diff options
Diffstat (limited to 'arch/tile/kernel/vdso.c')
| -rw-r--r-- | arch/tile/kernel/vdso.c | 197 |
1 files changed, 0 insertions, 197 deletions
diff --git a/arch/tile/kernel/vdso.c b/arch/tile/kernel/vdso.c deleted file mode 100644 index 5bc51d7dfdcb..000000000000 --- a/arch/tile/kernel/vdso.c +++ /dev/null @@ -1,197 +0,0 @@ -/* - * Copyright 2012 Tilera Corporation. All Rights Reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation, version 2. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or - * NON INFRINGEMENT. See the GNU General Public License for - * more details. - */ - -#include <linux/binfmts.h> -#include <linux/compat.h> -#include <linux/elf.h> -#include <linux/mm.h> -#include <linux/pagemap.h> - -#include <asm/vdso.h> -#include <asm/mman.h> -#include <asm/sections.h> - -#include <arch/sim.h> - -/* The alignment of the vDSO. */ -#define VDSO_ALIGNMENT PAGE_SIZE - - -static unsigned int vdso_pages; -static struct page **vdso_pagelist; - -#ifdef CONFIG_COMPAT -static unsigned int vdso32_pages; -static struct page **vdso32_pagelist; -#endif -static int vdso_ready; - -/* - * 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; - -static unsigned int __read_mostly vdso_enabled = 1; - -static struct page **vdso_setup(void *vdso_kbase, unsigned int pages) -{ - int i; - struct page **pagelist; - - pagelist = kzalloc(sizeof(struct page *) * (pages + 1), GFP_KERNEL); - BUG_ON(pagelist == NULL); - for (i = 0; i < pages - 1; i++) { - struct page *pg = virt_to_page(vdso_kbase + i*PAGE_SIZE); - ClearPageReserved(pg); - pagelist[i] = pg; - } - pagelist[pages - 1] = virt_to_page(vdso_data); - pagelist[pages] = NULL; - - return pagelist; -} - -static int __init vdso_init(void) -{ - int data_pages = sizeof(vdso_data_store) >> PAGE_SHIFT; - - /* - * We can disable vDSO support generally, but we need to retain - * one page to support the two-bundle (16-byte) rt_sigreturn path. - */ - if (!vdso_enabled) { - size_t offset = (unsigned long)&__vdso_rt_sigreturn; - static struct page *sigret_page; - sigret_page = alloc_page(GFP_KERNEL | __GFP_ZERO); - BUG_ON(sigret_page == NULL); - vdso_pagelist = &sigret_page; - vdso_pages = 1; - BUG_ON(offset >= PAGE_SIZE); - memcpy(page_address(sigret_page) + offset, - vdso_start + offset, 16); -#ifdef CONFIG_COMPAT - vdso32_pages = vdso_pages; - vdso32_pagelist = vdso_pagelist; -#endif - vdso_ready = 1; - return 0; - } - - vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; - vdso_pages += data_pages; - vdso_pagelist = vdso_setup(vdso_start, vdso_pages); - -#ifdef CONFIG_COMPAT - vdso32_pages = (vdso32_end - vdso32_start) >> PAGE_SHIFT; - vdso32_pages += data_pages; - vdso32_pagelist = vdso_setup(vdso32_start, vdso32_pages); -#endif - - smp_wmb(); - vdso_ready = 1; - - return 0; -} -arch_initcall(vdso_init); - -const char *arch_vma_name(struct vm_area_struct *vma) -{ - if (vma->vm_mm && vma->vm_start == VDSO_BASE) - return "[vdso]"; -#ifndef __tilegx__ - if (vma->vm_start == MEM_USER_INTRPT) - return "[intrpt]"; -#endif - return NULL; -} - -int setup_vdso_pages(void) -{ - struct page **pagelist; - unsigned long pages; - struct mm_struct *mm = current->mm; - unsigned long vdso_base = 0; - int retval = 0; - - if (!vdso_ready) - return 0; - - mm->context.vdso_base = 0; - - pagelist = vdso_pagelist; - pages = vdso_pages; -#ifdef CONFIG_COMPAT - if (is_compat_task()) { - pagelist = vdso32_pagelist; - pages = vdso32_pages; - } -#endif - - /* - * vDSO has a problem and was disabled, just don't "enable" it for the - * process. - */ - if (pages == 0) - return 0; - - vdso_base = get_unmapped_area(NULL, vdso_base, - (pages << PAGE_SHIFT) + - ((VDSO_ALIGNMENT - 1) & PAGE_MASK), - 0, 0); - if (IS_ERR_VALUE(vdso_base)) { - retval = vdso_base; - return retval; - } - - /* Add required alignment. */ - vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT); - - /* - * Put vDSO base into mm struct. We need to do this before calling - * install_special_mapping or the perf counter mmap tracking code - * will fail to recognise it as a vDSO (since arch_vma_name fails). - */ - mm->context.vdso_base = vdso_base; - - /* - * 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 - */ - retval = install_special_mapping(mm, vdso_base, - pages << PAGE_SHIFT, - VM_READ|VM_EXEC | - VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, - pagelist); - if (retval) - mm->context.vdso_base = 0; - - return retval; -} - -static __init int vdso_func(char *s) -{ - return kstrtouint(s, 0, &vdso_enabled); -} -__setup("vdso=", vdso_func); |