Re: [PATCH v10 6/8] ima: kexec: move IMA log copy from kexec load to execute

[steven chen <chenste@linux.microsoft.com>]

On 3/25/2025 7:27 PM, Baoquan He wrote:
> On 03/25/25 at 03:27pm, steven chen wrote:
>> On 3/24/2025 4:00 AM, Baoquan He wrote:
>>> On 03/21/25 at 09:23am, steven chen wrote:
>>>> On 3/19/2025 7:06 PM, Baoquan He wrote:
>>>>> On 03/17/25 at 06:04pm, steven chen wrote:
>>>>> ...snip...
>>>>>> ---
>>>>>>     kernel/kexec_file.c                | 10 ++++++
>>>>>>     security/integrity/ima/ima_kexec.c | 51 ++++++++++++++++++------------
>>>>>>     2 files changed, 40 insertions(+), 21 deletions(-)
>>>>>>
>>>>>> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
>>>>>> index 606132253c79..ab449b43aaee 100644
>>>>>> --- a/kernel/kexec_file.c
>>>>>> +++ b/kernel/kexec_file.c
>>>>>> @@ -201,6 +201,13 @@ kimage_validate_signature(struct kimage *image)
>>>>>>     }
>>>>>>     #endif
>>>>>> +static void kimage_file_post_load(struct kimage *image)
>>>>>> +{
>>>>>> +#ifdef CONFIG_IMA_KEXEC
>>>>>> +	ima_kexec_post_load(image);
>>>>>> +#endif
>>>>>> +}
>>>>>> +
>>>>>>     /*
>>>>>>      * In file mode list of segments is prepared by kernel. Copy relevant
>>>>>>      * data from user space, do error checking, prepare segment list
>>>>>> @@ -428,6 +435,9 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
>>>>>>     	kimage_terminate(image);
>>>>>> +	if (!(flags & KEXEC_FILE_ON_CRASH))
>>>>>> +		kimage_file_post_load(image);
>>>>> machine_kexec_post_load() is called by both kexec_load and kexec_file_load,
>>>>> we should use it to do things post load, but not introducing another
>>>>> kimage_file_post_load().
>>>> Hi Baoquan,
>>>>
>>>> Could you give me more detail about this?
>>> I mean machine_kexec_post_load() is the place where post load operations
>>> are done, including kexec_load and kexec_file_load. There's no need to
>>> specifically introduce a kimage_file_post_load() to do post load
>>> operaton for kexec_file_load.
>> Hi Baoquan,
>>
>> Updating the machine_kexec_post_load() API to carry flags would indeed
>> require changes to multiple files. This approach involves the condition
>> check if (!(flags & KEXEC_FILE_ON_CRASH)) and ensuring that the flags are
>> properly passed and handled across the relevant file
>>
>> if just adding a API kimage_file_post_load() here, it is much easy and
>> clean, right?
> Hmm, it's easier, while maybe not good. We should not repeatedly
> introduce similar things into codes. Here, it's similar as
> what kexec_apply_relocations() and arch_kexec_apply_relocations() are
> doing.
>
> int machine_kexec_post_load(struct kimage *image)
> {
> #ifdef CONFIG_IMA_KEXEC
>          ima_kexec_post_load(image);
> #endif
> 	return arch_machine_kexec_post_load();
> }
>
> Then a generic arch_machine_kexec_post_load(struct kimage *image)
> {return 0;} version, and a arm64 specific version.
>
> Is it OK to you?

Hi Baoquan,

Thanks for your suggestion. I will update in the next version.

Steven