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author | Oleg Nesterov <oleg@redhat.com> | 2011-08-03 16:21:04 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-08-03 14:25:20 -1000 |
commit | dfc428b656c4693a2334a8d9865b430beddb562a (patch) | |
tree | ad8aa91d2e3c5e9cedc5f4efb2e04a86b4a0784e /kernel | |
parent | 12b3e038e5bb4860c17d001e92a6fa9964c0a7b9 (diff) | |
download | linux-dfc428b656c4693a2334a8d9865b430beddb562a.tar.bz2 |
taskstats: add_del_listener() shouldn't use the wrong node
1. Commit 26c4caea9d69 "don't allow duplicate entries in listener mode"
changed add_del_listener(REGISTER) so that "next_cpu:" can reuse the
listener allocated for the previous cpu, this doesn't look exactly
right even if minor.
Change the code to kfree() in the already-registered case, this case
is unlikely anyway so the extra kmalloc_node() shouldn't hurt but
looke more correct and clean.
2. use the plain list_for_each_entry() instead of _safe() to scan
listeners->list.
3. Remove the unneeded INIT_LIST_HEAD(&s->list), we are going to
list_add(&s->list).
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Vasiliy Kulikov <segoon@openwall.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/taskstats.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/kernel/taskstats.c b/kernel/taskstats.c index d1db2880d1cf..a09a54936f19 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -291,30 +291,28 @@ static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd) if (!cpumask_subset(mask, cpu_possible_mask)) return -EINVAL; - s = NULL; if (isadd == REGISTER) { for_each_cpu(cpu, mask) { - if (!s) - s = kmalloc_node(sizeof(struct listener), - GFP_KERNEL, cpu_to_node(cpu)); + s = kmalloc_node(sizeof(struct listener), + GFP_KERNEL, cpu_to_node(cpu)); if (!s) goto cleanup; + s->pid = pid; - INIT_LIST_HEAD(&s->list); s->valid = 1; listeners = &per_cpu(listener_array, cpu); down_write(&listeners->sem); - list_for_each_entry_safe(s2, tmp, &listeners->list, list) { + list_for_each_entry(s2, &listeners->list, list) { if (s2->pid == pid) - goto next_cpu; + goto exists; } list_add(&s->list, &listeners->list); s = NULL; -next_cpu: +exists: up_write(&listeners->sem); + kfree(s); /* nop if NULL */ } - kfree(s); return 0; } |