PROG+PROB. SOLV W/C++, ENH (SPEC VAL)
6th Edition
ISBN: 9781284564266
Author: Dale
Publisher: Jones & Barlett
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Chapter 4, Problem 3EPE
Program Plan Intro
To determine the content of the variables a, b, c, d, e, f after the execution of the given statement.
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Character Hex value | Character Hex value Character Hex value
'A'
0x41
'J'
Ox4a
'S'
0x53
'B'
0x42
'K'
0x4b
"T"
0x54
0x43
'L'
Ox4c
'U'
0x55
0x44
'M'
0x4d
'V'
0x56
0x45
'N'
Ox4e
'W'
0x57
0x46
'0'
Ox4f
'X'
0x58
0x47
'P'
0x50
'Y'
0x59
0x48
'Q'
0x51
'Z'
Ox5a
'T'
0x49
'R'
0x52
'\0'
0x00
Now consider what happens on a Linux/x86 machine when callfoo calls foo with
the input string "ZYXWVUTSRQPONMLKJIHGFEDCBA".
A. On the left draw the state of the stack just before the execution of the instruction
at address Ox40053a; make sure to show the frames for callfoo and foo and
the exact return address, in Hex at the bottom of the callfoo frame.
Then, on the right, draw the state of the stack just after the instruction got
executed; make sure to show where the string "ZYXWVUTSRQPONMLKJIHGFEDCBA"
is placed and what part, if any, of the above return address has been overwritten.
B. Immediately after the ret instruction at address 0x400543 executes, what is
the value of the program counter register %rip?…
1 typedef struct node* {
2
struct node* next;
3
char* key;
4
char* val;
5} node_t;
6
7 char* find_node (node_t* node, char* key_to_find) {
while(strcmp (node->key, key_to_find ) != 0 ) {
node = node->next;
8
9
10
}
11
return node->val;
12 }
Match each of the assembler routines on the left with the equivalent C function on
the right. Write the name of the label (e.g., foo) to the right of the corresponding
function. Note: shrq is the logical right shift instruction, and sarq is the arithmetic
right shift instruction.
foo1:
leaq
0(,%rdi, 8), %rax
long choice1 (long x)
{
ret
return x -
8 >8;
foo3:
}
movq
sarq
%rdi, %rax
$8, %rax
long choice4 (long x)
ret
{
return x*256;
}
foo4:
long choice5 (long x)
leaq
-8 (%rdi), %rax
{
ret
return x-8;
}
long choice6 (long x)
foo5:
{
leaq
-8 (%rdi), %rax
return x+8;
shrq
$63, %rax
}
ret
Chapter 4 Solutions
PROG+PROB. SOLV W/C++, ENH (SPEC VAL)
Ch. 4 - Prob. 1PSCSCh. 4 - Prob. 1EPECh. 4 - Prob. 2EPECh. 4 - Prob. 3EPECh. 4 - Prob. 4EPECh. 4 - Prob. 5EPECh. 4 - Prob. 6EPECh. 4 - Prob. 7EPECh. 4 - Prob. 8EPECh. 4 - Prob. 9EPE
Ch. 4 - Prob. 10EPECh. 4 - Prob. 11EPECh. 4 - Prob. 12EPECh. 4 - Prob. 13EPECh. 4 - Prob. 14EPECh. 4 - Prob. 15EPECh. 4 - Prob. 16EPECh. 4 - Prob. 17EPECh. 4 - Prob. 18EPECh. 4 - Prob. 19EPECh. 4 - Prob. 20EPECh. 4 - Prob. 21EPECh. 4 - Prob. 22EPECh. 4 - Prob. 1PWECh. 4 - Prob. 2PWECh. 4 - Prob. 3PWECh. 4 - Prob. 4PWECh. 4 - Prob. 5PWECh. 4 - Prob. 6PWECh. 4 - Prob. 7PWECh. 4 - Prob. 8PWECh. 4 - Prob. 9PWECh. 4 - Prob. 10PWECh. 4 - Prob. 11PWECh. 4 - Prob. 12PWECh. 4 - Prob. 13PWECh. 4 - Prob. 14PWECh. 4 - Prob. 1PPCh. 4 - Prob. 2PPCh. 4 - Prob. 3PPCh. 4 - Prob. 4PPCh. 4 - Prob. 5PPCh. 4 - Prob. 6PPCh. 4 - Prob. 7PPCh. 4 - Prob. 1CSFCh. 4 - Prob. 2CSFCh. 4 - Prob. 3CSFCh. 4 - Prob. 4CSFCh. 4 - Prob. 5CSF
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