commit 083c53462aefaee142ddfb40ba0ed8d40e1ecda4
author Mark Salyzyn <salyzyn@google.com> Mon Mar 21 09:45:34 2016 -0700
committer Mark Salyzyn <salyzyn@google.com> Mon Mar 21 23:06:29 2016 +0000
tree 5df1743b5bab6d6f3bb8fc83523d2028c8661358
parent a01de8fee1fa47ef4893d2017ac8c390c3c08a00

liblog: logprint: deal with malformed log messages

Try to print as much content as possible should the application
logging only submit content as part of a tag with an empty message.
We search for the first non-printable ascii character in the tag, in
order to split it up for printing.

Applications (such as com.yahoo.mobile.client.android.weather) that
malform their log messages will no longer be punished by truncating
the content, but this should never be considered advocacy for their
bad behavior.

Bug: 27585978
Change-Id: Idb0680e8d6a6ad2bef5150661905acccb5b70afb

liblog/logprint.c

diff --git a/liblog/logprint.c b/liblog/logprint.c
index 02df8dd..7f02b46 100644
--- a/liblog/logprint.c
+++ b/liblog/logprint.c
@@ -512,8 +512,18 @@
     }
 
     if (msgStart == -1) {
-        fprintf(stderr, "+++ LOG: malformed log message\n");
-        return -1;
+        /* +++ LOG: malformed log message, DYB */
+        for (i = 1; i < buf->len; i++) {
+            /* odd characters in tag? */
+            if ((msg[i] <= ' ') || (msg[i] == ':') || (msg[i] >= 0x7f)) {
+                msg[i] = '\0';
+                msgStart = i + 1;
+                break;
+            }
+        }
+        if (msgStart == -1) {
+            msgStart = buf->len - 1; /* All tag, no message, print truncates */
+        }
     }
     if (msgEnd == -1) {
         /* incoming message not null-terminated; force it */

liblog/tests/liblog_test.cpp

diff --git a/liblog/tests/liblog_test.cpp b/liblog/tests/liblog_test.cpp
index 2767f73..ca2cda2 100644
--- a/liblog/tests/liblog_test.cpp
+++ b/liblog/tests/liblog_test.cpp
@@ -1062,8 +1062,10 @@
             fflush(stderr);
             int printLogLine =
                     android_log_printLogLine(logformat, fileno(stderr), &entry);
+            // Legacy tag truncation
             EXPECT_LE(128, printLogLine);
-            EXPECT_GT(LOGGER_ENTRY_MAX_PAYLOAD, printLogLine);
+            // Measured maximum if we try to print part of the tag as message
+            EXPECT_GT(LOGGER_ENTRY_MAX_PAYLOAD * 13 / 8, printLogLine);
         }
         android_log_format_free(logformat);
     }