security study guide

) or positive (s=0), and the sign bit with the value 0 is interpreted as a special case.Mantissa: M is a binary decimal order: E is weighted against floating-point numbers and can be negativeFloat:s=1 bit, exp=8 bit, frac=23 bitDouble:s=1 bit, exp=11 bit, frac=52 bit2. Integers and floating-point numbers indicate the relationship of the same number:P74: The relative region corresponds to the low of the integer, just before the highest significant bit equal to one stop, and a floating point repre

stack Load valid address LEAQ directive: Actually, the movq instruction is deformed. Shift operation: Sal and SHL Two left shift commands are the same effect Special arithmetic operations imulqSigned Full multiplication mulqunsigned full multiplication cltoConvert to eight idivqSigned Division divqUnsigned division Problems in teaching materials learning and the solving process ProblemWhat's the use of command rep and RepZ? SolveTextbook P141

address to a low address. Each invocation of each function has its own stack frame, which maintains all the necessary information. Register EBP points to the point of the current stack frame (high address), register ESP points to the top of the current stack frame (low address). Heterogeneous data structure The struct declaration of the C language creates a data type that aggregates objects that may be different types into an object. All components of the Structure are stored in a

^ WNormal: x + y = x + yOverflow: x + y = x + y + 2 ^ W Complement multiplication: X * Y = u2t (x · y) mod (2 ^ W )) Complement Division: Shift right-Big End The high byte of the index data is stored in the low address of the memory, while the low byte of the data is stored in the high address of the memory.-Small Client The high byte of the index data is stored in the high address of the memory, while the low byte of the data is stored in the low address of the memory.-Last week's incorrect qu

code to compile the installationTo install the Deb package from a local disk using dpkg:First use the Apt-get plus-d parameter only download not installed, download the Emacs Editor's Deb package, after the download is complete,We can view the contents of the/var/cache/apt/archives/directory, we will copy the first deb to the home directory and use dpkg to installTo view the installation directory for installed packages:Using Dpkg-l to view the Deb package directory informationTo install from a

)That is, the number is rounded up or down, and the lowest valid number of the result is even.Can be used in binary decimals.2. Rounding to 0That is, rounding down integers and negative numbers rounded up.3. Rounding DownBoth positive and negative numbers are rounded down.4. Rounding upBoth positive and negative numbers are rounded up.Iv. floating-point arithmetic 1. floating-point addition Floating-point addition is exchangeable Floating point addition not binding The floating-

他三种方式产生实际值的确界。P28 Code and operationSecond, the problems encountered and how to solveThis week's course is mainly the reading and comprehension of textbooks, and the proportion of experiments is small.With regard to the application of bit patterns, it was doubtful at first that the concept of coercion was not clear. After further understanding, you slowly begin to understand the actual concept of coercion. It is known that coercion type conversions cannot be transferred arbitrarily.This week, we

also very interesting (the original book uses 19 pages of volume to describe the principle and action of the dispenser), smart programmers use a number of techniques to achieve, refer to p568 page.9.10 garbage Collection (recycling)The garbage collector is a dynamic allocator that automatically frees the allocated blocks that are no longer needed by these programs. Garbage collection dates back to the the 1960s early-morning Lisp system developed at MIT. He is an important part of modern langua

address addressing, relative base address addressing, proportional addressing mode, base address proportional address mode, and relative base address proportional addressing modeV. directivesmov--transmitting dataadd--Plussub--minusimul--Multiply (signed)xor--XORor--orand--andleal--delivery addressinc--Plus Onedec--minus Oneneg--take negative?not--to take the supplement?Sal (SHL)--shift leftsar--Arithmetic Right Shiftshr--Logical Right Shiftloop--CycleJump instruction: SlightlySix, the flag bit

/12 20/200 Learn the contents of system level I/O and understand the intrinsic function Tenth Week 407/1035 1/13 30/230 Analyze and debug your code, system-level I/O content 11th Week 714/1749 2/15 40/270 Understanding anomalies and their types 12th Week 0/1749 4/19 30/300 Review the contents of the previous weeks 13th Week 797/2728 2/21 20/320 Learn t

Web site is not uncommon, although using stored procedures can improve execution efficiency. However, there are migration problems.database characters need to be uniformly encoded, preferably for UTF-87.3defend correctlySqlinjectedDefense methods:q using pre-compiled statementsq Using Stored Proceduresq Check Data typeq using Security Functions7.4Other injection attacksXML injectedXML injection is implemented by rewriting the XML's data cont

, and n = 23 bits respectively, resulting in a 32-bit representation;In a double, the S, exp, and Frac fields are 1 bits, k = 11 bits, and n = 52 bits, respectively, and a 64-bit representation is obtained.Problems in Learning:(1) about overflow:Due to the inherent flaw of C/D + + language, neither checking the array boundary nor checking type reliability, and the program developed in C + + language because the target code is very close to the machine core, so it can directly access the memory a

method)That is, the number is rounded up or down, and the lowest valid number of the result is even.Can be used in binary decimals.2. Rounding to 0That is, rounding down integers and negative numbers rounded up.3. Rounding downBoth positive and negative numbers are rounded down.4. Rounding upBoth positive and negative numbers are rounded up.Iv. Floating-point arithmetic1. Floating-point addition Floating-point addition is exchangeable Floating point addition not binding The flo

floating-point arithmeticP70:ieee floating point standard, float/double typep74: Integers and floating-point numbers represent the same number of relationshipsP78: Integer and floating-point conversion rulesP80: Homework can choose to do, coordination of each problem up to two groups to do, one star topic a person plus a point, two stars plus two points, Samsung plus three points, four stars plus four pointsIii. Key Exercises　P24 Binary Conversion CodeP24 Show_bytes, write a main function test,

result of statistics.sh script)Last week's summary of the wrong quiz 23. The following C language attributes are associated with code portability (ABC) A. DefineB. typedefC. sizeof ()D. UnionParsing: #define可以定义宏使得变量可移植, typedef can make type portability, and sizeof () makes different types of lengths portable. 29. To compile the prog.c on a 64-bit machine to a program that can run on a 32 machine, the following is correct (C) A.A program that cannot compile a 32-bit

2014-07-01 baoxinjian I. Summary An important concept in Po is file security control. In security control, many default attributes of documents are defined. 1. Related to the document approve Workflow approval flow used 2. view the access level related to the document Full Modified View Only 3. secturity level related to Document Modification Public Private Purchasing Hierarchy 4. Related to the

Number of lines of code (Add/accumulate) Blog volume (New/accumulated) Learning time (Add/accumulate) Important Growth Target 3000 rows 30 articles 300 hours WEEK 1 0/0 1/2 25/40 I learned basic Linux knowledge and core commands Week 2 0/0 0/2 0/40 Week 3 300/300 3/5 40/80 Learned vim, GCC, and gdb commands;Learned Information Representation and Processing Week 5 200/500

/selinux/config file:V. Modifying the Boolean value of SELinux modeUse the getsebool-a command to view all Boolean values[Email protected] html]# Getsebool-aabrt_anon_write--offabrt_handle_event--Offabrt_upload_watch_anon_ Write-OnIf a service is built and the client accesses the service and does not write anything, it can be checked as follows:1, check whether the configuration file opened the relevant write permission;2. File system permissions3, SELinux context and Boolean value whether the r

FeelingsJust beginning to touch Java, feel both confused and hard, because they have not been in a self-learning way to contact a new programming course, long time to find more difficult. I think, teacher and student relationship is eldest brother and brother! Why do you say that, because the teacher experienced the student age and more understanding of the situation of students, leading students to learn and impart some experience, so that students less detours, and exchange ideas with students

have exclusive access to the object, and the reader can share the object with an unlimited number of other readers. Concurrent server based on the prevention of threading session Use threading to improve parallelism: multicore processing can be parallel. Other concurrency issues unsafe function Classes Functions that do not protect shared variables Functions that maintain state across multiple calls Returns a function that points to a pointer