1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. 3 4 #include <linux/kernel.h> 5 #include <linux/err.h> 6 #include <linux/sched.h> 7 #include <linux/mm.h> 8 #include <linux/init.h> 9 #include <linux/binfmts.h> 10 #include <linux/elf.h> 11 #include <linux/vmalloc.h> 12 #include <linux/unistd.h> 13 #include <linux/uaccess.h> 14 15 #include <asm/vdso.h> 16 #include <asm/cacheflush.h> 17 18 static struct page *vdso_page; 19 20 static int __init init_vdso(void) 21 { 22 struct csky_vdso *vdso; 23 int err = 0; 24 25 vdso_page = alloc_page(GFP_KERNEL); 26 if (!vdso_page) 27 panic("Cannot allocate vdso"); 28 29 vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL); 30 if (!vdso) 31 panic("Cannot map vdso"); 32 33 clear_page(vdso); 34 35 err = setup_vdso_page(vdso->rt_signal_retcode); 36 if (err) 37 panic("Cannot set signal return code, err: %x.", err); 38 39 dcache_wb_range((unsigned long)vdso, (unsigned long)vdso + 16); 40 41 vunmap(vdso); 42 43 return 0; 44 } 45 subsys_initcall(init_vdso); 46 47 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 48 { 49 int ret; 50 unsigned long addr; 51 struct mm_struct *mm = current->mm; 52 53 mmap_write_lock(mm); 54 55 addr = get_unmapped_area(NULL, STACK_TOP, PAGE_SIZE, 0, 0); 56 if (IS_ERR_VALUE(addr)) { 57 ret = addr; 58 goto up_fail; 59 } 60 61 ret = install_special_mapping( 62 mm, 63 addr, 64 PAGE_SIZE, 65 VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 66 &vdso_page); 67 if (ret) 68 goto up_fail; 69 70 mm->context.vdso = (void *)addr; 71 72 up_fail: 73 mmap_write_unlock(mm); 74 return ret; 75 } 76 77 const char *arch_vma_name(struct vm_area_struct *vma) 78 { 79 if (vma->vm_mm == NULL) 80 return NULL; 81 82 if (vma->vm_start == (long)vma->vm_mm->context.vdso) 83 return "[vdso]"; 84 else 85 return NULL; 86 } 87