Here is the 3rd version of the series to improve preempt
related behavior in kprobes/x86. This actually includes
many enhancements/fixes from the 2nd version, which is
With the previous patch, lkp-bot reported that an issue
( https://lkml.org/lkml/2017/9/14/3 ) and I couldn't
reproduce it. However, I found a suspicious bug and fixed
Also, while I was checking the correct condition for
*probe handlers in Documentation/kprobes.txt, I also
found that current implementations for ftrace-based kprobe
and optprobe were mis-reading the document.
From the document, handlers must be run with preempt-disabled, but interrupt disabling is not guaranteed.
So in the middle of this series, patches ([4/7],[5/7],
[6/7]) adding preempt-disabling and removing irq-disabling.
And at last, I placed the original patch (Enable optprobe
The others are just for making sure this fix works well.
- [1/7] is just adding preemptible checker in kprobe
smake tests so that we can easily find mistake.
- [3/7] is adding an assert if user tries to change
execution path in optprobe, which is obviously
prohibited in the document (there also be how to