commit a93ac70955c08a516f66ec76de5fd83331449858
author Mark Salyzyn <salyzyn@google.com> Wed Mar 07 10:42:06 2018 -0800
committer Mark Salyzyn <salyzyn@google.com> Wed Mar 07 22:30:16 2018 +0000
tree 40c46b7226642660831fd2943448439cb2f5e239
parent f11e685edc7ea2cf5c27a4e9bfe3cc2196df12f0

liblog: save errno through log writing

(cherry picked from commit 72d3724ee57251e4056df95f58a55f0c9e2ab31c)

Test: compile
Bug: 74258013
Change-Id: I5163527826855bc506ed324aaba47f8695aaf668

liblog/logger_write.c

diff --git a/liblog/logger_write.c b/liblog/logger_write.c
index d03a2b6..2754e6e 100644
--- a/liblog/logger_write.c
+++ b/liblog/logger_write.c
@@ -243,7 +243,7 @@
 
 static int __write_to_log_daemon(log_id_t log_id, struct iovec* vec, size_t nr) {
   struct android_log_transport_write* node;
-  int ret;
+  int ret, save_errno;
   struct timespec ts;
   size_t len, i;
 
@@ -254,20 +254,24 @@
     return -EINVAL;
   }
 
+  save_errno = errno;
 #if defined(__ANDROID__)
   clock_gettime(android_log_clockid(), &ts);
 
   if (log_id == LOG_ID_SECURITY) {
     if (vec[0].iov_len < 4) {
+      errno = save_errno;
       return -EINVAL;
     }
 
     ret = check_log_uid_permissions();
     if (ret < 0) {
+      errno = save_errno;
       return ret;
     }
     if (!__android_log_security()) {
       /* If only we could reset downstream logd counter */
+      errno = save_errno;
       return -EPERM;
     }
   } else if (log_id == LOG_ID_EVENTS || log_id == LOG_ID_STATS) {
@@ -276,6 +280,7 @@
     EventTagMap *m, *f;
 
     if (vec[0].iov_len < 4) {
+      errno = save_errno;
       return -EINVAL;
     }
 
@@ -311,6 +316,7 @@
       android_closeEventTagMap(f);
     }
     if (!ret) {
+      errno = save_errno;
       return -EPERM;
     }
   } else {
@@ -340,6 +346,7 @@
     }
 
     if (!__android_log_is_loggable_len(prio, tag, len - 1, ANDROID_LOG_VERBOSE)) {
+      errno = save_errno;
       return -EPERM;
     }
   }
@@ -371,21 +378,23 @@
     }
   }
 
+  errno = save_errno;
   return ret;
 }
 
 static int __write_to_log_init(log_id_t log_id, struct iovec* vec, size_t nr) {
+  int ret, save_errno = errno;
+
   __android_log_lock();
 
   if (write_to_log == __write_to_log_init) {
-    int ret;
-
     ret = __write_to_log_initialize();
     if (ret < 0) {
       __android_log_unlock();
       if (!list_empty(&__android_log_persist_write)) {
         __write_to_log_daemon(log_id, vec, nr);
       }
+      errno = save_errno;
       return ret;
     }
 
@@ -394,7 +403,9 @@
 
   __android_log_unlock();
 
-  return write_to_log(log_id, vec, nr);
+  ret = write_to_log(log_id, vec, nr);
+  errno = save_errno;
+  return ret;
 }
 
 LIBLOG_ABI_PUBLIC int __android_log_write(int prio, const char* tag,