dynamic_debug: Remove uses of KERN_CONT in dynamic_emit_prefix

Multiple printks with KERN_CONT can be interleaved by
other printks.  Reduce the likelihood of that interleaving
by consolidating multiple calls to printk.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 23 insertions, 11 deletions

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 37217090aacf..a3eb6ab074a6 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -430,23 +430,35 @@ static int ddebug_exec_query(char *query_string)
 
 static int dynamic_emit_prefix(const struct _ddebug *descriptor)
 {
-        int res;
+        char tid[sizeof(int) + sizeof(int)/2 + 4];
+        char lineno[sizeof(int) + sizeof(int)/2];
 
-        res = printk(KERN_DEBUG);
         if (descriptor->flags & _DPRINTK_FLAGS_INCL_TID) {
                 if (in_interrupt())
-                        res += printk(KERN_CONT "<intr> ");
+                        snprintf(tid, sizeof(tid), "%s", "<intr> ");
                 else
-                        res += printk(KERN_CONT "[%d] ", task_pid_vnr(current));
+                        snprintf(tid, sizeof(tid), "[%d] ",
+                                 task_pid_vnr(current));
+        } else {
+                tid[0] = 0;
         }
-        if (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME)
-                res += printk(KERN_CONT "%s:", descriptor->modname);
-        if (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
-                res += printk(KERN_CONT "%s:", descriptor->function);
-        if (descriptor->flags & _DPRINTK_FLAGS_INCL_LINENO)
-                res += printk(KERN_CONT "%d ", descriptor->lineno);
 
-        return res;
+        if (descriptor->flags & _DPRINTK_FLAGS_INCL_LINENO)
+                snprintf(lineno, sizeof(lineno), "%d", descriptor->lineno);
+        else
+                lineno[0] = 0;
+
+        return printk(KERN_DEBUG "%s%s%s%s%s%s",
+                      tid,
+                      (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME) ?
+                      descriptor->modname : "",
+                      (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME) ?
+                      ":" : "",
+                      (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME) ?
+                      descriptor->function : "",
+                      (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME) ?
+                      ":" : "",
+                      lineno);
 }
 
 int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)