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ANDROID: kthread: cfi: disable callback pointer check with modules

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With CFI, a callback function passed to __kthread_queue_delayed_work
from a module can point to a jump table entry defined in the module
instead of the one used in the core kernel, which breaks this test:

  WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn);

To work around the problem, disable the warning when CFI and modules
are both enabled.

Bug: 145210207
Change-Id: I5b0a60bb69ce8e2bc0d8e4bf6736457b6425b6cf
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
This commit is contained in:
Sami Tolvanen 2020-09-25 18:31:59 -07:00 committed by Alistair Delva
parent 83eeb88742
commit 0f186b1e6e
1 changed files with 7 additions and 1 deletions
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8
kernel/kthread.c
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@ -912,7 +912,13 @@ static void __kthread_queue_delayed_work(struct kthread_worker *worker,
struct timer_list *timer = &dwork->timer;
struct kthread_work *work = &dwork->work;
WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn);
/*
* With CFI, timer->function can point to a jump table entry in a module,
* which fails the comparison. Disable the warning if CFI and modules are
* both enabled.
*/
if (!IS_ENABLED(CONFIG_CFI_CLANG) || !IS_ENABLED(CONFIG_MODULES))
WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn);
/*
* If @delay is 0, queue @dwork->work immediately. This is for