Messages in this thread | | | From | David Hildenbrand <> | Subject | [PATCH RFC 0/2] Reenable might_sleep() checks for might_fault() when atomic | Date | Thu, 27 Nov 2014 18:10:15 +0100 |
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Simple prototype to enable might_sleep() checks in might_fault(), avoiding false positives for scenarios involving explicit pagefault_disable().
So this should work: spin_lock(&lock); /* also if left away */ pagefault_disable() rc = copy_to_user(...) pagefault_enable(); spin_unlock(&lock); /*
And this should report a warning again: spin_lock(&lock); rc = copy_to_user(...); spin_unlock(&lock);
Still missing: - Split of preempt documentation update + preempt_active define reshuffle - Debug version to test for over/underflows - Change documentation of user access methods to reflect the real behavior - Don't touch the preempt counter, only the pagefault disable counter (future work)
David Hildenbrand (2): preempt: track pagefault_disable() calls in the preempt counter mm, sched: trigger might_sleep() in might_fault() when pagefaults are disabled
include/linux/kernel.h | 9 +++++++-- include/linux/preempt_mask.h | 24 +++++++++++++++++++----- include/linux/uaccess.h | 21 ++++++++++++++------- mm/memory.c | 15 ++++----------- 4 files changed, 44 insertions(+), 25 deletions(-)
-- 1.8.5.5
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