On Tue, 2011-12-13 at 13:01 +0800, tiejun.chen wrote:

Tiejun Chen wrote:

quoted

In entry_64.S version of ret_from_except_lite, you'll notice that
in the !preempt case, after we've checked MSR_PR we test for any
TIF flag in _TIF_USER_WORK_MASK to decide whether to go to do_work
or not. However, in the preempt case, we do a convoluted trick to
test SIGPENDING only if PR was set and always test NEED_RESCHED ...
but we forget to test any other bit of _TIF_USER_WORK_MASK !!! So
that means that with preempt, we completely fail to test for things
like single step, syscall tracing, etc...

This should be fixed as the following path:

 - Test PR. If set, go to test_work_user, else continue.

 - In test_work_user, always test for _TIF_USER_WORK_MASK to decide to
go to do_work, maybe call it do_user_work

 - In test_work_kernel, test for _TIF_KERNEL_WORK_MASK which is set to
our new flag along with NEED_RESCHED if preempt is enabled and branch to
do_kernel_work.

Ben,

Any comment for this?

Sorry, I didn't get to review that one yet (nor reply to your newer
responses), I have very sore eyes and basically had to get off the
computer. Hopefully I'll be better tomorrow.

Cheers,
Ben.