From: xingzhen <zhengjun.x...@intel.com>
3debb0a9ddb adding a "__used" to the variable in the
__trace_printk_fmt section. Sometimes it will cause
*iter to be NULL, then strcmp in lookup_format and
strcpy in hold_module_trace_bprintk_format will panic.
Signed-off-by: xingzhen <zhengjun.x...@intel.com>
---
kernel/trace/trace_printk.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index f96f038..82ecfb5 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -55,6 +55,8 @@ void hold_module_trace_bprintk_format(const char **start,
const char **end)
mutex_lock(&btrace_mutex);
for (iter = start; iter < end; iter++) {
+ if (!*iter)
+ goto err;
struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter);
if (tb_fmt) {
*iter = tb_fmt->fmt;
@@ -75,6 +77,7 @@ void hold_module_trace_bprintk_format(const char **start,
const char **end)
*iter = fmt;
}
+err:
mutex_unlock(&btrace_mutex);
}
--
1.9.1
