Clean up init /proc/cmdline handling.
Helped debug a problem where the N9 bootloader incorrectly
concatenated the various command lines.
Bug: http://b/20906691
Change-Id: I0580b06f4185129c7eedf0bdf74b5ce17f88bf9c
diff --git a/init/log.cpp b/init/log.cpp
index d32f2da..eb5ec42 100644
--- a/init/log.cpp
+++ b/init/log.cpp
@@ -14,30 +14,35 @@
* limitations under the License.
*/
+#include "log.h"
+
#include <stdlib.h>
#include <string.h>
#include <sys/uio.h>
#include <selinux/selinux.h>
-#include "log.h"
+#include <base/stringprintf.h>
static void init_klog_vwrite(int level, const char* fmt, va_list ap) {
static const char* tag = basename(getprogname());
- char prefix[64];
- snprintf(prefix, sizeof(prefix), "<%d>%s: ", level, tag);
+ // The kernel's printk buffer is only 1024 bytes.
+ // TODO: should we automatically break up long lines into multiple lines?
+ // Or we could log but with something like "..." at the end?
+ char buf[1024];
+ size_t prefix_size = snprintf(buf, sizeof(buf), "<%d>%s: ", level, tag);
+ size_t msg_size = vsnprintf(buf + prefix_size, sizeof(buf) - prefix_size, fmt, ap);
+ if (msg_size >= sizeof(buf) - prefix_size) {
+ msg_size = snprintf(buf + prefix_size, sizeof(buf) - prefix_size,
+ "(%zu-byte message too long for printk)\n", msg_size);
+ }
- char msg[512];
- vsnprintf(msg, sizeof(msg), fmt, ap);
+ iovec iov[1];
+ iov[0].iov_base = buf;
+ iov[0].iov_len = prefix_size + msg_size;
- iovec iov[2];
- iov[0].iov_base = prefix;
- iov[0].iov_len = strlen(prefix);
- iov[1].iov_base = msg;
- iov[1].iov_len = strlen(msg);
-
- klog_writev(level, iov, 2);
+ klog_writev(level, iov, 1);
}
void init_klog_write(int level, const char* fmt, ...) {