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;
fault_flags |= FAULT_FLAG_WRITE;
if (nonblocking)
fault_flags |= FAULT_FLAG_ALLOW_RETRY;
+ if (foll_flags & FOLL_NOWAIT)
+ fault_flags |= (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT);
ret = handle_mm_fault(mm, vma, start,
fault_flags);
if (ret & VM_FAULT_ERROR) {
if (ret & VM_FAULT_OOM)
return i ? i : -ENOMEM;
- if (ret &
- (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE|
- VM_FAULT_SIGBUS))
+ if (ret & (VM_FAULT_HWPOISON |
+ VM_FAULT_HWPOISON_LARGE)) {
+ if (i)
+ return i;
+ else if (gup_flags & FOLL_HWPOISON)
+ return -EHWPOISON;
+ else
+ return -EFAULT;
+ }
+ if (ret & VM_FAULT_SIGBUS)
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) {
- *nonblocking = 0;
+ if (nonblocking)
+ *nonblocking = 0;
return i;
}
/**
* 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
* handle_pte_fault chooses page fault handler according to an entry
* which was read non-atomically. Before making any commitment, on
* those architectures or configurations (e.g. i386 with PAE) which
- * might give a mix of unmatched parts, do_swap_page and do_file_page
+ * might give a mix of unmatched parts, do_swap_page and do_nonlinear_fault
* must check under lock before unmapping the pte and proceeding
* (but do_wp_page is only called after already making such a check;
- * and do_anonymous_page and do_no_page can safely check later on).
+ * and do_anonymous_page can safely check later on).
*/
static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
pte_t *page_table, pte_t orig_pte)
* bit after it clear all dirty ptes, but before a racing
* do_wp_page installs a dirty pte.
*
- * do_no_page is protected similarly.
+ * __do_fault is protected similarly.
*/
if (!page_mkwrite) {
wait_on_page_locked(dirty_page);
swp_entry_t entry;
pte_t pte;
int locked;
- struct mem_cgroup *ptr = NULL;
+ struct mem_cgroup *ptr;
int exclusive = 0;
int ret = 0;
__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;
#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))
#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) {
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.
*/
git.openpandora.org / pandora-kernel.git / blobdiff