检测到 glibc，realloc()：无效指针

Question

对于冗长的代码，我深表歉意。我有一个简单的问题，但我想我包含了我的代码，这样就可以清楚我来自哪里。 我遇到了重新分配损坏。我认为腐败是因为我没有正确释放。事实上，我不确定 glibc 到底说什么或意味着什么。任何人都可以向我简要解释一下吗？ 再次对冗长的代码表示歉意。

---

#include "draw2.h"
#include "draw2a.h"
#include "draw2b.h"

const char Exec_c[]  = "java -jar Sketchpad.jar";

void parseFile(FILE * fp, FILE *sketcher){ 
    char line [MAX_WORD] = {"NULL"}; 
    char word [MAX_WORD] = {"NULL"};
    char figureName [MAX_WORD] = {"NULL"};
    struct figure *pointsAndname;                     
    long int countNumberoffigures = 0;
    printOutput();
    long int temp = 10;
    pointsAndname = malloc(temp * sizeof(struct figure));
    assert(pointsAndname != NULL);
    while ( fgets(line, MAX_WORD - 1, fp) != NULL ){
        int nuRead = sscanf(line, "%s", word);
        assert(pointsAndname != NULL);
        if ( nuRead > 0 ){
            if(strncmp(word, "Figure", MAX_WORD)==0){ 
                countNumberoffigures += 1;                      
                if (temp == countNumberoffigures - 1){
                    temp = temp * 2;
                    printf("pointsAndname is %x\n", pointsAndname);
                    pointsAndname = realloc(&pointsAndname, temp * sizeof(struct figure));
                    printf("pointsAndname is %x after realloc\n", pointsAndname);
                }
                assert(pointsAndname != NULL);
                figureFunction(fp,line, word, figureName, countNumberoffigures, pointsAndname + countNumberoffigures);  
            }                                                 
            if(strncmp(word, "printFigure", MAX_WORD)==0){      //4)read the command printFigure, name of the figure
                if (countNumberoffigures == 1){
                    printFigure(fp, line, countNumberoffigures, pointsAndname + countNumberoffigures);
                }else{
                    printFigure(fp, line, countNumberoffigures, pointsAndname + countNumberoffigures - 1);
                }
            }
            if(strncmp(word, "drawFigure", MAX_WORD)==0){       //5)read the command drawFigure and the name of the figure
                if (countNumberoffigures == 1){
                    drawFigure(sketcher, line, countNumberoffigures, pointsAndname + countNumberoffigures);
                }else{
                    drawFigure(sketcher, line, countNumberoffigures, pointsAndname + countNumberoffigures - 1);
                }
            }
            if(strncmp(word, "translate", MAX_WORD)==0){        //6)read the command translate 
                if (countNumberoffigures == 1){
                    translate(line, sketcher, countNumberoffigures, pointsAndname + countNumberoffigures);
                }else{
                    translate(line, sketcher, countNumberoffigures, pointsAndname + countNumberoffigures - 1);
                }
            }
            if(strncmp(word, "child", MAX_WORD)==0){            //7)reads command child and the name of the figure
                child(line, word, figureName, sketcher);
            }
            if(strncmp(word, "#", MAX_WORD)==0){                //8)reads the whole line until the \n
                printf(line);
                //printf("ani po\n");
            }
            if(strncmp(word, "end", MAX_WORD)==0){
                fprintf (sketcher, "end\n");
                //printf("ani po\n");
            }
            if(strncmp(word, "rotate", MAX_WORD)==0){
                if (countNumberoffigures == 1){
                    rotate(line, sketcher, countNumberoffigures, pointsAndname + countNumberoffigures);
                }else{
                    rotate(line, sketcher, countNumberoffigures, pointsAndname + countNumberoffigures - 1);
                }
            }
        }
    }
    free(pointsAndname->vertices);
    free(pointsAndname);
}

void processArgument(char argument[]){
    FILE *sketcher;
    FILE *fp;
    fp = fopen (argument, "r");
    sketcher = popen(Exec_c, "w");
    if (fp == NULL){
        printf ("Could not open pipe to %s\n", argument);
        exit (EXIT_FAILURE);
    }
    if (sketcher == NULL){
        printf ("Could not open pipe to %s\n", argument);
        exit (EXIT_FAILURE);
    }else{
        parseFile(fp, sketcher);
        if(fclose(fp)==EOF){
            printf("couldn't close pipe to %s.\n", argument);
            exit(EXIT_FAILURE);
        }
        if (pclose(sketcher) == -1){                                                 //if (pclose(sketcher) == -1){
            fprintf(stderr, "draw_line error: couldn't close pipe to %s.\n", Exec_c);//fprintf(stderr,"",E);
            exit(EXIT_FAILURE);    
        }
    }
}

int main (int argc,  char *argv[]){
    int i;
    if ( argc < 2 ){
        printf ("%s\n", "0 comment(s)");
        exit(EXIT_FAILURE);
    }else{
        for (i = 1; i < argc; i++){
            processArgument(argv[i]);
        }
    }
    return 0;
}

---

#include "draw2.h"
#include "draw2a.h"

void printOutput(){
    printf("./draw2 started on:");

    fflush(stdout);
    system("date\n");
}
/*send what ever there is after the child to sketchpad(in that specific line)*/
void child (char line[], char word[], char nameFigure[], FILE * sketcher){          
    sscanf(line, "%s%s", word, nameFigure);
    fprintf (sketcher, "%s\n", &line[6]);
} 

/*I construct the struct by reading from the Figure line to the end figure line.*/
void figureFunction (FILE * fp, char line[], char word[], char figureName[], long int countNumberoffigures, struct figure *figureHere){
    double startx, starty;
    long int temp = 10;
    figureHere->vertices = malloc(temp * sizeof(struct pointxy));
    sscanf(line, "%s%s%lf%lf%*s", word, figureHere->figureName, &startx, &starty);
    printf("This is the figureHere->vertices inside the figureFunction: %s\n", figureHere->vertices);
    (*(figureHere->vertices)).x = startx;              
    (*(figureHere->vertices)).y = starty;
    fgets(line, MAX_WORD - 1, fp);                  
    int nuRead = sscanf(line, "%s", word);              
    long int i = 1;                                                     
    while (strncmp(word, "End", MAX_WORD)!=0){ 
        if (strncmp(word, "#", MAX_WORD) == 0){
            printf("%s",line);
        }           
        if (strncmp(word, "draw", MAX_WORD) == 0){
            //printf("lepo ani magia?????\n\n");
            sscanf (line, "%s%lf%lf", word, &startx, &starty);
            //printf("this is my startx and starty: %lf %lf\n\n",startx, starty);
            figureHere->vertices[i].x = figureHere->vertices[i-1].x + startx;
            figureHere->vertices[i].y = figureHere->vertices[i-1].y + starty;
            i += 1;
        }
        fgets(line, MAX_WORD - 1, fp);
        nuRead = sscanf(line, "%s", word);
        if (temp == figureHere->countPoints){
            temp = temp * 2;
            figureHere->vertices = realloc(figureHere->vertices, temp * sizeof(struct pointxy));
        }
    }                                          
    figureHere->countPoints = i;                        
}         

---

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <math.h>
#include <assert.h>

void parseFile(FILE * fp, FILE * sketcher); 
void processArgument(char argument[]);
void printOutput();

#define MAX_WORD 256
#define initial_size 17

extern const char argument[];

/* prototypes for non-c99 library functions */
FILE* popen(const char*, const char*);
int pclose(FILE*);
struct pointxy {
    double x;
    double y;
};

struct figure{
      char figureName[MAX_WORD];
    struct pointxy *vertices;
    long int countPoints;
};

---

*** glibc detected *** ./draw2: realloc(): invalid pointer: 0xbf9c3a28 ***
======= Backtrace: =========
/lib/libc.so.6(realloc+0x3a8)[0x400cb548]
/lib/libc.so.6(realloc+0x3c)[0x400cb1dc]
./draw2[0x8048ab8]
./draw2[0x8048ec1]
./draw2[0x8048f84]
/lib/libc.so.6(__libc_start_main+0xe0)[0x40072390]
./draw2[0x8048891]
======= Memory map: ========
08048000-0804a000 r-xp 00000000 00:16 160237     /home/dsk07/ugrad/pkardash/c201/assignment2/draw2
0804a000-0804b000 rw-p 00002000 00:16 160237     /home/dsk07/ugrad/pkardash/c201/assignment2/draw2
0804b000-0804c000 rw-p 00000000 00:00 0 
09283000-092a4000 rw-p 00000000 00:00 0          [heap]
40000000-4001c000 r-xp 00000000 08:01 94922      /lib/ld-2.7.so
4001c000-4001d000 r--p 0001b000 08:01 94922      /lib/ld-2.7.so
4001d000-4001e000 rw-p 0001c000 08:01 94922      /lib/ld-2.7.so
4001e000-40022000 rw-p 00000000 00:00 0 
40022000-4002c000 r-xp 00000000 08:07 150880     /usr/lib/libgcc_s.so.1
4002c000-4002d000 rw-p 00009000 08:07 150880     /usr/lib/libgcc_s.so.1
40036000-4005a000 r-xp 00000000 08:01 94889      /lib/libm-2.7.so
4005a000-4005b000 r--p 00023000 08:01 94889      /lib/libm-2.7.so
4005b000-4005c000 rw-p 00024000 08:01 94889      /lib/libm-2.7.so
4005c000-401a1000 r-xp 00000000 08:01 94899      /lib/libc-2.7.so
401a1000-401a2000 ---p 00145000 08:01 94899      /lib/libc-2.7.so
401a2000-401a4000 r--p 00145000 08:01 94899      /lib/libc-2.7.so
401a4000-401a5000 rw-p 00147000 08:01 94899      /lib/libc-2.7.so
401a5000-401a9000 rw-p 00000000 00:00 0 
bf9b0000-bf9c5000 rw-p 00000000 00:00 0          [stack]
ffffe000-fffff000 r-xp 00000000 00:00 0          [vdso]
make: *** [run] Aborted

Answer 1

glibc 告诉您正在传递一个无法从 malloc/realloc 返回的地址。这是因为您正在传递 pointsAndName 堆栈变量的地址。您需要传入从 malloc 收到的值。另外，每当调用realloc时，都应该使用临时变量。这样，如果realloc失败，您仍然可以释放原始值。

struct figure *tempPtr = realloc(pointsAndname, temp * sizeof(struct figure));
if(tempPtr == NULL)
{
  // Handle allocation error...
  free(pointsAndname);
}
pointsAndname = tempPtr;