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authorAndi Kleen <ak@suse.de>2006-01-17 07:03:38 +0100
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-16 23:18:35 -0800
commit8817210d4d968e58f7d93db2eecd17b20dd03d40 (patch)
tree4a4084011f348f44c388e1876e55c0d2a03f46b4
parent562795fe5770d0c7ee7fe269890e37d9fd475fdf (diff)
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[PATCH] x86_64: Flexmap for 32bit and randomized mappings for 64bit
Another try at this. For 32bit follow the 32bit implementation from Ingo - mappings are growing down from the end of stack now and vary randomly by 1GB. Randomized mappings for 64bit just vary the normal mmap break by 1TB. I didn't bother implementing full flex mmap for 64bit because it shouldn't be needed there. Cc: mingo@elte.hu Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/x86_64/ia32/Makefile3
-rw-r--r--arch/x86_64/ia32/mmap32.c78
-rw-r--r--arch/x86_64/mm/Makefile2
-rw-r--r--arch/x86_64/mm/mmap.c30
-rw-r--r--include/asm-x86_64/ia32.h2
-rw-r--r--include/asm-x86_64/processor.h2
6 files changed, 115 insertions, 2 deletions
diff --git a/arch/x86_64/ia32/Makefile b/arch/x86_64/ia32/Makefile
index 051608d55920..929e6b0771f8 100644
--- a/arch/x86_64/ia32/Makefile
+++ b/arch/x86_64/ia32/Makefile
@@ -3,7 +3,8 @@
#
obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o tls32.o \
- ia32_binfmt.o fpu32.o ptrace32.o syscall32.o syscall32_syscall.o
+ ia32_binfmt.o fpu32.o ptrace32.o syscall32.o syscall32_syscall.o \
+ mmap32.o
sysv-$(CONFIG_SYSVIPC) := ipc32.o
obj-$(CONFIG_IA32_EMULATION) += $(sysv-y)
diff --git a/arch/x86_64/ia32/mmap32.c b/arch/x86_64/ia32/mmap32.c
new file mode 100644
index 000000000000..079f4132575c
--- /dev/null
+++ b/arch/x86_64/ia32/mmap32.c
@@ -0,0 +1,78 @@
+/*
+ * linux/arch/x86_64/ia32/mm/mmap.c
+ *
+ * flexible mmap layout support
+ *
+ * Based on the i386 version which was
+ *
+ * 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>
+
+/*
+ * Top of mmap area (just below the process stack).
+ *
+ * Leave an at least ~128 MB hole.
+ */
+#define MIN_GAP (128*1024*1024)
+#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:
+ */
+void ia32_pick_mmap_layout(struct mm_struct *mm)
+{
+ /*
+ * 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;
+ }
+}
diff --git a/arch/x86_64/mm/Makefile b/arch/x86_64/mm/Makefile
index 1d232a87f113..d25ac86fe27a 100644
--- a/arch/x86_64/mm/Makefile
+++ b/arch/x86_64/mm/Makefile
@@ -2,7 +2,7 @@
# Makefile for the linux x86_64-specific parts of the memory manager.
#
-obj-y := init.o fault.o ioremap.o extable.o pageattr.o
+obj-y := init.o fault.o ioremap.o extable.o pageattr.o mmap.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_NUMA) += numa.o
obj-$(CONFIG_K8_NUMA) += k8topology.o
diff --git a/arch/x86_64/mm/mmap.c b/arch/x86_64/mm/mmap.c
new file mode 100644
index 000000000000..43e9b99bdf25
--- /dev/null
+++ b/arch/x86_64/mm/mmap.c
@@ -0,0 +1,30 @@
+/* Copyright 2005 Andi Kleen, SuSE Labs.
+ * Licensed under GPL, v.2
+ */
+#include <linux/config.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/random.h>
+#include <asm/ia32.h>
+
+/* Notebook: move the mmap code from sys_x86_64.c over here. */
+
+void arch_pick_mmap_layout(struct mm_struct *mm)
+{
+#ifdef CONFIG_IA32_EMULATION
+ if (current_thread_info()->flags & _TIF_IA32)
+ return ia32_pick_mmap_layout(mm);
+#endif
+ mm->mmap_base = TASK_UNMAPPED_BASE;
+ if (current->flags & PF_RANDOMIZE) {
+ /* 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) */
+ unsigned rnd = get_random_int() & 0xfffffff;
+ mm->mmap_base += ((unsigned long)rnd) << PAGE_SHIFT;
+ }
+ mm->get_unmapped_area = arch_get_unmapped_area;
+ mm->unmap_area = arch_unmap_area;
+}
+
diff --git a/include/asm-x86_64/ia32.h b/include/asm-x86_64/ia32.h
index c7bc9c0525ba..e6b7f2234e43 100644
--- a/include/asm-x86_64/ia32.h
+++ b/include/asm-x86_64/ia32.h
@@ -169,6 +169,8 @@ int ia32_child_tls(struct task_struct *p, struct pt_regs *childregs);
struct linux_binprm;
extern int ia32_setup_arg_pages(struct linux_binprm *bprm,
unsigned long stack_top, int exec_stack);
+struct mm_struct;
+extern void ia32_pick_mmap_layout(struct mm_struct *mm);
#endif
diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index a1ba7c97465a..8c8d88c036ed 100644
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -477,4 +477,6 @@ extern unsigned long boot_option_idle_override;
/* Boot loader type from the setup header */
extern int bootloader_type;
+#define HAVE_ARCH_PICK_MMAP_LAYOUT 1
+
#endif /* __ASM_X86_64_PROCESSOR_H */