+ mm-constify-process_shares_mm-for-improved-const-correctness.patch added to mm-new branch

+ mm-constify-process_shares_mm-for-improved-const-correctness.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm: constify process_shares_mm() for improved const-correctness
has been added to the -mm mm-new branch.  Its filename is
     mm-constify-process_shares_mm-for-improved-const-correctness.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-constify-process_shares_mm-for-improved-const-correctness.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.

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Max Kellermann <max.kellermann@ionos.com>
Subject: mm: constify process_shares_mm() for improved const-correctness
Date: Mon, 1 Sep 2025 22:50:14 +0200

This function only reads from the pointer arguments.

Local (loop) variables are also annotated with `const` to clarify that
these will not be written to.

Link: https://lkml.kernel.org/r/20250901205021.3573313-6-max.kellermann@ionos.com
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christian Zankel <chris@zankel.net>
Cc: David Rientjes <rientjes@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Bottomley <james.bottomley@HansenPartnership.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Nysal Jan K.A" <nysal@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Huth <thuth@redhat.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mm.h |    2 +-
 mm/oom_kill.c      |    6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

--- a/include/linux/mm.h~mm-constify-process_shares_mm-for-improved-const-correctness
+++ a/include/linux/mm.h
@@ -3872,7 +3872,7 @@ static inline int in_gate_area(struct mm
 }
 #endif	/* __HAVE_ARCH_GATE_AREA */
 
-extern bool process_shares_mm(struct task_struct *p, struct mm_struct *mm);
+bool process_shares_mm(const struct task_struct *p, const struct mm_struct *mm);
 
 void drop_slab(void);
 
--- a/mm/oom_kill.c~mm-constify-process_shares_mm-for-improved-const-correctness
+++ a/mm/oom_kill.c
@@ -490,12 +490,12 @@ static bool oom_killer_disabled __read_m
  * task's threads: if one of those is using this mm then this task was also
  * using it.
  */
-bool process_shares_mm(struct task_struct *p, struct mm_struct *mm)
+bool process_shares_mm(const struct task_struct *p, const struct mm_struct *mm)
 {
-	struct task_struct *t;
+	const struct task_struct *t;
 
 	for_each_thread(p, t) {
-		struct mm_struct *t_mm = READ_ONCE(t->mm);
+		const struct mm_struct *t_mm = READ_ONCE(t->mm);
 		if (t_mm)
 			return t_mm == mm;
 	}
_

Patches currently in -mm which might be from max.kellermann@ionos.com are

pagevech-add-const-to-pointer-parameters-of-getter-functions.patch
huge_mmh-disallow-is_huge_zero_folionull.patch
mm-constify-shmem-related-test-functions-for-improved-const-correctness.patch
mm-constify-pagemap-related-test-getter-functions.patch
mm-constify-zone-related-test-getter-functions.patch
fs-constify-mapping-related-test-functions-for-improved-const-correctness.patch
mm-constify-process_shares_mm-for-improved-const-correctness.patch
mm-s390-constify-mapping-related-test-getter-functions.patch
parisc-constify-mmap_upper_limit-parameter.patch
mm-constify-arch_pick_mmap_layout-for-improved-const-correctness.patch
mm-constify-ptdesc_pmd_pts_count-and-folio_get_private.patch
mm-constify-various-inline-functions-for-improved-const-correctness.patch
mm-constify-assert-test-functions-in-mmh.patch
mm-constify-highmem-related-functions-for-improved-const-correctness.patch