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Diffstat (limited to 'kernel/events/uprobes.c')
-rw-r--r--kernel/events/uprobes.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index ece7e13f6e4a..cc2095607c74 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -867,10 +867,6 @@ 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);
@@ -1166,6 +1162,15 @@ 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)
@@ -2014,6 +2019,9 @@ 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();