| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Martin Schwidefsky | 1203 | 93.69% | 11 | 35.48% |
| Heiko Carstens | 29 | 2.26% | 9 | 29.03% |
| Vasily Gorbik | 24 | 1.87% | 1 | 3.23% |
| Kees Cook | 10 | 0.78% | 1 | 3.23% |
| Michal Hocko | 8 | 0.62% | 1 | 3.23% |
| David Howells | 3 | 0.23% | 1 | 3.23% |
| Greg Kroah-Hartman | 2 | 0.16% | 2 | 6.45% |
| Jason Baron | 1 | 0.08% | 1 | 3.23% |
| Tim Abbott | 1 | 0.08% | 1 | 3.23% |
| Souptick Joarder | 1 | 0.08% | 1 | 3.23% |
| Paul Gortmaker | 1 | 0.08% | 1 | 3.23% |
| Mike Rapoport | 1 | 0.08% | 1 | 3.23% |
| Total | 1284 | 31 |
// SPDX-License-Identifier: GPL-2.0 /* * vdso setup for s390 * * Copyright IBM Corp. 2008 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) */ #include <linux/init.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/smp.h> #include <linux/stddef.h> #include <linux/unistd.h> #include <linux/slab.h> #include <linux/user.h> #include <linux/elf.h> #include <linux/security.h> #include <linux/memblock.h> #include <linux/compat.h> #include <asm/asm-offsets.h> #include <asm/pgtable.h> #include <asm/processor.h> #include <asm/mmu.h> #include <asm/mmu_context.h> #include <asm/sections.h> #include <asm/vdso.h> #include <asm/facility.h> #ifdef CONFIG_COMPAT extern char vdso32_start, vdso32_end; static void *vdso32_kbase = &vdso32_start; static unsigned int vdso32_pages; static struct page **vdso32_pagelist; #endif extern char vdso64_start, vdso64_end; static void *vdso64_kbase = &vdso64_start; static unsigned int vdso64_pages; static struct page **vdso64_pagelist; /* * Should the kernel map a VDSO page into processes and pass its * address down to glibc upon exec()? */ unsigned int __read_mostly vdso_enabled = 1; static vm_fault_t vdso_fault(const struct vm_special_mapping *sm, struct vm_area_struct *vma, struct vm_fault *vmf) { struct page **vdso_pagelist; unsigned long vdso_pages; vdso_pagelist = vdso64_pagelist; vdso_pages = vdso64_pages; #ifdef CONFIG_COMPAT if (vma->vm_mm->context.compat_mm) { vdso_pagelist = vdso32_pagelist; vdso_pages = vdso32_pages; } #endif if (vmf->pgoff >= vdso_pages) return VM_FAULT_SIGBUS; vmf->page = vdso_pagelist[vmf->pgoff]; get_page(vmf->page); return 0; } static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *vma) { unsigned long vdso_pages; vdso_pages = vdso64_pages; #ifdef CONFIG_COMPAT if (vma->vm_mm->context.compat_mm) vdso_pages = vdso32_pages; #endif if ((vdso_pages << PAGE_SHIFT) != vma->vm_end - vma->vm_start) return -EINVAL; if (WARN_ON_ONCE(current->mm != vma->vm_mm)) return -EFAULT; current->mm->context.vdso_base = vma->vm_start; return 0; } static const struct vm_special_mapping vdso_mapping = { .name = "[vdso]", .fault = vdso_fault, .mremap = vdso_mremap, }; static int __init vdso_setup(char *s) { unsigned long val; int rc; rc = 0; if (strncmp(s, "on", 3) == 0) vdso_enabled = 1; else if (strncmp(s, "off", 4) == 0) vdso_enabled = 0; else { rc = kstrtoul(s, 0, &val); vdso_enabled = rc ? 0 : !!val; } return !rc; } __setup("vdso=", vdso_setup); /* * The vdso data page */ static union { struct vdso_data data; u8 page[PAGE_SIZE]; } vdso_data_store __page_aligned_data; struct vdso_data *vdso_data = &vdso_data_store.data; /* * Setup vdso data page. */ static void __init vdso_init_data(struct vdso_data *vd) { vd->ectg_available = test_facility(31); } /* * Allocate/free per cpu vdso data. */ #define SEGMENT_ORDER 2 /* * The initial vdso_data structure for the boot CPU. Eventually * it is replaced with a properly allocated structure in vdso_init. * This is necessary because a valid S390_lowcore.vdso_per_cpu_data * pointer is required to be able to return from an interrupt or * program check. See the exit paths in entry.S. */ struct vdso_data boot_vdso_data __initdata; void __init vdso_alloc_boot_cpu(struct lowcore *lowcore) { lowcore->vdso_per_cpu_data = (unsigned long) &boot_vdso_data; } int vdso_alloc_per_cpu(struct lowcore *lowcore) { unsigned long segment_table, page_table, page_frame; struct vdso_per_cpu_data *vd; segment_table = __get_free_pages(GFP_KERNEL, SEGMENT_ORDER); page_table = get_zeroed_page(GFP_KERNEL); page_frame = get_zeroed_page(GFP_KERNEL); if (!segment_table || !page_table || !page_frame) goto out; arch_set_page_dat(virt_to_page(segment_table), SEGMENT_ORDER); arch_set_page_dat(virt_to_page(page_table), 0); /* Initialize per-cpu vdso data page */ vd = (struct vdso_per_cpu_data *) page_frame; vd->cpu_nr = lowcore->cpu_nr; vd->node_id = cpu_to_node(vd->cpu_nr); /* Set up page table for the vdso address space */ memset64((u64 *)segment_table, _SEGMENT_ENTRY_EMPTY, _CRST_ENTRIES); memset64((u64 *)page_table, _PAGE_INVALID, PTRS_PER_PTE); *(unsigned long *) segment_table = _SEGMENT_ENTRY + page_table; *(unsigned long *) page_table = _PAGE_PROTECT + page_frame; lowcore->vdso_asce = segment_table + _ASCE_TABLE_LENGTH + _ASCE_USER_BITS + _ASCE_TYPE_SEGMENT; lowcore->vdso_per_cpu_data = page_frame; return 0; out: free_page(page_frame); free_page(page_table); free_pages(segment_table, SEGMENT_ORDER); return -ENOMEM; } void vdso_free_per_cpu(struct lowcore *lowcore) { unsigned long segment_table, page_table, page_frame; segment_table = lowcore->vdso_asce & PAGE_MASK; page_table = *(unsigned long *) segment_table; page_frame = *(unsigned long *) page_table; free_page(page_frame); free_page(page_table); free_pages(segment_table, SEGMENT_ORDER); } /* * This is called from binfmt_elf, we create the special vma for the * vDSO and insert it into the mm struct tree */ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; unsigned long vdso_pages; unsigned long vdso_base; int rc; if (!vdso_enabled) return 0; /* * Only map the vdso for dynamically linked elf binaries. */ if (!uses_interp) return 0; vdso_pages = vdso64_pages; #ifdef CONFIG_COMPAT if (is_compat_task()) { vdso_pages = vdso32_pages; mm->context.compat_mm = 1; } #endif /* * vDSO has a problem and was disabled, just don't "enable" it for * the process */ if (vdso_pages == 0) return 0; /* * pick a base address for the vDSO in process space. We try to put * it at vdso_base which is the "natural" base for it, but we might * fail and end up putting it elsewhere. */ if (down_write_killable(&mm->mmap_sem)) return -EINTR; vdso_base = get_unmapped_area(NULL, 0, vdso_pages << PAGE_SHIFT, 0, 0); if (IS_ERR_VALUE(vdso_base)) { rc = vdso_base; goto out_up; } /* * our vma flags don't have VM_WRITE so by default, the process * isn't allowed to write those pages. * gdb can break that with ptrace interface, and thus trigger COW * on those pages but it's then your responsibility to never do that * on the "data" page of the vDSO or you'll stop getting kernel * updates and your nice userland gettimeofday will be totally dead. * It's fine to use that for setting breakpoints in the vDSO code * pages though. */ vma = _install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT, VM_READ|VM_EXEC| VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, &vdso_mapping); if (IS_ERR(vma)) { rc = PTR_ERR(vma); goto out_up; } current->mm->context.vdso_base = vdso_base; rc = 0; out_up: up_write(&mm->mmap_sem); return rc; } static int __init vdso_init(void) { int i; vdso_init_data(vdso_data); #ifdef CONFIG_COMPAT /* Calculate the size of the 32 bit vDSO */ vdso32_pages = ((&vdso32_end - &vdso32_start + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1; /* Make sure pages are in the correct state */ vdso32_pagelist = kcalloc(vdso32_pages + 1, sizeof(struct page *), GFP_KERNEL); BUG_ON(vdso32_pagelist == NULL); for (i = 0; i < vdso32_pages - 1; i++) { struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE); ClearPageReserved(pg); get_page(pg); vdso32_pagelist[i] = pg; } vdso32_pagelist[vdso32_pages - 1] = virt_to_page(vdso_data); vdso32_pagelist[vdso32_pages] = NULL; #endif /* Calculate the size of the 64 bit vDSO */ vdso64_pages = ((&vdso64_end - &vdso64_start + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1; /* Make sure pages are in the correct state */ vdso64_pagelist = kcalloc(vdso64_pages + 1, sizeof(struct page *), GFP_KERNEL); BUG_ON(vdso64_pagelist == NULL); for (i = 0; i < vdso64_pages - 1; i++) { struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE); ClearPageReserved(pg); get_page(pg); vdso64_pagelist[i] = pg; } vdso64_pagelist[vdso64_pages - 1] = virt_to_page(vdso_data); vdso64_pagelist[vdso64_pages] = NULL; if (vdso_alloc_per_cpu(&S390_lowcore)) BUG(); get_page(virt_to_page(vdso_data)); return 0; } early_initcall(vdso_init);
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