1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 25c48b108SAl Viro /* 35c48b108SAl Viro * Copyright (C) 2011 Richard Weinberger <richrd@nod.at> 45c48b108SAl Viro */ 55c48b108SAl Viro 65c48b108SAl Viro #include <linux/mm.h> 727795673SRichard Weinberger #include <asm/elf.h> 85c48b108SAl Viro 95c48b108SAl Viro static struct vm_area_struct gate_vma; 105c48b108SAl Viro gate_vma_init(void)115c48b108SAl Virostatic int __init gate_vma_init(void) 125c48b108SAl Viro { 135c48b108SAl Viro if (!FIXADDR_USER_START) 145c48b108SAl Viro return 0; 155c48b108SAl Viro 162c4541e2SKirill A. Shutemov vma_init(&gate_vma, NULL); 175c48b108SAl Viro gate_vma.vm_start = FIXADDR_USER_START; 185c48b108SAl Viro gate_vma.vm_end = FIXADDR_USER_END; 19*1c71222eSSuren Baghdasaryan vm_flags_init(&gate_vma, VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC); 2091a8da02SAnshuman Khandual gate_vma.vm_page_prot = PAGE_READONLY; 215c48b108SAl Viro 225c48b108SAl Viro return 0; 235c48b108SAl Viro } 245c48b108SAl Viro __initcall(gate_vma_init); 255c48b108SAl Viro get_gate_vma(struct mm_struct * mm)265c48b108SAl Virostruct vm_area_struct *get_gate_vma(struct mm_struct *mm) 275c48b108SAl Viro { 285c48b108SAl Viro return FIXADDR_USER_START ? &gate_vma : NULL; 295c48b108SAl Viro } 305c48b108SAl Viro in_gate_area_no_mm(unsigned long addr)315c48b108SAl Viroint in_gate_area_no_mm(unsigned long addr) 325c48b108SAl Viro { 335c48b108SAl Viro if (!FIXADDR_USER_START) 345c48b108SAl Viro return 0; 355c48b108SAl Viro 365c48b108SAl Viro if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END)) 375c48b108SAl Viro return 1; 385c48b108SAl Viro 395c48b108SAl Viro return 0; 405c48b108SAl Viro } 415c48b108SAl Viro in_gate_area(struct mm_struct * mm,unsigned long addr)425c48b108SAl Viroint in_gate_area(struct mm_struct *mm, unsigned long addr) 435c48b108SAl Viro { 445c48b108SAl Viro struct vm_area_struct *vma = get_gate_vma(mm); 455c48b108SAl Viro 465c48b108SAl Viro if (!vma) 475c48b108SAl Viro return 0; 485c48b108SAl Viro 495c48b108SAl Viro return (addr >= vma->vm_start) && (addr < vma->vm_end); 505c48b108SAl Viro } 51