diff options
| -rw-r--r-- | arch/powerpc/kernel/vdso.c | 104 |
1 files changed, 27 insertions, 77 deletions
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index ae0ede19879..50149ec6efa 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -49,9 +49,13 @@ /* Max supported size for symbol names */ #define MAX_SYMNAME 64 +#define VDSO32_MAXPAGES (((0x3000 + PAGE_MASK) >> PAGE_SHIFT) + 2) +#define VDSO64_MAXPAGES (((0x3000 + PAGE_MASK) >> PAGE_SHIFT) + 2) + extern char vdso32_start, vdso32_end; static void *vdso32_kbase = &vdso32_start; unsigned int vdso32_pages; +static struct page *vdso32_pagelist[VDSO32_MAXPAGES]; unsigned long vdso32_sigtramp; unsigned long vdso32_rt_sigtramp; @@ -59,6 +63,7 @@ unsigned long vdso32_rt_sigtramp; extern char vdso64_start, vdso64_end; static void *vdso64_kbase = &vdso64_start; unsigned int vdso64_pages; +static struct page *vdso64_pagelist[VDSO64_MAXPAGES]; unsigned long vdso64_rt_sigtramp; #endif /* CONFIG_PPC64 */ @@ -165,55 +170,6 @@ static void dump_vdso_pages(struct vm_area_struct * vma) #endif /* DEBUG */ /* - * Keep a dummy vma_close for now, it will prevent VMA merging. - */ -static void vdso_vma_close(struct vm_area_struct * vma) -{ -} - -/* - * Our nopage() function, maps in the actual vDSO kernel pages, they will - * be mapped read-only by do_no_page(), and eventually COW'ed, either - * right away for an initial write access, or by do_wp_page(). - */ -static struct page * vdso_vma_nopage(struct vm_area_struct * vma, - unsigned long address, int *type) -{ - unsigned long offset = address - vma->vm_start; - struct page *pg; -#ifdef CONFIG_PPC64 - void *vbase = (vma->vm_mm->task_size > TASK_SIZE_USER32) ? - vdso64_kbase : vdso32_kbase; -#else - void *vbase = vdso32_kbase; -#endif - - DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n", - current->comm, address, offset); - - if (address < vma->vm_start || address > vma->vm_end) - return NOPAGE_SIGBUS; - - /* - * Last page is systemcfg. - */ - if ((vma->vm_end - address) <= PAGE_SIZE) - pg = virt_to_page(vdso_data); - else - pg = virt_to_page(vbase + offset); - - get_page(pg); - DBG(" ->page count: %d\n", page_count(pg)); - - return pg; -} - -static struct vm_operations_struct vdso_vmops = { - .close = vdso_vma_close, - .nopage = vdso_vma_nopage, -}; - -/* * This is called from binfmt_elf, we create the special vma for the * vDSO and insert it into the mm struct tree */ @@ -221,20 +177,23 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int executable_stack) { struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; + struct page **vdso_pagelist; unsigned long vdso_pages; unsigned long vdso_base; int rc; #ifdef CONFIG_PPC64 if (test_thread_flag(TIF_32BIT)) { + vdso_pagelist = vdso32_pagelist; vdso_pages = vdso32_pages; vdso_base = VDSO32_MBASE; } else { + vdso_pagelist = vdso64_pagelist; vdso_pages = vdso64_pages; vdso_base = VDSO64_MBASE; } #else + vdso_pagelist = vdso32_pagelist; vdso_pages = vdso32_pages; vdso_base = VDSO32_MBASE; #endif @@ -262,17 +221,6 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, goto fail_mmapsem; } - - /* Allocate a VMA structure and fill it up */ - vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); - if (vma == NULL) { - rc = -ENOMEM; - goto fail_mmapsem; - } - vma->vm_mm = mm; - vma->vm_start = vdso_base; - vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT); - /* * our vma flags don't have VM_WRITE so by default, the process isn't * allowed to write those pages. @@ -282,32 +230,26 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, * 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->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC; - /* + * * Make sure the vDSO gets into every core dump. * Dumping its contents makes post-mortem fully interpretable later * without matching up the same kernel and hardware config to see * what PC values meant. */ - vma->vm_flags |= VM_ALWAYSDUMP; - vma->vm_flags |= mm->def_flags; - vma->vm_page_prot = protection_map[vma->vm_flags & 0x7]; - vma->vm_ops = &vdso_vmops; - - /* Insert new VMA */ - rc = insert_vm_struct(mm, vma); + rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT, + VM_READ|VM_EXEC| + VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC| + VM_ALWAYSDUMP, + vdso_pagelist); if (rc) - goto fail_vma; + goto fail_mmapsem; - /* Put vDSO base into mm struct and account for memory usage */ + /* Put vDSO base into mm struct */ current->mm->context.vdso_base = vdso_base; - mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + up_write(&mm->mmap_sem); return 0; - fail_vma: - kmem_cache_free(vm_area_cachep, vma); fail_mmapsem: up_write(&mm->mmap_sem); return rc; @@ -778,18 +720,26 @@ void __init vdso_init(void) } /* Make sure pages are in the correct state */ + BUG_ON(vdso32_pages + 2 > VDSO32_MAXPAGES); for (i = 0; i < vdso32_pages; i++) { struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE); ClearPageReserved(pg); get_page(pg); - + vdso32_pagelist[i] = pg; } + vdso32_pagelist[i++] = virt_to_page(vdso_data); + vdso32_pagelist[i] = NULL; + #ifdef CONFIG_PPC64 + BUG_ON(vdso64_pages + 2 > VDSO64_MAXPAGES); for (i = 0; i < vdso64_pages; i++) { struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE); ClearPageReserved(pg); get_page(pg); + vdso64_pagelist[i] = pg; } + vdso64_pagelist[i++] = virt_to_page(vdso_data); + vdso64_pagelist[i] = NULL; #endif /* CONFIG_PPC64 */ get_page(virt_to_page(vdso_data)); |