hi, as part of the effort on speeding up the uprobes [0] coming with return uprobe optimization by using syscall instead of the trap on the uretprobe trampoline. The speed up depends on instruction type that uprobe is installed and depends on specific HW type, please check patch 1 for details. I added extra selftests to check on registers values before and after uretprobe to make sure the syscall saves all the needed regs and that uprobe consumer can still change registers. Patch 1 is based on: https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git probes/for-next and patches 2,3 are based on bpf-next/master and can be taken separately through bpf-next tree without patch 1. v2 changes: - reposted to proper tracing mailing list [Masami] - renamed selftest trigger functions [Andrii] - kept bpf_testmod register call pattern [Andrii] - added acks [Andrii/Oleg] thanks, jirka [0] https://lore.kernel.org/bpf/ZeCXHKJ--iYYbmLj@krava/ --- Jiri Olsa (3): uprobe: Add uretprobe syscall to speed up return probe selftests/bpf: Add uretprobe syscall test for regs integrity selftests/bpf: Add uretprobe syscall test for regs changes arch/x86/entry/syscalls/syscall_64.tbl | 1 + arch/x86/kernel/uprobes.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/syscalls.h | 2 ++ include/linux/uprobes.h | 2 ++ include/uapi/asm-generic/unistd.h | 5 +++- kernel/events/uprobes.c | 18 +++++++++--- kernel/sys_ni.c | 2 ++ tools/include/linux/compiler.h | 4 +++ tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c | 230 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/testing/selftests/bpf/progs/uprobe_syscall.c | 15 ++++++++++ 11 files changed, 478 insertions(+), 6 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall.c
