Merge "logger: Add the update kernel struct to userspace"

include/cutils/logger.h

@@ -11,7 +11,13 @@
 #define _UTILS_LOGGER_H
 
 #include <stdint.h>
+#include <sys/types.h>
 
+/*
+ * The userspace structure for version 1 of the logger_entry ABI.
+ * This structure is returned to userspace by the kernel logger
+ * driver unless an upgrade to a newer ABI version is requested.
+ */
 struct logger_entry {
     uint16_t    len;    /* length of the payload */
     uint16_t    __pad;  /* no matter what, we get 2 bytes of padding */
@@ -22,14 +28,41 @@ struct logger_entry {
     char        msg[0]; /* the entry's payload */
 };
 
+/*
+ * The userspace structure for version 2 of the logger_entry ABI.
+ * This structure is returned to userspace if ioctl(LOGGER_SET_VERSION)
+ * is called with version==2
+ */
+struct logger_entry_v2 {
+    uint16_t    len;       /* length of the payload */
+    uint16_t    hdr_size;  /* sizeof(struct logger_entry_v2) */
+    int32_t     pid;       /* generating process's pid */
+    int32_t     tid;       /* generating process's tid */
+    int32_t     sec;       /* seconds since Epoch */
+    int32_t     nsec;      /* nanoseconds */
+    uid_t       euid;      /* effective UID of logger */
+    char        msg[0];    /* the entry's payload */
+};
+
 #define LOGGER_LOG_MAIN		"log/main"
 #define LOGGER_LOG_RADIO	"log/radio"
 #define LOGGER_LOG_EVENTS	"log/events"
 #define LOGGER_LOG_SYSTEM	"log/system"
 
-#define LOGGER_ENTRY_MAX_LEN		(4*1024)
-#define LOGGER_ENTRY_MAX_PAYLOAD	\
-	(LOGGER_ENTRY_MAX_LEN - sizeof(struct logger_entry))
+/*
+ * The maximum size of the log entry payload that can be
+ * written to the kernel logger driver. An attempt to write
+ * more than this amount to /dev/log/* will result in a
+ * truncated log entry.
+ */
+#define LOGGER_ENTRY_MAX_PAYLOAD	4076
+
+/*
+ * The maximum size of a log entry which can be read from the
+ * kernel logger driver. An attempt to read less than this amount
+ * may result in read() returning EINVAL.
+ */
+#define LOGGER_ENTRY_MAX_LEN		(5*1024)
 
 #ifdef HAVE_IOCTL
 
@@ -41,6 +74,8 @@ struct logger_entry {
 #define LOGGER_GET_LOG_LEN		_IO(__LOGGERIO, 2) /* used log len */
 #define LOGGER_GET_NEXT_ENTRY_LEN	_IO(__LOGGERIO, 3) /* next entry len */
 #define LOGGER_FLUSH_LOG		_IO(__LOGGERIO, 4) /* flush log */
+#define LOGGER_GET_VERSION		_IO(__LOGGERIO, 5) /* abi version */
+#define LOGGER_SET_VERSION		_IO(__LOGGERIO, 6) /* abi version */
 
 #endif // HAVE_IOCTL