duptext: export fault data structure, add mmu notifier when memory unmap and add an offset to heap segment

Signed-off-by: wangzhimin1179@phytium.com.cn

arch/arm64/mm/fault.c

@@ -48,7 +48,8 @@ struct fault_info {
 	const char *name;
 };
 
-static const struct fault_info fault_info[];
+struct fault_info fault_info[];
+EXPORT_SYMBOL(fault_info);
 static struct fault_info debug_fault_info[];
 
 static inline const struct fault_info *esr_to_fault_info(unsigned int esr)
@@ -387,7 +388,7 @@ static void set_thread_esr(unsigned long address, unsigned int esr)
 	current->thread.fault_code = esr;
 }
 
-static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 {
 	/*
 	 * If we are in kernel mode at this point, we have no context to
@@ -403,6 +404,7 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re
 		__do_kernel_fault(addr, esr, regs);
 	}
 }
+EXPORT_SYMBOL(do_bad_area);
 
 #define VM_FAULT_BADMAP		0x010000
 #define VM_FAULT_BADACCESS	0x020000
@@ -1593,7 +1595,7 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 	return 0;
 }
 
-static const struct fault_info fault_info[] = {
+struct fault_info fault_info[] = {
 	{ do_bad,		SIGKILL, SI_KERNEL,	"ttbr address size fault"	},
 	{ do_bad,		SIGKILL, SI_KERNEL,	"level 1 address size fault"	},
 	{ do_bad,		SIGKILL, SI_KERNEL,	"level 2 address size fault"	},

arch/arm64/mm/mmu.c

@@ -75,6 +75,7 @@ void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd)
 	pgd_clear_fixmap();
 	spin_unlock(&swapper_pgdir_lock);
 }
+EXPORT_SYMBOL(set_swapper_pgd);
 
 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 			      unsigned long size, pgprot_t vma_prot)
@@ -694,6 +695,7 @@ void __init paging_init(void)
 
 	memblock_allow_resize();
 }
+EXPORT_SYMBOL(swapper_pg_dir);
 
 /*
  * Check whether a kernel address is valid (derived from arch/x86/).

fs/binfmt_elf.c

@@ -57,6 +57,13 @@
 #define elf_check_fdpic(ex) false
 #endif
 
+#ifndef CONFIG_COMPAT_BINFMT_ELF
+unsigned long brk_offset = PMD_SIZE;
+EXPORT_SYMBOL(brk_offset);
+#endif
+
+extern struct static_key_false phytium_duptext_static_key;
+
 static int load_elf_binary(struct linux_binprm *bprm);
 
 #ifdef CONFIG_USELIB
@@ -1118,9 +1125,12 @@ out_free_interp:
 		    loc->elf_ex.e_type == ET_DYN && !interpreter)
 			current->mm->brk = current->mm->start_brk =
 				ELF_ET_DYN_BASE;
+                if (static_branch_unlikely(&phytium_duptext_static_key)) {
+                        current->mm->brk = current->mm->start_brk = arch_randomize_brk(current->mm) + brk_offset;
+                } else {
+                        current->mm->brk = current->mm->start_brk = arch_randomize_brk(current->mm);
+                }
 
-		current->mm->brk = current->mm->start_brk =
-			arch_randomize_brk(current->mm);
 #ifdef compat_brk_randomized
 		current->brk_randomized = 1;
 #endif

fs/compat_binfmt_elf.c

@@ -130,4 +130,9 @@
 /*
  * We share all the actual code with the native (64-bit) version.
  */
+#ifdef CONFIG_COMPAT_BINFMT_ELF
+unsigned long brk_offset = PMD_SIZE;
+EXPORT_SYMBOL(brk_offset);
+#endif
+
 #include "binfmt_elf.c"

include/linux/fs.h

@@ -85,6 +85,7 @@ extern int sysctl_protected_hardlinks;
 extern int sysctl_protected_fifos;
 extern int sysctl_protected_regular;
 extern unsigned int sysctl_nvidia_smi_trap;
+extern unsigned long brk_offset;
 
 typedef __kernel_rwf_t rwf_t;
 

mm/mmap.c

@@ -2640,6 +2640,9 @@ static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)
 	validate_mm(mm);
 }
 
+DEFINE_STATIC_KEY_FALSE(phytium_duptext_static_key);
+EXPORT_SYMBOL(phytium_duptext_static_key);
+
 /*
  * Get rid of page table information in the indicated region.
  *
@@ -2649,6 +2652,7 @@ static void unmap_region(struct mm_struct *mm,
 		struct vm_area_struct *vma, struct vm_area_struct *prev,
 		unsigned long start, unsigned long end)
 {
+	struct mmu_notifier_range range;
 	struct vm_area_struct *next = prev ? prev->vm_next : mm->mmap;
 	struct mmu_gather tlb;
 	struct vm_area_struct *cur_vma;
@@ -2675,6 +2679,12 @@ static void unmap_region(struct mm_struct *mm,
 
 	free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
 				 next ? next->vm_start : USER_PGTABLES_CEILING);
+	if (static_branch_unlikely(&phytium_duptext_static_key)) {
+		mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, vma->vm_mm,
+				start, end);
+		mmu_notifier_invalidate_range_start(&range);
+		mmu_notifier_invalidate_range_end(&range);
+	}
 	tlb_finish_mmu(&tlb, start, end);
 }