+ mm-mm_init-replace-simple_strtoul-with-kstrtobool-in-set_hashdist.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/mm_init: replace simple_strtoul with kstrtobool in set_hashdist
has been added to the -mm mm-new branch.  Its filename is
     mm-mm_init-replace-simple_strtoul-with-kstrtobool-in-set_hashdist.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mm_init-replace-simple_strtoul-with-kstrtobool-in-set_hashdist.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

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------------------------------------------------------
From: Thorsten Blum <thorsten.blum@linux.dev>
Subject: mm/mm_init: replace simple_strtoul with kstrtobool in set_hashdist
Date: Wed, 17 Dec 2025 12:02:13 +0100

Use bool for 'hashdist' and replace simple_strtoul() with kstrtobool() for
parsing the 'hashdist=' boot parameter.  Unlike simple_strtoul(), which
returns an unsigned long, kstrtobool() converts the string directly to
bool and avoids implicit casting.

Check the return value of kstrtobool() and reject invalid values.  This
adds error handling while preserving behavior for existing values, and
removes use of the deprecated simple_strtoul() helper.  The current code
silently sets 'hashdist = 0' if parsing fails, instead of leaving the
default value (HASHDIST_DEFAULT) unchanged.

Additionally, kstrtobool() accepts common boolean strings such as "on" and
"off".

Link: https://lkml.kernel.org/r/20251217110214.50807-1-thorsten.blum@linux.dev
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/memblock.h |    4 ++--
 mm/mm_init.c             |    9 +++------
 2 files changed, 5 insertions(+), 8 deletions(-)

--- a/include/linux/memblock.h~mm-mm_init-replace-simple_strtoul-with-kstrtobool-in-set_hashdist
+++ a/include/linux/memblock.h
@@ -598,9 +598,9 @@ extern void *alloc_large_system_hash(con
  */
 #ifdef CONFIG_NUMA
 #define HASHDIST_DEFAULT IS_ENABLED(CONFIG_64BIT)
-extern int hashdist;		/* Distribute hashes across NUMA nodes? */
+extern bool hashdist;		/* Distribute hashes across NUMA nodes? */
 #else
-#define hashdist (0)
+#define hashdist (false)
 #endif
 
 #ifdef CONFIG_MEMTEST
--- a/mm/mm_init.c~mm-mm_init-replace-simple_strtoul-with-kstrtobool-in-set_hashdist
+++ a/mm/mm_init.c
@@ -646,21 +646,18 @@ int __meminit early_pfn_to_nid(unsigned
 	return nid;
 }
 
-int hashdist = HASHDIST_DEFAULT;
+bool hashdist = HASHDIST_DEFAULT;
 
 static int __init set_hashdist(char *str)
 {
-	if (!str)
-		return 0;
-	hashdist = simple_strtoul(str, &str, 0);
-	return 1;
+	return kstrtobool(str, &hashdist) == 0;
 }
 __setup("hashdist=", set_hashdist);
 
 static inline void fixup_hashdist(void)
 {
 	if (num_node_state(N_MEMORY) == 1)
-		hashdist = 0;
+		hashdist = false;
 }
 #else
 static inline void fixup_hashdist(void) {}
_

Patches currently in -mm which might be from thorsten.blum@linux.dev are

mm-mm_init-replace-simple_strtoul-with-kstrtobool-in-set_hashdist.patch