| commit | 05eeae208d08a05a6980cf2ff61f02843c0955fd | |
| author | Andrew Morton <akpm@osdl.org> | |
| Sat, 25 Mar 2006 11:07:48 +0000 (25 03:07 -0800) | ||
| committer | Linus Torvalds <torvalds@g5.osdl.org> | |
| Sat, 25 Mar 2006 16:22:57 +0000 (25 08:22 -0800) | ||
| tree | be6c6c4e16cfac07edf437a1f74ef027ada8ccc7 | treesnapshot (tar.gz zip) |
| parent | c1f5a1944657ba6abe375e3bb2a3238a46849f70 | commitdiff |
[PATCH] find_task_by_pid() needs tasklist_lock
A couple of places are forgetting to take it.
The kswapd case is probably unimportant. keventd_create_kthread() was racy.
The whole thing is a bit flakey: you start a kernel thread, get its pid from
kernel_thread() then look up its task_struct.
a) It assumes that pid recycling takes a "long" time.
b) We get a task_struct but no reference was taken on it. The owner of the
kswapd and kthread task_struct*'s must assume that the new thread won't
exit unexpectedly. Because if it does, they're left holding dead memory
and any attempt to control or stop that task will crash.
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A couple of places are forgetting to take it.
The kswapd case is probably unimportant. keventd_create_kthread() was racy.
The whole thing is a bit flakey: you start a kernel thread, get its pid from
kernel_thread() then look up its task_struct.
a) It assumes that pid recycling takes a "long" time.
b) We get a task_struct but no reference was taken on it. The owner of the
kswapd and kthread task_struct*'s must assume that the new thread won't
exit unexpectedly. Because if it does, they're left holding dead memory
and any attempt to control or stop that task will crash.
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| kernel/kthread.c | diffblobblamehistory | |
| mm/vmscan.c | diffblobblamehistory |