Class: HeapInfo::Arena

Inherits:
Object
  • Object
show all
Defined in:
lib/heapinfo/arena.rb

Overview

Records status of an arena, including bin(s) and top chunk.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(base, size_t, dumper) ⇒ Arena

Instantiate a HeapInfo::Arena object.

Parameters:

  • base (Integer) —

    Base address of arena.

  • size_t (Integer) —

    Either 8 or 4.

  • dumper (Proc) —

    For dumping more data.



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# File 'lib/heapinfo/arena.rb', line 26

def initialize(base, size_t, dumper)
  @base = base
  @size_t = size_t
  @dumper = dumper
  reload!
end

Instance Attribute Details

#fastbin ⇒ Array<HeapInfo::Fastbin> (readonly)

Returns Fastbins in an array.

Returns:



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# File 'lib/heapinfo/arena.rb', line 8

def fastbin
  @fastbin
end

#last_remainder ⇒ HeapInfo::Chunk (readonly)

Returns Current last remainder.

Returns:



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# File 'lib/heapinfo/arena.rb', line 12

def last_remainder
  @last_remainder
end

#smallbin ⇒ Array<HeapInfo::Smallbin> (readonly)

Returns Smallbins in an array.

Returns:



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# File 'lib/heapinfo/arena.rb', line 16

def smallbin
  @smallbin
end

#system_mem ⇒ Integer (readonly)

Returns The system_mem in arena.

Returns:

  • (Integer) —

    The system_mem in arena.



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# File 'lib/heapinfo/arena.rb', line 18

def system_mem
  @system_mem
end

#top_chunk ⇒ HeapInfo::Chunk (readonly)

Returns Current top chunk.

Returns:



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# File 'lib/heapinfo/arena.rb', line 10

def top_chunk
  @top_chunk
end

#unsorted_bin ⇒ Array<HeapInfo::UnsortedBin> (readonly)

Returns The unsorted bin (array size will always be one).

Returns:



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# File 'lib/heapinfo/arena.rb', line 14

def unsorted_bin
  @unsorted_bin
end

Instance Method Details

#layouts(*args) ⇒ String

Pretty dump of bins layouts.

Examples:

puts h.libc.main_arena.layouts(:fast, :unsorted, :small)
puts h.libc.main_arena.layouts(:all)

Parameters:

  • args (Symbol) —

    Bin type(s) you want to see.

Returns:

  • (String) —

    Bin layouts that wrapper with color codes.



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# File 'lib/heapinfo/arena.rb', line 64

def layouts(*args)
  args.concat(%i[fast unsort small large]) if args.map(&:to_s).include?('all')
  args = args.map(&:to_s).join('|')
  res = ''
  res += fastbin.map(&:inspect).join if args.include?('fast')
  res += unsorted_bin.inspect if args.include?('unsort')
  res += smallbin.map(&:inspect).join if args.include?('small')
  res
end

#reload! ⇒ HeapInfo::Arena

Refresh all attributes. Retrive data using @dumper, load bins, top chunk etc.

Returns:



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# File 'lib/heapinfo/arena.rb', line 36

def reload!
  top_ptr_offset = @base + 8 + size_t * 10
  top_ptr = Helper.unpack(size_t, @dumper.call(top_ptr_offset, size_t))
  @fastbin = []
  return self if top_ptr.zero? # arena not init yet
  @top_chunk = Chunk.new(size_t, top_ptr, @dumper)
  @last_remainder = Chunk.new(size_t, top_ptr_offset + 8, @dumper)
  # this offset diff after 2.23
  @system_mem = Array.new(2) do |off|
    Helper.unpack(size_t, @dumper.call(top_ptr_offset + 258 * size_t + 16 + off * size_t, size_t))
  end.find { |val| val >= 0x21000 && (val & 0xfff).zero? }
  @fastbin = Array.new(7) do |idx|
    Fastbin.new(size_t, @base + 8 - size_t * 2 + size_t * idx, @dumper, head: true).tap { |f| f.index = idx }
  end
  @unsorted_bin = UnsortedBin.new(size_t, top_ptr_offset, @dumper, head: true)
  @smallbin = Array.new(62) do |idx|
    Smallbin.new(size_t, @base + 8 + size_t * (12 + 2 * idx), @dumper, head: true).tap { |s| s.index = idx }
  end
  self
end