bpf.lua: Add support for CFLAGS and LLVM debug flags

nanshuaibo · Mar 30, 2016 · e789360 · e789360
1 parent a978401
commit e789360
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Showing 6 changed files with 34 additions and 7 deletions.
diff --git a/examples/lua/bashreadline.lua b/examples/lua/bashreadline.lua
@@ -16,7 +16,7 @@ limitations under the License.
 local ffi = require("ffi")
 
 return function(BPF)
- local b = BPF:new{src_file="bashreadline.c", debug=true}
+ local b = BPF:new{src_file="bashreadline.c", debug=0}
  b:attach_uprobe{name="/bin/bash", sym="readline", fn_name="printret", retprobe=true}
 
  local function print_readline(cpu, event)

diff --git a/examples/lua/memleak.lua b/examples/lua/memleak.lua
@@ -123,7 +123,7 @@ return function(BPF, utils)
  text = text:gsub("SHOULD_PRINT", args.trace and "1" or "0")
  text = text:gsub("SAMPLE_EVERY_N", tostring(args.sample_rate))
 
- local bpf = BPF:new{text=text, debug=true}
+ local bpf = BPF:new{text=text, debug=0}
  local syms = nil
  local min_age_ns = args.older * 1e6
 

diff --git a/examples/lua/strlen_count.lua b/examples/lua/strlen_count.lua
@@ -32,7 +32,7 @@ int printarg(struct pt_regs *ctx) {
 ]], "PID", arg[1])
 
 return function(BPF)
- local b = BPF:new{text=program, debug=true}
+ local b = BPF:new{text=program, debug=0}
  b:attach_uprobe{name="c", sym="strlen", fn_name="printarg"}
 
  local pipe = b:pipe()

diff --git a/examples/lua/task_switch.lua b/examples/lua/task_switch.lua
@@ -38,7 +38,7 @@ int count_sched(struct pt_regs *ctx, struct task_struct *prev) {
 ]]
 
 return function(BPF)
- local b = BPF:new{text=program, debug=true}
+ local b = BPF:new{text=program, debug=0}
  b:attach_kprobe{event="finish_task_switch", fn_name="count_sched"}
 
  print("Press any key...")

diff --git a/src/lua/bcc/bpf.lua b/src/lua/bcc/bpf.lua
@@ -27,6 +27,11 @@ Bpf.static.open_uprobes = {}
 Bpf.static.process_symbols = {}
 Bpf.static.KPROBE_LIMIT = 1000
 Bpf.static.tracer_pipe = nil
+Bpf.static.DEFAULT_CFLAGS = {
+ '-D__HAVE_BUILTIN_BSWAP16__',
+ '-D__HAVE_BUILTIN_BSWAP32__',
+ '-D__HAVE_BUILTIN_BSWAP64__',
+}
 
 function Bpf.static.check_probe_quota(n)
  local cur = table.count(Bpf.static.open_kprobes) + table.count(Bpf.static.open_uprobes)
@@ -101,17 +106,23 @@ function Bpf:initialize(args)
  self.funcs = {}
  self.tables = {}
 
+ local cflags = table.join(Bpf.DEFAULT_CFLAGS, args.cflags)
+ local cflags_ary = ffi.new("const char *[?]", #cflags, cflags)
+
+ local llvm_debug = args.debug or 0
+ assert(type(llvm_debug) == "number")
+
  if args.text then
  log.info("\n%s\n", args.text)
- self.module = libbcc.bpf_module_create_c_from_string(args.text, args.llvm_debug or 0, nil, 0)
+ self.module = libbcc.bpf_module_create_c_from_string(args.text, llvm_debug, cflags_ary, #cflags)
  elseif args.src_file then
  local src = _find_file(Bpf.SCRIPT_ROOT, args.src_file)
 
  if src:ends(".b") then
  local hdr = _find_file(Bpf.SCRIPT_ROOT, args.hdr_file)
- self.module = libbcc.bpf_module_create_b(src, hdr, args.llvm_debug or 0)
+ self.module = libbcc.bpf_module_create_b(src, hdr, llvm_debug)
  else
- self.module = libbcc.bpf_module_create_c(src, args.llvm_debug or 0, nil, 0)
+ self.module = libbcc.bpf_module_create_c(src, llvm_debug, cflags_ary, #cflags)
  end
  end
 

diff --git a/src/lua/bcc/vendor/helpers.lua b/src/lua/bcc/vendor/helpers.lua
@@ -65,6 +65,22 @@ function table.bsearch(list, value, mkval)
  return nil
 end
 
+function table.join(a, b)
+ assert(a)
+ if b == nil or #b == 0 then
+ return a
+ end
+
+ local res = {}
+ for _, v in ipairs(a) do
+ table.insert(res, v)
+ end
+ for _, v in ipairs(b) do
+ table.insert(res, v)
+ end
+ return res
+end
+
 function table.build(iterator_fn, build_fn)
  build_fn = (build_fn or function(arg) return arg end)
  local res = {}