On Wed, Jul 05, 2023 at 02:46:44PM +0800, Li Huafei wrote:
We found an issue with null pointer access due to kprobe debug exception error handling on 5.10, and I proposed a separate fix patch for 5.10, see [1]. But as Greg gave advice, we always choose to backport relevant patches from upstream to fix issues with stable kernels, so I made this patch set.
The main one we need to backport is patch 5, which uses int3 instead of debug trap for single-stepping, thus avoiding the problems we encountered with kprobe debug exception error handling. Patches 1-4 are pre-patches, and patches 6-9 are fixes for patch 5. The major modifications are patch 2 and patch 5. Patch 2 optimizes resume_execution() to avoid repeated instruction decoding, and patch 5 uses int3 instead of debug trap, and as Masami said in the commit message this patch will change some behavior of kprobe, but it has almost no effect on the actual usage.
Please let me know if there are any problems, thanks!
Looks good, thanks for the backports, all now queued up.
greg k-h