On Wed, Jan 6, 2016 at 10:32 AM, Mateusz Guzik <mguzik@xxxxxxxxxx> wrote:
(down/up)_read does not protect against concurrent readers ?
The code was taking the semaphore for reading, which does not protect
against readers nor concurrent modifications.
(down/up)_read does not protect against concurrent readers ?
The problem could cause a sanity checks to fail in procfs's cmdline
reader, resulting in an OOPS.
Can you explain this a bit and may be give some examples ?
Note that some functions perform an unlocked read of various mm fields,
but they seem to be fine despite possible modificaton.
Those need to be fixed as well ?
Signed-off-by: Mateusz Guzik <mguzik@xxxxxxxxxx>