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-rw-r--r--arch/mips/include/asm/elf.h5
-rw-r--r--arch/mips/kernel/syscall.c28
2 files changed, 33 insertions, 0 deletions
diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index ea77a42c5f8c..fd1d39eb7431 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -372,4 +372,9 @@ extern const char *__elf_platform;
372struct linux_binprm; 372struct linux_binprm;
373extern int arch_setup_additional_pages(struct linux_binprm *bprm, 373extern int arch_setup_additional_pages(struct linux_binprm *bprm,
374 int uses_interp); 374 int uses_interp);
375
376struct mm_struct;
377extern unsigned long arch_randomize_brk(struct mm_struct *mm);
378#define arch_randomize_brk arch_randomize_brk
379
375#endif /* _ASM_ELF_H */ 380#endif /* _ASM_ELF_H */
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 9824a829f61d..58bab2ef257f 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -30,6 +30,7 @@
30#include <linux/uaccess.h> 30#include <linux/uaccess.h>
31#include <linux/slab.h> 31#include <linux/slab.h>
32#include <linux/random.h> 32#include <linux/random.h>
33#include <linux/elf.h>
33 34
34#include <asm/asm.h> 35#include <asm/asm.h>
35#include <asm/branch.h> 36#include <asm/branch.h>
@@ -153,6 +154,33 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
153 mm->unmap_area = arch_unmap_area; 154 mm->unmap_area = arch_unmap_area;
154} 155}
155 156
157static inline unsigned long brk_rnd(void)
158{
159 unsigned long rnd = get_random_int();
160
161 rnd = rnd << PAGE_SHIFT;
162 /* 8MB for 32bit, 256MB for 64bit */
163 if (TASK_IS_32BIT_ADDR)
164 rnd = rnd & 0x7ffffful;
165 else
166 rnd = rnd & 0xffffffful;
167
168 return rnd;
169}
170
171unsigned long arch_randomize_brk(struct mm_struct *mm)
172{
173 unsigned long base = mm->brk;
174 unsigned long ret;
175
176 ret = PAGE_ALIGN(base + brk_rnd());
177
178 if (ret < mm->brk)
179 return mm->brk;
180
181 return ret;
182}
183
156SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len, 184SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
157 unsigned long, prot, unsigned long, flags, unsigned long, 185 unsigned long, prot, unsigned long, flags, unsigned long,
158 fd, off_t, offset) 186 fd, off_t, offset)