search

intelxed / xed

The X86 Encoder Decoder (XED), is a software library for encoding and decoding X86 (IA32 and Intel64) instructions
https://intelxed.github.io/
Apache License 2.0
1.39k stars 145 forks source link

Xed general errors and Not HANDLING CTYPE INVALID. #289

Closed loizos01 closed 1 year ago

loizos01 commented 1 year ago

Hello,

I am trying to figure out why XED throws general errors. This is a test code that collects and decodes using a stripped down Intel-ipt library, I have eliminated all things that can go wrong with libipt and I resorted here.

Also what is indicated by "NOT HANDLING CTYPE INVALID", cant seem to find documentation for this What do xed general errors indicate?Are the linked to improper image mapping.


00007fe2757baaff 41 89 c0 3d 00 f0 ff ff 77 1f 48 8b 44 24 18 [xed decode error: (2) GENERAL_ERROR]
[2f, 7fe2757baaff: reconstruct error: decoder out of sync]
First Instruction: 00007fe2757baaff Last Instruction 00007fe2757bab07

64-bit
00007fe2757bab09 48 8b 44 24 18 64 48 2b 04 25 28 00 00 00 75 [xed decode error: (2) GENERAL_ERROR]
[2f, 7fe2757bab09: reconstruct error: decoder out of sync]
First Instruction: 00007fe2757bab09 Last Instruction 00007fe2757bab17

64-bit
00007fe2757bab19 44 89 c0 48 83 c4 58 c3 0f 1f 80 00 00 00 00 [xed decode error: (2) GENERAL_ERROR]
[38, 7fe2757bab19: reconstruct error: decoder out of sync]
First Instruction: 00007fe2757bab19 Last Instruction 00007fe2757bab20

64-bit
0000556d3274c8d4 test NOT HANDLING CTYPE INVALID, NOT HANDLING CTYPE INVALID 
0000556d3274c8d6 jns 0x556d3274c8fc 
First Instruction: 0000556d3274c8d4 Last Instruction 0000556d3274c8d6

64-bit
0000556d3274c8fc nop 
0000556d3274c8fd cmp ptr [rbp], 0xffffff90 
0000556d3274c900 add ptr [rax+rax*1], NOT HANDLING CTYPE INVALID 
[3f, 556d3274c900: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274c8fc Last Instruction 0000556d3274c901

64-bit
0000556d3274c903 48 8d 45 d0 48 89 c7 e8 d1 ee ff ff 83 f8 ff [xed decode error: (2) GENERAL_ERROR]
[3f, 556d3274c903: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274c903 Last Instruction 0000556d3274c90a

64-bit
0000556d3274b7e0 f3 0f 1e fa f2 ff 25 dd 67 00 00 0f 1f 44 00 [xed decode error: (2) GENERAL_ERROR]
[48, 556d3274b7e0: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274b7e0 Last Instruction 0000556d3274b7e4

64-bit
00007fe27573c0d0 f3 0f 1e fa 31 c0 c3 66 0f 1f 84 00 00 00 00 [xed decode error: (2) GENERAL_ERROR]
[4f, 7fe27573c0d0: reconstruct error: decoder out of sync]
First Instruction: 00007fe27573c0d0 Last Instruction 00007fe27573c0d6

64-bit
0000556d3274c90f cmp NOT HANDLING CTYPE INVALID, 0xffffffff 
0000556d3274c912 jnz 0x556d3274c936 
First Instruction: 0000556d3274c90f Last Instruction 0000556d3274c912

64-bit
0000556d3274c936 cmp ptr [rbp], 0xffffff98 
0000556d3274c939 add ptr [rbp], NOT HANDLING CTYPE INVALID 
[4f, 556d3274c939: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274c936 Last Instruction 0000556d3274c93a

64-bit
0000556d3274c988 cmp ptr [rbp], 0xffffff98 
0000556d3274c98b add ptr [rdi], NOT HANDLING CTYPE INVALID 
0000556d3274c98d xchg NOT HANDLING CTYPE INVALID, NOT HANDLING CTYPE INVALID 
0000556d3274c98e ror ptr [rax], 0x8b 
0000556d3274c991 push NOT HANDLING CTYPE INVALID 
[4f, 556d3274c991: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274c988 Last Instruction 0000556d3274c99c

64-bit
0000556d3274c9a3 leave  
0000556d3274c9a4 ret  
First Instruction: 0000556d3274c9a3 Last Instruction 0000556d3274c9a4

64-bit
0000556d3274eb6a xor NOT HANDLING CTYPE INVALID, 0x1 
0000556d3274eb6d test NOT HANDLING CTYPE INVALID, NOT HANDLING CTYPE INVALID 
0000556d3274eb6f jz 0x556d3274eb80 
First Instruction: 0000556d3274eb6a Last Instruction 0000556d3274eb6f

*************************************************START OF WHILE LOOP

64-bit
0000556d3274eb80 mov ptr [rbp], 0x0 
0000556d3274eb82 c4 00 00 00 00 eb 04 83 45 c4 01 83 7d c4 04 [xed decode error: (10) BAD_MAP]
[59, 556d3274eb82: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274eb80 Last Instruction 0000556d3274eb87

64-bit
0000556d3274eb8d cmp ptr [rbp], 0xffffffc4 
0000556d3274eb90 add NOT HANDLING CTYPE INVALID, 0x7e 
[59, 556d3274eb90: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274eb8d Last Instruction 0000556d3274eb91

64-bit
0000556d3274eb89 add ptr [rbp], 0xffffffc4 
64-bit
0000556d3274eb8d cmp ptr [rbp], 0xffffffc4 
0000556d3274eb90 add NOT HANDLING CTYPE INVALID, 0x7e 
[59, 556d3274eb90: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274eb89 Last Instruction 0000556d3274eb91

64-bit
0000556d3274eb89 add ptr [rbp], 0xffffffc4 
0000556d3274eb8c add ptr [rbx], NOT HANDLING CTYPE INVALID 
0000556d3274eb8e jnl 0x556d3274eb54 
[59, 556d3274eb8e: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274eb89 Last Instruction 0000556d3274eb91

64-bit
0000556d3274eb89 add ptr [rbp], 0xffffffc4 
0000556d3274eb8c add ptr [rbx], NOT HANDLING CTYPE INVALID 
0000556d3274eb8e jnl 0x556d3274eb54 
[59, 556d3274eb8e: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274eb89 Last Instruction 0000556d3274eb91

64-bit
0000556d3274eb89 add ptr [rbp], 0xffffffc4 
0000556d3274eb8c add ptr [rbx], NOT HANDLING CTYPE INVALID 
0000556d3274eb8e jnl 0x556d3274eb54 
[59, 556d3274eb8e: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274eb89 Last Instruction 0000556d3274eb91

64-bit
0000556d3274eb89 add ptr [rbp], 0xffffffc4 
0000556d3274eb8c add ptr [rbx], NOT HANDLING CTYPE INVALID 
0000556d3274eb8e jnl 0x556d3274eb54 
[5f, 556d3274eb8e: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274eb89 Last Instruction 0000556d3274eb91

*************************************************************END OF WHILE LOOP

64-bit
0000556d3274eb93 48 8b 45 e0 48 8d 15 f2 34 00 00 48 89 d6 48 [xed decode error: (2) GENERAL_ERROR]
[5f, 556d3274eb93: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274eb93 Last Instruction 0000556d3274eba4

64-bit
0000556d3274c9a5 f3 0f 1e fa 55 48 89 e5 48 83 ec 30 48 89 7d [xed decode error: (2) GENERAL_ERROR]
[5f, 556d3274c9a5: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274c9a5 Last Instruction 0000556d3274c9e7

64-bit
0000556d3274b560 f3 0f 1e fa f2 ff 25 1d 69 00 00 0f 1f 44 00 [xed decode error: (2) GENERAL_ERROR]
[400000, 556d3274b560: reconstruct error: decoder out of sync]
First Instruction: 0000556d3274b560 Last Instruction 0000556d3274b564

64-bit
00007fe2757baac0 f3 0f 1e fa 48 83 ec 58 48 89 54 24 30 64 48 [xed decode error: (2) GENERAL_ERROR]
[400000, 7fe2757baac0: reconstruct error: decoder out of sync]
First Instruction: 00007fe2757baac0 Last Instruction 00007fe2757baafd````
marjevan commented 1 year ago

I see a lot of reconstruct error: decoder out of sync errors which may point to a wrong XED APIs usage. Do you still encounter this issue?

loizos01 commented 1 year ago

Hi,

I solved this issue, please refer to https://github.com/intel/libipt/issues/93 I forgot to call xed_tables_init() to initialise xed tables.

Thank you, Loizos