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🚧 It's at an early stage and may contain bugs on more platforms and eBPF programs. We are working on to improve the stability and compatibility. It's not suitable for production use now.

If you find any bugs or suggestions, please feel free to open an issue, thanks!

Table of Contents

Uprobe and uretprobe

With bpftime, you can build eBPF applications using familiar tools like clang and libbpf, and execute them in userspace. For instance, the malloc eBPF program traces malloc calls using uprobe and aggregates the counts using a hash map.

You can refer to documents/ for how to build the project.

To get started, you can build and run a libbpf based eBPF program starts with bpftime cli:

make -C example/malloc # Build the eBPF program example
bpftime load ./example/malloc/malloc

In another shell, Run the target program with eBPF inside:

$ bpftime start ./example/malloc/victim
Hello malloc!
malloc called from pid 250215
continue malloc...
malloc called from pid 250215

You can also dynamically attach the eBPF program with a running process:

$ ./example/malloc/victim & echo $! # The pid is 101771
[1] 101771
continue malloc...
continue malloc...

And attach to it:

$ sudo bpftime attach 101771 # You may need to run make install in root
Inject: "/root/.bpftime/"
Successfully injected. ID: 1

You can see the output from original program:

$ bpftime load ./example/malloc/malloc
        pid=247299      malloc calls: 10
        pid=247322      malloc calls: 10

Alternatively, you can also run our sample eBPF program directly in the kernel eBPF, to see the similar output:

$ sudo example/malloc/malloc
        pid=30415       malloc calls: 1079
        pid=30393       malloc calls: 203
        pid=29882       malloc calls: 1076
        pid=34809       malloc calls: 8

Syscall tracing

An example can be found at examples/opensnoop

$ sudo ~/.bpftime/bpftime load ./example/opensnoop/opensnoop
[2023-10-09 04:36:33.891] [info] manager constructed
[2023-10-09 04:36:33.892] [info] global_shm_open_type 0 for bpftime_maps_shm
[2023-10-09 04:36:33][info][23999] Enabling helper groups ffi, kernel, shm_map by default
PID    COMM              FD ERR PATH
72101  victim             3   0 test.txt
72101  victim             3   0 test.txt
72101  victim             3   0 test.txt
72101  victim             3   0 test.txt

In another terminal, run the victim program:

$ sudo ~/.bpftime/bpftime start -s example/opensnoop/victim
[2023-10-09 04:38:16.196] [info] Entering new main..
[2023-10-09 04:38:16.197] [info] Using agent /root/.bpftime/
[2023-10-09 04:38:16.198] [info] Page zero setted up..
[2023-10-09 04:38:16.198] [info] Rewriting executable segments..
[2023-10-09 04:38:19.260] [info] Loading dynamic library..
test.txt closed
Opening test.txt
test.txt opened, fd=3
Closing test.txt...

Run with LD_PRELOAD directly

If the command line interface is not enough, you can also run the eBPF program with LD_PRELOAD directly.

The command line tool is a wrapper of LD_PRELOAD and can work with ptrace to inject the runtime shared library into a running target process.

Run the eBPF tool with libbpf:

LD_PRELOAD=build/runtime/syscall-server/ example/malloc/malloc

Start the target program to trace:

LD_PRELOAD=build/runtime/agent/ example/malloc/victim

Run with JIT enabled

If the performance is not good enough, you can try to enable JIT. The JIT will be enabled by default in the future after more tests.

Set BPFTIME_USE_JIT=true in the server to enable JIT, for example, when running the server:

LD_PRELOAD=~/.bpftime/ BPFTIME_USE_JIT=true example/malloc/malloc

The default behavior is using ubpf JIT, you can also use LLVM JIT by compile with LLVM JIT enabled. See documents/ for more details.

Run with kernel eBPF

You can run the eBPF program in userspace with kernel eBPF in two ways. The kernel must have eBPF support enabled, and kernel version should be higher enough to support mmap eBPF map.

  1. with the shared library, for example:
BPFTIME_NOT_LOAD_PATTERN=start_.* BPFTIME_RUN_WITH_KERNEL=true LD_PRELOAD=~/.bpftime/ example/malloc/malloc
  1. Using daemon mode, see

Control Log Level

Set SPDLOG_LEVEL to control the log level dynamically, for example, when running the server:

SPDLOG_LEVEL=debug LD_PRELOAD=~/.bpftime/ example/malloc/malloc

Available log level include:

  • trace
  • debug
  • info
  • warn
  • err
  • critical
  • off

See for more details.

Log can also be controled at compile time by specifying -DSPDLOG_ACTIVE_LEVEL=SPDLOG_LEVEL_INFO in the cmake compile command.