x86: unify mmap_{32|64}.c (675a0813) · Commits · 戴 / test

arch/x86/mm/Makefile_32

+1 −1

Original line number	Diff line number	Diff line
		@@ -2,7 +2,7 @@
		# Makefile for the linux i386-specific parts of the memory manager.
		#

		obj-y := init_32.o pgtable_32.o fault_32.o ioremap_32.o extable_32.o pageattr_32.o mmap_32.o
		obj-y := init_32.o pgtable_32.o fault_32.o ioremap_32.o extable_32.o pageattr_32.o mmap.o

		obj-$(CONFIG_NUMA) += discontig_32.o
		obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o

arch/x86/mm/Makefile_64

+1 −2

Original line number	Diff line number	Diff line
		@@ -2,9 +2,8 @@
		# Makefile for the linux x86_64-specific parts of the memory manager.
		#

		obj-y := init_64.o fault_64.o ioremap_64.o extable_64.o pageattr_64.o mmap_64.o
		obj-y := init_64.o fault_64.o ioremap_64.o extable_64.o pageattr_64.o mmap.o
		obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
		obj-$(CONFIG_NUMA) += numa_64.o
		obj-$(CONFIG_K8_NUMA) += k8topology_64.o
		obj-$(CONFIG_ACPI_NUMA) += srat_64.o
		obj-$(CONFIG_IA32_EMULATION) += mmap_32.o

arch/x86/mm/mmap_64.c→arch/x86/mm/mmap.c

+51 −44

Original line number	Diff line number	Diff line
		/*
		* linux/arch/x86-64/mm/mmap.c
		*
		* flexible mmap layout support
		* Flexible mmap layout support
		*
		* Based on code by Ingo Molnar and Andi Kleen, copyrighted
		* as follows:
		@@ -24,7 +22,6 @@
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
		*
		*/

		#include <linux/personality.h>
		@@ -32,7 +29,6 @@
		#include <linux/random.h>
		#include <linux/limits.h>
		#include <linux/sched.h>
		#include <asm/ia32.h>

		/*
		* Top of mmap area (just below the process stack).
		@@ -42,20 +38,14 @@
		#define MIN_GAP (12810241024)
		#define MAX_GAP (TASK_SIZE/6*5)

		static unsigned long mmap_base(void)
		{
		unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;

		if (gap < MIN_GAP)
		gap = MIN_GAP;
		else if (gap > MAX_GAP)
		gap = MAX_GAP;

		return TASK_SIZE - (gap & PAGE_MASK);
		}

		static int mmap_is_32(void)
		/*
		* True on X86_32 or when emulating IA32 on X86_64
		*/
		static int mmap_is_ia32(void)
		{
		#ifdef CONFIG_X86_32
		return 1;
		#endif
		#ifdef CONFIG_IA32_EMULATION
		if (test_thread_flag(TIF_IA32))
		return 1;
		@@ -74,43 +64,60 @@ static int mmap_is_legacy(void)
		return sysctl_legacy_va_layout;
		}

		static unsigned long mmap_rnd(void)
		{
		unsigned long rnd = 0;

		/*
		* This function, called very early during the creation of a new
		* process VM image, sets up which VM layout function to use:
		* 8 bits of randomness in 32bit mmaps, 20 address space bits
		* 28 bits of randomness in 64bit mmaps, 40 address space bits
		*/
		void arch_pick_mmap_layout(struct mm_struct *mm)
		{
		int rnd = 0;
		if (current->flags & PF_RANDOMIZE) {
		if (mmap_is_ia32())
		rnd = (long)get_random_int() % (1<<8);
		else
		rnd = (long)(get_random_int() % (1<<28));
		}
		return rnd << PAGE_SHIFT;
		}

		static unsigned long mmap_base(void)
		{
		unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;

		if (gap < MIN_GAP)
		gap = MIN_GAP;
		else if (gap > MAX_GAP)
		gap = MAX_GAP;

		return PAGE_ALIGN(TASK_SIZE - gap - mmap_rnd());
		}

		/*
		* Add 28bit randomness which is about 40bits of address space
		* because mmap base has to be page aligned.
		* or ~1/128 of the total user VM
		* (total user address space is 47bits)
		* Bottom-up (legacy) layout on X86_32 did not support randomization, X86_64
		* does, but not when emulating X86_32
		*/
		rnd = get_random_int() & 0xfffffff;
		static unsigned long mmap_legacy_base(void)
		{
		if (mmap_is_ia32())
		return TASK_UNMAPPED_BASE;
		else
		return TASK_UNMAPPED_BASE + mmap_rnd();
		}

		/*
		* Fall back to the standard layout if the personality
		* bit is set, or if the expected stack growth is unlimited:
		* This function, called very early during the creation of a new
		* process VM image, sets up which VM layout function to use:
		*/
		if (mmap_is_32()) {
		#ifdef CONFIG_IA32_EMULATION
		/* ia32_pick_mmap_layout has its own. */
		return ia32_pick_mmap_layout(mm);
		#endif
		} else if (mmap_is_legacy()) {
		mm->mmap_base = TASK_UNMAPPED_BASE;
		void arch_pick_mmap_layout(struct mm_struct *mm)
		{
		if (mmap_is_legacy()) {
		mm->mmap_base = mmap_legacy_base();
		mm->get_unmapped_area = arch_get_unmapped_area;
		mm->unmap_area = arch_unmap_area;
		} else {
		mm->mmap_base = mmap_base();
		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
		mm->unmap_area = arch_unmap_area_topdown;
		if (current->flags & PF_RANDOMIZE)
		rnd = -rnd;
		}
		if (current->flags & PF_RANDOMIZE)
		mm->mmap_base += ((long)rnd) << PAGE_SHIFT;
		}

arch/x86/mm/mmap_32.c

deleted100644 → 0

+0 −81

Original line number	Diff line number	Diff line
		/*
		* linux/arch/i386/mm/mmap.c
		*
		* flexible mmap layout support
		*
		* Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
		* All Rights Reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
		*
		*
		* Started by Ingo Molnar <mingo@elte.hu>
		*/

		#include <linux/personality.h>
		#include <linux/mm.h>
		#include <linux/random.h>
		#include <linux/sched.h>

		/*
		* Top of mmap area (just below the process stack).
		*
		* Leave an at least ~128 MB hole.
		*/
		#define MIN_GAP (12810241024)
		#define MAX_GAP (TASK_SIZE/6*5)

		static inline unsigned long mmap_base(struct mm_struct *mm)
		{
		unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
		unsigned long random_factor = 0;

		if (current->flags & PF_RANDOMIZE)
		random_factor = get_random_int() % (1024*1024);

		if (gap < MIN_GAP)
		gap = MIN_GAP;
		else if (gap > MAX_GAP)
		gap = MAX_GAP;

		return PAGE_ALIGN(TASK_SIZE - gap - random_factor);
		}

		/*
		* This function, called very early during the creation of a new
		* process VM image, sets up which VM layout function to use:
		*/
		#ifdef CONFIG_X86_32
		void arch_pick_mmap_layout(struct mm_struct *mm)
		#else
		void ia32_pick_mmap_layout(struct mm_struct *mm)
		#endif
		{
		/*
		* Fall back to the standard layout if the personality
		* bit is set, or if the expected stack growth is unlimited:
		*/
		if (sysctl_legacy_va_layout \|\|
		(current->personality & ADDR_COMPAT_LAYOUT) \|\|
		current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY) {
		mm->mmap_base = TASK_UNMAPPED_BASE;
		mm->get_unmapped_area = arch_get_unmapped_area;
		mm->unmap_area = arch_unmap_area;
		} else {
		mm->mmap_base = mmap_base(mm);
		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
		mm->unmap_area = arch_unmap_area_topdown;
		}
		}

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