| Message ID | 1556034593-3692-1-git-send-email-andrew.cooper3@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen/timers: Fix memory leak with cpu unplug/plug (take 2) | expand |
>>> On 23.04.19 at 17:49, <andrew.cooper3@citrix.com> wrote: > Previous attempts to fix this leak failed to identify the root cause, and > ultimately failed. The cause is the CPU_UP_PREPARE case (re)initialising > ts->heap back to dummy_heap, which leaks the previous allocation. > > Rearrange the logic to only initialise ts once. This also avoids the > redundant (but benign, due to ts->inactive always being empty) initialising of > the other ts fields. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
diff --git a/xen/common/timer.c b/xen/common/timer.c index f60712a..650e398 100644 --- a/xen/common/timer.c +++ b/xen/common/timer.c @@ -657,9 +657,13 @@ static int cpu_callback( switch ( action ) { case CPU_UP_PREPARE: - INIT_LIST_HEAD(&ts->inactive); - spin_lock_init(&ts->lock); - ts->heap = dummy_heap; + /* Only initialise ts once. */ + if ( !ts->heap ) + { + INIT_LIST_HEAD(&ts->inactive); + spin_lock_init(&ts->lock); + ts->heap = dummy_heap; + } break; case CPU_UP_CANCELED:
Previous attempts to fix this leak failed to identify the root cause, and ultimately failed. The cause is the CPU_UP_PREPARE case (re)initialising ts->heap back to dummy_heap, which leaks the previous allocation. Rearrange the logic to only initialise ts once. This also avoids the redundant (but benign, due to ts->inactive always being empty) initialising of the other ts fields. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: George Dunlap <George.Dunlap@eu.citrix.com> CC: Jan Beulich <JBeulich@suse.com> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: Stefano Stabellini <sstabellini@kernel.org> CC: Tim Deegan <tim@xen.org> CC: Wei Liu <wei.liu2@citrix.com> CC: Julien Grall <julien.grall@arm.com> --- xen/common/timer.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)