From ba5aaf58ce10ccbc9d2440a4844715efdefda228 Mon Sep 17 00:00:00 2001
From: Greg Kurz <groug@kaod.org>
Date: Fri, 16 Sep 2016 08:56:15 +0200
Subject: [PATCH] 9pfs: introduce v9fs_path_sprintf() helper
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This helper is similar to v9fs_string_sprintf(), but it includes the
terminating NUL character in the size field.

This is to avoid doing v9fs_string_sprintf((V9fsString *) &path) and
then bumping the size.

Affected users are changed to use this new helper.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
(cherry picked from commit e3e83f2e2130a3afbd41a2893d23397f03f6d9d0)
[BR: support patch for BSC#1034866]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/9pfs/9p-local.c |  7 ++-----
 hw/9pfs/9p-proxy.c |  7 ++-----
 hw/9pfs/9p.c       | 19 ++++++++++++++++---
 hw/9pfs/9p.h       |  1 +
 4 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 102f09fec7..9b02fc8a16 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -953,13 +953,10 @@ static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
                               const char *name, V9fsPath *target)
 {
     if (dir_path) {
-        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
-                            dir_path->data, name);
+        v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
     } else {
-        v9fs_string_sprintf((V9fsString *)target, "%s", name);
+        v9fs_path_sprintf(target, "%s", name);
     }
-    /* Bump the size for including terminating NULL */
-    target->size++;
     return 0;
 }
 
diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
index 08eb21c1ce..0a0b600de1 100644
--- a/hw/9pfs/9p-proxy.c
+++ b/hw/9pfs/9p-proxy.c
@@ -1032,13 +1032,10 @@ static int proxy_name_to_path(FsContext *ctx, V9fsPath *dir_path,
                               const char *name, V9fsPath *target)
 {
     if (dir_path) {
-        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
-                            dir_path->data, name);
+        v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
     } else {
-        v9fs_string_sprintf((V9fsString *)target, "%s", name);
+        v9fs_path_sprintf(target, "%s", name);
     }
-    /* Bump the size for including terminating NULL */
-    target->size++;
     return 0;
 }
 
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 06196d447d..0c6904cc6e 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -13,6 +13,7 @@
 
 #include "hw/virtio.h"
 #include "hw/pc.h"
+#include <glib/gprintf.h>
 #include "qemu/sockets.h"
 #include "virtio-9p.h"
 #include "fsdev/qemu-fsdev.h"
@@ -176,6 +177,20 @@ void v9fs_path_free(V9fsPath *path)
     path->size = 0;
 }
 
+
+void GCC_FMT_ATTR(2, 3)
+v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...)
+{
+    va_list ap;
+
+    v9fs_path_free(path);
+
+    va_start(ap, fmt);
+    /* Bump the size for including terminating NULL */
+    path->size = g_vasprintf(&path->data, fmt, ap) + 1;
+    va_end(ap);
+}
+
 void v9fs_path_copy(V9fsPath *lhs, V9fsPath *rhs)
 {
     v9fs_path_free(lhs);
@@ -913,10 +928,8 @@ static void v9fs_fix_path(V9fsPath *dst, V9fsPath *src, int len)
     V9fsPath str;
     v9fs_path_init(&str);
     v9fs_path_copy(&str, dst);
-    v9fs_string_sprintf((V9fsString *)dst, "%s%s", src->data, str.data+len);
+    v9fs_path_sprintf(dst, "%s%s", src->data, str.data + len);
     v9fs_path_free(&str);
-    /* +1 to include terminating NULL */
-    dst->size++;
 }
 
 static inline bool is_ro_export(FsContext *ctx)
diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
index 04b3119b0f..529c876f27 100644
--- a/hw/9pfs/9p.h
+++ b/hw/9pfs/9p.h
@@ -316,6 +316,7 @@ static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
 extern void v9fs_reclaim_fd(V9fsPDU *pdu);
 extern void v9fs_path_init(V9fsPath *path);
 extern void v9fs_path_free(V9fsPath *path);
+extern void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
 extern void v9fs_path_copy(V9fsPath *lhs, V9fsPath *rhs);
 extern int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
                              const char *name, V9fsPath *path);
