[PATCH -next 0/2] two fixes in kho_populate()

[PATCH -next 0/2] two fixes in kho_populate()

[ranxiaokai627]

From: Ran Xiaokai <ran.xiaokai@zte.com.cn>

Patch1 fixes unpaired call of early_memmap()/early_memunmap()
Patch2 cleans up unnecessary call of WARN_ON()

Ran Xiaokai (2):
  kho: fix missing early_memunmap() call in kho_populate()
  kho: remove unnecessary WARN_ON(err) in kho_populate()

 kernel/liveupdate/kexec_handover.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

-- 
2.25.1

Re: [PATCH -next 2/2] kho: remove unnecessary WARN_ON(err) in kho_populate()

[Pasha Tatashin]

On Thu, Feb 5, 2026 at 11:31 PM <ranxiaokai627@163.com> wrote:
>
> From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>
> The following pr_warn() provides detailed error and location
> information, WARN_ON(err) adds no additional debugging value,
> so remove the redundant WARN_ON() call.
>
> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
> ---
>  kernel/liveupdate/kexec_handover.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
> index 76b714db175d..b851b09a8e99 100644
> --- a/kernel/liveupdate/kexec_handover.c
> +++ b/kernel/liveupdate/kexec_handover.c
> @@ -1507,7 +1507,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
>
>                 memblock_add(area->addr, size);
>                 err = memblock_mark_kho_scratch(area->addr, size);
> -               if (WARN_ON(err)) {
> +               if (err) {
>                         pr_warn("failed to mark the scratch region 0x%pa+0x%pa: %pe",
>                                 &area->addr, &size, ERR_PTR(err));
>                         goto err_unmap_scratch;
> --
> 2.25.1
>
>
>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>

Re: [PATCH -next 2/2] kho: remove unnecessary WARN_ON(err) in kho_populate()

[Pratyush Yadav]

On Fri, Feb 06 2026, ranxiaokai627@163.com wrote:

> From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>
> The following pr_warn() provides detailed error and location
> information, WARN_ON(err) adds no additional debugging value,
> so remove the redundant WARN_ON() call.
>
> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>

Reviewed-by: Pratyush Yadav <pratyush@kernel.org>

[...]

-- 
Regards,
Pratyush Yadav

Re: [PATCH -next 1/2] kho: fix missing early_memunmap() call in kho_populate()

[Pratyush Yadav]

Hi Ran,

Thanks for the fix.

On Fri, Feb 06 2026, ranxiaokai627@163.com wrote:

> From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>
> kho_populate() returns without calling early_memunmap() on success
> path, this will cause early ioremap virtual address space leak.
>
> Fixes: b50634c5e84a ("kho: cleanup error handling in kho_populate()")
> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
> ---
>
> b50634c5e84a ("kho: cleanup error handling in kho_populate()")
> has not landed in upstream, so
> Cc: <stable@vger.kernel.org> is unnecessary?
>
>  kernel/liveupdate/kexec_handover.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
> index fb3a7b67676e..76b714db175d 100644
> --- a/kernel/liveupdate/kexec_handover.c
> +++ b/kernel/liveupdate/kexec_handover.c
> @@ -1463,6 +1463,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
>  	struct kho_scratch *scratch = NULL;
>  	phys_addr_t mem_map_phys;
>  	void *fdt = NULL;
> +	int populated = 0;

Nit: Please use a bool and true/false. I think it reads much nicer.

>  	int err;
>  
>  	/* Validate the input FDT */
> @@ -1529,16 +1530,17 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
>  	kho_in.scratch_phys = scratch_phys;
>  	kho_in.mem_map_phys = mem_map_phys;
>  	kho_scratch_cnt = scratch_cnt;
> -	pr_info("found kexec handover data.\n");
>  
> -	return;
> +	populated = 1;
> +	pr_info("found kexec handover data.\n");
>  
>  err_unmap_scratch:
>  	early_memunmap(scratch, scratch_len);
>  err_unmap_fdt:
>  	early_memunmap(fdt, fdt_len);
>  err_report:

Nit: now that this code can be reached by non-error paths, we should
re-name the labels. I think dropping the "err_" prefix should be enough.

With these fixed,

Reviewed-by: Pratyush Yadav <pratyush@kernel.org>

> -	pr_warn("disabling KHO revival\n");
> +	if (!populated)
> +		pr_warn("disabling KHO revival\n");
>  }
>  
>  /* Helper functions for kexec_file_load */

-- 
Regards,
Pratyush Yadav

Re: [PATCH -next 1/2] kho: fix missing early_memunmap() call in kho_populate()

[ranxiaokai627]

>Hi Ran,
>
>Thanks for the fix.
>
>On Fri, Feb 06 2026, ranxiaokai627@163.com wrote:
>
>> From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>>
>> kho_populate() returns without calling early_memunmap() on success
>> path, this will cause early ioremap virtual address space leak.
>>
>> Fixes: b50634c5e84a ("kho: cleanup error handling in kho_populate()")
>> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>> ---
>>
>> b50634c5e84a ("kho: cleanup error handling in kho_populate()")
>> has not landed in upstream, so
>> Cc: <stable@vger.kernel.org> is unnecessary?
>>
>>  kernel/liveupdate/kexec_handover.c | 8 +++++---
>>  1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
>> index fb3a7b67676e..76b714db175d 100644
>> --- a/kernel/liveupdate/kexec_handover.c
>> +++ b/kernel/liveupdate/kexec_handover.c
>> @@ -1463,6 +1463,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
>>  	struct kho_scratch *scratch = NULL;
>>  	phys_addr_t mem_map_phys;
>>  	void *fdt = NULL;
>> +	int populated = 0;
>
>Nit: Please use a bool and true/false. I think it reads much nicer.

yes.

>>  	int err;
>>  
>>  	/* Validate the input FDT */
>> @@ -1529,16 +1530,17 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
>>  	kho_in.scratch_phys = scratch_phys;
>>  	kho_in.mem_map_phys = mem_map_phys;
>>  	kho_scratch_cnt = scratch_cnt;
>> -	pr_info("found kexec handover data.\n");
>>  
>> -	return;
>> +	populated = 1;
>> +	pr_info("found kexec handover data.\n");
>>  
>>  err_unmap_scratch:
>>  	early_memunmap(scratch, scratch_len);
>>  err_unmap_fdt:
>>  	early_memunmap(fdt, fdt_len);
>>  err_report:
>
>Nit: now that this code can be reached by non-error paths, we should
>re-name the labels. I think dropping the "err_" prefix should be enough.

Thanks for your review.
Very helpful suggestion. I will send a v2.

>With these fixed,
>
>Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
>
>> -	pr_warn("disabling KHO revival\n");
>> +	if (!populated)
>> +		pr_warn("disabling KHO revival\n");
>>  }
>>  
>>  /* Helper functions for kexec_file_load */