diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 73 | ||||
| -rw-r--r-- | mm/mlock.c | 4 | ||||
| -rw-r--r-- | mm/nommu.c | 2 |
3 files changed, 57 insertions, 22 deletions
diff --git a/mm/memory.c b/mm/memory.c index 20d5f74..51a5c23 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1486,9 +1486,9 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, struct vm_area_struct *vma; vma = find_extend_vma(mm, start); - if (!vma && in_gate_area(tsk, start)) { + if (!vma && in_gate_area(mm, start)) { unsigned long pg = start & PAGE_MASK; - struct vm_area_struct *gate_vma = get_gate_vma(tsk); + struct vm_area_struct *gate_vma = get_gate_vma(mm); pgd_t *pgd; pud_t *pud; pmd_t *pmd; @@ -1591,10 +1591,13 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, return i ? i : -EFAULT; BUG(); } - if (ret & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; + + if (tsk) { + if (ret & VM_FAULT_MAJOR) + tsk->maj_flt++; + else + tsk->min_flt++; + } if (ret & VM_FAULT_RETRY) { if (nonblocking) @@ -1641,7 +1644,8 @@ EXPORT_SYMBOL(__get_user_pages); /** * get_user_pages() - pin user pages in memory - * @tsk: task_struct of target task + * @tsk: the task_struct to use for page fault accounting, or + * NULL if faults are not to be recorded. * @mm: mm_struct of target mm * @start: starting user address * @nr_pages: number of pages from start to pin @@ -3499,7 +3503,7 @@ static int __init gate_vma_init(void) __initcall(gate_vma_init); #endif -struct vm_area_struct *get_gate_vma(struct task_struct *tsk) +struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { #ifdef AT_SYSINFO_EHDR return &gate_vma; @@ -3508,7 +3512,7 @@ struct vm_area_struct *get_gate_vma(struct task_struct *tsk) #endif } -int in_gate_area_no_task(unsigned long addr) +int in_gate_area_no_mm(unsigned long addr) { #ifdef AT_SYSINFO_EHDR if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END)) @@ -3649,20 +3653,15 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, #endif /* - * Access another process' address space. - * Source/target buffer must be kernel space, - * Do not walk the page table directly, use get_user_pages + * Access another process' address space as given in mm. If non-NULL, use the + * given task for page fault accounting. */ -int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) +static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, + unsigned long addr, void *buf, int len, int write) { - struct mm_struct *mm; struct vm_area_struct *vma; 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 successfully transferred */ while (len) { @@ -3711,11 +3710,47 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in addr += bytes; } up_read(&mm->mmap_sem); - mmput(mm); return buf - old_buf; } +/** + * @access_remote_vm - access another process' address space + * @mm: the mm_struct of the target address space + * @addr: start address to access + * @buf: source or destination buffer + * @len: number of bytes to transfer + * @write: whether the access is a write + * + * The caller must hold a reference on @mm. + */ +int access_remote_vm(struct mm_struct *mm, unsigned long addr, + void *buf, int len, int write) +{ + return __access_remote_vm(NULL, mm, addr, buf, len, write); +} + +/* + * 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; + int ret; + + mm = get_task_mm(tsk); + if (!mm) + return 0; + + ret = __access_remote_vm(tsk, mm, addr, buf, len, write); + mmput(mm); + + return ret; +} + /* * Print the name of a VMA. */ @@ -237,7 +237,7 @@ long mlock_vma_pages_range(struct vm_area_struct *vma, if (!((vma->vm_flags & (VM_DONTEXPAND | VM_RESERVED)) || is_vm_hugetlb_page(vma) || - vma == get_gate_vma(current))) { + vma == get_gate_vma(current->mm))) { __mlock_vma_pages_range(vma, start, end, NULL); @@ -332,7 +332,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev, int lock = newflags & VM_LOCKED; if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) || - is_vm_hugetlb_page(vma) || vma == get_gate_vma(current)) + is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm)) goto out; /* don't set VM_LOCKED, don't count */ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); @@ -1963,7 +1963,7 @@ error: return -ENOMEM; } -int in_gate_area_no_task(unsigned long addr) +int in_gate_area_no_mm(unsigned long addr) { return 0; } |