I just realized that none of the live kernel patching folks are Cc'd on this thread. I think they will care much more about this than I do. -- Steve On Thu, 2 Jun 2022 12:37:01 -0700 Song Liu <song@xxxxxxxxxx> wrote: > Changes v1 => v2: > 1. Fix build errors for different config. (kernel test robot) > > Kernel Live Patch (livepatch, or klp) and bpf trampoline are important > features for modern systems. This set allows the two to work on the same > kernel function as the same time. > > live patch uses ftrace with IPMODIFY, while bpf trampoline use direct > ftrace. Existing policy does not allow the two to attach to the same kernel > function. This is changed by fine tuning ftrace IPMODIFY policy, and allows > one non-DIRECT IPMODIFY ftrace_ops and one non-IPMODIFY DIRECT ftrace_ops > on the same kernel function at the same time. Please see 3/5 for more > details on this. > > Note that, one of the constraint here is to let bpf trampoline use direct > call when it is not working on the same function as live patch. This is > achieved by allowing ftrace code to ask bpf trampoline to make changes. > > Jiri Olsa (1): > bpf, x64: Allow to use caller address from stack > > Song Liu (4): > ftrace: allow customized flags for ftrace_direct_multi ftrace_ops > ftrace: add modify_ftrace_direct_multi_nolock > ftrace: introduce FTRACE_OPS_FL_SHARE_IPMODIFY > bpf: trampoline: support FTRACE_OPS_FL_SHARE_IPMODIFY > > arch/x86/net/bpf_jit_comp.c | 13 +- > include/linux/bpf.h | 8 ++ > include/linux/ftrace.h | 79 +++++++++++ > kernel/bpf/trampoline.c | 109 +++++++++++++-- > kernel/trace/ftrace.c | 269 +++++++++++++++++++++++++++++++----- > 5 files changed, 424 insertions(+), 54 deletions(-) > > -- > 2.30.2
