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author | Oleg Nesterov <oleg@redhat.com> | 2008-11-17 15:39:47 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-11-17 16:49:35 +0100 |
commit | ad133ba3dc283300e5b62b5b7211d2f39fbf6ee7 (patch) | |
tree | 4762492d6c564e0ac1ec47122a0d0d49b0d41e90 /kernel/cpuset.c | |
parent | 29d7b90c15035741d15421b36000509212b3e135 (diff) | |
download | lwn-ad133ba3dc283300e5b62b5b7211d2f39fbf6ee7.tar.gz lwn-ad133ba3dc283300e5b62b5b7211d2f39fbf6ee7.zip |
sched, signals: fix the racy usage of ->signal in account_group_xxx/run_posix_cpu_timers
Impact: fix potential NULL dereference
Contrary to ad474caca3e2a0550b7ce0706527ad5ab389a4d4 changelog, other
acct_group_xxx() helpers can be called after exit_notify() by timer tick.
Thanks to Roland for pointing out this. Somehow I missed this simple fact
when I read the original patch, and I am afraid I confused Frank during
the discussion. Sorry.
Fortunately, these helpers work with current, we can check ->exit_state
to ensure that ->signal can't go away under us.
Also, add the comment and compiler barrier to account_group_exec_runtime(),
to make sure we load ->signal only once.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/cpuset.c')
0 files changed, 0 insertions, 0 deletions