sbsigntool: fix compile error when enable DEBUG_BUILD

Fixes the following errors when set DEBUG_BUILD = "1":
fileio.c: In function ‘__fileio_read_file’:
fileio.c:179:12: error: ‘len’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  179 |   *out_len = len;
      |   ~~~~~~~~~^~~~~
fileio.c:178:12: error: ‘buf’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  178 |   *out_buf = buf;
      |   ~~~~~~~~~^~~~~

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>

2 files changed, 44 insertions, 2 deletions

diff --git a/meta-signing-key/recipes-devtools/sbsigntool/sbsigntool/0001-fileio.c-initialize-local-variables-before-use-in-fu.patch b/meta-signing-key/recipes-devtools/sbsigntool/sbsigntool/0001-fileio.c-initialize-local-variables-before-use-in-fu.patch
new file mode 100644
index 0000000..634225a
--- /dev/null
+++ b/meta-signing-key/recipes-devtools/sbsigntool/sbsigntool/0001-fileio.c-initialize-local-variables-before-use-in-fu.patch
@@ -0,0 +1,43 @@
+From 8a2dfef2fbb68d72ee8b5a542cfb22817050ebdb Mon Sep 17 00:00:00 2001
+From: Yi Zhao <yi.zhao@windriver.com>
+Date: Tue, 22 Jun 2021 11:20:17 +0800
+Subject: [PATCH] fileio.c: initialize local variables before use in function
+ __fileio_read_file
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Fixes:
+fileio.c: In function ‘__fileio_read_file’:
+fileio.c:179:26: error: ‘len’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
+  179 |                 *out_len = len;
+      |                 ~~~~~~~~~^~~~~
+fileio.c:178:26: error: ‘buf’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
+  178 |                 *out_buf = buf;
+      |                 ~~~~~~~~~^~~~~
+
+Upstream-Status: Pending
+
+Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
+---
+ src/fileio.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/fileio.c b/src/fileio.c
+index 032eb1e..929bb00 100644
+--- a/src/fileio.c
++++ b/src/fileio.c
+@@ -142,8 +142,8 @@ static int __fileio_read_file(void *ctx, const char *filename,
+                 uint8_t **out_buf, size_t *out_len, int flags)
+ {
+        struct stat statbuf;
+-       uint8_t *buf;
+-       size_t len;
++       uint8_t *buf = NULL;
++       size_t len = 0;
+        int fd, rc;
+ 
+        rc = -1;
+-- 
+2.17.1
+
diff --git a/meta-signing-key/recipes-devtools/sbsigntool/sbsigntool_git.bb b/meta-signing-key/recipes-devtools/sbsigntool/sbsigntool_git.bb
index c38fa42..b742e08 100644
--- a/meta-signing-key/recipes-devtools/sbsigntool/sbsigntool_git.bb
+++ b/meta-signing-key/recipes-devtools/sbsigntool/sbsigntool_git.bb
@@ -17,6 +17,7 @@ SRC_URI = " \
     file://0002-docs-Don-t-build-man-pages.patch \
     file://0003-sbsign-add-x-option-to-avoid-overwrite-existing-sign.patch  \
     file://0001-src-Makefile.am-Add-read_write_all.c-to-common_SOURC.patch \
+    file://0001-fileio.c-initialize-local-variables-before-use-in-fu.patch \
 "
 SRCREV_sbsigntools  ?= "f12484869c9590682ac3253d583bf59b890bb826"
 SRCREV_ccan         ?= "b1f28e17227f2320d07fe052a8a48942fe17caa5"
@@ -42,8 +43,6 @@ def efi_arch(d):
 #    --with-libtool-sysroot \
 #"
 
-CFLAGS += "-Wno-error=maybe-uninitialized"
-
 HOST_EXTRACFLAGS += "\
     INCLUDES+='-I${S}/lib/ccan.git/ \
               -I${STAGING_INCDIR_NATIVE}/efi \