From: Eugene Syromyatnikov <evgsyr@gmail.com>
Date: Wed, 14 Aug 2019 15:15:47 +0000 (+0200)
Subject: v4l2: avoid shifting left a signed number by 31 bit
X-Git-Tag: v5.3~46
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=91281fec7823f1cd3df3374fbcbd14af52a3fa1b;p=strace

v4l2: avoid shifting left a signed number by 31 bit

cppcheck warns about it with the following diagnostics:

    error[shiftTooManyBitsSigned]: Shifting signed 32-bit value by 31 bits is
    undefined behaviour

* v4l2.c [!v4l2_fourcc_be] (v4l2_fourcc_be): Shift left 1U and not 1 in
order to get 0x80000000.
---

diff --git a/v4l2.c b/v4l2.c
index 5da457c6..505e7b87 100644
--- a/v4l2.c
+++ b/v4l2.c
@@ -47,7 +47,7 @@ typedef struct v4l2_standard struct_v4l2_standard;
 
 /* v4l2_fourcc_be was added by Linux commit v3.18-rc1~101^2^2~127 */
 #ifndef v4l2_fourcc_be
-# define v4l2_fourcc_be(a, b, c, d) (v4l2_fourcc(a, b, c, d) | (1 << 31))
+# define v4l2_fourcc_be(a, b, c, d) (v4l2_fourcc(a, b, c, d) | (1U << 31))
 #endif
 
 #define FMT_FRACT "%u/%u"