The patch titled
Subject: mm: x86: introduce arch_mmap_hint()
has been added to the -mm mm-unstable branch. Its filename is
mm-x86-introduce-arch_mmap_hint.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-x86-introduce-arch_mmap_hint.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
Subject: mm: x86: introduce arch_mmap_hint()
Date: Wed, 11 Dec 2024 15:27:40 -0800
Introduce x86 arch_mmap_hint() and define HAVE_ARCH_MMAP_HINT. This is a
preparatory patch, no functional change is introduced.
Fallback to generic_mmap_hint() if an architecture doesn't provide
HAVE_ARCH_MMAP_HINT.
Link: https://lkml.kernel.org/r/20241211232754.1583023-3-kaleshsingh@xxxxxxxxxx
Signed-off-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
Cc: Andreas Larsson <andreas@xxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Breno Leitao <leitao@xxxxxxxxxx>
Cc: Chris Zankel <chris@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: Jason Andryuk <jason.andryuk@xxxxxxx>
Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Yang Shi <yang@xxxxxxxxxxxxxxxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/pgtable_64.h | 1
arch/x86/kernel/sys_x86_64.c | 64 +++++++++++++---------------
include/linux/sched/mm.h | 5 ++
mm/mmap.c | 9 +++
4 files changed, 45 insertions(+), 34 deletions(-)
--- a/arch/x86/include/asm/pgtable_64.h~mm-x86-introduce-arch_mmap_hint
+++ a/arch/x86/include/asm/pgtable_64.h
@@ -245,6 +245,7 @@ extern void cleanup_highmap(void);
#define HAVE_ARCH_UNMAPPED_AREA
#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+#define HAVE_ARCH_MMAP_HINT
#define PAGE_AGP PAGE_KERNEL_NOCACHE
#define HAVE_PAGE_AGP 1
--- a/arch/x86/kernel/sys_x86_64.c~mm-x86-introduce-arch_mmap_hint
+++ a/arch/x86/kernel/sys_x86_64.c
@@ -123,31 +123,44 @@ static inline unsigned long stack_guard_
return 0;
}
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+ unsigned long len, unsigned long pgoff,
+ unsigned long flags)
+{
+ unsigned long begin, end;
+
+ find_start_end(addr, flags, &begin, &end);
+
+ /* requested length too big for entire address space */
+ if (len > end || len > TASK_SIZE)
+ return -ENOMEM;
+
+ /* No address checking. See comment at mmap_address_hint_valid() */
+ if (flags & MAP_FIXED)
+ return addr;
+
+ addr = PAGE_ALIGN(addr);
+
+ /* Fallback to VA space search? */
+ if (!mmap_address_hint_valid(addr, len))
+ return 0;
+
+ return generic_mmap_hint(filp, addr, len, pgoff, flags);
+}
+
unsigned long
arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
{
- struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
struct vm_unmapped_area_info info = {};
unsigned long begin, end;
- if (flags & MAP_FIXED)
+ addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+ if (addr)
return addr;
find_start_end(addr, flags, &begin, &end);
- if (len > end)
- return -ENOMEM;
-
- if (addr) {
- addr = PAGE_ALIGN(addr);
- vma = find_vma(mm, addr);
- if (end - len >= addr &&
- (!vma || addr + len <= vm_start_gap(vma)))
- return addr;
- }
-
info.length = len;
info.low_limit = begin;
info.high_limit = end;
@@ -168,34 +181,17 @@ arch_get_unmapped_area_topdown(struct fi
unsigned long len, unsigned long pgoff,
unsigned long flags, vm_flags_t vm_flags)
{
- struct vm_area_struct *vma;
- struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
struct vm_unmapped_area_info info = {};
- /* requested length too big for entire address space */
- if (len > TASK_SIZE)
- return -ENOMEM;
-
- /* No address checking. See comment at mmap_address_hint_valid() */
- if (flags & MAP_FIXED)
- return addr;
-
/* for MAP_32BIT mappings we force the legacy mmap base */
if (!in_32bit_syscall() && (flags & MAP_32BIT))
goto bottomup;
/* requesting a specific address */
- if (addr) {
- addr &= PAGE_MASK;
- if (!mmap_address_hint_valid(addr, len))
- goto get_unmapped_area;
-
- vma = find_vma(mm, addr);
- if (!vma || addr + len <= vm_start_gap(vma))
- return addr;
- }
-get_unmapped_area:
+ addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+ if (addr)
+ return addr;
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
--- a/include/linux/sched/mm.h~mm-x86-introduce-arch_mmap_hint
+++ a/include/linux/sched/mm.h
@@ -205,6 +205,11 @@ unsigned long generic_mmap_hint(struct f
unsigned long len, unsigned long pgoff,
unsigned long flags);
+/* See generic_mmap_hint() */
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+ unsigned long len, unsigned long pgoff,
+ unsigned long flags);
+
unsigned long
generic_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff,
--- a/mm/mmap.c~mm-x86-introduce-arch_mmap_hint
+++ a/mm/mmap.c
@@ -705,6 +705,15 @@ arch_get_unmapped_area(struct file *filp
}
#endif
+#ifndef HAVE_ARCH_MMAP_HINT
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+ unsigned long len, unsigned long pgoff,
+ unsigned long flags)
+{
+ return generic_mmap_hint(filp, addr, len, pgoff, flags);
+}
+#endif
+
/*
* This mmap-allocator allocates new areas top-down from below the
* stack's low limit (the base):
_
Patches currently in -mm which might be from kaleshsingh@xxxxxxxxxx are
mm-introduce-generic_mmap_hint.patch
mm-x86-introduce-arch_mmap_hint.patch
mm-arm-introduce-arch_mmap_hint.patch
mm-alpha-introduce-arch_mmap_hint.patch
mm-arc-use-generic_mmap_hint.patch
mm-csky-introduce-arch_mmap_hint.patch
mm-loongarch-introduce-arch_mmap_hint.patch
mm-mips-introduce-arch_align_mmap_hint.patch
mm-parisc-introduce-arch_align_mmap_hint.patch
mm-s390-use-generic_mmap_hint.patch
mm-sh-introduce-arch_mmap_hint.patch
mm-sparc32-introduce-arch_mmap_hint.patch
mm-sparc64-introduce-arch_mmap_hint.patch
mm-xtensa-introduce-arch_mmap_hint.patch
mm-powerpc-introduce-arch_mmap_hint.patch
mm-respect-mmap-hint-before-thp-alignment-if-allocation-is-possible.patch
