[Spice-devel] [PATCH] common: add backtrace via gstack

[Alon Levy]

Add a backtrace printing function copied from xserver os/backtrace.c
that uses gstack which seems to be available enough that xserver uses it :)
Used in ASSERT, tested on F15.
---
 common/Makefile.am    |    2 +
 common/backtrace.c    |   88 +++++++++++++++++++++++++++++++++++++++++++++++++
 common/backtrace.h    |   24 +++++++++++++
 common/spice_common.h |    2 +
 4 files changed, 116 insertions(+), 0 deletions(-)
 create mode 100644 common/backtrace.c
 create mode 100644 common/backtrace.h

diff --git a/common/Makefile.am b/common/Makefile.am
index e0f4d49..f07f948 100644
--- a/common/Makefile.am
+++ b/common/Makefile.am
@@ -36,6 +36,8 @@ libspice_common_la_SOURCES =		\
 	spice_common.h			\
 	ssl_verify.c			\
 	ssl_verify.h			\
+	backtrace.c			\
+	backtrace.h			\
 	$(NULL)
 
 if SUPPORT_GL
diff --git a/common/backtrace.c b/common/backtrace.c
new file mode 100644
index 0000000..658b6b0
--- /dev/null
+++ b/common/backtrace.c
@@ -0,0 +1,88 @@
+/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+   Copyright (C) 2011 Red Hat, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ * Taken from xserver os/backtrace.c:
+ * Copyright 2008 Red Hat, Inc.
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include "common/spice_common.h"
+
+static int backtrace_gstack(void) {
+    pid_t kidpid;
+    int pipefd[2];
+
+    if (pipe(pipefd) != 0) {
+        return -1;
+    }
+
+    kidpid = fork();
+
+    if (kidpid == -1) {
+        /* ERROR */
+        return -1;
+    } else if (kidpid == 0) {
+        /* CHILD */
+        char parent[16];
+
+        seteuid(0);
+        close(STDIN_FILENO);
+        close(STDOUT_FILENO);
+        dup2(pipefd[1],STDOUT_FILENO);
+        close(STDERR_FILENO);
+
+        snprintf(parent, sizeof(parent), "%d", getppid());
+        execle("/usr/bin/gstack", "gstack", parent, NULL, NULL);
+        exit(1);
+    } else {
+        /* PARENT */
+        char btline[256];
+        int kidstat;
+        int bytesread;
+        int done = 0;
+
+        close(pipefd[1]);
+
+        while (!done) {
+            bytesread = read(pipefd[0], btline, sizeof(btline) - 1);
+
+            if (bytesread > 0) {
+                btline[bytesread] = 0;
+                red_printf("%s", btline);
+            }
+            else if ((bytesread < 0) ||
+                     ((errno != EINTR) && (errno != EAGAIN)))
+                done = 1;
+        }
+        close(pipefd[0]);
+        waitpid(kidpid, &kidstat, 0);
+        if (kidstat != 0)
+            return -1;
+    }
+    return 0;
+}
+
+void backtrace() {
+    backtrace_gstack(); /* no implementation other then via gstack */
+}
diff --git a/common/backtrace.h b/common/backtrace.h
new file mode 100644
index 0000000..83a54a1
--- /dev/null
+++ b/common/backtrace.h
@@ -0,0 +1,24 @@
+/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+   Copyright (C) 2011 Red Hat, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef BACKTRACE_H
+#define BACKTRACE_H
+
+void backtrace(void);
+
+#endif // BACKTRACE_H
diff --git a/common/spice_common.h b/common/spice_common.h
index bc74486..d58c558 100644
--- a/common/spice_common.h
+++ b/common/spice_common.h
@@ -22,9 +22,11 @@
 #include <stdint.h>
 #include <time.h>
 #include <stdlib.h>
+#include "backtrace.h"
 
 #define ASSERT(x) if (!(x)) {                               \
     printf("%s: ASSERT %s failed\n", __FUNCTION__, #x);     \
+    backtrace();                                           \
     abort();                                                \
 }
 
-- 
1.7.6