logd: improve details on chatty records
(Cherry pick from commit bf91832fb127dae9794a4cb81f8d6fb6eda86e98)
- Report applications UID, TID/PID by name.
- change wording to have an accurate connotation
- drop privilege check since filtered upstream
Bug: 19608965
Bug: 20334069
Bug: 20370119
Change-Id: I2b1c26580b4c2de293874214ff5ae745546f3cca
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index 62f29e7..b6b6124 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -631,7 +631,7 @@
pthread_mutex_unlock(&mLogElementsLock);
// range locking in LastLogTimes looks after us
- max = element->flushTo(reader);
+ max = element->flushTo(reader, this);
if (max == element->FLUSH_ERROR) {
return max;
diff --git a/logd/LogBuffer.h b/logd/LogBuffer.h
index 9ee243d..00b19b6 100644
--- a/logd/LogBuffer.h
+++ b/logd/LogBuffer.h
@@ -74,6 +74,7 @@
// helper
char *pidToName(pid_t pid) { return stats.pidToName(pid); }
uid_t pidToUid(pid_t pid) { return stats.pidToUid(pid); }
+ char *uidToName(uid_t uid) { return stats.uidToName(uid); }
private:
void maybePrune(log_id_t id);
diff --git a/logd/LogBufferElement.cpp b/logd/LogBufferElement.cpp
index a173e63..6a05700 100644
--- a/logd/LogBufferElement.cpp
+++ b/logd/LogBufferElement.cpp
@@ -14,7 +14,9 @@
* limitations under the License.
*/
+#include <ctype.h>
#include <endian.h>
+#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
@@ -48,19 +50,89 @@
delete [] mMsg;
}
-// assumption: mMsg == NULL
-size_t LogBufferElement::populateDroppedMessage(char *&buffer, bool privileged) {
- static const char format_uid[] = "uid=%u dropped=%u";
- static const size_t unprivileged_offset = 7;
- static const char tag[] = "logd";
-
- size_t len;
- if (privileged) {
- len = snprintf(NULL, 0, format_uid, mUid, mDropped);
- } else {
- len = snprintf(NULL, 0, format_uid + unprivileged_offset, mDropped);
+// caller must own and free character string
+static char *tidToName(pid_t tid) {
+ char *retval = NULL;
+ char buffer[256];
+ snprintf(buffer, sizeof(buffer), "/proc/%u/comm", tid);
+ int fd = open(buffer, O_RDONLY);
+ if (fd >= 0) {
+ ssize_t ret = read(fd, buffer, sizeof(buffer));
+ if (ret >= (ssize_t)sizeof(buffer)) {
+ ret = sizeof(buffer) - 1;
+ }
+ while ((ret > 0) && isspace(buffer[ret - 1])) {
+ --ret;
+ }
+ if (ret > 0) {
+ buffer[ret] = '\0';
+ retval = strdup(buffer);
+ }
+ close(fd);
}
+ // if nothing for comm, check out cmdline
+ char *name = android::pidToName(tid);
+ if (!retval) {
+ retval = name;
+ name = NULL;
+ }
+
+ // check if comm is truncated, see if cmdline has full representation
+ if (name) {
+ // impossible for retval to be NULL if name not NULL
+ size_t retval_len = strlen(retval);
+ size_t name_len = strlen(name);
+ // KISS: ToDo: Only checks prefix truncated, not suffix, or both
+ if ((retval_len < name_len) && !strcmp(retval, name + name_len - retval_len)) {
+ free(retval);
+ retval = name;
+ } else {
+ free(name);
+ }
+ }
+ return retval;
+}
+
+// assumption: mMsg == NULL
+size_t LogBufferElement::populateDroppedMessage(char *&buffer,
+ LogBuffer *parent) {
+ static const char tag[] = "logd";
+ static const char format_uid[] = "uid=%u%s too chatty%s, expire %u line%s";
+
+ char *name = parent->uidToName(mUid);
+ char *commName = tidToName(mTid);
+ if (!commName && (mTid != mPid)) {
+ commName = tidToName(mPid);
+ }
+ if (!commName) {
+ commName = parent->pidToName(mPid);
+ }
+ if (name && commName && !strcmp(name, commName)) {
+ free(commName);
+ commName = NULL;
+ }
+ if (name) {
+ char *p = NULL;
+ asprintf(&p, "(%s)", name);
+ if (p) {
+ free(name);
+ name = p;
+ }
+ }
+ if (commName) {
+ char *p = NULL;
+ asprintf(&p, " comm=%s", commName);
+ if (p) {
+ free(commName);
+ commName = p;
+ }
+ }
+ // identical to below to calculate the buffer size required
+ size_t len = snprintf(NULL, 0, format_uid, mUid, name ? name : "",
+ commName ? commName : "",
+ mDropped, (mDropped > 1) ? "s" : "");
+
size_t hdrLen;
if (mLogId == LOG_ID_EVENTS) {
hdrLen = sizeof(android_log_event_string_t);
@@ -70,6 +142,8 @@
buffer = static_cast<char *>(calloc(1, hdrLen + len + 1));
if (!buffer) {
+ free(name);
+ free(commName);
return 0;
}
@@ -86,16 +160,16 @@
strcpy(buffer + 1, tag);
}
- if (privileged) {
- snprintf(buffer + hdrLen, len + 1, format_uid, mUid, mDropped);
- } else {
- snprintf(buffer + hdrLen, len + 1, format_uid + unprivileged_offset, mDropped);
- }
+ snprintf(buffer + hdrLen, len + 1, format_uid, mUid, name ? name : "",
+ commName ? commName : "",
+ mDropped, (mDropped > 1) ? "s" : "");
+ free(name);
+ free(commName);
return retval;
}
-uint64_t LogBufferElement::flushTo(SocketClient *reader) {
+uint64_t LogBufferElement::flushTo(SocketClient *reader, LogBuffer *parent) {
struct logger_entry_v3 entry;
memset(&entry, 0, sizeof(struct logger_entry_v3));
@@ -114,7 +188,7 @@
char *buffer = NULL;
if (!mMsg) {
- entry.len = populateDroppedMessage(buffer, clientHasLogCredentials(reader));
+ entry.len = populateDroppedMessage(buffer, parent);
if (!entry.len) {
return mSequence;
}
diff --git a/logd/LogBufferElement.h b/logd/LogBufferElement.h
index 7b6456d..059c031 100644
--- a/logd/LogBufferElement.h
+++ b/logd/LogBufferElement.h
@@ -28,15 +28,19 @@
namespace android {
// Furnished in main.cpp. Caller must own and free returned value
-// This function is designed for a single caller and is NOT thread-safe
char *uidToName(uid_t uid);
+// Furnished in LogStatistics.cpp. Caller must own and free returned value
+char *pidToName(pid_t pid);
+
}
static inline bool worstUidEnabledForLogid(log_id_t id) {
return (id != LOG_ID_CRASH) && (id != LOG_ID_EVENTS);
}
+class LogBuffer;
+
class LogBufferElement {
const log_id_t mLogId;
const uid_t mUid;
@@ -52,7 +56,8 @@
static atomic_int_fast64_t sequence;
// assumption: mMsg == NULL
- size_t populateDroppedMessage(char *&buffer, bool privileged);
+ size_t populateDroppedMessage(char *&buffer,
+ LogBuffer *parent);
public:
LogBufferElement(log_id_t log_id, log_time realtime,
@@ -78,7 +83,7 @@
log_time getRealTime(void) const { return mRealTime; }
static const uint64_t FLUSH_ERROR;
- uint64_t flushTo(SocketClient *writer);
+ uint64_t flushTo(SocketClient *writer, LogBuffer *parent);
};
#endif
diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index eadc4dd..b063630 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -39,7 +39,7 @@
namespace android {
// caller must own and free character string
-static char *pidToName(pid_t pid) {
+char *pidToName(pid_t pid) {
char *retval = NULL;
if (pid == 0) { // special case from auditd for kernel
retval = strdup("logd.auditd");
diff --git a/logd/main.cpp b/logd/main.cpp
index eb29596..237c7c1 100644
--- a/logd/main.cpp
+++ b/logd/main.cpp
@@ -210,18 +210,26 @@
return NULL;
}
+static sem_t sem_name;
+
char *android::uidToName(uid_t u) {
if (!u || !reinit_running) {
return NULL;
}
- // Not multi-thread safe, we know there is only one caller
+ sem_wait(&sem_name);
+
+ // Not multi-thread safe, we use sem_name to protect
uid = u;
name = NULL;
sem_post(&reinit);
sem_wait(&uidName);
- return name;
+ char *ret = name;
+
+ sem_post(&sem_name);
+
+ return ret;
}
// Serves as a global method to trigger reinitialization
@@ -277,6 +285,7 @@
// Reinit Thread
sem_init(&reinit, 0, 0);
sem_init(&uidName, 0, 0);
+ sem_init(&sem_name, 0, 1);
pthread_attr_t attr;
if (!pthread_attr_init(&attr)) {
struct sched_param param;
