diff options
| -rw-r--r-- | kernel/ptrace.c | 54 | ||||
| -rw-r--r-- | mm/memory.c | 53 | ||||
| -rw-r--r-- | mm/nommu.c | 47 |
3 files changed, 100 insertions, 54 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 9a111f70145c..8aad0331d82e 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -241,60 +241,6 @@ int ptrace_detach(struct task_struct *child, unsigned int data) return 0; } -/* - * Access another process' address space. - * Source/target buffer must be kernel space, - * Do not walk the page table directly, use get_user_pages - */ - -int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) -{ - struct mm_struct *mm; - struct vm_area_struct *vma; - struct page *page; - void *old_buf = buf; - - mm = get_task_mm(tsk); - if (!mm) - return 0; - - down_read(&mm->mmap_sem); - /* ignore errors, just check how much was sucessfully transfered */ - while (len) { - int bytes, ret, offset; - void *maddr; - - ret = get_user_pages(tsk, mm, addr, 1, - write, 1, &page, &vma); - if (ret <= 0) - break; - - bytes = len; - offset = addr & (PAGE_SIZE-1); - if (bytes > PAGE_SIZE-offset) - bytes = PAGE_SIZE-offset; - - maddr = kmap(page); - if (write) { - copy_to_user_page(vma, page, addr, - maddr + offset, buf, bytes); - set_page_dirty_lock(page); - } else { - copy_from_user_page(vma, page, addr, - buf, maddr + offset, bytes); - } - kunmap(page); - page_cache_release(page); - len -= bytes; - buf += bytes; - addr += bytes; - } - up_read(&mm->mmap_sem); - mmput(mm); - - return buf - old_buf; -} - int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) { int copied = 0; diff --git a/mm/memory.c b/mm/memory.c index f2ef1dcfff77..601159a46ab6 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2604,3 +2604,56 @@ int in_gate_area_no_task(unsigned long addr) } #endif /* __HAVE_ARCH_GATE_AREA */ + +/* + * Access another process' address space. + * Source/target buffer must be kernel space, + * Do not walk the page table directly, use get_user_pages + */ +int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) +{ + struct mm_struct *mm; + struct vm_area_struct *vma; + struct page *page; + void *old_buf = buf; + + mm = get_task_mm(tsk); + if (!mm) + return 0; + + down_read(&mm->mmap_sem); + /* ignore errors, just check how much was sucessfully transfered */ + while (len) { + int bytes, ret, offset; + void *maddr; + + ret = get_user_pages(tsk, mm, addr, 1, + write, 1, &page, &vma); + if (ret <= 0) + break; + + bytes = len; + offset = addr & (PAGE_SIZE-1); + if (bytes > PAGE_SIZE-offset) + bytes = PAGE_SIZE-offset; + + maddr = kmap(page); + if (write) { + copy_to_user_page(vma, page, addr, + maddr + offset, buf, bytes); + set_page_dirty_lock(page); + } else { + copy_from_user_page(vma, page, addr, + buf, maddr + offset, bytes); + } + kunmap(page); + page_cache_release(page); + len -= bytes; + buf += bytes; + addr += bytes; + } + up_read(&mm->mmap_sem); + mmput(mm); + + return buf - old_buf; +} diff --git a/mm/nommu.c b/mm/nommu.c index d99dea31e443..d08acdae0036 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1206,3 +1206,50 @@ struct page *filemap_nopage(struct vm_area_struct *area, BUG(); return NULL; } + +/* + * Access another process' address space. + * - source/target buffer must be kernel space + */ +int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) +{ + struct vm_list_struct *vml; + struct vm_area_struct *vma; + struct mm_struct *mm; + + if (addr + len < addr) + return 0; + + mm = get_task_mm(tsk); + if (!mm) + return 0; + + down_read(&mm->mmap_sem); + + /* the access must start within one of the target process's mappings */ + for (vml = mm->context.vmlist; vml; vml = vml->next) + if (addr >= vml->vma->vm_start && addr < vml->vma->vm_end) + break; + + if (vml) { + vma = vml->vma; + + /* don't overrun this mapping */ + if (addr + len >= vma->vm_end) + len = vma->vm_end - addr; + + /* only read or write mappings where it is permitted */ + if (write && vma->vm_flags & VM_WRITE) + len -= copy_to_user((void *) addr, buf, len); + else if (!write && vma->vm_flags & VM_READ) + len -= copy_from_user(buf, (void *) addr, len); + else + len = 0; + } else { + len = 0; + } + + up_read(&mm->mmap_sem); + mmput(mm); + return len; +} |