.
>>> How come renaming kexec_file_dbg_print is a justification in this case.
>>>
>>> No, kexec_file_dbg_print is named because it's only for kexec_file
>>> debugging printing. Because we have had enough debugging printing for
>>> kexec_load interface. Do you have difficulty on debugging printing of
>>> kexec_load?
>> It's sufficient now, but there might be a need in the future.
>> Also, there's kexec_dprintk. Judging from its name, it seems like a
> Hmm, as I ever said in earlier discussion, kexec sometime means generic
> handling including kexec_load and kexec_file_load interfaces. Both possible
> future need and kexec_dprintk which seems a little ambiguous to you are
> not justified. We do not suggest adding these meaningless code to
> kernel. Please do't continue spending effort on this, that is not good.
>
> I welcome cleanup/refactoring/fix for kexec/kdump to improve code, but
> adding non-reasonable code is not included.
I agree that meaningless code should not be added to the kernel,
but it is meaningful for this patchset and has reasonable reasons.

Let me summarize again the purpose of submitting this patchset:

First, unify the print flag of kexec_file and kexec as kexec_dbg_print,
so that both kexec and kexec_file can be used both now and in the future.

Secondly, in the current code, for instance, I saw in the arm64 code
that under the kexec_load interface, the kexec_image_info() already uses 
kexec_dprintk.
When unset CONFIG_KEXEC_FILE, specifying '-d' for kexec_load interface, 
print nothing in the kernel space.
static void _kexec_image_info(const char *func, int line,
         const struct kimage *kimage)
{
         kexec_dprintk("%s:%d:\n", func, line);
         kexec_dprintk("  kexec kimage info:\n");
         kexec_dprintk("    type:        %d\n", kimage->type);

         kexec_dprintk("    head:        %lx\n", kimage->head);


Thirdly, for instance, in the arm64 code, the kexec_image_info() prints 
type/head of kimage,
while in the RISC-V code, the type/head of kimage under kexec_load and 
kexec_file_load is removed.
We can remove the print(type/head of kimage) in arm64, and then add it 
to the general code.

For points 1 and 2, Patch 2 can implement: "kexec: add kexec flag to 
control debug printing"
For point 3, Patch 3 can be implemented: "kexec: print out debugging 
message if required for kexec_load"

Additionally, if it is necessary to remove the type/head of kimage 
printed in the kexec_image_info()
in the arm64 code, another patch can be provided.
>> universal kexec print.
>> Looking at the code, it feels like not only the kexec_file interface path
>> uses it for printing.
>>
>> So, would it be better to rename kexec_file_dbg_print to kexec_dbg_print.
>>
>>
>>>
>