On Fri, Nov 6, 2020 at 9:02 AM Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx> wrote: > > On Sat, 17 Oct 2020 00:06:13 PDT (-0700), guoren@xxxxxxxxxx wrote: > > From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > > > This patch enables "kprobe & kretprobe" to work with ftrace > > interface. It utilized software breakpoint as single-step > > mechanism. > > > > Some instructions which can't be single-step executed must be > > simulated in kernel execution slot, such as: branch, jal, auipc, > > la ... > > > > Some instructions should be rejected for probing and we use a > > blacklist to filter, such as: ecall, ebreak, ... > > > > We use ebreak & c.ebreak to replace origin instruction and the > > kprobe handler prepares an executable memory slot for out-of-line > > execution with a copy of the original instruction being probed. > > In execution slot we add ebreak behind original instruction to > > simulate a single-setp mechanism. > > > > The patch is based on packi's work [1] and csky's work [2]. > > - The kprobes_trampoline.S is all from packi's patch > > - The single-step mechanism is new designed for riscv without hw > > single-step trap > > - The simulation codes are from csky > > - Frankly, all codes refer to other archs' implementation > > > > [1] https://lore.kernel.org/linux-riscv/20181113195804.22825-1-me@xxxxxxxx/ > > [2] https://lore.kernel.org/linux-csky/20200403044150.20562-9-guoren@xxxxxxxxxx/ > > > > Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > Co-Developed-by: Patrick Stählin <me@xxxxxxxx> > > Checkpatch says > > WARNING: 'Co-developed-by:' is the preferred signature form > #108: > Co-Developed-by: Patrick Stählin <me@xxxxxxxx> > > WARNING: Co-developed-by: must be immediately followed by Signed-off-by: > #108: > Co-Developed-by: Patrick Stählin <me@xxxxxxxx> > Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> > > There's some other checkpatch warnings throughout the patch set, but this is > one I'm not supposed to fix up. Can one of you re-post the patches with the > correct DCO? Ok, I'll fix it up in V5 and rebase 5.10-rc2 -- Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/
