Merge branch 'for-linus' of git://www.jni.nu/cris

[sfrench/cifs-2.6.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index e48945ab362b87904d3a541e27902dc0d492cecb..9da8cab1b1b0abceae9569a794447f3ddb0c1134 100644 (file)
--- 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;
@@ -1569,6 +1569,8 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                                        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);
@@ -1589,13 +1591,17 @@ 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) {
-                                       *nonblocking = 0;
+                                       if (nonblocking)
+                                               *nonblocking = 0;
                                        return i;
                                }
 
@@ -1638,7 +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
@@ -2764,7 +2771,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
        swp_entry_t entry;
        pte_t pte;
        int locked;
-       struct mem_cgroup *ptr = NULL;
+       struct mem_cgroup *ptr;
        int exclusive = 0;
        int ret = 0;
 
@@ -3496,7 +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;
@@ -3505,7 +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))
@@ -3646,20 +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) {
@@ -3708,11 +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.
  */