Commit a955cca3 authored by Max Kellermann's avatar Max Kellermann Committed by Andrew Morton
Browse files

mm: constify arch_pick_mmap_layout() for improved const-correctness 

This function only reads from the rlimit pointer (but writes to the
mm_struct pointer which is kept without `const`).

All callees are already const-ified or (internal functions) are being
constified by this patch.

Link: https://lkml.kernel.org/r/20250901205021.3573313-9-max.kellermann@ionos.com


Signed-off-by: default avatarMax Kellermann <max.kellermann@ionos.com>
Reviewed-by: default avatarVishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: default avatarShakeel Butt <shakeel.butt@linux.dev>
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: 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: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e7f77876

arch/s390/mm/mmap.c

+2 −2
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ static unsigned long mmap_base_legacy(unsigned long rnd) 
}



static inline unsigned long mmap_base(unsigned long rnd,

				      struct rlimit *rlim_stack)

				      const struct rlimit *rlim_stack)

{

	unsigned long gap = rlim_stack->rlim_cur;

	unsigned long pad = stack_maxrandom_size() + stack_guard_gap;
@@ -169,7 +169,7 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long ad 
 * This function, called very early during the creation of a new

 * process VM image, sets up which VM layout function to use:

 */

void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)

void arch_pick_mmap_layout(struct mm_struct *mm, const struct rlimit *rlim_stack)

{

	unsigned long random_factor = 0UL;

arch/sparc/kernel/sys_sparc_64.c

+1 −1
Original line number Diff line number Diff line
@@ -294,7 +294,7 @@ static unsigned long mmap_rnd(void) 
	return rnd << PAGE_SHIFT;

}



void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)

void arch_pick_mmap_layout(struct mm_struct *mm, const struct rlimit *rlim_stack)

{

	unsigned long random_factor = mmap_rnd();

	unsigned long gap;

arch/x86/mm/mmap.c

+3 −3
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ unsigned long arch_mmap_rnd(void) 
}



static unsigned long mmap_base(unsigned long rnd, unsigned long task_size,

			       struct rlimit *rlim_stack)

			       const struct rlimit *rlim_stack)

{

	unsigned long gap = rlim_stack->rlim_cur;

	unsigned long pad = stack_maxrandom_size(task_size) + stack_guard_gap;
@@ -110,7 +110,7 @@ static unsigned long mmap_legacy_base(unsigned long rnd, 
 */

static void arch_pick_mmap_base(unsigned long *base, unsigned long *legacy_base,

		unsigned long random_factor, unsigned long task_size,

		struct rlimit *rlim_stack)

		const struct rlimit *rlim_stack)

{

	*legacy_base = mmap_legacy_base(random_factor, task_size);

	if (mmap_is_legacy())
@@ -119,7 +119,7 @@ static void arch_pick_mmap_base(unsigned long *base, unsigned long *legacy_base, 
		*base = mmap_base(random_factor, task_size, rlim_stack);

}



void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)

void arch_pick_mmap_layout(struct mm_struct *mm, const struct rlimit *rlim_stack)

{

	if (mmap_is_legacy())

		mm_flags_clear(MMF_TOPDOWN, mm);

include/linux/sched/mm.h

+2 −2
Original line number Diff line number Diff line
@@ -178,7 +178,7 @@ static inline void mm_update_next_owner(struct mm_struct *mm) 
#endif



extern void arch_pick_mmap_layout(struct mm_struct *mm,

				  struct rlimit *rlim_stack);

				  const struct rlimit *rlim_stack);



unsigned long

arch_get_unmapped_area(struct file *filp, unsigned long addr,
@@ -211,7 +211,7 @@ generic_get_unmapped_area_topdown(struct file *filp, unsigned long addr, 
				  unsigned long flags, vm_flags_t vm_flags);

#else

static inline void arch_pick_mmap_layout(struct mm_struct *mm,

					 struct rlimit *rlim_stack) {}

					 const struct rlimit *rlim_stack) {}

#endif



static inline bool in_vfork(struct task_struct *tsk)

mm/util.c

+3 −3
Original line number Diff line number Diff line
@@ -431,7 +431,7 @@ static int mmap_is_legacy(const struct rlimit *rlim_stack) 
#define MIN_GAP		(SZ_128M)

#define MAX_GAP		(STACK_TOP / 6 * 5)



static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack)

static unsigned long mmap_base(const unsigned long rnd, const struct rlimit *rlim_stack)

{

#ifdef CONFIG_STACK_GROWSUP

	/*
@@ -462,7 +462,7 @@ static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) 
#endif

}



void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)

void arch_pick_mmap_layout(struct mm_struct *mm, const struct rlimit *rlim_stack)

{

	unsigned long random_factor = 0UL;
@@ -478,7 +478,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) 
	}

}

#elif defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT)

void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)

void arch_pick_mmap_layout(struct mm_struct *mm, const struct rlimit *rlim_stack)

{

	mm->mmap_base = TASK_UNMAPPED_BASE;

	mm_flags_clear(MMF_TOPDOWN, mm);