+ liveupdate-kho-use-%pe-format-specifier-for-error-pointer-printing.patch added to mm-nonmm-unstable branch

+ liveupdate-kho-use-%pe-format-specifier-for-error-pointer-printing.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: liveupdate: kho: use %pe format specifier for error pointer printing
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     liveupdate-kho-use-%pe-format-specifier-for-error-pointer-printing.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/liveupdate-kho-use-%pe-format-specifier-for-error-pointer-printing.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Zhu Yanjun <yanjun.zhu@linux.dev>
Subject: liveupdate: kho: use %pe format specifier for error pointer printing
Date: Sat, 1 Nov 2025 10:23:25 -0400

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.

Note, that some err are still printed by value, as those errors might come
from libfdt and not regular errnos.

Link: https://lkml.kernel.org/r/20251101142325.1326536-10-pasha.tatashin@soleen.com
Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Co-developed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Changyuan Lyu <changyuanl@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
Cc: Pratyush Yadav <pratyush@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/liveupdate/kexec_handover.c         |    4 ++--
 kernel/liveupdate/kexec_handover_debugfs.c |   10 ++++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

--- a/kernel/liveupdate/kexec_handover.c~liveupdate-kho-use-%pe-format-specifier-for-error-pointer-printing
+++ a/kernel/liveupdate/kexec_handover.c
@@ -1449,8 +1449,8 @@ void __init kho_populate(phys_addr_t fdt
 		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);
--- a/kernel/liveupdate/kexec_handover_debugfs.c~liveupdate-kho-use-%pe-format-specifier-for-error-pointer-printing
+++ a/kernel/liveupdate/kexec_handover_debugfs.c
@@ -150,8 +150,8 @@ __init void kho_in_debugfs_init(struct k
 		err = __kho_debugfs_fdt_add(&dbg->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;
 		}
 	}
@@ -168,8 +168,10 @@ err_out:
 	 * reviving state from KHO and setting up KHO for the next
 	 * kexec.
 	 */
-	if (err)
-		pr_err("failed exposing handover FDT in debugfs: %d\n", err);
+	if (err) {
+		pr_err("failed exposing handover FDT in debugfs: %pe\n",
+		       ERR_PTR(err));
+	}
 }
 
 __init int kho_out_debugfs_init(struct kho_debugfs *dbg)
_

Patches currently in -mm which might be from yanjun.zhu@linux.dev are

liveupdate-kho-use-%pe-format-specifier-for-error-pointer-printing.patch