[PATCH v2 0/2] two fixes in kho_populate()

[PATCH v2 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()

v2
 - Improve code readability suggested by Pratyush
 - collect reviewed-by

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 | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

-- 
2.25.1

[PATCH v2 1/2] kho: fix missing early_memunmap() call in kho_populate()

[ranxiaokai627]

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()")
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
---
 kernel/liveupdate/kexec_handover.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index fb3a7b67676e..3c705b08a489 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -1463,13 +1463,14 @@ 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;
+	bool populated = false;
 	int err;
 
 	/* Validate the input FDT */
 	fdt = early_memremap(fdt_phys, fdt_len);
 	if (!fdt) {
 		pr_warn("setup: failed to memremap FDT (0x%llx)\n", fdt_phys);
-		goto err_report;
+		goto report;
 	}
 	err = fdt_check_header(fdt);
 	if (err) {
@@ -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 = true;
+	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:
-	pr_warn("disabling KHO revival\n");
+report:
+	if (!populated)
+		pr_warn("disabling KHO revival\n");
 }
 
 /* Helper functions for kexec_file_load */
-- 
2.25.1

[PATCH v2 2/2] kho: remove unnecessary WARN_ON(err) in kho_populate()

[ranxiaokai627]

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>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
 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 3c705b08a489..eb87d23e8da6 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

Re: [PATCH v2 1/2] kho: fix missing early_memunmap() call in kho_populate()

[Pratyush Yadav]

Hi Ran,

On Wed, Feb 11 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()")
> Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
> ---
>  kernel/liveupdate/kexec_handover.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
> index fb3a7b67676e..3c705b08a489 100644
> --- a/kernel/liveupdate/kexec_handover.c
> +++ b/kernel/liveupdate/kexec_handover.c
> @@ -1463,13 +1463,14 @@ 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;
> +	bool populated = false;
>  	int err;
>  
>  	/* Validate the input FDT */
>  	fdt = early_memremap(fdt_phys, fdt_len);
>  	if (!fdt) {
>  		pr_warn("setup: failed to memremap FDT (0x%llx)\n", fdt_phys);
> -		goto err_report;
> +		goto report;
>  	}
>  	err = fdt_check_header(fdt);
>  	if (err) {
> @@ -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 = true;
> +	pr_info("found kexec handover data.\n");
>  
>  err_unmap_scratch:
>  	early_memunmap(scratch, scratch_len);
>  err_unmap_fdt:
>  	early_memunmap(fdt, fdt_len);

I meant to say all these labels should be renamed, not just err_report.
So "err_unmap_scratch" should be "unmap_scratch", and "err_unmap_fdt"
should be "unmap_fdt".

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

-- 
Regards,
Pratyush Yadav

Re: [PATCH v2 1/2] kho: fix missing early_memunmap() call in kho_populate()

[ranxiaokai627]

>Hi Ran,
>
>On Wed, Feb 11 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()")
>> Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
>> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>> ---
>>  kernel/liveupdate/kexec_handover.c | 12 +++++++-----
>>  1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
>> index fb3a7b67676e..3c705b08a489 100644
>> --- a/kernel/liveupdate/kexec_handover.c
>> +++ b/kernel/liveupdate/kexec_handover.c
>> @@ -1463,13 +1463,14 @@ 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;
>> +	bool populated = false;
>>  	int err;
>>  
>>  	/* Validate the input FDT */
>>  	fdt = early_memremap(fdt_phys, fdt_len);
>>  	if (!fdt) {
>>  		pr_warn("setup: failed to memremap FDT (0x%llx)\n", fdt_phys);
>> -		goto err_report;
>> +		goto report;
>>  	}
>>  	err = fdt_check_header(fdt);
>>  	if (err) {
>> @@ -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 = true;
>> +	pr_info("found kexec handover data.\n");
>>  
>>  err_unmap_scratch:
>>  	early_memunmap(scratch, scratch_len);
>>  err_unmap_fdt:
>>  	early_memunmap(fdt, fdt_len);
>
>I meant to say all these labels should be renamed, not just err_report.
>So "err_unmap_scratch" should be "unmap_scratch", and "err_unmap_fdt"
>should be "unmap_fdt".

Hi, Pratyush,

Thank you so much for your patient guidance and detailed help.
v2 did look a bit strange. I will update the code.

>> -err_report:
>> -	pr_warn("disabling KHO revival\n");
>> +report:
>> +	if (!populated)
>> +		pr_warn("disabling KHO revival\n");
>>  }
>>  
>>  /* Helper functions for kexec_file_load */
>
>-- 
>Regards,
>Pratyush Yadav