bpf.lua: Implement dump_func

weibang6liu · Mar 30, 2016 · 81990c3 · 81990c3
1 parent 72d7aa3
commit 81990c3
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Showing 2 changed files with 19 additions and 1 deletion.
diff --git a/src/lua/bcc/bpf.lua b/src/lua/bcc/bpf.lua
@@ -157,7 +157,8 @@ function Bpf:load_func(fn_name, prog_type)
  return self.funcs[fn_name]
  end
 
- assert(libbcc.bpf_function_start(self.module, fn_name), "unknown program: "..fn_name)
+ assert(libbcc.bpf_function_start(self.module, fn_name) ~= nil,
+ "unknown program: "..fn_name)
 
  local fd = libbcc.bpf_prog_load(prog_type,
  libbcc.bpf_function_start(self.module, fn_name),
@@ -173,6 +174,14 @@ function Bpf:load_func(fn_name, prog_type)
  return fn
 end
 
+function Bpf:dump_func(fn_name)
+ local start = libbcc.bpf_function_start(self.module, fn_name)
+ assert(start ~= nil, "unknown program")
+
+ local len = libbcc.bpf_function_size(self.module, fn_name)
+ return ffi.string(start, tonumber(len))
+end
+
 function Bpf:attach_uprobe(args)
  Bpf.check_probe_quota(1)
 

diff --git a/tests/lua/test_dump.lua b/tests/lua/test_dump.lua
@@ -0,0 +1,9 @@
+require("test_helper")
+
+function test_dump_func()
+ local raw = "\xb7\x00\x00\x00\x01\x00\x00\x00\x95\x00\x00\x00\x00\x00\x00\x00"
+ local b = BPF:new{text=[[int entry(void) { return 1; }]]}
+ assert_equals(b:dump_func("entry"), raw)
+end
+
+os.exit(LuaUnit.run())