Re: [PATCH v5 11/17] crash: Normalize the kexec_load elfcorehdr at load time

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] kexec: elfcorehdr_updated in struct kimage is write-only and unused
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commit 463b7b7692d8e96dc1be8ffaed1b6d0c8d298c9f
Author: Jinjie Ruan <[email protected]>

crash: Normalize the kexec_load elfcorehdr at load time

This commit changes kexec_load to normalize the elfcorehdr at load time
instead of waiting for the first crash hotplug event. By doing this while
the device_hotplug_lock can be safely taken, it allows hotplug paths to
skip CPU events safely and avoid racing with memory hotplug.

> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index 3c9f4fbbe7ff0..f34fa8dba0288 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -457,9 +457,8 @@ void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
>  	 * possible CPUs, there is no need to update the elfcorehdr
>  	 * for additional CPU changes.
>  	 */
> -	if ((image->file_mode || image->elfcorehdr_updated) &&
> -		((image->hp_action == KEXEC_CRASH_HP_ADD_CPU) ||
> -		(image->hp_action == KEXEC_CRASH_HP_REMOVE_CPU)))
> +	if (image->hp_action == KEXEC_CRASH_HP_ADD_CPU ||
> +	    image->hp_action == KEXEC_CRASH_HP_REMOVE_CPU)
>  		return;

[Severity: Low]
Does this leave elfcorehdr_updated as a write-only and unused field?

Since this patch removes the last reader of image->elfcorehdr_updated,
the field is now only written to in crash_handle_hotplug_event() and
initialized in kernel/kexec_core.c:

kernel/crash_core.c:crash_handle_hotplug_event() {
    ...
    image->hp_action = KEXEC_CRASH_HP_NONE;
    image->elfcorehdr_updated = true;
    ...
}

Should the elfcorehdr_updated field be completely removed from struct kimage
in include/linux/kexec.h along with its assignments to avoid dead code and
structure overhead?

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Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=11