What's the meaning of “Internal” in “!heap -h”

I am following this stackoverflow post What do the different columns in the "!heap -flt -s xxxx" windbg command represent

I am trying to understand the information printed out for one of the heaps that using up a lot of memory.

I can understand most of the columns but on my windbg, I see an additional column. Most of my entries are marked as Internal. I wonder what that means. I have done !gflags +ust. So, I can see the call stack for making the memory allocation. I can do it on most of the entries except the ones marked as Internal.

What does Internal mean? Is it something related to the implementation of LFH? If this is the internal implementation of LFH, how and when will these Internal heap entries return to the free list? It's holding up my memory for no reasons now.

Here is the output of !heap -h 0000000002330000 for your reference.

Index   Address  Name      Debugging options enabled
  8:   02330000 
    Segment at 0000000002330000 to 0000000002340000 (00010000 bytes committed)
    Segment at 00000000032b0000 to 00000000033b0000 (00100000 bytes committed)
    Segment at 00000000065a0000 to 00000000067a0000 (00200000 bytes committed)
    Segment at 00000000067a0000 to 0000000006ba0000 (00400000 bytes committed)
    Segment at 0000000006d80000 to 0000000007580000 (006f2000 bytes committed)
    Flags:                08001002
    ForceFlags:           00000000
    Granularity:          16 bytes
    Segment Reserve:      01000000
    Segment Commit:       00002000
    DeCommit Block Thres: 00000400
    DeCommit Total Thres: 00001000
    Total Free Size:      0000274d
    Max. Allocation Size: 000007fffffdefff
    Lock Variable at:     00000000023301f8
    Next TagIndex:        0000
    Maximum TagIndex:     0000
    Tag Entries:          00000000
    PsuedoTag Entries:    00000000
    Virtual Alloc List:   02330118
    Uncommitted ranges:   023300f8
    FreeList[ 00 ] at 0000000002330158: 0000000007454600 . 00000000032e3de0   (24 blocks)

Heap entries for Segment00 in Heap 0000000002330000
    0000000002330000: 00000 . 00a70 [101] - busy (a6f)
    0000000002330a70: 00a70 . 00860 [101] - busy (85f)
    00000000023312d0: 00860 . 038b0 [101] - busy (38af)
    0000000002334b80: 038b0 . 00330 [100]
    0000000002334eb0: 00330 . 00b60 [101] - busy (b34)
    0000000002335a10: 00b60 . 00160 [101] - busy (134)
    0000000002335b70: 00160 . 00090 [101] - busy (5c)
    0000000002335c00: 00090 . 00090 [101] - busy (5c)
    0000000002335c90: 00090 . 00040 [100]
    0000000002335cd0: 00040 . 00090 [101] - busy (5c)
    0000000002335d60: 00090 . 00020 [100]
    0000000002335d80: 00020 . 00130 [101] - busy (104)
    0000000002335eb0: 00130 . 00080 [101] - busy (53)
    0000000002335f30: 00080 . 00090 [101] - busy (65)
    0000000002335fc0: 00090 . 01060 [101] - busy (1034)
    0000000002337020: 01060 . 01020 [101] - busy (ff0) Internal 
    0000000002338040: 01020 . 00420 [101] - busy (3f0) Internal 
    0000000002338460: 00420 . 00090 [101] - busy (64)
    00000000023384f0: 00090 . 00260 [101] - busy (234)
    0000000002338750: 00260 . 00090 [101] - busy (5c)
    00000000023387e0: 00090 . 00080 [101] - busy (54)
    0000000002338860: 00080 . 00080 [101] - busy (4c)
    00000000023388e0: 00080 . 00030 [100]
    0000000002338910: 00030 . 00090 [101] - busy (5c)
    00000000023389a0: 00090 . 00090 [101] - busy (64)
    0000000002338a30: 00090 . 00260 [101] - busy (234)
    0000000002338c90: 00260 . 00060 [101] - busy (35)
    0000000002338cf0: 00060 . 00160 [101] - busy (134)
    0000000002338e50: 00160 . 00260 [101] - busy (234)
    00000000023390b0: 00260 . 00160 [101] - busy (134)
    0000000002339210: 00160 . 000c0 [101] - busy (94)
    00000000023392d0: 000c0 . 00080 [101] - busy (4c)
    0000000002339350: 00080 . 000c0 [101] - busy (84)
    0000000002339410: 000c0 . 000c0 [101] - busy (84)
    00000000023394d0: 000c0 . 000c0 [101] - busy (94)
    0000000002339590: 000c0 . 000c0 [101] - busy (94)
    0000000002339650: 000c0 . 000a0 [101] - busy (6c)
    00000000023396f0: 000a0 . 000c0 [101] - busy (94)
    00000000023397b0: 000c0 . 000a0 [101] - busy (6c)
    0000000002339850: 000a0 . 000a0 [101] - busy (6c)
    00000000023398f0: 000a0 . 02020 [101] - busy (1ff0) Internal 
    000000000233b910: 02020 . 000a0 [101] - busy (74)
    000000000233b9b0: 000a0 . 00060 [101] - busy (35)
    000000000233ba10: 00060 . 02020 [101] - busy (1ff0) Internal 
    000000000233da30: 02020 . 000a0 [101] - busy (6c)
    000000000233dad0: 000a0 . 000c0 [101] - busy (94)
    000000000233db90: 000c0 . 000a0 [101] - busy (6c)
    000000000233dc30: 000a0 . 00060 [100]
    000000000233dc90: 00060 . 001c0 [101] - busy (194)
    000000000233de50: 001c0 . 00260 [101] - busy (234)
    000000000233e0b0: 00260 . 000b0 [101] - busy (80)
    000000000233e160: 000b0 . 00020 [100]
    000000000233e180: 00020 . 000c0 [101] - busy (94)
    000000000233e240: 000c0 . 000a0 [101] - busy (6c)
    000000000233e2e0: 000a0 . 000a0 [101] - busy (74)
    000000000233e380: 000a0 . 001c0 [101] - busy (194)
    000000000233e540: 001c0 . 00020 [100]
    000000000233e560: 00020 . 000c0 [101] - busy (84)
    000000000233e620: 000c0 . 000c0 [101] - busy (84)
    000000000233e6e0: 000c0 . 000c0 [101] - busy (94)
    000000000233e7a0: 000c0 . 000c0 [101] - busy (94)
    000000000233e860: 000c0 . 00260 [101] - busy (234)
    000000000233eac0: 00260 . 000b0 [101] - busy (82)
    000000000233eb70: 000b0 . 00350 [100]
    000000000233eec0: 00350 . 00330 [101] - busy (2fc)
    000000000233f1f0: 00330 . 00440 [101] - busy (40c)
    000000000233f630: 00440 . 00420 [101] - busy (3f0) Internal 
    000000000233fa50: 00420 . 00460 [100]
    000000000233feb0: 00460 . 000b0 [101] - busy (80)
    000000000233ff60: 000b0 . 00060 [100]
    000000000233ffc0: 00060 . 00040 [111] - busy (3d)
    0000000002340000:      00000000      - uncommitted bytes.
Heap entries for Segment01 in Heap 0000000002330000
    00000000032b0000: 00000 . 00070 [101] - busy (6f)
    00000000032b0070: 00070 . 0c470 [101] - busy (c440) Internal 
    00000000032bc4e0: 0c470 . 00280 [101] - busy (254)
    00000000032bc760: 00280 . 000a0 [101] - busy (70)
    00000000032bc800: 000a0 . 00080 [101] - busy (4c)
    00000000032bc880: 00080 . 00080 [101] - busy (58)
    00000000032bc900: 00080 . 00070 [101] - busy (48)
    00000000032bc970: 00070 . 00080 [101] - busy (4b)
    00000000032bc9f0: 00080 . 00070 [101] - busy (42)
    00000000032bca60: 00070 . 00080 [101] - busy (4d)
    00000000032bcae0: 00080 . 000a0 [101] - busy (72)
    00000000032bcb80: 000a0 . 00080 [101] - busy (51)
    00000000032bcc00: 00080 . 000b0 [101] - busy (7c)
    00000000032bccb0: 000b0 . 00070 [101] - busy (46)
    00000000032bcd20: 00070 . 00080 [101] - busy (4c)
    00000000032bcda0: 00080 . 00080 [101] - busy (4f)
    00000000032bce20: 00080 . 00080 [101] - busy (52)
    00000000032bcea0: 00080 . 00090 [101] - busy (5d)
    00000000032bcf30: 00090 . 00080 [101] - busy (4b)
    00000000032bcfb0: 00080 . 00070 [101] - busy (43)
    00000000032bd020: 00070 . 00080 [101] - busy (4a)
    00000000032bd0a0: 00080 . 00080 [101] - busy (49)
    00000000032bd120: 00080 . 00070 [101] - busy (48)
    00000000032bd190: 00070 . 00070 [101] - busy (44)
    00000000032bd200: 00070 . 000a0 [101] - busy (69)
    00000000032bd2a0: 000a0 . 00070 [101] - busy (46)
    00000000032bd310: 00070 . 00070 [101] - busy (3c)
    00000000032bd380: 00070 . 000c0 [101] - busy (8c)
    00000000032bd440: 000c0 . 00070 [101] - busy (3c)
    00000000032bd4b0: 00070 . 00090 [101] - busy (5c)
    00000000032bd540: 00090 . 00090 [101] - busy (5c)
    00000000032bd5d0: 00090 . 00090 [101] - busy (5c)
    00000000032bd660: 00090 . 000a0 [101] - busy (5c)
    00000000032bd700: 000a0 . 00070 [101] - busy (44)
    00000000032bd770: 00070 . 00090 [101] - busy (5c)
    00000000032bd800: 00090 . 00070 [101] - busy (3c)
    00000000032bd870: 00070 . 00050 [100]
    00000000032bd8c0: 00050 . 00260 [101] - busy (234)
    00000000032bdb20: 00260 . 00070 [101] - busy (3c)
    00000000032bdb90: 00070 . 00090 [101] - busy (5c)
    00000000032bdc20: 00090 . 00070 [101] - busy (3c)
    00000000032bdc90: 00070 . 00070 [101] - busy (3c)
    00000000032bdd00: 00070 . 00090 [101] - busy (5c)
    00000000032bdd90: 00090 . 00070 [101] - busy (3c)
    00000000032bde00: 00070 . 00070 [101] - busy (3c)
    00000000032bde70: 00070 . 00090 [101] - busy (5c)
    00000000032bdf00: 00090 . 00070 [101] - busy (3c)
    00000000032bdf70: 00070 . 00cc0 [100]
    00000000032bec30: 00cc0 . 00330 [101] - busy (2fc)
    00000000032bef60: 00330 . 00440 [101] - busy (40a)
    00000000032bf3a0: 00440 . 00220 [100]
    00000000032bf5c0: 00220 . 00330 [101] - busy (2fc)
    00000000032bf8f0: 00330 . 04020 [101] - busy (3ff0) Internal 
    00000000032c3910: 04020 . 02020 [101] - busy (1ff0) Internal 
    00000000032c5930: 02020 . 00210 [100]
    00000000032c5b40: 00210 . 01020 [101] - busy (ff0) Internal 
    00000000032c6b60: 01020 . 01020 [101] - busy (ff0) Internal 
    00000000032c7b80: 01020 . 00440 [101] - busy (40c)
    00000000032c7fc0: 00440 . 00440 [101] - busy (40a)
    00000000032c8400: 00440 . 00430 [101] - busy (3f0) Internal 
    00000000032c8830: 00430 . 02020 [101] - busy (1ff0) Internal 
    00000000032ca850: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000032cc870: 02020 . 01020 [101] - busy (ff0) Internal 
    00000000032cd890: 01020 . 00420 [101] - busy (3f0) Internal 
    00000000032cdcb0: 00420 . 00420 [101] - busy (3f0) Internal 
    00000000032ce0d0: 00420 . 00420 [101] - busy (3f0) Internal 
    00000000032ce4f0: 00420 . 003a0 [100]
    00000000032ce890: 003a0 . 02020 [101] - busy (1ff0) Internal 
    00000000032d08b0: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000032d28d0: 02020 . 01020 [101] - busy (ff0) Internal 
    00000000032d38f0: 01020 . 00420 [101] - busy (3f0) Internal 
    00000000032d3d10: 00420 . 00420 [101] - busy (3f0) Internal 
    00000000032d4130: 00420 . 003a0 [100]
    00000000032d44d0: 003a0 . 00420 [101] - busy (3f0) Internal 
    00000000032d48f0: 00420 . 01020 [101] - busy (ff0) Internal 
    00000000032d5910: 01020 . 04020 [101] - busy (3ff0) Internal 
    00000000032d9930: 04020 . 01020 [101] - busy (ff0) Internal 
    00000000032da950: 01020 . 04020 [101] - busy (3ff0) Internal 
    00000000032de970: 04020 . 01020 [101] - busy (ff0) Internal 
    00000000032df990: 01020 . 04020 [101] - busy (3ff0) Internal 
    00000000032e39b0: 04020 . 00420 [101] - busy (3f0) Internal 
    00000000032e3dd0: 00420 . 00020 [100]
    00000000032e3df0: 00020 . 04020 [101] - busy (3ff0) Internal 
    00000000032e7e10: 04020 . 02020 [101] - busy (1ff0) Internal 
    00000000032e9e30: 02020 . 01020 [101] - busy (ff0) Internal 
    00000000032eae50: 01020 . 02020 [101] - busy (1ff0) Internal 
    00000000032ece70: 02020 . 01020 [101] - busy (ff0) Internal 
    00000000032ede90: 01020 . 000f0 [100]
    00000000032edf80: 000f0 . 01020 [101] - busy (ff0) Internal 
    00000000032eefa0: 01020 . 01020 [101] - busy (ff0) Internal 
    00000000032effc0: 01020 . 02020 [101] - busy (1ff0) Internal 
    00000000032f1fe0: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000032f4000: 02020 . 00420 [101] - busy (3f0) Internal 
    00000000032f4420: 00420 . 00160 [100]
    00000000032f4580: 00160 . 02020 [101] - busy (1ff0) Internal 
    00000000032f65a0: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000032f85c0: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000032fa5e0: 02020 . 08020 [101] - busy (7ff0) Internal 
    0000000003302600: 08020 . 02020 [101] - busy (1ff0) Internal 
    0000000003304620: 02020 . 01020 [101] - busy (ff0) Internal 
    0000000003305640: 01020 . 02020 [101] - busy (1ff0) Internal 
    0000000003307660: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003309680: 02020 . 08020 [101] - busy (7ff0) Internal 
    00000000033116a0: 08020 . 02020 [101] - busy (1ff0) Internal 
    00000000033136c0: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000033156e0: 02020 . 01020 [101] - busy (ff0) Internal 
    0000000003316700: 01020 . 02020 [101] - busy (1ff0) Internal 
    0000000003318720: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000331a740: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000331c760: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000331e780: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000033207a0: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000033227c0: 02020 . 01020 [101] - busy (ff0) Internal 
    00000000033237e0: 01020 . 02020 [101] - busy (1ff0) Internal 
    0000000003325800: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003327820: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003329840: 02020 . 01020 [101] - busy (ff0) Internal 
    000000000332a860: 01020 . 02020 [101] - busy (1ff0) Internal 
    000000000332c880: 02020 . 01020 [101] - busy (ff0) Internal 
    000000000332d8a0: 01020 . 02020 [101] - busy (1ff0) Internal 
    000000000332f8c0: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000033318e0: 02020 . 08020 [101] - busy (7ff0) Internal 
    0000000003339900: 08020 . 01020 [101] - busy (ff0) Internal 
    000000000333a920: 01020 . 02020 [101] - busy (1ff0) Internal 
    000000000333c940: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000333e960: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003340980: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000033429a0: 02020 . 01020 [101] - busy (ff0) Internal 
    00000000033439c0: 01020 . 02020 [101] - busy (1ff0) Internal 
    00000000033459e0: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003347a00: 02020 . 01020 [101] - busy (ff0) Internal 
    0000000003348a20: 01020 . 02020 [101] - busy (1ff0) Internal 
    000000000334aa40: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000334ca60: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000334ea80: 02020 . 01020 [101] - busy (ff0) Internal 
    000000000334faa0: 01020 . 02020 [101] - busy (1ff0) Internal 
    0000000003351ac0: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003353ae0: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003355b00: 02020 . 01020 [101] - busy (ff0) Internal 
    0000000003356b20: 01020 . 02020 [101] - busy (1ff0) Internal 
    0000000003358b40: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000335ab60: 02020 . 02000 [100]
    000000000335cb60: 02000 . 02020 [101] - busy (1ff0) Internal 
    000000000335eb80: 02020 . 04020 [101] - busy (3ff0) Internal 
    0000000003362ba0: 04020 . 02020 [101] - busy (1ff0) Internal 
    0000000003364bc0: 02020 . 01020 [101] - busy (ff0) Internal 
    0000000003365be0: 01020 . 02020 [101] - busy (1ff0) Internal 
    0000000003367c00: 02020 . 01020 [101] - busy (ff0) Internal 
    0000000003368c20: 01020 . 04020 [101] - busy (3ff0) Internal 
    000000000336cc40: 04020 . 02020 [101] - busy (1ff0) Internal 
    000000000336ec60: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003370c80: 02020 . 01020 [101] - busy (ff0) Internal 
    0000000003371ca0: 01020 . 02020 [101] - busy (1ff0) Internal 
    0000000003373cc0: 02020 . 01020 [101] - busy (ff0) Internal 
    0000000003374ce0: 01020 . 02020 [101] - busy (1ff0) Internal 
    0000000003376d00: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003378d20: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000337ad40: 02020 . 04020 [101] - busy (3ff0) Internal 
    000000000337ed60: 04020 . 02020 [101] - busy (1ff0) Internal 
    0000000003380d80: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003382da0: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003384dc0: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003386de0: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003388e00: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000338ae20: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000338ce40: 02020 . 02020 [101] - busy (1ff0) Internal 
    000000000338ee60: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003390e80: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003392ea0: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003394ec0: 02020 . 02020 [101] - busy (1ff0) Internal 
    0000000003396ee0: 02020 . 08020 [101] - busy (7ff0) Internal 
    000000000339ef00: 08020 . 02020 [101] - busy (1ff0) Internal 
    00000000033a0f20: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000033a2f40: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000033a4f60: 02020 . 08020 [101] - busy (7ff0) Internal 
    00000000033acf80: 08020 . 02020 [101] - busy (1ff0) Internal 
    00000000033aefa0: 02020 . 00420 [101] - busy (3f0) Internal 
    00000000033af3c0: 00420 . 00420 [101] - busy (3f0) Internal 
    00000000033af7e0: 00420 . 00420 [101] - busy (3f0) Internal 
    00000000033afc00: 00420 . 003c0 [100]
    00000000033affc0: 003c0 . 00040 [111] - busy (3d)
    00000000033b0000:      00000000      - uncommitted bytes.
Heap entries for Segment02 in Heap 0000000002330000
    00000000065a0000: 00000 . 00070 [101] - busy (6f)
    00000000065a0070: 00070 . 04020 [101] - busy (3ff0) Internal 
    00000000065a4090: 04020 . 04020 [101] - busy (3ff0) Internal 
    00000000065a80b0: 04020 . 02020 [101] - busy (1ff0) Internal 
    00000000065aa0d0: 02020 . 02020 [101] - busy (1ff0) Internal 
    00000000065ac0f0: 02020 . 08020 [101] - busy (7ff0) Internal 
    00000000065b4110: 08020 . 02020 [101] - busy (1ff0) Internal 
    00000000065b6130: 02020 . 04020 [101] - busy (3ff0) Internal 
    00000000065ba150: 04020 . 04020 [101] - busy (3ff0) Internal 
    00000000065be170: 04020 . 08020 [101] - busy (7ff0) Internal 
    00000000065c6190: 08020 . 04020 [101] - busy (3ff0) Internal 
    00000000065ca1b0: 04020 . 02020 [101] - busy (1ff0) Internal 
    00000000065cc1d0: 02020 . 04020 [101] - busy (3ff0) Internal 
    00000000065d01f0: 04020 . 04020 [101] - busy (3ff0) Internal 
    00000000065d4210: 04020 . 04020 [101] - busy (3ff0) Internal 
    00000000065d8230: 04020 . 04020 [101] - busy (3ff0) Internal 
    00000000065dc250: 04020 . 02020 [101] - busy (1ff0) Internal 
    00000000065de270: 02020 . 08020 [101] - busy (7ff0) Internal 
    00000000065e6290: 08020 . 04020 [101] - busy (3ff0) Internal 
    00000000065ea2b0: 04020 . 04020 [101] - busy (3ff0) Internal 
    00000000065ee2d0: 04020 . 08020 [101] - busy (7ff0) Internal 
    00000000065f62f0: 08020 . 04020 [101] - busy (3ff0) Internal 
    00000000065fa310: 04020 . 04020 [101] - busy (3ff0) Internal 
    00000000065fe330: 04020 . 08020 [101] - busy (7ff0) Internal 
    0000000006606350: 08020 . 04020 [101] - busy (3ff0) Internal 
    000000000660a370: 04020 . 04020 [101] - busy (3ff0) Internal 
    000000000660e390: 04020 . 04020 [101] - busy (3ff0) Internal 
    00000000066123b0: 04020 . 10020 [101] - busy (fff0) Internal 
    00000000066223d0: 10020 . 04020 [101] - busy (3ff0) Internal 
    00000000066263f0: 04020 . 04020 [101] - busy (3ff0) Internal 
    000000000662a410: 04020 . 04020 [101] - busy (3ff0) Internal 
    000000000662e430: 04020 . 04020 [101] - busy (3ff0) Internal 
    0000000006632450: 04020 . 10020 [101] - busy (fff0) Internal 
    0000000006642470: 10020 . 04020 [101] - busy (3ff0) Internal 
    0000000006646490: 04020 . 04020 [101] - busy (3ff0) Internal 
    000000000664a4b0: 04020 . 04020 [101] - busy (3ff0) Internal 
    000000000664e4d0: 04020 . 04020 [101] - busy (3ff0) Internal 
    00000000066524f0: 04020 . 08020 [101] - busy (7ff0) Internal 
    000000000665a510: 08020 . 08020 [101] - busy (7ff0) Internal 
    0000000006662530: 08020 . 04020 [101] - busy (3ff0) Internal 
    0000000006666550: 04020 . 04020 [101] - busy (3ff0) Internal 
    000000000666a570: 04020 . 10020 [101] - busy (fff0) Internal 
    000000000667a590: 10020 . 04020 [101] - busy (3ff0) Internal 
    000000000667e5b0: 04020 . 08020 [101] - busy (7ff0) Internal 
    00000000066865d0: 08020 . 08020 [101] - busy (7ff0) Internal 
    000000000668e5f0: 08020 . 10020 [101] - busy (fff0) Internal 
    000000000669e610: 10020 . 04020 [101] - busy (3ff0) Internal 
    00000000066a2630: 04020 . 10020 [101] - busy (fff0) Internal 
    00000000066b2650: 10020 . 08020 [101] - busy (7ff0) Internal 
    00000000066ba670: 08020 . 02020 [101] - busy (1ff0) Internal 
    00000000066bc690: 02020 . 08020 [101] - busy (7ff0) Internal 
    00000000066c46b0: 08020 . 08020 [101] - busy (7ff0) Internal 
    00000000066cc6d0: 08020 . 10020 [101] - busy (fff0) Internal 
    00000000066dc6f0: 10020 . 08020 [101] - busy (7ff0) Internal 
    00000000066e4710: 08020 . 08020 [101] - busy (7ff0) Internal 
    00000000066ec730: 08020 . 08020 [101] - busy (7ff0) Internal 
    00000000066f4750: 08020 . 10020 [101] - busy (fff0) Internal 
    0000000006704770: 10020 . 08020 [101] - busy (7ff0) Internal 
    000000000670c790: 08020 . 10020 [101] - busy (fff0) Internal 
    000000000671c7b0: 10020 . 08020 [101] - busy (7ff0) Internal 
    00000000067247d0: 08020 . 08020 [101] - busy (7ff0) Internal 
    000000000672c7f0: 08020 . 20020 [101] - busy (1fff0) Internal 
    000000000674c810: 20020 . 08020 [101] - busy (7ff0) Internal 
    0000000006754830: 08020 . 08020 [101] - busy (7ff0) Internal 
    000000000675c850: 08020 . 08020 [101] - busy (7ff0) Internal 
    0000000006764870: 08020 . 08020 [101] - busy (7ff0) Internal 
    000000000676c890: 08020 . 20020 [101] - busy (1fff0) Internal 
    000000000678c8b0: 20020 . 08020 [101] - busy (7ff0) Internal 
    00000000067948d0: 08020 . 08020 [101] - busy (7ff0) Internal 
    000000000679c8f0: 08020 . 02020 [101] - busy (1ff0) Internal 
    000000000679e910: 02020 . 016b0 [100]
    000000000679ffc0: 016b0 . 00040 [111] - busy (3d)
    00000000067a0000:      00000000      - uncommitted bytes.
Heap entries for Segment03 in Heap 0000000002330000
    00000000067a0000: 00000 . 00070 [101] - busy (6f)
    00000000067a0070: 00070 . 08020 [101] - busy (7ff0) Internal 
    00000000067a8090: 08020 . 08020 [101] - busy (7ff0) Internal 
    00000000067b00b0: 08020 . 08020 [101] - busy (7ff0) Internal 
    00000000067b80d0: 08020 . 20020 [101] - busy (1fff0) Internal 
    00000000067d80f0: 20020 . 08020 [101] - busy (7ff0) Internal 
    00000000067e0110: 08020 . 08020 [101] - busy (7ff0) Internal 
    00000000067e8130: 08020 . 08020 [101] - busy (7ff0) Internal 
    00000000067f0150: 08020 . 08020 [101] - busy (7ff0) Internal 
    00000000067f8170: 08020 . 10020 [101] - busy (fff0) Internal 
    0000000006808190: 10020 . 10020 [101] - busy (fff0) Internal 
    00000000068181b0: 10020 . 20020 [101] - busy (1fff0) Internal 
    00000000068381d0: 20020 . 10020 [101] - busy (fff0) Internal 
    00000000068481f0: 10020 . 08020 [101] - busy (7ff0) Internal 
    0000000006850210: 08020 . 20020 [101] - busy (1fff0) Internal 
    0000000006870230: 20020 . 10020 [101] - busy (fff0) Internal 
    0000000006880250: 10020 . 08020 [101] - busy (7ff0) Internal 
    0000000006888270: 08020 . 10020 [101] - busy (fff0) Internal 
    0000000006898290: 10020 . 20020 [101] - busy (1fff0) Internal 
    00000000068b82b0: 20020 . 10020 [101] - busy (fff0) Internal 
    00000000068c82d0: 10020 . 10020 [101] - busy (fff0) Internal 
    00000000068d82f0: 10020 . 20020 [101] - busy (1fff0) Internal 
    00000000068f8310: 20020 . 10020 [101] - busy (fff0) Internal 
    0000000006908330: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006918350: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006928370: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006938390: 10020 . 20020 [101] - busy (1fff0) Internal 
    00000000069583b0: 20020 . 10020 [101] - busy (fff0) Internal 
    00000000069683d0: 10020 . 10020 [101] - busy (fff0) Internal 
    00000000069783f0: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006988410: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006998430: 10020 . 10020 [101] - busy (fff0) Internal 
    00000000069a8450: 10020 . 40020 [101] - busy (3fff0) Internal 
    00000000069e8470: 40020 . 10020 [101] - busy (fff0) Internal 
    00000000069f8490: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006a084b0: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006a184d0: 10020 . 04020 [101] - busy (3ff0) Internal 
    0000000006a1c4f0: 04020 . 10020 [101] - busy (fff0) Internal 
    0000000006a2c510: 10020 . 40020 [101] - busy (3fff0) Internal 
    0000000006a6c530: 40020 . 10020 [101] - busy (fff0) Internal 
    0000000006a7c550: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006a8c570: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006a9c590: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006aac5b0: 10020 . 40020 [101] - busy (3fff0) Internal 
    0000000006aec5d0: 40020 . 10020 [101] - busy (fff0) Internal 
    0000000006afc5f0: 10020 . 10020 [101] - busy (fff0) Internal 
    0000000006b0c610: 10020 . 20020 [101] - busy (1fff0) Internal 
    0000000006b2c630: 20020 . 40020 [101] - busy (3fff0) Internal 
    0000000006b6c650: 40020 . 10020 [101] - busy (fff0) Internal 
    0000000006b7c670: 10020 . 20020 [101] - busy (1fff0) Internal 
    0000000006b9c690: 20020 . 03930 [100]
    0000000006b9ffc0: 03930 . 00040 [111] - busy (3d)
    0000000006ba0000:      00000000      - uncommitted bytes.
Heap entries for Segment04 in Heap 0000000002330000
    0000000006d80000: 00000 . 00070 [101] - busy (6f)
    0000000006d80070: 00070 . 10020 [101] - busy (fff0) Internal 
    0000000006d90090: 10020 . 40020 [101] - busy (3fff0) Internal 
    0000000006dd00b0: 40020 . 20020 [101] - busy (1fff0) Internal 
    0000000006df00d0: 20020 . 20020 [101] - busy (1fff0) Internal 
    0000000006e100f0: 20020 . 20020 [101] - busy (1fff0) Internal 
    0000000006e30110: 20020 . 40020 [101] - busy (3fff0) Internal 
    0000000006e70130: 40020 . 20020 [101] - busy (1fff0) Internal 
    0000000006e90150: 20020 . 40020 [101] - busy (3fff0) Internal 
    0000000006ed0170: 40020 . 20020 [101] - busy (1fff0) Internal 
    0000000006ef0190: 20020 . 20020 [101] - busy (1fff0) Internal 
    0000000006f101b0: 20020 . 20020 [101] - busy (1fff0) Internal 
    0000000006f301d0: 20020 . 40020 [101] - busy (3fff0) Internal 
    0000000006f701f0: 40020 . 04020 [101] - busy (3ff0) Internal 
    0000000006f74210: 04020 . 20020 [101] - busy (1fff0) Internal 
    0000000006f94230: 20020 . 20020 [101] - busy (1fff0) Internal 
    0000000006fb4250: 20020 . 40020 [101] - busy (3fff0) Internal 
    0000000006ff4270: 40020 . 04020 [101] - busy (3ff0) Internal 
    0000000006ff8290: 04020 . 20020 [101] - busy (1fff0) Internal 
    00000000070182b0: 20020 . 20020 [101] - busy (1fff0) Internal 
    00000000070382d0: 20020 . 04020 [101] - busy (3ff0) Internal 
    000000000703c2f0: 04020 . 08020 [101] - busy (7ff0) Internal 
    0000000007044310: 08020 . 40020 [101] - busy (3fff0) Internal 
    0000000007084330: 40020 . 20020 [101] - busy (1fff0) Internal

EDIT 10/26/2012

I finally found out the place that causing the leak, by inspecting the memory content inside the Internal heap entry. It contains a number of memory allocation caused by the same operator new. I don't know why they are all combined into one single heap entry but by looking at the content, I managed to find out the code causing the leak. Perhaps, it's a CRT feature to combine all similar data into one heap entry? Or do I misunderstand the meaning of heap entry completely?

标签： c++ windows memory-leaks heap windbg

1条回答

狗以群分

2楼-- · 2019-01-25 16:20

TL;DR: Heap blocks marked as "internal" have a special flag in _HEAP_ENTRY.Flags

[edit] revised my previous answer with a proper answer.

Here's my guess attempt to your question.

According to the windbg help, the "!heap" command code is located in exts.dll (i.e. \winxp\exts.dll).

Put this DLL on IDA and downloaded symbols for it. There’s only one occurrence of "Internal" in the DLL, inside the DumpHeapEntry() function :

.text:0192463D                 movzx   eax, byte_1963152
.text:01924644                 test    eax, eax
.text:01924646                 jz      short loc_1924656
.text:01924648                 push    offset aInternal ; " Internal "
.text:0192464D                 call    _ExtensionApis.lpOutputRoutine ; some sort of printf routine

The output of "Internal" is therefore conditioned by the value of byte_1963152 : if byte_1963152 is not 0, then "Internal" is printed. Only once occurrence of write value with anything else than 0 happens (in ReadHeapEntry() which is called at the start of DumpHeapEntry() ):

.text:0191F025                 movzx   eax, [ebp+var_B]
.text:0191F029                 and     eax, 8
.text:0191F02C                 jz      short loc_191F035
.text:0191F02E                 mov     byte_1963152, 1

This translates to:

if((UINT)var_B & 8)
    byte_1963152 = 1;

var_B is set here :

text:0191EFF7                 mov     eax, [ebp+var_18]
.text:0191EFFA                 mov     edx, [ebp+var_14]
.text:0191EFFD                 mov     cl, 10h          ; shift right by 0x10 bits
.text:0191EFFF                 call    __aullshr
.text:0191F004                 mov     [ebp+var_B], al

__aullshr stands for "Arithmetic Unsigned Long Long Shift Right". In the above code eax is the low 32-bit part of a 64-bit unsigned long long, while edx is the high 32-bit part. Notice that var_B is a 8-bit quantity ('al' register is used).

Hence:

// where var_14_18 is a combination (64-bit) of var_14 and var_18
var_B = (char)(var_14_18 >> 0x10 );

var_14 and var_18 are set here :

.text:0191EF01                 push    0
.text:0191EF03                 push    offset aAgregatecode ; "AgregateCode"
.text:0191EF08                 push    0
.text:0191EF0A                 push    0
.text:0191EF0C                 call    _GetShortField@16 ; GetShortField(x,x,x,x)
.text:0191EF11                 mov     [ebp+var_18], eax  ; high part
.text:0191EF14                 mov     [ebp+var_14], edx  ; low part
; cut
.text:0191EF28                 mov     ecx, [ebp+var_18]
.text:0191EF2B                 and     ecx, _EncodeFlagMask ; from HEAP.EncodeFlagMask
.text:0191EF31                 jz      short loc_191EF75
.text:0191EF33                 mov     edx, [ebp+var_18]
.text:0191EF36                 xor     edx, _CrtHeapCode ; from HEAP.Encoding.Code1
.text:0191EF3C                 mov     eax, [ebp+var_14]
.text:0191EF3F                 xor     eax, dword_1963194 ; from HEAP.Encoding.Code2
.text:0191EF45                 mov     [ebp+var_18], edx
.text:0191EF48                 mov     [ebp+var_14], eax

So, windbg use the GetShortField() function on "AgregateCode" and sets both of the aforementioned variable (which is also a single unsigned long long value). Note that it also uses the HEAP.Encoding.Code1 and HEAP.Encoding.Code2 to XOR both of the value (HEAP is the the current heap from which the heap entry is a part).

"AgregateCode" is a field of both HEAP_ENTRY and HEAP_FREE_ENTRY structures (from Win 8.1 x86):

0:000> dt _heap_entry -r2
ntdll!_HEAP_ENTRY
   +0x000 Size             : Uint2B
   +0x002 Flags            : UChar
   +0x003 SmallTagIndex    : UChar
   +0x000 SubSegmentCode   : Uint4B
   +0x004 PreviousSize     : Uint2B
   +0x006 SegmentOffset    : UChar
   +0x006 LFHFlags         : UChar
   +0x007 UnusedBytes      : UChar
   +0x000 FunctionIndex    : Uint2B
   +0x002 ContextValue     : Uint2B
   +0x000 InterceptorValue : Uint4B
   +0x004 UnusedBytesLength : Uint2B
   +0x006 EntryOffset      : UChar
   +0x007 ExtendedBlockSignature : UChar
   +0x000 Code1            : Uint4B
   +0x004 Code2            : Uint2B
   +0x006 Code3            : UChar
   +0x007 Code4            : UChar
   +0x004 Code234          : Uint4B
   +0x000 AgregateCode     : Uint8B

This translated to C, gives:

          typedef struct _HEAP_ENTRY                       // 20 elements, 0x8 bytes (sizeof) 
          {                                                                                   
              union                                        // 6 elements, 0x8 bytes (sizeof)  
              {                                                                               
                  struct                                   // 3 elements, 0x8 bytes (sizeof)  
                  {                                                                           
/*0x000*/             UINT16       Size;                                                      
/*0x002*/             UINT8        Flags;                                                     
/*0x003*/             UINT8        SmallTagIndex;                                             
/*0x004*/             UINT8        _PADDING0_[0x4];                                           
                  };                                                                          
                  struct                                   // 4 elements, 0x8 bytes (sizeof)  
                  {                                                                           
/*0x000*/             ULONG32      SubSegmentCode;                                            
/*0x004*/             UINT16       PreviousSize;                                              
                      union                                // 2 elements, 0x1 bytes (sizeof)  
                      {                                                                       
/*0x006*/                 UINT8        SegmentOffset;                                         
/*0x006*/                 UINT8        LFHFlags;                                              
                      };                                                                      
/*0x007*/             UINT8        UnusedBytes;                                               
                  };                                                                          
                  struct                                   // 2 elements, 0x8 bytes (sizeof)  
                  {                                                                           
/*0x000*/             UINT16       FunctionIndex;                                             
/*0x002*/             UINT16       ContextValue;                                              
/*0x004*/             UINT8        _PADDING1_[0x4];                                           
                  };                                                                          
                  struct                                   // 4 elements, 0x8 bytes (sizeof)  
                  {                                                                           
/*0x000*/             ULONG32      InterceptorValue;                                          
/*0x004*/             UINT16       UnusedBytesLength;                                         
/*0x006*/             UINT8        EntryOffset;                                               
/*0x007*/             UINT8        ExtendedBlockSignature;                                    
                  };                                                                          
                  struct                                   // 2 elements, 0x8 bytes (sizeof)  
                  {                                                                           
/*0x000*/             ULONG32      Code1;                                                     
                      union                                // 2 elements, 0x4 bytes (sizeof)  
                      {                                                                       
                          struct                           // 3 elements, 0x4 bytes (sizeof)  
                          {                                                                   
/*0x004*/                     UINT16       Code2;                                             
/*0x006*/                     UINT8        Code3;                                             
/*0x007*/                     UINT8        Code4;                                             
                          };                                                                  
/*0x004*/                 ULONG32      Code234;                                               
                      };                                                                      
                  };                                                                          
/*0x000*/         UINT64       AgregateCode;                                                  
              };                                                                              
          }HEAP_ENTRY, *PHEAP_ENTRY;

Thus we have the following pseudo-code (minus some other checks):

high_part, low_part = GetShortField(0,0,"AgregateCode", 0);
high_part ^= HEAP.Encoding.Code1;
low_part ^= HEAP.Encoding.Code2;
AgregateCode = Make64BitFromTwo32Bit(high_part, low_part);    
char var_B = (char)(AgregateCode >> 0x10);
if(var_B & 8)
    printf("Internal");

Given that "AgregateCode" is ... well, an aggregate of Code1 to Code 4 :

                  struct                                   // 2 elements, 0x8 bytes (sizeof)  
                  {                                                                           
/*0x000*/             ULONG32      Code1;                                                     
                      union                                // 2 elements, 0x4 bytes (sizeof)  
                      {                                                                       
                          struct                           // 3 elements, 0x4 bytes (sizeof)  
                          {                                                                   
/*0x004*/                     UINT16       Code2;                                             
/*0x006*/                     UINT8        Code3;                                             
/*0x007*/                     UINT8        Code4;                                             
                          };                                                                  
/*0x004*/                 ULONG32      Code234;                                               
                      };                                                                      
                  };                                                                          
/*0x000*/         UINT64       AgregateCode;

If you shift 0x10 and AND 8 the AgregateCode field you end up finally testing the 11th bit (start counting at 0) of Code1.

As the structure is a big union, you finally end up testing: _HEAP_ENTRY.Flags

It happens that a heap flag has already the value 8, its name is: HEAP_ENTRY_VIRTUAL_ALLOC

http://doxygen.reactos.org/da/ddb/heap_8h_source.html#l00044

https://os-design.googlecode.com/svn/trunk/ntos/inc/heap.h

It seems that this flag is used to manage big allocations, although those blocks are used internally by the system and not available directly to the end user.

Typically such internal blocks have Flags member set to 9: HEAP_ENTRY_VIRTUAL_ALLOC | HEAP_ENTRY_BUSY

[edit] Example :

Say I have a heap at 0x005b0000 :

0:004> !heap -h
Index   Address  Name      Debugging options enabled
  1:   005b0000

This heap (_HEAP) has a HEAP_ENTRY marked as "Internal" at 0x005b8d00:

0:004> !heap -h 005b0000
Index   Address  Name      Debugging options enabled
  1:   005b0000 
    Segment at 005b0000 to 006b0000 (0009d000 bytes committed)
    Flags:                00000002
    ForceFlags:           00000000
    Granularity:          8 bytes
    Segment Reserve:      00100000
    Segment Commit:       00002000
    DeCommit Block Thres: 00000800
    DeCommit Total Thres: 00002000
    Total Free Size:      00001ae8
    Max. Allocation Size: 7ffdefff
    Lock Variable at:     005b0138
    Next TagIndex:        0000
    Maximum TagIndex:     0000
    Tag Entries:          00000000
    PsuedoTag Entries:    00000000
    Virtual Alloc List:   005b00a0
    Uncommitted ranges:   005b0090
    FreeList[ 00 ] at 005b00c4: 0063fbc0 . 00633060   (7 blocks)

    Heap entries for Segment00 in Heap 005b0000
        005b0000: 00000 . 00588 [101] - busy (587)
        //[cut]
        005b8d00: 03d20 . 378b0 [101] - busy (378a8) Internal

A detailed view of the HEAP structure (notice the "Encoding" structure (_HEAP_ENTRY) at offset 0x50 which helps to decode the encoded heap entry with an XOR):

0:004> dt _heap 005b0000 -r1
ntdll!_HEAP
   +0x000 Entry            : _HEAP_ENTRY
      +0x000 Size             : 0xbe38
      +0x002 Flags            : 0xf5 ''
      +0x003 SmallTagIndex    : 0xff ''
      +0x000 SubSegmentCode   : 0xfff5be38 
      +0x004 PreviousSize     : 0xcf53
      +0x006 SegmentOffset    : 0 ''
      +0x006 LFHFlags         : 0 ''
      +0x007 UnusedBytes      : 0x1 ''
      +0x000 FunctionIndex    : 0xbe38
      +0x002 ContextValue     : 0xfff5
      +0x000 InterceptorValue : 0xfff5be38
      +0x004 UnusedBytesLength : 0xcf53
      +0x006 EntryOffset      : 0 ''
      +0x007 ExtendedBlockSignature : 0x1 ''
      +0x000 Code1            : 0xfff5be38
      +0x004 Code2            : 0xcf53
      +0x006 Code3            : 0 ''
      +0x007 Code4            : 0x1 ''
      +0x000 AgregateCode     : 0x100cf53`fff5be38
   +0x008 SegmentSignature : 0xffeeffee
   +0x00c SegmentFlags     : 0
   +0x010 SegmentListEntry : _LIST_ENTRY [ 0x5b00a8 - 0x5b00a8 ]
      +0x000 Flink            : 0x005b00a8 _LIST_ENTRY [ 0x5b0010 - 0x5b0010 ]
      +0x004 Blink            : 0x005b00a8 _LIST_ENTRY [ 0x5b0010 - 0x5b0010 ]
   +0x018 Heap             : 0x005b0000 _HEAP
      +0x000 Entry            : _HEAP_ENTRY
      +0x008 SegmentSignature : 0xffeeffee
      +0x00c SegmentFlags     : 0
      +0x010 SegmentListEntry : _LIST_ENTRY [ 0x5b00a8 - 0x5b00a8 ]
      +0x018 Heap             : 0x005b0000 _HEAP
      +0x01c BaseAddress      : 0x005b0000 
      +0x020 NumberOfPages    : 0x100
      +0x024 FirstEntry       : 0x005b0588 _HEAP_ENTRY
      +0x028 LastValidEntry   : 0x006b0000 _HEAP_ENTRY
      +0x02c NumberOfUnCommittedPages : 0x63
      +0x030 NumberOfUnCommittedRanges : 1
      +0x034 SegmentAllocatorBackTraceIndex : 0
      +0x036 Reserved         : 0
      +0x038 UCRSegmentList   : _LIST_ENTRY [ 0x64cff0 - 0x64cff0 ]
      +0x040 Flags            : 2
      +0x044 ForceFlags       : 0
      +0x048 CompatibilityFlags : 0
      +0x04c EncodeFlagMask   : 0x100000
      +0x050 Encoding         : _HEAP_ENTRY
      +0x058 PointerKey       : 0x75c3a7b
      +0x05c Interceptor      : 0
      +0x060 VirtualMemoryThreshold : 0xfe00
      +0x064 Signature        : 0xeeffeeff
      +0x068 SegmentReserve   : 0x100000
      +0x06c SegmentCommit    : 0x2000
      +0x070 DeCommitFreeBlockThreshold : 0x800
      +0x074 DeCommitTotalFreeThreshold : 0x2000
      +0x078 TotalFreeSize    : 0x1ae8
      +0x07c MaximumAllocationSize : 0x7ffdefff
      +0x080 ProcessHeapsListIndex : 1
      +0x082 HeaderValidateLength : 0x138
      +0x084 HeaderValidateCopy : (null) 
      +0x088 NextAvailableTagIndex : 0
      +0x08a MaximumTagIndex  : 0
      +0x08c TagEntries       : (null) 
      +0x090 UCRList          : _LIST_ENTRY [ 0x64cfe8 - 0x64cfe8 ]
      +0x098 AlignRound       : 0xf
      +0x09c AlignMask        : 0xfffffff8
      +0x0a0 VirtualAllocdBlocks : _LIST_ENTRY [ 0x5b00a0 - 0x5b00a0 ]
      +0x0a8 SegmentList      : _LIST_ENTRY [ 0x5b0010 - 0x5b0010 ]
      +0x0b0 AllocatorBackTraceIndex : 0
      +0x0b4 NonDedicatedListLength : 0
      +0x0b8 BlocksIndex      : 0x005b0150 
      +0x0bc UCRIndex         : 0x005b0590 
      +0x0c0 PseudoTagEntries : (null) 
      +0x0c4 FreeLists        : _LIST_ENTRY [ 0x633060 - 0x63fbc0 ]
      +0x0cc LockVariable     : 0x005b0138 _HEAP_LOCK
      +0x0d0 CommitRoutine    : 0x075c3a7b        long  +75c3a7b
      +0x0d4 FrontEndHeap     : 0x005b8d08 
      +0x0d8 FrontHeapLockCount : 0
      +0x0da FrontEndHeapType : 0x2 ''
      +0x0dc Counters         : _HEAP_COUNTERS
      +0x130 TuningParameters : _HEAP_TUNING_PARAMETERS
   +0x01c BaseAddress      : 0x005b0000 
   +0x020 NumberOfPages    : 0x100
   +0x024 FirstEntry       : 0x005b0588 _HEAP_ENTRY
      +0x000 Size             : 0xbec1
      +0x002 Flags            : 0xf5 ''
      +0x003 SmallTagIndex    : 0x6 ''
      +0x000 SubSegmentCode   : 0x06f5bec1 
      +0x004 PreviousSize     : 0xcfe2
      +0x006 SegmentOffset    : 0 ''
      +0x006 LFHFlags         : 0 ''
      +0x007 UnusedBytes      : 0x1 ''
      +0x000 FunctionIndex    : 0xbec1
      +0x002 ContextValue     : 0x6f5
      +0x000 InterceptorValue : 0x6f5bec1
      +0x004 UnusedBytesLength : 0xcfe2
      +0x006 EntryOffset      : 0 ''
      +0x007 ExtendedBlockSignature : 0x1 ''
      +0x000 Code1            : 0x6f5bec1
      +0x004 Code2            : 0xcfe2
      +0x006 Code3            : 0 ''
      +0x007 Code4            : 0x1 ''
      +0x000 AgregateCode     : 0x100cfe2`06f5bec1
   +0x028 LastValidEntry   : 0x006b0000 _HEAP_ENTRY
      +0x000 Size             : 0xeff8
      +0x002 Flags            : 0xe7 ''
      +0x003 SmallTagIndex    : 0xff ''
      +0x000 SubSegmentCode   : 0xffe7eff8 
      +0x004 PreviousSize     : 0xd3df
      +0x006 SegmentOffset    : 0xc7 ''
      +0x006 LFHFlags         : 0xc7 ''
      +0x007 UnusedBytes      : 0xff ''
      +0x000 FunctionIndex    : 0xeff8
      +0x002 ContextValue     : 0xffe7
      +0x000 InterceptorValue : 0xffe7eff8
      +0x004 UnusedBytesLength : 0xd3df
      +0x006 EntryOffset      : 0xc7 ''
      +0x007 ExtendedBlockSignature : 0xff ''
      +0x000 Code1            : 0xffe7eff8
      +0x004 Code2            : 0xd3df
      +0x006 Code3            : 0xc7 ''
      +0x007 Code4            : 0xff ''
      +0x000 AgregateCode     : 0xffc7d3df`ffe7eff8
   +0x02c NumberOfUnCommittedPages : 0x63
   +0x030 NumberOfUnCommittedRanges : 1
   +0x034 SegmentAllocatorBackTraceIndex : 0
   +0x036 Reserved         : 0
   +0x038 UCRSegmentList   : _LIST_ENTRY [ 0x64cff0 - 0x64cff0 ]
      +0x000 Flink            : 0x0064cff0 _LIST_ENTRY [ 0x5b0038 - 0x5b0038 ]
      +0x004 Blink            : 0x0064cff0 _LIST_ENTRY [ 0x5b0038 - 0x5b0038 ]
   +0x040 Flags            : 2
   +0x044 ForceFlags       : 0
   +0x048 CompatibilityFlags : 0
   +0x04c EncodeFlagMask   : 0x100000
   +0x050 Encoding         : _HEAP_ENTRY
      +0x000 Size             : 0xbe89
      +0x002 Flags            : 0xf4 ''
      +0x003 SmallTagIndex    : 0x4f 'O'
      +0x000 SubSegmentCode   : 0x4ff4be89 
      +0x004 PreviousSize     : 0xcf53
      +0x006 SegmentOffset    : 0 ''
      +0x006 LFHFlags         : 0 ''
      +0x007 UnusedBytes      : 0 ''
      +0x000 FunctionIndex    : 0xbe89
      +0x002 ContextValue     : 0x4ff4
      +0x000 InterceptorValue : 0x4ff4be89
      +0x004 UnusedBytesLength : 0xcf53
      +0x006 EntryOffset      : 0 ''
      +0x007 ExtendedBlockSignature : 0 ''
      +0x000 Code1            : 0x4ff4be89
      +0x004 Code2            : 0xcf53
      +0x006 Code3            : 0 ''
      +0x007 Code4            : 0 ''
      +0x000 AgregateCode     : 0xcf53`4ff4be89
   +0x058 PointerKey       : 0x75c3a7b
   +0x05c Interceptor      : 0
   +0x060 VirtualMemoryThreshold : 0xfe00
   +0x064 Signature        : 0xeeffeeff
   +0x068 SegmentReserve   : 0x100000
   +0x06c SegmentCommit    : 0x2000
   +0x070 DeCommitFreeBlockThreshold : 0x800
   +0x074 DeCommitTotalFreeThreshold : 0x2000
   +0x078 TotalFreeSize    : 0x1ae8
   +0x07c MaximumAllocationSize : 0x7ffdefff
   +0x080 ProcessHeapsListIndex : 1
   +0x082 HeaderValidateLength : 0x138
   +0x084 HeaderValidateCopy : (null) 
   +0x088 NextAvailableTagIndex : 0
   +0x08a MaximumTagIndex  : 0
   +0x08c TagEntries       : (null) 
   +0x090 UCRList          : _LIST_ENTRY [ 0x64cfe8 - 0x64cfe8 ]
      +0x000 Flink            : 0x0064cfe8 _LIST_ENTRY [ 0x5b0090 - 0x5b0090 ]
      +0x004 Blink            : 0x0064cfe8 _LIST_ENTRY [ 0x5b0090 - 0x5b0090 ]
   +0x098 AlignRound       : 0xf
   +0x09c AlignMask        : 0xfffffff8
   +0x0a0 VirtualAllocdBlocks : _LIST_ENTRY [ 0x5b00a0 - 0x5b00a0 ]
      +0x000 Flink            : 0x005b00a0 _LIST_ENTRY [ 0x5b00a0 - 0x5b00a0 ]
      +0x004 Blink            : 0x005b00a0 _LIST_ENTRY [ 0x5b00a0 - 0x5b00a0 ]
   +0x0a8 SegmentList      : _LIST_ENTRY [ 0x5b0010 - 0x5b0010 ]
      +0x000 Flink            : 0x005b0010 _LIST_ENTRY [ 0x5b00a8 - 0x5b00a8 ]
      +0x004 Blink            : 0x005b0010 _LIST_ENTRY [ 0x5b00a8 - 0x5b00a8 ]
   +0x0b0 AllocatorBackTraceIndex : 0
   +0x0b4 NonDedicatedListLength : 0
   +0x0b8 BlocksIndex      : 0x005b0150 
   +0x0bc UCRIndex         : 0x005b0590 
   +0x0c0 PseudoTagEntries : (null) 
   +0x0c4 FreeLists        : _LIST_ENTRY [ 0x633060 - 0x63fbc0 ]
      +0x000 Flink            : 0x00633060 _LIST_ENTRY [ 0x632fc8 - 0x5b00c4 ]
      +0x004 Blink            : 0x0063fbc0 _LIST_ENTRY [ 0x5b00c4 - 0x633390 ]
   +0x0cc LockVariable     : 0x005b0138 _HEAP_LOCK
      +0x000 Lock             : <unnamed-tag>
   +0x0d0 CommitRoutine    : 0x075c3a7b     long  +75c3a7b
   +0x0d4 FrontEndHeap     : 0x005b8d08 
   +0x0d8 FrontHeapLockCount : 0
   +0x0da FrontEndHeapType : 0x2 ''
   +0x0dc Counters         : _HEAP_COUNTERS
      +0x000 TotalMemoryReserved : 0x100000
      +0x004 TotalMemoryCommitted : 0x9d000
      +0x008 TotalMemoryLargeUCR : 0
      +0x00c TotalSizeInVirtualBlocks : 0
      +0x010 TotalSegments    : 1
      +0x014 TotalUCRs        : 1
      +0x018 CommittOps       : 0x19
      +0x01c DeCommitOps      : 0
      +0x020 LockAcquires     : 0xd37
      +0x024 LockCollisions   : 0
      +0x028 CommitRate       : 0x24
      +0x02c DecommittRate    : 0xb
      +0x030 CommitFailures   : 0
      +0x034 InBlockCommitFailures : 0
      +0x038 CompactHeapCalls : 0
      +0x03c CompactedUCRs    : 0
      +0x040 AllocAndFreeOps  : 0
      +0x044 InBlockDeccommits : 0
      +0x048 InBlockDeccomitSize : 0
      +0x04c HighWatermarkSize : 0x9cde0
      +0x050 LastPolledSize   : 0x8f9c8
   +0x130 TuningParameters : _HEAP_TUNING_PARAMETERS
      +0x000 CommittThresholdShift : 4
      +0x004 MaxPreCommittThreshold : 0xfe000

Now a detailed view of the _HEAP_ENTRY (marked as internal). This is an encoded structure, which can be decoded by XORing it with _HEAP.Encoding member:

0:004> dt _heap_entry 005b8d00
ntdll!_HEAP_ENTRY
   +0x000 Size             : 0xd19f
   +0x002 Flags            : 0xfd ''
   +0x003 SmallTagIndex    : 0x3f '?'
   +0x000 SubSegmentCode   : 0x3ffdd19f 
   +0x004 PreviousSize     : 0xc8f7
   +0x006 SegmentOffset    : 0 ''
   +0x006 LFHFlags         : 0 ''
   +0x007 UnusedBytes      : 0x8 ''
   +0x000 FunctionIndex    : 0xd19f
   +0x002 ContextValue     : 0x3ffd
   +0x000 InterceptorValue : 0x3ffdd19f
   +0x004 UnusedBytesLength : 0xc8f7
   +0x006 EntryOffset      : 0 ''
   +0x007 ExtendedBlockSignature : 0x8 ''
   +0x000 Code1            : 0x3ffdd19f
   +0x004 Code2            : 0xc8f7
   +0x006 Code3            : 0 ''
   +0x007 Code4            : 0x8 ''
   +0x000 AgregateCode     : 0x800c8f7`3ffdd19f

Now the commented code :

1) Fetch Aggregate form HEAP_ENTRY
2) Decode (XOR) HEAP_ENTRY with HEAP.Encoding member
3) Shift result to get _HEAP_ENTRY.Flags
4) AND result with HEAP_ENTRY_VIRTUAL_ALLOC (8) to see if it's an internal block

CPU Disasm
Address     Command                                  Comments
730AEF01    PUSH 0                                   ; /Arg4 = 0
730AEF03    PUSH ??_C@_0N@BCMFEPJJ@AgregateCode?$AA@ ; |Arg3 = ASCII "AgregateCode"
730AEF08    PUSH 0                                   ; |Arg2 = 0
730AEF0A    PUSH 0                                   ; |Arg1 = 0
730AEF0C    CALL GetShortField                       ; \exts.GetShortField
730AEF11    MOV DWORD PTR SS:[LOCAL.6],EAX           ; low part = 0x3FFDD19F (_HEAP_ENTRY.Code1)
730AEF14    MOV DWORD PTR SS:[LOCAL.5],EDX           ; high part = 0x0800C8F7
730AEF17    MOV EDX,DWORD PTR SS:[LOCAL.6]
730AEF1A    MOV DWORD PTR DS:[730F3158],EDX
730AEF20    MOV EAX,DWORD PTR SS:[LOCAL.5]
730AEF23    MOV DWORD PTR DS:[730F315C],EAX
730AEF28    MOV ECX,DWORD PTR SS:[LOCAL.6]           ; 0x3FFDD19F
730AEF2B    AND ECX,DWORD PTR DS:[EncodeFlagMask]    ; ecx = 0x3FFDD19F ^ 0x00100000 = 0x00100000
730AEF31    JE SHORT 730AEF75
730AEF33    MOV EDX,DWORD PTR SS:[LOCAL.6]           ; edx = 0x3FFDD19F
730AEF36    XOR EDX,DWORD PTR DS:[CrtHeapCode]       ; edx = 0x3FFDD19F ^ 0x4FF4BE89 = 0x70096F16
730AEF3C    MOV EAX,DWORD PTR SS:[LOCAL.5]           ; eax = 0x0800C8F7
730AEF3F    XOR EAX,DWORD PTR DS:[730F3194]          ; eax = 0x0800C8F7 ^ 0xCF53 = 0x080007A4
730AEF45    MOV DWORD PTR SS:[LOCAL.6],EDX           ; edx = 0x70096F16
730AEF48    MOV DWORD PTR SS:[LOCAL.5],EAX           ; eax = 0x080007A4
;[...]    
730AEFEE    MOVZX EAX,WORD PTR SS:[LOCAL.6]
730AEFF2    MOV DWORD PTR DS:[CrtHeapEntry],EAX      ; entry = 0x6f16
730AEFF7    MOV EAX,DWORD PTR SS:[LOCAL.6]           ; low part = 0x70096F16
730AEFFA    MOV EDX,DWORD PTR SS:[LOCAL.5]           ; high part = 0x080007A4
730AEFFD    MOV CL,10
730AEFFF    CALL _aullshr
730AF004    MOV BYTE PTR SS:[LOCAL.3+1],AL           ; 0x00000800:07A47009 -> al = 9
730AF007    MOVZX ECX,BYTE PTR SS:[LOCAL.3+1]
730AF00B    AND ECX,FFFFFFE6
730AF00E    OR ECX,DWORD PTR DS:[730F3148]
730AF014    MOV DWORD PTR DS:[730F3148],ECX
730AF01A    MOV EDX,DWORD PTR DS:[730F3148]
730AF020    AND EDX,00000001
730AF023    JE SHORT 730AF035
730AF025    MOVZX EAX,BYTE PTR SS:[LOCAL.3+1]        ; eax = 9 
730AF029    AND EAX,00000008                         ; 9 & 8 = 1
730AF02C    JE SHORT 730AF035
730AF02E    MOV BYTE PTR DS:[730F3152],1             ; set "Internal" flag

Hope it helps!

0人赞添加讨论(0) 举报

What's the meaning of “Internal” in “!heap -h”

采纳回答

编辑标签

举报内容

检举类型

检举原因

检举说明(必填)

打开微信“扫一扫”，打开网页后点击屏幕右上角分享按钮

付费偷看金额在0.1-10元之间