Hi, Here is the 6th version of the series of patches which introduces IPMODIFY flag for ftrace_ops to detect conflicts of ftrace users who can modify regs->ip in their handler.
This version is basically an update of previous version to the latest ftrace/core tree. Currently, only kprobes can change the regs->ip in the handler, but recent Kernel Live Patching also changes it. Here we talked on github. https://github.com/dynup/kpatch/issues/47 To protect modified regs-ip from each other, this series introduces FTRACE_OPS_FL_IPMODIFY flag and ftrace now ensures the flag can be set on each function entry location. If there is someone who already reserve regs->ip on target function entry, ftrace_set_filter_ip or register_ftrace_function will return -EBUSY. Users must handle that. The ftrace_ops with IPMODIFY flag requires at least one entry for filter hash, and its notrace_hash must be empty, because the IPMODIFY action is very address sensitve and user must consider the ip address. Thank you, --- Masami Hiramatsu (5): kprobes/ftrace: Recover original IP if pre_handler doesn't change it ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict kprobes: Add IPMODIFY flag to kprobe_ftrace_ops kprobes: Set IPMODIFY flag only if the probe can change regs->ip kselftest,ftrace: Add ftrace IPMODIFY flag test Documentation/kprobes.txt | 12 + Documentation/trace/ftrace.txt | 5 + arch/x86/kernel/kprobes/ftrace.c | 9 + include/linux/ftrace.h | 16 ++ kernel/kprobes.c | 123 +++++++++++++- kernel/trace/ftrace.c | 142 ++++++++++++++++- tools/testing/selftests/ftrace/Makefile | 11 + tools/testing/selftests/ftrace/ipmodify/Makefile | 15 ++ tools/testing/selftests/ftrace/ipmodify/ipmodify.c | 170 ++++++++++++++++++++ .../selftests/ftrace/ipmodify/run_ipmodify.sh | 6 + 10 files changed, 480 insertions(+), 29 deletions(-) create mode 100644 tools/testing/selftests/ftrace/ipmodify/Makefile create mode 100644 tools/testing/selftests/ftrace/ipmodify/ipmodify.c create mode 100644 tools/testing/selftests/ftrace/ipmodify/run_ipmodify.sh -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
