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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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53634237e7
Now that the SPDX tag is in all arch/s390/kernel/ files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
325 lines
8.1 KiB
C
325 lines
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* vdso setup for s390
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*
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* Copyright IBM Corp. 2008
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
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*/
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/slab.h>
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#include <linux/user.h>
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#include <linux/elf.h>
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#include <linux/security.h>
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#include <linux/bootmem.h>
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#include <linux/compat.h>
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#include <asm/asm-offsets.h>
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#include <asm/pgtable.h>
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#include <asm/processor.h>
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#include <asm/mmu.h>
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#include <asm/mmu_context.h>
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#include <asm/sections.h>
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#include <asm/vdso.h>
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#include <asm/facility.h>
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#ifdef CONFIG_COMPAT
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extern char vdso32_start, vdso32_end;
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static void *vdso32_kbase = &vdso32_start;
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static unsigned int vdso32_pages;
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static struct page **vdso32_pagelist;
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#endif
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extern char vdso64_start, vdso64_end;
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static void *vdso64_kbase = &vdso64_start;
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static unsigned int vdso64_pages;
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static struct page **vdso64_pagelist;
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/*
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* Should the kernel map a VDSO page into processes and pass its
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* address down to glibc upon exec()?
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*/
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unsigned int __read_mostly vdso_enabled = 1;
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static int vdso_fault(const struct vm_special_mapping *sm,
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struct vm_area_struct *vma, struct vm_fault *vmf)
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{
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struct page **vdso_pagelist;
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unsigned long vdso_pages;
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vdso_pagelist = vdso64_pagelist;
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vdso_pages = vdso64_pages;
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#ifdef CONFIG_COMPAT
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if (is_compat_task()) {
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vdso_pagelist = vdso32_pagelist;
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vdso_pages = vdso32_pages;
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}
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#endif
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if (vmf->pgoff >= vdso_pages)
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return VM_FAULT_SIGBUS;
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vmf->page = vdso_pagelist[vmf->pgoff];
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get_page(vmf->page);
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return 0;
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}
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static int vdso_mremap(const struct vm_special_mapping *sm,
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struct vm_area_struct *vma)
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{
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unsigned long vdso_pages;
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vdso_pages = vdso64_pages;
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#ifdef CONFIG_COMPAT
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if (is_compat_task())
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vdso_pages = vdso32_pages;
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#endif
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if ((vdso_pages << PAGE_SHIFT) != vma->vm_end - vma->vm_start)
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return -EINVAL;
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if (WARN_ON_ONCE(current->mm != vma->vm_mm))
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return -EFAULT;
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current->mm->context.vdso_base = vma->vm_start;
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return 0;
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}
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static const struct vm_special_mapping vdso_mapping = {
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.name = "[vdso]",
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.fault = vdso_fault,
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.mremap = vdso_mremap,
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};
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static int __init vdso_setup(char *s)
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{
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unsigned long val;
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int rc;
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rc = 0;
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if (strncmp(s, "on", 3) == 0)
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vdso_enabled = 1;
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else if (strncmp(s, "off", 4) == 0)
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vdso_enabled = 0;
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else {
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rc = kstrtoul(s, 0, &val);
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vdso_enabled = rc ? 0 : !!val;
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}
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return !rc;
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}
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__setup("vdso=", vdso_setup);
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/*
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* The vdso data page
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*/
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static union {
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struct vdso_data data;
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u8 page[PAGE_SIZE];
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} vdso_data_store __page_aligned_data;
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struct vdso_data *vdso_data = &vdso_data_store.data;
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/*
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* Setup vdso data page.
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*/
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static void __init vdso_init_data(struct vdso_data *vd)
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{
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vd->ectg_available = test_facility(31);
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}
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/*
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* Allocate/free per cpu vdso data.
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*/
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#define SEGMENT_ORDER 2
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/*
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* The initial vdso_data structure for the boot CPU. Eventually
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* it is replaced with a properly allocated structure in vdso_init.
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* This is necessary because a valid S390_lowcore.vdso_per_cpu_data
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* pointer is required to be able to return from an interrupt or
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* program check. See the exit paths in entry.S.
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*/
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struct vdso_data boot_vdso_data __initdata;
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void __init vdso_alloc_boot_cpu(struct lowcore *lowcore)
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{
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lowcore->vdso_per_cpu_data = (unsigned long) &boot_vdso_data;
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}
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int vdso_alloc_per_cpu(struct lowcore *lowcore)
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{
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unsigned long segment_table, page_table, page_frame;
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struct vdso_per_cpu_data *vd;
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segment_table = __get_free_pages(GFP_KERNEL, SEGMENT_ORDER);
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page_table = get_zeroed_page(GFP_KERNEL);
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page_frame = get_zeroed_page(GFP_KERNEL);
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if (!segment_table || !page_table || !page_frame)
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goto out;
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arch_set_page_dat(virt_to_page(segment_table), SEGMENT_ORDER);
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arch_set_page_dat(virt_to_page(page_table), 0);
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/* Initialize per-cpu vdso data page */
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vd = (struct vdso_per_cpu_data *) page_frame;
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vd->cpu_nr = lowcore->cpu_nr;
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vd->node_id = cpu_to_node(vd->cpu_nr);
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/* Set up page table for the vdso address space */
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memset64((u64 *)segment_table, _SEGMENT_ENTRY_EMPTY, _CRST_ENTRIES);
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memset64((u64 *)page_table, _PAGE_INVALID, PTRS_PER_PTE);
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*(unsigned long *) segment_table = _SEGMENT_ENTRY + page_table;
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*(unsigned long *) page_table = _PAGE_PROTECT + page_frame;
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lowcore->vdso_asce = segment_table +
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_ASCE_TABLE_LENGTH + _ASCE_USER_BITS + _ASCE_TYPE_SEGMENT;
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lowcore->vdso_per_cpu_data = page_frame;
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return 0;
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out:
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free_page(page_frame);
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free_page(page_table);
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free_pages(segment_table, SEGMENT_ORDER);
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return -ENOMEM;
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}
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void vdso_free_per_cpu(struct lowcore *lowcore)
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{
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unsigned long segment_table, page_table, page_frame;
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segment_table = lowcore->vdso_asce & PAGE_MASK;
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page_table = *(unsigned long *) segment_table;
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page_frame = *(unsigned long *) page_table;
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free_page(page_frame);
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free_page(page_table);
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free_pages(segment_table, SEGMENT_ORDER);
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}
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/*
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* This is called from binfmt_elf, we create the special vma for the
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* vDSO and insert it into the mm struct tree
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*/
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int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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unsigned long vdso_pages;
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unsigned long vdso_base;
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int rc;
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if (!vdso_enabled)
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return 0;
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/*
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* Only map the vdso for dynamically linked elf binaries.
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*/
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if (!uses_interp)
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return 0;
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vdso_pages = vdso64_pages;
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#ifdef CONFIG_COMPAT
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if (is_compat_task())
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vdso_pages = vdso32_pages;
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#endif
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/*
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* vDSO has a problem and was disabled, just don't "enable" it for
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* the process
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*/
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if (vdso_pages == 0)
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return 0;
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/*
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* pick a base address for the vDSO in process space. We try to put
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* it at vdso_base which is the "natural" base for it, but we might
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* fail and end up putting it elsewhere.
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*/
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if (down_write_killable(&mm->mmap_sem))
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return -EINTR;
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vdso_base = get_unmapped_area(NULL, 0, vdso_pages << PAGE_SHIFT, 0, 0);
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if (IS_ERR_VALUE(vdso_base)) {
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rc = vdso_base;
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goto out_up;
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}
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/*
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* our vma flags don't have VM_WRITE so by default, the process
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* isn't allowed to write those pages.
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* gdb can break that with ptrace interface, and thus trigger COW
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* on those pages but it's then your responsibility to never do that
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* on the "data" page of the vDSO or you'll stop getting kernel
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* updates and your nice userland gettimeofday will be totally dead.
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* It's fine to use that for setting breakpoints in the vDSO code
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* pages though.
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*/
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vma = _install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
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VM_READ|VM_EXEC|
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VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
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&vdso_mapping);
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if (IS_ERR(vma)) {
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rc = PTR_ERR(vma);
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goto out_up;
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}
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current->mm->context.vdso_base = vdso_base;
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rc = 0;
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out_up:
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up_write(&mm->mmap_sem);
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return rc;
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}
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static int __init vdso_init(void)
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{
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int i;
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vdso_init_data(vdso_data);
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#ifdef CONFIG_COMPAT
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/* Calculate the size of the 32 bit vDSO */
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vdso32_pages = ((&vdso32_end - &vdso32_start
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+ PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
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/* Make sure pages are in the correct state */
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vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 1),
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GFP_KERNEL);
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BUG_ON(vdso32_pagelist == NULL);
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for (i = 0; i < vdso32_pages - 1; i++) {
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struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
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ClearPageReserved(pg);
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get_page(pg);
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vdso32_pagelist[i] = pg;
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}
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vdso32_pagelist[vdso32_pages - 1] = virt_to_page(vdso_data);
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vdso32_pagelist[vdso32_pages] = NULL;
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#endif
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/* Calculate the size of the 64 bit vDSO */
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vdso64_pages = ((&vdso64_end - &vdso64_start
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+ PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
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/* Make sure pages are in the correct state */
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vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 1),
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GFP_KERNEL);
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BUG_ON(vdso64_pagelist == NULL);
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for (i = 0; i < vdso64_pages - 1; i++) {
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struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
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ClearPageReserved(pg);
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get_page(pg);
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vdso64_pagelist[i] = pg;
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}
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vdso64_pagelist[vdso64_pages - 1] = virt_to_page(vdso_data);
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vdso64_pagelist[vdso64_pages] = NULL;
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if (vdso_alloc_per_cpu(&S390_lowcore))
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BUG();
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get_page(virt_to_page(vdso_data));
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return 0;
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}
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early_initcall(vdso_init);
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