On Mon, 6 May 2019 09:17:19 -0700 Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > So what is it that doesn't actually work? I've looked at the patch > even more, and I can't for the life of me see how it wouldn't work. > > Of course, I didn't test any of the actual ftrace parts, since I > short-circuited them intentionally with the above test function hack. > I have no idea what the semantics for those > ftrace_location(ip)/is_ftrace_caller(ip) cases are supposed to be, I > only tested that yes, the infrastructure clearly emulates a call > instruction. Can you try booting with: CONFIG_KPROBE_EVENTS=y CONFIG_UPROBE_EVENTS=y CONFIG_DYNAMIC_EVENTS=y CONFIG_PROBE_EVENTS=y CONFIG_DYNAMIC_FTRACE=y CONFIG_DYNAMIC_FTRACE_WITH_REGS=y CONFIG_FUNCTION_PROFILER=y CONFIG_FTRACE_MCOUNT_RECORD=y CONFIG_FTRACE_SELFTEST=y CONFIG_FTRACE_STARTUP_TEST=y CONFIG_TRACEPOINT_BENCHMARK=y CONFIG_RING_BUFFER_BENCHMARK=y CONFIG_RING_BUFFER_STARTUP_TEST=y And see if it boots? -- Steve
