jmp cycles

. Implementation of spin lock # Define spin_lock_string"N1: t""Lock; decb % 0nt""JS 2fn"". Section. Text. Lock," ax "N""2: t""Cmpb $0, % 0nt""Rep; nopnt""Jle 2bnt""JMP 1bn"". Previous" # Define spin_unlock_string"Movb $1, % 0": "= M" (lock-> lock): "Memory" Static inline void spin_lock (spinlock_t * Lock){_ ASM _ volatile __(Spin_lock_string: "= M" (lock-> lock): "Memory ");} Static inline void spin_unlock (spinlock_t * Lock){Char oldval = 1; _ ASM _

Four collected documents 1. Ajax security:Http://bbs.hackbase.com/search.php? Searchid = 607 orderby = lastpost ascdesc = DESC searchsubmit = Yes2. Ajax materials from the Chinese IT lab:Http://web.chinaitlab.com/List_1905.html3. Ajax video tutorialHttp://bbs.langsin.com/forumdisplay.php? FID = 214. Foreign Ajax Learning WebsitesHttp://www.asp.net/ajax/5. Get started with Ajax!Http://www.ibm.com/developerworks/cn/web/wa-aj-backend? S_tact = 105agx52 s_cmp = tec-csdn Ajax from entry to entry

supported test software for multithreading, it is perfectly normal to lead a dual-Xeon platform that supports hyper-Threading technology in processor testing. 220X 220A Memory bandwidth 4031.20 MB/s 1928 MB/s L1 Cache Latency Bytes Stride 3 Cycles/1.00ns 3 Cycles/1.00ns L2 Cache Latency 4 Bytes Stride 6

Usage 1:jmp short label (go to label to execute instruction)The JMP directive in this format implements a short transfer within a segment that modifies the IP to a range of -128~127, that is, it can move forward up to 128 bytes, and a backward transfer can be up to 127 bytes.Transfer, only modify IP, such as JMP axTransfer between segments, while modifying CS and

plays a similar role, it can direct location-independent function calls to absolute addresses. The link editor cannot resolve the transfer of a program from an executable file or shared library target to another execution. As a result, the connection editor can only arrange some entries containing the transfer control to the program connection table (PLT. In system V, the program connection tables are located in the shared body, but they use the addresses in the private global offset table. Dyn

is filled, the cmp [Addr] And 0xff will be used to determine whether to check the encryption option for processing. There is Magic JUMP, but the Shell API address has been redirected, and the Patch code needs to be restored.>The code is not optimized, and there is no time to optimize it. There are too many records to analyze the main program.The Patch code is as follows:Code:00B60000 60 pushad00B60001 9C pushfd00B60002 BE 00104000 mov esi, 0x401000 Code segment Addr00B60007 BF 00404000 mov edi,

0013b8820013b882 "uuu" Rasmans + 0xcc3c:7e51cc3c 59 pop ecx012cd128 7e51cc3c 02f1be72 0013b88a0013b88a "ppp" You can use OD to look at the relevant code near the return address above. 7E51CB81/$ mov edi, edi7E51CB83 |. push ebp7E51CB84 |. mov ebp, esp7E51CB86 |. push ebx7E51CB87 |. push esi7E51CB88 |. mov esi, dword ptr [ebp + 8]7E51CB8B |. xor ebx, ebx7E51CB8D |. push edi7E51CB8E |. mov dword ptr [ebp + 8], ebx7E51CB91 |. jmp 7E51CC927E51CB96 |>/

, while the functionsInitbreakThe value is 004120f0, and their values are different. Why? Just move forward and there will be an answer, 0: 000> U 41118b-8Testc! ILT + 380 (_ rtc_initialize) + 0x2:00411183 25.0e985 and eax, 85e90000h00411188 0e push CS00411189 0000 add byte PTR [eax], AlTestc! ILT + 390 (_ initbreak ):0041118b e9600f0000 JMP testc! Initbreak (004120f0)Testc! ILT + 395 (_ controlfp_s ):00411190 e987300000

8807 mov byte PTR [EDI], al83c8ce8d 83c701 add EDI, 183c8ce90 83ea01 edX sub, 183c8ce93 75f6 JNE nt! Memset + 0x4b (83c8ce8b) 83c8ce95 8b442408 mov eax, dword ptr [esp + 8] 83c8ce99 5f pop edi83c8ce9a C3 4408b442404 mov eax, dword ptr [esp + 4] 83c8ce9f C3 retnt! Strcpy: 83c8cea0 57 push edi83c8cea1 8b7c2408 mov EDI, dword ptr [esp + 8] 83c8cea5 eb6e JMP nt! Strcat + 0x65 (83c8cf15) 83c8cea7 8da1_00000000 Lea ESP, [esp] 83c8ceae 8bff mov EDI, edint!

to 'if (a = B) in the code ). The Cmp command indicates the subtraction operation. Therefore, it means to compare two variables. If they are not equal, jump to the memory address and print the string "a B are not equal". Otherwise, if the variables are equal, the jnz command will be skipped and the string "a B are equal" will be printed ". If multiple if statements are embedded, you will see multiple cmp, jnz, and jz, and then print strings or other operations in the future.Loop The cyclic st

Technical Exchange, DH explanation. I used Delphi to get the next loop body. Now let's get a conditional judgment.First, it must be the if statement we often see. VaR I: integer; begin I: = 99; if (I> 0) and (I What will the disassembly look like? Project5.dpr. 12: I: = 99; 004ac44c b863000000 mov eax, $20170063project5. dpr.13: if (I> 0) and (I here we can easily obtain the if statement structure in Delphi. Judge 1 skip ------------------------- if the condition is not met | the co

The instructions that can modify IP or cs:ip are called transfer instructions.Only modify IP, called intra-segment transfer such as JMP Ax, is divided into short transfers and near transitions based on the range of IP modifications, ranging from 128 to 127 and 32768 to 32767, respectivelySimultaneous modification of CS and IP instructions is called inter-segment transfer, such as JMP 1000:09.1 OffsetThe off

variableThere is a memory trick when EBP is not used as a universal register, that is, most of the time, when the displacement is positive, the parameters are accessed. When the displacement is negative, the local variable is accessed.Note that the typical first argument passed to a function is ebp+8② Heap VariablesHeap variables exist on the heap, and they are accessed by pointers. Typically, more than one instruction is required to access the heap variable.MOV ESI, Test2!_m_pfilelist; Load th

Implement Inline hook and inlinehook under existing software shelling ProtectionIf not, please forgive me. I am at a limited level. Resume and level :. Http://www.cnblogs.com/hackdragon/p/3662599.htmlNormal situation: After receiving a project to obtain the screen output content, the OD is loaded and XX shelling protection is discovered, normally, use jmp to jump to your own code and use the CHookApi_Jmp class source code used by the predecessors at h

raw binary is at offset 0, but if you need it you can change the offset to something different and make it work. forInstance the following snippet accesses the variable MSG with segment 0x7c0. ASM example: ; boot.asm mov ax, 0x07c0 mov ds, ax mov si, msgch_loop:lodsb or al, al ; zero=end or str jz hang ; get out mov ah, 0x0E int 0x10 jmp ch_loophang: jmp hangmsg db 'Welcome to Macinto

TopicAnalysis program, before running to think: whether this program can return correctly?After running, think again: why is this result?Through this program to deepen the understanding of the relevant content.Paste in the code as follows:assueme cs:codesgcodesg segment mov ax,4c00h int 21hstart: mov ax,0 s: nop nop mov di,offset s mov si,offset s2 mov ax,cs:[si] mov cs:[di],ax s0: jmp short s

,----------------------------get_char:mov ah,0; 16h No. 0 function, ah mid-scan code, AL in ASC II yards int 16h cmp al,0; if function key then al=0 JE K;-----Use ASCII code to judge-----------------------cmp Al,esc_key JE Exit CMP al,0dh JE Enter cmp al,board_back JE back;---read the current cursor position---------------mov ah,3 mov bh, 0 int 10h;---------------------push dx; protect variable cmp DL,WIN_LRC; Enter characters over right column value Jge NK

the Linux "Practice --2.3 program Hack20135306 HuangFirst, Master NOP , JNE , JE , JMP , CMP Machine code for assembly instructions The NOP:NOP instruction is the "null instruction". When executing to the NOP instruction, the CPU does nothing, just as an instruction to execute the past and continue executing a command behind NOP. (Machine code: 90) JNE: Conditional transfer directives, if not equal, jumps. (Machine code: 75) JE: Condi

directly, the level of privilege (CPL) will only get lower, want to increase the level of privilege, can be through the task gate and other means. Here's a look at some of the things that use the task gate.First look at the case of the invocation gate in the descriptor: most notably, the door descriptor contains a selector, which, by the last experiment, can be used to move to the code snippet that the selector contains in the door task. A program calls the task door, must follow the above ment

Tags: Performance Analysis Starting from kernel 2.6.31, the Linux kernel comes with a performance analysis tool perf, which can be used for function-level and command-level hotspot searches. Perf Performance analysis tools for Linux. Performance counters for Linux are a new kernel-based subsystem that provide a framework for all things Performance analysis. It covers hardware level (CPU/PMU, Performance Monitoring Unit) features and Software features (software counters, tracepoints) as well. P