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Merge "libc: Fix leak in the DNS thread-specific state." into honeycomb-mr1

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This commit is contained in:
David 'Digit' Turner 2011-03-25 01:45:49 -07:00 committed by Android (Google) Code Review
commit 2f16916246
2 changed files with 72 additions and 32 deletions
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6
libc/netbsd/resolv/res_init.c
View file

@ -225,6 +225,9 @@ __res_vinit(res_state statp, int preinit) {
char dnsProperty[PROP_VALUE_MAX];
#endif
if ((statp->options & RES_INIT) != 0U)
res_ndestroy(statp);
if (!preinit) {
statp->retrans = RES_TIMEOUT;
statp->retry = RES_DFLRETRY;
@ -232,9 +235,6 @@ __res_vinit(res_state statp, int preinit) {
statp->id = res_randomid();
}
if ((statp->options & RES_INIT) != 0U)
res_ndestroy(statp);
memset(u, 0, sizeof(u));
#ifdef USELOOPBACK
u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);

98
libc/netbsd/resolv/res_state.c
View file

@ -38,21 +38,32 @@
#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <sys/_system_properties.h>
/* Set to 1 to enable debug traces */
#define DEBUG 0
#if DEBUG
# include <logd.h>
# include <unistd.h> /* for gettid() */
# define D(...) __libc_android_log_print(ANDROID_LOG_DEBUG,"libc", __VA_ARGS__)
#else
# define D(...) do{}while(0)
#endif
static pthread_key_t _res_key;
static pthread_once_t _res_once;
typedef struct {
int _h_errno;
struct __res_state _nres[1];
unsigned _serial;
struct prop_info* _pi;
struct res_static _rstatic[1];
int _h_errno;
struct __res_state _nres[1];
unsigned _serial;
struct prop_info* _pi;
struct res_static _rstatic[1];
} _res_thread;
static _res_thread*
_res_thread_alloc(void)
{
_res_thread* rt = malloc(sizeof(*rt));
_res_thread* rt = calloc(1, sizeof(*rt));
if (rt) {
rt->_h_errno = 0;
@ -62,12 +73,7 @@ _res_thread_alloc(void)
if (rt->_pi) {
rt->_serial = rt->_pi->serial;
}
if ( res_ninit( rt->_nres ) < 0 ) {
free(rt);
rt = NULL;
} else {
memset(rt->_rstatic, 0, sizeof rt->_rstatic);
}
memset(rt->_rstatic, 0, sizeof rt->_rstatic);
}
return rt;
}
@ -91,6 +97,8 @@ _res_thread_free( void* _rt )
{
_res_thread* rt = _rt;
D("%s: rt=%p for thread=%d", __FUNCTION__, rt, gettid());
_res_static_done(rt->_rstatic);
res_ndestroy(rt->_nres);
free(rt);
@ -108,27 +116,59 @@ _res_thread_get(void)
_res_thread* rt;
pthread_once( &_res_once, _res_init_key );
rt = pthread_getspecific( _res_key );
if (rt == NULL) {
if ((rt = _res_thread_alloc()) == NULL) {
return NULL;
if (rt != NULL) {
/* We already have one thread-specific DNS state object.
* Check the serial value for any changes to net.* properties */
D("%s: Called for tid=%d rt=%p rt->pi=%p rt->serial=%d",
__FUNCTION__, gettid(), rt, rt->_pi, rt->_serial);
if (rt->_pi == NULL) {
/* The property wasn't created when _res_thread_get() was
* called the last time. This should only happen very
* early during the boot sequence. First, let's try to see if it
* is here now. */
rt->_pi = (struct prop_info*) __system_property_find("net.change");
if (rt->_pi == NULL) {
/* Still nothing, return current state */
D("%s: exiting for tid=%d rt=%d since system property not found",
__FUNCTION__, gettid(), rt);
return rt;
}
}
rt->_h_errno = 0;
rt->_serial = 0;
pthread_setspecific( _res_key, rt );
if (rt->_serial == rt->_pi->serial) {
/* Nothing changed, so return the current state */
D("%s: tid=%d rt=%p nothing changed, returning",
__FUNCTION__, gettid(), rt);
return rt;
}
/* Update the recorded serial number, and go reset the state */
rt->_serial = rt->_pi->serial;
goto RESET_STATE;
}
/* Check the serial value for any chanes to net.* properties. */
if (rt->_pi == NULL) {
rt->_pi = (struct prop_info*) __system_property_find("net.change");
/* It is the first time this function is called in this thread,
* we need to create a new thread-specific DNS resolver state. */
rt = _res_thread_alloc();
if (rt == NULL) {
return NULL;
}
if (rt->_pi == NULL || rt->_serial == rt->_pi->serial) {
return rt;
}
rt->_serial = rt->_pi->serial;
/* Reload from system properties. */
pthread_setspecific( _res_key, rt );
D("%s: tid=%d Created new DNS state rt=%p",
__FUNCTION__, gettid(), rt);
RESET_STATE:
/* Reset the state, note that res_ninit() can now properly reset
* an existing state without leaking memory.
*/
D("%s: tid=%d, rt=%p, resetting DNS state (options RES_INIT=%d)",
__FUNCTION__, gettid(), rt, (rt->_nres->options & RES_INIT) != 0);
if ( res_ninit( rt->_nres ) < 0 ) {
free(rt);
rt = NULL;
pthread_setspecific( _res_key, rt );
/* This should not happen */
D("%s: tid=%d rt=%p, woot, res_ninit() returned < 0",
__FUNCTION__, gettid(), rt);
_res_thread_free(rt);
pthread_setspecific( _res_key, NULL );
return NULL;
}
_resolv_cache_reset(rt->_serial);
return rt;