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mop Advanced Cheater
Reputation: 7
Joined: 05 Mar 2009 Posts: 55
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Posted: Mon Feb 24, 2025 5:18 am Post subject: LUA jump range Question? |
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i dont use lua much but wanted to know when i used the following code
Code: | {$lua}
if syntexcheck then return end
[ENABLE]
ScanX1 = "lib_burst_generated.dll.text+A22C3A"
registerSymbol("bloop" ,ScanX1)
--local scan1 = AOBScan("45 89 44 1B 40 48 83 C4 28 5B 5D 5F 5E 41 5E 41 5F C3 CC CC CC CC 41 57 41 56 41 55 41 54 56 57 55 53 48 83 EC 58 F6 82 D2 01 00 00 01")
--registerSymbol("bloop" ,scan1)
mem = allocateMemory(0x1000)
registerSymbol("newmem" ,mem)
autoAssemble([[
label(return)
newmem:
mov [r11+rbx+40],r8d
jmp return
bloop:
jmp newmem
return:
]])
[DISABLE]
writeBytes(ScanX1, 0x45, 0x89, 0x44, 0x1B, 0x40)
unregisterSymbol("newmem")
unregisterSymbol("bloop")
deAlloc(mem, 0x1000)
ScanX1 = nil
mem = nil |
i get a 14 byte jmp
Code: | 7FF800D63C3A - FF25 00000000 000092F821020000 - jmp 221F8920000
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but then i use
Code: | [ENABLE]
//code from here to '[DISABLE]' will be used to enable the cheat
aobscanmodule(INJECT,lib_burst_generated.dll,45 89 44 1B 40 48 83 C4 28 5B 5D 5F 5E 41 5E 41 5F C3 CC CC CC CC 41 57 41 56 41 55 41 54 56 57 55 53 48 83 EC 58 F6 82 D2 01 00 00 01) // should be unique
alloc(newmem,$1000,INJECT)
label(code)
label(return)
newmem:
mov r8d,(float)1
code:
mov [r11+rbx+40],r8d
jmp return
INJECT:
jmp newmem
return:
registersymbol(INJECT)
[DISABLE]
//code from here till the end of the code will be used to disable the cheat
INJECT:
db 45 89 44 1B 40
unregistersymbol(INJECT)
dealloc(newmem) |
i get a 5 byte jmp
Code: | 7FF800D63C3A - E9 C1C35CFF - jmp 7FF800330000
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how can i set it so lua jumps near by like the asm script, i dont quite undurstand why the lua "mem = allocateMemory(0x1000)" creates a jump so far
i belive there is a paramater for alloc "AllocateNearThisAddress" which might help create a jump near by
is there a way to do this with lua allocateMemory(), or is this intended?
--
i have also tried to put alloc(newmem,$1000,bloop) inside autoAssemble() for the lua this works but then dealloc for the lua does not seem to work so well but a issue for another day
--
mainly want to to know why the 2 scripts lua an asm jump so differently and if there is a way to get lua function to jmp near
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ParkourPenguin I post too much
Reputation: 150
Joined: 06 Jul 2014 Posts: 4654
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Posted: Mon Feb 24, 2025 2:07 pm Post subject: |
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`jmp <address>` can only jump to addresses within a signed 32-bit displacement relative to RIP. Basically, the address must be within +-2GiB of the `jmp` instruction. It's possible for CE to assemble a pseudoinstruction that can jump farther than 2GiB, but that pseudoinstruction takes up 14 bytes.
That's what the second parameter to `allocateMemory` is for. It is an address CE should allocate memory at (see `VirtualAllocEx`). You should probably call `enumMemoryRegions` to find some free memory nearby, but CE tries to find a free block on its own if the first call to `VirtualAllocEx` fails, so maybe passing the address of the injection point is fine.
If you're calling `autoAssemble` from inside a {$lua} block inside an auto assembler script, you're probably doing something wrong. In this case, you shouldn't be using a {$lua} block at all. Everything could've been done from the AA script itself.
{$lua} blocks can return a string that gets substituted into the AA script in place of the {$lua} block. e.g. you can do `AOBScanUnique(aobstring, '+X')` to only scan through executable memory and pass the result back to the AA script by returning the string `define(foo,<result>)`.
mop wrote: | Code: | --local scan1 = AOBScan("45 89 44 1B 40 48 83 C4 28 5B 5D 5F 5E 41 5E 41 5F C3 CC CC CC CC 41 57 41 56 41 55 41 54 56 57 55 53 48 83 EC 58 F6 82 D2 01 00 00 01")
--registerSymbol("bloop" ,scan1) |
| `AOBScan` returns a stringlist, not an address. Try `AOBScanUnique` instead
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I don't know where I'm going, but I'll figure it out when I get there. |
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Dark Byte Site Admin
Reputation: 468
Joined: 09 May 2003 Posts: 25707 Location: The netherlands
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Posted: Mon Feb 24, 2025 4:37 pm Post subject: |
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allocateMemory has as 2nd parameter the preferred region to allocate at. If you don't specify it, it will be a random location, likely further than 2GB
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