logd: propagate ::log status
Add a return value for the ::log() methods, this allows
us to optimize the wakeup for the readers to only occur
when the log message is actually placed.
This is for a future where we may dedupe identical log
messages, filter out log messages, and certainly if we
filter the messages out with an internal logd check of
__android_log_is_loggable().
Change-Id: I763b2a7c29502ab7fa0a5d5022c7b60244fcfde4
diff --git a/logd/LogAudit.cpp b/logd/LogAudit.cpp
index 90370e9..caae54b 100644
--- a/logd/LogAudit.cpp
+++ b/logd/LogAudit.cpp
@@ -155,12 +155,14 @@
event->length = htole32(l);
memcpy(event->data, str, l);
- logbuf->log(LOG_ID_EVENTS, now, uid, pid, tid,
- reinterpret_cast<char *>(event),
- (n <= USHRT_MAX) ? (unsigned short) n : USHRT_MAX);
+ rc = logbuf->log(LOG_ID_EVENTS, now, uid, pid, tid,
+ reinterpret_cast<char *>(event),
+ (n <= USHRT_MAX) ? (unsigned short) n : USHRT_MAX);
free(event);
- notify = true;
+ if (rc >= 0) {
+ notify = true;
+ }
}
// log to main
@@ -197,17 +199,22 @@
strncpy(newstr + 1 + l, str, estr - str);
strcpy(newstr + 1 + l + (estr - str), ecomm);
- logbuf->log(LOG_ID_MAIN, now, uid, pid, tid, newstr,
- (n <= USHRT_MAX) ? (unsigned short) n : USHRT_MAX);
+ rc = logbuf->log(LOG_ID_MAIN, now, uid, pid, tid, newstr,
+ (n <= USHRT_MAX) ? (unsigned short) n : USHRT_MAX);
free(newstr);
- notify = true;
+ if (rc >= 0) {
+ notify = true;
+ }
}
free(str);
if (notify) {
reader->notifyNewLog();
+ if (rc < 0) {
+ rc = n;
+ }
}
return rc;
@@ -216,7 +223,7 @@
int LogAudit::log(char *buf) {
char *audit = strstr(buf, " audit(");
if (!audit) {
- return 0;
+ return -EXDEV;
}
*audit = '\0';
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index 260e237..a0436ef 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -15,6 +15,7 @@
*/
#include <ctype.h>
+#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/user.h>
@@ -132,11 +133,11 @@
init();
}
-void LogBuffer::log(log_id_t log_id, log_time realtime,
- uid_t uid, pid_t pid, pid_t tid,
- const char *msg, unsigned short len) {
+int LogBuffer::log(log_id_t log_id, log_time realtime,
+ uid_t uid, pid_t pid, pid_t tid,
+ const char *msg, unsigned short len) {
if ((log_id >= LOG_ID_MAX) || (log_id < 0)) {
- return;
+ return -EINVAL;
}
LogBufferElement *elem = new LogBufferElement(log_id, realtime,
uid, pid, tid, msg, len);
@@ -193,6 +194,8 @@
stats.add(elem);
maybePrune(log_id);
pthread_mutex_unlock(&mLogElementsLock);
+
+ return len;
}
// If we're using more than 256K of memory for log entries, prune
diff --git a/logd/LogBuffer.h b/logd/LogBuffer.h
index a29e015..9ee243d 100644
--- a/logd/LogBuffer.h
+++ b/logd/LogBuffer.h
@@ -48,9 +48,9 @@
LogBuffer(LastLogTimes *times);
void init();
- void log(log_id_t log_id, log_time realtime,
- uid_t uid, pid_t pid, pid_t tid,
- const char *msg, unsigned short len);
+ int log(log_id_t log_id, log_time realtime,
+ uid_t uid, pid_t pid, pid_t tid,
+ const char *msg, unsigned short len);
uint64_t flushTo(SocketClient *writer, const uint64_t start,
bool privileged,
int (*filter)(const LogBufferElement *element, void *arg) = NULL,
diff --git a/logd/LogListener.cpp b/logd/LogListener.cpp
index 3b4ef88..05ced06 100644
--- a/logd/LogListener.cpp
+++ b/logd/LogListener.cpp
@@ -98,10 +98,11 @@
// NB: hdr.msg_flags & MSG_TRUNC is not tested, silently passing a
// truncated message to the logs.
- logbuf->log((log_id_t)header->id, header->realtime,
- cred->uid, cred->pid, header->tid, msg,
- ((size_t) n <= USHRT_MAX) ? (unsigned short) n : USHRT_MAX);
- reader->notifyNewLog();
+ if (logbuf->log((log_id_t)header->id, header->realtime,
+ cred->uid, cred->pid, header->tid, msg,
+ ((size_t) n <= USHRT_MAX) ? (unsigned short) n : USHRT_MAX) >= 0) {
+ reader->notifyNewLog();
+ }
return true;
}
diff --git a/logd/main.cpp b/logd/main.cpp
index 4aa38b3..eb29596 100644
--- a/logd/main.cpp
+++ b/logd/main.cpp
@@ -367,12 +367,12 @@
int rc = klogctl(KLOG_READ_ALL, buf, len);
- buf[len - 1] = '\0';
+ if (rc >= 0) {
+ buf[len - 1] = '\0';
- for(char *ptr, *tok = buf;
- (rc >= 0) && ((tok = strtok_r(tok, "\r\n", &ptr)));
- tok = NULL) {
- rc = al->log(tok);
+ for (char *ptr, *tok = buf; (tok = strtok_r(tok, "\r\n", &ptr)); tok = NULL) {
+ al->log(tok);
+ }
}
}