* [PATCH 1/2] MIPS: Randomize mmap if randomize_va_space is set
2010-07-19 20:14 [PATCH 0/2] MIPS memory space randomization David Daney
@ 2010-07-19 20:14 ` David Daney
2010-07-23 5:11 ` Ralf Baechle
2010-07-19 20:14 ` [PATCH 2/2] MIPS: Enable heap randomization David Daney
1 sibling, 1 reply; 5+ messages in thread
From: David Daney @ 2010-07-19 20:14 UTC (permalink / raw)
To: linux-mips, ralf; +Cc: David Daney
Fairly straight forward: For 32-bit address spaces randomize within a
16MB space, for 64-bit within a 256MB space.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
---
arch/mips/include/asm/processor.h | 11 +++++++++++
arch/mips/kernel/syscall.c | 21 ++++++++++++++++++++-
2 files changed, 31 insertions(+), 1 deletions(-)
diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
index 5d33b72..24d91f8 100644
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -34,6 +34,11 @@ extern void (*cpu_wait)(void);
extern unsigned int vced_count, vcei_count;
/*
+ * MIPS does have an arch_pick_mmap_layout()
+ */
+#define HAVE_ARCH_PICK_MMAP_LAYOUT 1
+
+/*
* A special page (the vdso) is mapped into all processes at the very
* top of the virtual memory space.
*/
@@ -52,6 +57,9 @@ extern unsigned int vced_count, vcei_count;
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE ((TASK_SIZE / 3) & ~(PAGE_SIZE))
+
+#define TASK_IS_32BIT_ADDR 1
+
#endif
#ifdef CONFIG_64BIT
@@ -77,6 +85,9 @@ extern unsigned int vced_count, vcei_count;
PAGE_ALIGN(TASK_SIZE32 / 3) : PAGE_ALIGN(TASK_SIZE / 3))
#define TASK_SIZE_OF(tsk) \
(test_tsk_thread_flag(tsk, TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE)
+
+#define TASK_IS_32BIT_ADDR test_thread_flag(TIF_32BIT_ADDR)
+
#endif
#ifdef __KERNEL__
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index dd81b0f..9824a82 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -29,6 +29,7 @@
#include <linux/ipc.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
+#include <linux/random.h>
#include <asm/asm.h>
#include <asm/branch.h>
@@ -116,7 +117,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
(!vmm || addr + len <= vmm->vm_start))
return addr;
}
- addr = TASK_UNMAPPED_BASE;
+ addr = current->mm->mmap_base;
if (do_color_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
@@ -134,6 +135,24 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
}
}
+void arch_pick_mmap_layout(struct mm_struct *mm)
+{
+ unsigned long random_factor = 0UL;
+
+ if (current->flags & PF_RANDOMIZE) {
+ random_factor = get_random_int();
+ random_factor = random_factor << PAGE_SHIFT;
+ if (TASK_IS_32BIT_ADDR)
+ random_factor &= 0xfffffful;
+ else
+ random_factor &= 0xffffffful;
+ }
+
+ mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
+ mm->get_unmapped_area = arch_get_unmapped_area;
+ mm->unmap_area = arch_unmap_area;
+}
+
SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags, unsigned long,
fd, off_t, offset)
--
1.7.1.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/2] MIPS: Enable heap randomization.
2010-07-19 20:14 [PATCH 0/2] MIPS memory space randomization David Daney
2010-07-19 20:14 ` [PATCH 1/2] MIPS: Randomize mmap if randomize_va_space is set David Daney
@ 2010-07-19 20:14 ` David Daney
2010-07-23 5:12 ` Ralf Baechle
1 sibling, 1 reply; 5+ messages in thread
From: David Daney @ 2010-07-19 20:14 UTC (permalink / raw)
To: linux-mips, ralf; +Cc: David Daney
Based somewhat on the PPC implementation.
32-bit processes have the heap randomized in an 8MB space, 256MB for
64-bit processes.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
---
arch/mips/include/asm/elf.h | 5 +++++
arch/mips/kernel/syscall.c | 28 ++++++++++++++++++++++++++++
2 files changed, 33 insertions(+), 0 deletions(-)
diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index ea77a42..fd1d39e 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -372,4 +372,9 @@ extern const char *__elf_platform;
struct linux_binprm;
extern int arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp);
+
+struct mm_struct;
+extern unsigned long arch_randomize_brk(struct mm_struct *mm);
+#define arch_randomize_brk arch_randomize_brk
+
#endif /* _ASM_ELF_H */
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 9824a82..58bab2e 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -30,6 +30,7 @@
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/random.h>
+#include <linux/elf.h>
#include <asm/asm.h>
#include <asm/branch.h>
@@ -153,6 +154,33 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
mm->unmap_area = arch_unmap_area;
}
+static inline unsigned long brk_rnd(void)
+{
+ unsigned long rnd = get_random_int();
+
+ rnd = rnd << PAGE_SHIFT;
+ /* 8MB for 32bit, 256MB for 64bit */
+ if (TASK_IS_32BIT_ADDR)
+ rnd = rnd & 0x7ffffful;
+ else
+ rnd = rnd & 0xffffffful;
+
+ return rnd;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+ unsigned long base = mm->brk;
+ unsigned long ret;
+
+ ret = PAGE_ALIGN(base + brk_rnd());
+
+ if (ret < mm->brk)
+ return mm->brk;
+
+ return ret;
+}
+
SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags, unsigned long,
fd, off_t, offset)
--
1.7.1.1
^ permalink raw reply related [flat|nested] 5+ messages in thread