Jemalloc SEGV for 1MB chunk
Christoph Mallon
christoph.mallon at gmx.de
Wed Jan 28 04:10:21 PST 2009
Channa schrieb:
> Hi,
> Thanks for your reply.
> You mean to say i should modify the test as below:
>
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
>
>
> int main()
> {
> int i;
> char *buf;
> size_t size = 1048576 ;
>
> buf = malloc(size);
> for (i = 0; i <= 1048575; i++)
> buf[i] = 'a';
> buf[size]='\0';
> printf("The length of buff is : %d\n",strlen(buf));
> free(buf);
> return 0;
> }
>
> I NULL terminated the string
> buf[size] = '\0' <== The last character is NULL
>
> But still i get a SEGV at strlen.
>
> Could you please tell me if my changes above are correct?
You write the '\0' one element past the end of the buffer. The buffer
has 1.048.576 elements, the indices go from 0 to 1.048.575. This is
*the* typical off-by-one error.
It most probably does not segfault at the strlen(), but when writing the
'\0'.
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