Merge branch 'akpm' (patches from Andrew)

[platform/kernel/linux-starfive.git] / kernel / events / uprobes.c

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 4f4993d..bb08628 100644 (file)
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -861,10 +861,6 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
        if (ret)
                goto out;
 
-       /* uprobe_write_opcode() assumes we don't cross page boundary */
-       BUG_ON((uprobe->offset & ~PAGE_MASK) +
-                       UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
-
        smp_wmb(); /* pairs with the smp_rmb() in handle_swbp() */
        set_bit(UPROBE_COPY_INSN, &uprobe->flags);
 
@@ -1160,6 +1156,15 @@ static int __uprobe_register(struct inode *inode, loff_t offset,
        if (offset > i_size_read(inode))
                return -EINVAL;
 
+       /*
+        * This ensures that copy_from_page(), copy_to_page() and
+        * __update_ref_ctr() can't cross page boundary.
+        */
+       if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE))
+               return -EINVAL;
+       if (!IS_ALIGNED(ref_ctr_offset, sizeof(short)))
+               return -EINVAL;
+
  retry:
        uprobe = alloc_uprobe(inode, offset, ref_ctr_offset);
        if (!uprobe)
@@ -2008,6 +2013,9 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
        uprobe_opcode_t opcode;
        int result;
 
+       if (WARN_ON_ONCE(!IS_ALIGNED(vaddr, UPROBE_SWBP_INSN_SIZE)))
+               return -EINVAL;
+
        pagefault_disable();
        result = __get_user(opcode, (uprobe_opcode_t __user *)vaddr);
        pagefault_enable();