[PATCH 1/1] kexec: Use %pe format specifier for error pointer printing

[PATCH 1/1] kexec: Use %pe format specifier for error pointer printing

[Zhu Yanjun]

Make pr_xxx() call to use the %pe format specifier instead of %d.
The %pe specifier prints a symbolic error string (e.g., -ENOMEM,
-EINVAL) when given an error pointer created with ERR_PTR(err).

This change enhances the clarity and diagnostic value of the error
message by showing a descriptive error name rather than a numeric
error code.

Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
CC: graf@amazon.com
CC: rppt@kernel.org
CC: changyuanl@google.com
CC: akpm@linux-foundation.org
CC: bhe@redhat.com

---
 kernel/kexec_handover.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/kernel/kexec_handover.c b/kernel/kexec_handover.c
index 76f0940fb485..77af377022b0 100644
--- a/kernel/kexec_handover.c
+++ b/kernel/kexec_handover.c
@@ -1095,7 +1095,7 @@ static int kho_abort(void)
 	err = notifier_to_errno(err);
 
 	if (err)
-		pr_err("Failed to abort KHO finalization: %d\n", err);
+		pr_err("Failed to abort KHO finalization: %pe\n", ERR_PTR(err));
 
 	return err;
 }
@@ -1142,7 +1142,7 @@ static int kho_finalize(void)
 
 abort:
 	if (err) {
-		pr_err("Failed to convert KHO state tree: %d\n", err);
+		pr_err("Failed to convert KHO state tree: %pe\n", ERR_PTR(err));
 		kho_abort();
 	}
 
@@ -1355,8 +1355,8 @@ static __init int kho_in_debugfs_init(const void *fdt)
 		err = kho_debugfs_fdt_add(&kho_in.fdt_list, sub_fdt_dir, name,
 					  phys_to_virt(*fdt_phys));
 		if (err) {
-			pr_warn("failed to add fdt `%s` to debugfs: %d\n", name,
-				err);
+			pr_warn("failed to add fdt `%s` to debugfs: %pe\n", name,
+				ERR_PTR(err));
 			continue;
 		}
 	}
@@ -1400,8 +1400,8 @@ static __init int kho_init(void)
 		 * kexec.
 		 */
 		if (err)
-			pr_err("failed exposing handover FDT in debugfs: %d\n",
-			       err);
+			pr_err("failed exposing handover FDT in debugfs: %pe\n",
+			       ERR_PTR(err));
 
 		return 0;
 	}
@@ -1524,8 +1524,8 @@ 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)) {
-			pr_warn("failed to mark the scratch region 0x%pa+0x%pa: %d",
-				&area->addr, &size, err);
+			pr_warn("failed to mark the scratch region 0x%pa+0x%pa: %pe",
+				&area->addr, &size, ERR_PTR(err));
 			goto out;
 		}
 		pr_debug("Marked 0x%pa+0x%pa as scratch", &area->addr, &size);
@@ -1553,7 +1553,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
 	if (scratch)
 		early_memunmap(scratch, scratch_len);
 	if (err)
-		pr_warn("disabling KHO revival: %d\n", err);
+		pr_warn("disabling KHO revival: %pe\n", ERR_PTR(err));
 }
 
 /* Helper functions for kexec_file_load */
-- 
2.51.0

Re: [PATCH 1/1] kexec: Use %pe format specifier for error pointer printing

[Simon Horman]

On Thu, Oct 16, 2025 at 08:03:20PM +0000, Zhu Yanjun wrote:
> Make pr_xxx() call to use the %pe format specifier instead of %d.
> The %pe specifier prints a symbolic error string (e.g., -ENOMEM,
> -EINVAL) when given an error pointer created with ERR_PTR(err).
> 
> This change enhances the clarity and diagnostic value of the error
> message by showing a descriptive error name rather than a numeric
> error code.
> 
> Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>

Thanks,

This looks good to me, even though I note that this file
has moved in linux-next.

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH 1/1] kexec: Use %pe format specifier for error pointer printing

[Zhu Yanjun]

在 2025/10/21 2:41, Simon Horman 写道:
> On Thu, Oct 16, 2025 at 08:03:20PM +0000, Zhu Yanjun wrote:
>> Make pr_xxx() call to use the %pe format specifier instead of %d.
>> The %pe specifier prints a symbolic error string (e.g., -ENOMEM,
>> -EINVAL) when given an error pointer created with ERR_PTR(err).
>>
>> This change enhances the clarity and diagnostic value of the error
>> message by showing a descriptive error name rather than a numeric
>> error code.
>>
>> Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
> Thanks,
>
> This looks good to me, even though I note that this file
> has moved in linux-next.

Thanks a lot.

Yanjun.Zhu

>
> Reviewed-by: Simon Horman <horms@kernel.org>

-- 
Best Regards,
Yanjun.Zhu

Re: [PATCH 1/1] kexec: Use %pe format specifier for error pointer printing

[yanjun.zhu]

On 10/21/25 2:41 AM, Simon Horman wrote:
> On Thu, Oct 16, 2025 at 08:03:20PM +0000, Zhu Yanjun wrote:
>> Make pr_xxx() call to use the %pe format specifier instead of %d.
>> The %pe specifier prints a symbolic error string (e.g., -ENOMEM,
>> -EINVAL) when given an error pointer created with ERR_PTR(err).
>>
>> This change enhances the clarity and diagnostic value of the error
>> message by showing a descriptive error name rather than a numeric
>> error code.
>>
>> Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
> 
> Thanks,
> 
> This looks good to me, even though I note that this file
> has moved in linux-next.

Thank you very much. In next-20251021, I noticed that the directory is 
now kernel/liveupdate/.

If a new commit is needed to reflect this change, please feel free to 
let me know.

Yanjun.Zhu

> 
> Reviewed-by: Simon Horman <horms@kernel.org>
>