Valgrind multiple errors: Conditional branch or move depends on uninitialized value (s)
I run Valgrind and I get the following error (this is not the only one):
==21743== Conditional jump or move depends on uninitialised value(s)
==21743== at 0x4A06509: index (mc_replace_strmem.c:164)
==21743== by 0x33B7CBB3CD: gaih_inet (in /lib64/libc-2.5.so)
==21743== by 0x33B7CBD629: getaddrinfo (in /lib64/libc-2.5.so)
==21743== by 0x401A5F: tunnelURL (proxy.c:336)
==21743== by 0x40142A: client_thread (proxy.c:194)
==21743== by 0x33B8806616: start_thread (in /lib64/libpthread-2.5.so)
==21743== by 0x33B7CD3C2C: clone (in /lib64/libc-2.5.so)
The my function tunnelURL()
looks like this (C code):
char * tunnelURL(char *url) {
char * a = strstr(url, "//");
a += 2;
char * path = strstr(a, "/");
char host[256];
strncpy (host, a, strlen(a)-strlen(path));
/*
* The following is courtesy of Beej Guide
*/
int status;
int proxySocketFD;
struct addrinfo hints;
struct addrinfo *servinfo; // will point to the results
memset(&hints, 0, sizeof(hints)); // make sure the struct is empty
hints.ai_family = AF_INET; // don't care IPv4 or IPv6
hints.ai_socktype = SOCK_STREAM; // TCP stream sockets
hints.ai_flags = AI_PASSIVE; // fill in my IP for me
if ((status = getaddrinfo(host, "80", &hints, &servinfo)) != 0) {
perror("getaddrinfo() fail");
exit(1);
}
// create socket
if ((proxySocketFD = socket(servinfo->ai_family, servinfo->ai_socktype, servinfo->ai_protocol)) == -1) {
perror("proxy socket() fail");
exit(1);
}
// connect
if (connect(proxySocketFD, servinfo->ai_addr, servinfo->ai_addrlen) != 0) {
printf("connect() fail");
exit(1);
}
// construct request
char request[strlen(path) + strlen(host) + 26];
sprintf(request, "GET %s HTTP/1.1\r\nHost: %s\r\n\r\n", path, host);
printf("%s", request);
// send request
send(proxySocketFD, request, strlen(request), 0);
// receive response
int i = 0;
int amntRecvd = 0;
char *pageContentBuffer = (char*) malloc(4096 * sizeof(char));
while ((amntRecvd = recv(proxySocketFD, pageContentBuffer + i, 4096, 0)) > 0) {
i += amntRecvd;
realloc(pageContentBuffer, i * 4096 * sizeof(char));
}
// close proxy socket
close(proxySocketFD);
// deallocate memory
freeaddrinfo(servinfo);
return pageContentBuffer;
}
Line 336 corresponds if
to a function call statement getaddrinfo()
. I'm not sure if I haven't initialized. The string I am passing in should already be set. I print it just fine. I also get another error corresponding to the same line of code:
==21743== Use of uninitialised value of size 8
==21743== at 0x33B7D05816: __nscd_cache_search (in /lib64/libc-2.5.so)
==21743== by 0x33B7D0438B: nscd_gethst_r (in /lib64/libc-2.5.so)
==21743== by 0x33B7D04B26: __nscd_gethostbyname2_r (in /lib64/libc-2.5.so)
==21743== by 0x33B7CE9F5E: gethostbyname2_r@@GLIBC_2.2.5 (in /lib64/libc-2.5.so)
==21743== by 0x33B7CBC522: gaih_inet (in /lib64/libc-2.5.so)
==21743== by 0x33B7CBD629: getaddrinfo (in /lib64/libc-2.5.so)
==21743== by 0x401A5F: tunnelURL (proxy.c:336)
==21743== by 0x40142A: client_thread (proxy.c:194)
==21743== by 0x33B8806616: start_thread (in /lib64/libpthread-2.5.so)
==21743== by 0x33B7CD3C2C: clone (in /lib64/libc-2.5.so)
Any ideas as to what might be causing this?
a source to share
// receive response
int i = 0;
int amntRecvd = 0;
char *pageContentBuffer = (char*) malloc(4096 * sizeof(char));
while ((amntRecvd = recv(proxySocketFD, pageContentBuffer + i, 4096, 0)) > 0) {
i += amntRecvd;
realloc(pageContentBuffer, i * 4096 * sizeof(char));
}
realloc(pageContentBuffer, i * 4096 * sizeof(char))
looks wrong. If you received 4096 bytes first, you would allocate 4096 * 4096 bytes, then 2 * 4096 * 4096 bytes, and so on. Did you mean adding?
a source to share