Commit cc359d18 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Ingo Molnar

uprobes: __copy_insn() should ensure a_ops->readpage != NULL

__copy_insn() blindly calls read_mapping_page(), this will crash
the kernel if ->readpage == NULL, add the necessary check. For
example, hugetlbfs_aops->readpage is NULL. Perhaps we should
change read_mapping_page() instead.
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120615154325.GA9568@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent ea131377
...@@ -610,6 +610,9 @@ __copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *ins ...@@ -610,6 +610,9 @@ __copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *ins
if (!filp) if (!filp)
return -EINVAL; return -EINVAL;
if (!mapping->a_ops->readpage)
return -EIO;
idx = (unsigned long)(offset >> PAGE_CACHE_SHIFT); idx = (unsigned long)(offset >> PAGE_CACHE_SHIFT);
off1 = offset &= ~PAGE_MASK; off1 = offset &= ~PAGE_MASK;
......
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