[Qemu-devel] [PATCH] qtest: Don't segfault with invalid -qtest option

[Fam Zheng]

This prints an error message, instead of core dump, when "-qtest"
option value is invalid, e.g.:

    $ ./x86_64-softmmu/qemu-system-x86_64 -qtest unknown
    qemu-system-x86_64: Failed to initialize device for qtest: "unknown"

Signed-off-by: Fam Zheng <address@hidden>
---
 include/sysemu/qtest.h |  2 +-
 qtest.c                | 10 +++++++++-
 vl.c                   |  5 ++++-
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/include/sysemu/qtest.h b/include/sysemu/qtest.h
index 112a661..fc108c7 100644
--- a/include/sysemu/qtest.h
+++ b/include/sysemu/qtest.h
@@ -24,7 +24,7 @@ static inline bool qtest_enabled(void)
 }
 
 int qtest_init_accel(void);
-void qtest_init(const char *qtest_chrdev, const char *qtest_log);
+int qtest_init(const char *qtest_chrdev, const char *qtest_log);
 
 static inline int qtest_available(void)
 {
diff --git a/qtest.c b/qtest.c
index dcf1301..a037b3b 100644
--- a/qtest.c
+++ b/qtest.c
@@ -19,6 +19,7 @@
 #include "hw/irq.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/cpus.h"
+#include "qemu/error-report.h"
 
 #define MAX_IRQ 256
 
@@ -507,12 +508,18 @@ int qtest_init_accel(void)
     return 0;
 }
 
-void qtest_init(const char *qtest_chrdev, const char *qtest_log)
+int qtest_init(const char *qtest_chrdev, const char *qtest_log)
 {
     CharDriverState *chr;
 
     chr = qemu_chr_new("qtest", qtest_chrdev, NULL);
 
+    if (chr == NULL) {
+        error_report("Failed to initialize device for qtest: \"%s\"",
+                     qtest_chrdev);
+        return -1;
+    }
+
     qemu_chr_add_handlers(chr, qtest_can_read, qtest_read, qtest_event, chr);
     qemu_chr_fe_set_echo(chr, true);
 
@@ -527,4 +534,5 @@ void qtest_init(const char *qtest_chrdev, const char 
*qtest_log)
     }
 
     qtest_chr = chr;
+    return 0;
 }
diff --git a/vl.c b/vl.c
index 383be1b..97ca823 100644
--- a/vl.c
+++ b/vl.c
@@ -4078,7 +4078,10 @@ int main(int argc, char **argv, char **envp)
     configure_accelerator();
 
     if (qtest_chrdev) {
-        qtest_init(qtest_chrdev, qtest_log);
+        int ret = qtest_init(qtest_chrdev, qtest_log);
+        if (ret) {
+            exit(1);
+        }
     }
 
     machine_opts = qemu_get_machine_opts();
-- 
1.8.5.4