queue-4.9/soc-mediatek-pwrap-zero-initialize-rdata-in-pwrap_in.patch

   1 From 7a8109d5e352a052b658f8052eebff2e92464b77 Mon Sep 17 00:00:00 2001
   2 From: Nathan Chancellor <natechancellor@gmail.com>
   3 Date: Thu, 7 Mar 2019 15:56:51 -0700
   4 Subject: soc: mediatek: pwrap: Zero initialize rdata in pwrap_init_cipher
   5
   6 [ Upstream commit 89e28da82836530f1ac7a3a32fecc31f22d79b3e ]
   7
   8 When building with -Wsometimes-uninitialized, Clang warns:
   9
  10 drivers/soc/mediatek/mtk-pmic-wrap.c:1358:6: error: variable 'rdata' is
  11 used uninitialized whenever '||' condition is true
  12 [-Werror,-Wsometimes-uninitialized]
  13
  14 If pwrap_write returns non-zero, pwrap_read will not be called to
  15 initialize rdata, meaning that we will use some random uninitialized
  16 stack value in our print statement. Zero initialize rdata in case this
  17 happens.
  18
  19 Link: https://github.com/ClangBuiltLinux/linux/issues/401
  20 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
  21 Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
  22 Reviewed-by: Arnd Bergmann <arnd@arndb.de>
  23 Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
  24 Signed-off-by: Sasha Levin <sashal@kernel.org>
  25 ---
  26  drivers/soc/mediatek/mtk-pmic-wrap.c | 2 +-
  27  1 file changed, 1 insertion(+), 1 deletion(-)
  28
  29 diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
  30 index e929f5142862..36226976773f 100644
  31 --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
  32 +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
  33 @@ -778,7 +778,7 @@ static bool pwrap_is_pmic_cipher_ready(struct pmic_wrapper *wrp)
  34  static int pwrap_init_cipher(struct pmic_wrapper *wrp)
  35  {
  36         int ret;
  37 -       u32 rdata;
  38 +       u32 rdata = 0;
  39
  40         pwrap_writel(wrp, 0x1, PWRAP_CIPHER_SWRST);
  41         pwrap_writel(wrp, 0x0, PWRAP_CIPHER_SWRST);
  42 --
  43 2.20.1
  44