diff options
author | Oleg Nesterov | 2012-01-31 17:15:11 +0100 |
---|---|---|
committer | Linus Torvalds | 2012-02-01 14:39:01 -0800 |
commit | 6d08f2c7139790c268820a2e590795cb8333181a (patch) | |
tree | 78b2773b8ca6949f9561af641908e4086ba193cb /lib/mpi | |
parent | 572d34b946bae070debd42db1143034d9687e13f (diff) |
proc: make sure mem_open() doesn't pin the target's memory
Once /proc/pid/mem is opened, the memory can't be released until
mem_release() even if its owner exits.
Change mem_open() to do atomic_inc(mm_count) + mmput(), this only
pins mm_struct. Change mem_rw() to do atomic_inc_not_zero(mm_count)
before access_remote_vm(), this verifies that this mm is still alive.
I am not sure what should mem_rw() return if atomic_inc_not_zero()
fails. With this patch it returns zero to match the "mm == NULL" case,
may be it should return -EINVAL like it did before e268337d.
Perhaps it makes sense to add the additional fatal_signal_pending()
check into the main loop, to ensure we do not hold this memory if
the target task was oom-killed.
Cc: stable@kernel.org
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/mpi')
0 files changed, 0 insertions, 0 deletions