linux-kernel - [PATCH v2 3/3] math-emu: Use statement expressions to fix Wshift-count-overflow warning

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <1558937841-4222-4-git-send-email-vincentc@andestech.com>
Date:   Mon, 27 May 2019 14:17:21 +0800
From:   Vincent Chen <vincentc@...estech.com>
To:     <linux-kernel@...r.kernel.org>, <arnd@...db.de>,
        <linux-arch@...r.kernel.org>, <greentime@...estech.com>,
        <green.hu@...il.com>, <deanbo422@...il.com>
CC:     <vincentc@...estech.com>
Subject: [PATCH v2 3/3] math-emu: Use statement expressions to fix Wshift-count-overflow warning

To avoid "shift count >= width of type" warning, using statement
expressions to implement the conditional controlling before constant shift

The modification in op-2.h is taken from the glibc
commit 'sysdeps/unix/sysv/lin ("fe0b1e854ad32")'.

Signed-off-by: Vincent Chen <vincentc@...estech.com>
---
 Changes in v2
 - This is an new patch to fix Wshift-count-overflow warning

 include/math-emu/op-2.h      |   17 +++++++----------
 include/math-emu/op-common.h |   11 ++++++-----
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/include/math-emu/op-2.h b/include/math-emu/op-2.h
index 13a374f..244522b 100644
--- a/include/math-emu/op-2.h
+++ b/include/math-emu/op-2.h
@@ -567,16 +567,13 @@
  */
 
 #define _FP_FRAC_ASSEMBLE_2(r, X, rsize)	\
-  do {						\
-    if (rsize <= _FP_W_TYPE_SIZE)		\
-      r = X##_f0;				\
-    else					\
-      {						\
-	r = X##_f1;				\
-	r <<= _FP_W_TYPE_SIZE;			\
-	r += X##_f0;				\
-      }						\
-  } while (0)
+	(void) (((rsize) <= _FP_W_TYPE_SIZE)	\
+		? ({ (r) = X##_f0; })		\
+		: ({				\
+		     (r) = X##_f1;		\
+		     (r) <<= _FP_W_TYPE_SIZE;	\
+		     (r) += X##_f0;		\
+		    }))
 
 #define _FP_FRAC_DISASSEMBLE_2(X, r, rsize)				\
   do {									\
diff --git a/include/math-emu/op-common.h b/include/math-emu/op-common.h
index 6bdf8c6..f37d128 100644
--- a/include/math-emu/op-common.h
+++ b/include/math-emu/op-common.h
@@ -795,11 +795,12 @@
 	  ur_ = (unsigned rtype) -r;					\
 	else								\
 	  ur_ = (unsigned rtype) r;					\
-	if (rsize <= _FP_W_TYPE_SIZE)					\
-	  __FP_CLZ(X##_e, ur_);						\
-	else								\
-	  __FP_CLZ_2(X##_e, (_FP_W_TYPE)(ur_ >> _FP_W_TYPE_SIZE), 	\
-		     (_FP_W_TYPE)ur_);					\
+	(void) (((rsize) <= _FP_W_TYPE_SIZE)				\
+		? ({ __FP_CLZ(X##_e, ur_); })				\
+		: ({							\
+		     __FP_CLZ_2(X##_e, (_FP_W_TYPE)(ur_ >> _FP_W_TYPE_SIZE),  \
+							    (_FP_W_TYPE)ur_); \
+		  }));							\
 	if (rsize < _FP_W_TYPE_SIZE)					\
 		X##_e -= (_FP_W_TYPE_SIZE - rsize);			\
 	X##_e = rsize - X##_e - 1;					\
-- 
1.7.1