memleak: linter cleanup

tools/memleak.py

@@ -281,7 +281,7 @@ def run_command_get_pid(command):
 
  memptrs.delete(&pid);
 
- if (bpf_probe_read(&addr, sizeof(void*), (void*)(size_t)*memptr64) != 0)
+ if (bpf_probe_read(&addr, sizeof(void*), (void*)(size_t)*memptr64))
  return 0;
 
  u64 addr64 = (u64)(size_t)addr;
@@ -382,7 +382,7 @@ def run_command_get_pid(command):
  stack_flags += "|BPF_F_USER_STACK"
 bpf_source = bpf_source.replace("STACK_FLAGS", stack_flags)
 
-bpf_program = BPF(text=bpf_source)
+bpf = BPF(text=bpf_source)
 
 if not kernel_trace:
  print("Attaching to pid %d, Ctrl+C to quit." % pid)
@@ -392,12 +392,12 @@ def attach_probes(sym, fn_prefix=None, can_fail=False):
  fn_prefix = sym
 
  try:
- bpf_program.attach_uprobe(name=obj, sym=sym,
-  fn_name=fn_prefix+"_enter",
-  pid=pid)
- bpf_program.attach_uretprobe(name=obj, sym=sym,
-  fn_name=fn_prefix+"_exit",
-  pid=pid)
+ bpf.attach_uprobe(name=obj, sym=sym,
+ fn_name=fn_prefix + "_enter",
+ pid=pid)
+ bpf.attach_uretprobe(name=obj, sym=sym,
+ fn_name=fn_prefix + "_exit",
+ pid=pid)
  except Exception:
  if can_fail:
  return
@@ -411,8 +411,8 @@ def attach_probes(sym, fn_prefix=None, can_fail=False):
  attach_probes("valloc")
  attach_probes("memalign")
  attach_probes("pvalloc")
- attach_probes("aligned_alloc", can_fail=True) # added in C11
- bpf_program.attach_uprobe(name=obj, sym="free", fn_name="free_enter",
+ attach_probes("aligned_alloc", can_fail=True)  # added in C11
+ bpf.attach_uprobe(name=obj, sym="free", fn_name="free_enter",
  pid=pid)
 
 else:
@@ -423,11 +423,12 @@ def attach_probes(sym, fn_prefix=None, can_fail=False):
  #
  # Memory allocations in Linux kernel are not limited to malloc/free
  # equivalents. It's also common to allocate a memory page or multiple
- # pages. Page allocator have two interfaces, one working with page frame
- # numbers (PFN), while other working with page addresses. It's possible
- # to allocate pages with one kind of functions, and free them with
- # another. Code in kernel can easy convert PFNs to addresses and back,
- # but it's hard to do the same in eBPF kprobe without fragile hacks.
+ # pages. Page allocator have two interfaces, one working with page
+ # frame numbers (PFN), while other working with page addresses. It's
+ # possible to allocate pages with one kind of functions, and free them
+ # with another. Code in kernel can easy convert PFNs to addresses and
+ # back, but it's hard to do the same in eBPF kprobe without fragile
+ # hacks.
  #
  # Fortunately, Linux exposes tracepoints for memory allocations, which
  # can be instrumented by eBPF programs. Tracepoint for page allocations
@@ -438,8 +439,8 @@ def print_outstanding():
  print("[%s] Top %d stacks with outstanding allocations:" %
  (datetime.now().strftime("%H:%M:%S"), top_stacks))
  alloc_info = {}
- allocs = bpf_program["allocs"]
- stack_traces = bpf_program["stack_traces"]
+ allocs = bpf["allocs"]
+ stack_traces = bpf["stack_traces"]
  for address, info in sorted(allocs.items(), key=lambda a: a[1].size):
  if BPF.monotonic_time() - min_age_ns < info.timestamp_ns:
  continue
@@ -451,7 +452,7 @@ def print_outstanding():
  stack = list(stack_traces.walk(info.stack_id))
  combined = []
  for addr in stack:
- combined.append(bpf_program.sym(addr, pid,
+ combined.append(bpf.sym(addr, pid,
  show_module=True, show_offset=True))
  alloc_info[info.stack_id] = Allocation(combined,
  info.size)
@@ -465,16 +466,16 @@ def print_outstanding():
  (alloc.size, alloc.count, "\n\t\t".join(alloc.stack)))
 
 def print_outstanding_combined():
- stack_traces = bpf_program["stack_traces"]
- stacks = sorted(bpf_program["combined_allocs"].items(),
+ stack_traces = bpf["stack_traces"]
+ stacks = sorted(bpf["combined_allocs"].items(),
  key=lambda a: -a[1].total_size)
  cnt = 1
  entries = []
  for stack_id, info in stacks:
  try:
  trace = []
  for addr in stack_traces.walk(stack_id.value):
- sym = bpf_program.sym(addr, pid,
+ sym = bpf.sym(addr, pid,
  show_module=True,
  show_offset=True)
  trace.append(sym)
@@ -498,7 +499,7 @@ def print_outstanding_combined():
 count_so_far = 0
 while True:
  if trace_all:
- print(bpf_program.trace_fields())
+ print(bpf.trace_fields())
  else:
  try:
  sleep(interval)