diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2012-05-29 21:27:59 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-06-06 17:14:49 +0200 |
| commit | a3d7bb47937b3a40b9f0c75655e97b3bb6407cbe (patch) | |
| tree | ac573bd042efa291c71c956930c81d80e79e4a69 /kernel/events | |
| parent | c00b275043adc14d668f36266b890f0c53d46640 (diff) | |
uprobes: Change read_opcode() to use FOLL_FORCE
set_orig_insn()->read_opcode() should not fail if the probed
task did mprotect() after uprobe_register(), change it to use
FOLL_FORCE. Without FOLL_WRITE this doesn't have any "side"
effect but allows to read the !VM_READ memory.
There is another reason for this change, we are going to use
is_swbp_at_addr() from handle_swbp() which can race with another
thread doing mprotect().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120529192759.GB8057@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/uprobes.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index d0f5ec0dcdea..a0dbc87a2ec6 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -312,7 +312,7 @@ static int read_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_ void *vaddr_new; int ret; - ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &page, NULL); + ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL); if (ret <= 0) return ret; |