On Mon, Nov 07, 2022 at 02:49:31PM +0000, Will Deacon wrote: > [+Mark R] > > On Thu, Jul 28, 2022 at 02:02:50AM +0000, Jianlin Lv wrote: > > This is the arm64 version of ftrace-based kprobes to avoid the overhead > > with regular kprobes, by using the ftrace infrastructure. > > > > Signed-off-by: Jianlin Lv <iecedge@xxxxxxxxx> > > --- > > .../debug/kprobes-on-ftrace/arch-support.txt | 2 +- > > arch/arm64/Kconfig | 1 + > > arch/arm64/kernel/probes/Makefile | 1 + > > arch/arm64/kernel/probes/kprobes-ftrace.c | 81 +++++++++++++++++++ > > include/linux/kprobes.h | 2 + > > kernel/kprobes.c | 4 +- > > 6 files changed, 88 insertions(+), 3 deletions(-) > > create mode 100644 arch/arm64/kernel/probes/kprobes-ftrace.c > > Sorry for the slow reply on this, but I think this deserved to be split > into two patches: the first one reworking the core check_ftrace_location() > logic to work properly with branch-and-link style architectures, and the > second one adding support for arm64. I'd prefer we don't do this at all; there a bunch of issues with kprobes *not* taking an exception, since we get a dodgy not-quite-real pt_regs, and to clean up the existing issues the plan is: 1) Move ftrace over to ftrace_regs 2) Implement fprobes using ftrace_regs 3) Remove kretprobes ... and regular kprobes will need to take an exception (via BRK) to get a real pt_regs, so that can't be optimized to use ftrace. Thanks, Mark.
