From 1fc51769ded79c74f15d59611c5ae4bd0547b32b Mon Sep 17 00:00:00 2001
From: Andy McFadden <fadden@android.com>
Date: Thu, 26 Jan 2012 13:21:19 -0800
Subject: [PATCH] Log debuggerd connection failures
Write a message to the log file if the signal handler is not able
to connect to debuggerd. This is especially handy if the failure
was caused by running out of file descriptors, since there's some
chance that the lack of fds relates to the crash.
Sample:
F libc : Fatal signal 11 (SIGSEGV) at 0xdeadbaad (code=1)
F libc : Unable to open connection to debuggerd: Too many open files
Bug 5926330
Change-Id: I0ff210d82ab1db39b08f328bae5e08f67a69e5d7
---
linker/debugger.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/linker/debugger.c b/linker/debugger.c
index 648dc78f4..ef8286cd9 100644
--- a/linker/debugger.c
+++ b/linker/debugger.c
@@ -126,6 +126,7 @@ static void logSignalSummary(int signum, const siginfo_t* info)
*/
void debugger_signal_handler(int n, siginfo_t* info, void* unused)
{
+ char msgbuf[128];
unsigned tid;
int s;
@@ -134,7 +135,7 @@ void debugger_signal_handler(int n, siginfo_t* info, void* unused)
tid = gettid();
s = socket_abstract_client("android:debuggerd", SOCK_STREAM);
- if(s >= 0) {
+ if (s >= 0) {
/* debugger knows our pid from the credentials on the
* local socket but we need to tell it our tid. It
* is paranoid and will verify that we are giving a tid
@@ -147,9 +148,24 @@ void debugger_signal_handler(int n, siginfo_t* info, void* unused)
/* if the write failed, there is no point to read on
* the file descriptor. */
RETRY_ON_EINTR(ret, read(s, &tid, 1));
+ int savedErrno = errno;
notify_gdb_of_libraries();
+ errno = savedErrno;
}
+
+ if (ret < 0) {
+ /* read or write failed -- broken connection? */
+ format_buffer(msgbuf, sizeof(msgbuf),
+ "Failed while talking to debuggerd: %s", strerror(errno));
+ __libc_android_log_write(ANDROID_LOG_FATAL, "libc", msgbuf);
+ }
+
close(s);
+ } else {
+ /* socket failed; maybe process ran out of fds */
+ format_buffer(msgbuf, sizeof(msgbuf),
+ "Unable to open connection to debuggerd: %s", strerror(errno));
+ __libc_android_log_write(ANDROID_LOG_FATAL, "libc", msgbuf);
}
/* remove our net so we fault for real when we return */