Fix undefined behavior: (1 << 31) is not defined as 1 is an int and this

shifts into the sign bit.  Instead use (1U << 31) which gets the
expected result.

This fix is not ideal as it assumes a 32 bit int, but does fix the issue
for most cases.

A similar change was made in OpenBSD.

Discussed with:	-arch, rdivacky
Reviewed by:	cperciva

3 files changed, 5 insertions, 5 deletions

diff --git a/lib/libc/sparc64/fpu/fpu.c b/lib/libc/sparc64/fpu/fpu.c
index 4e92788114d5..431207f8a585 100644
--- a/lib/libc/sparc64/fpu/fpu.c
+++ b/lib/libc/sparc64/fpu/fpu.c
@@ -202,7 +202,7 @@ static const int opmask[] = {0, 0, 1, 3, 1};
  * Implement a move operation for all supported operand types. The additional
  * nand and xor parameters will be applied to the upper 32 bit word of the
  * source operand. This allows to implement fabs and fneg (for fp operands
- * only!) using this functions, too, by passing (1 << 31) for one of the
+ * only!) using this functions, too, by passing (1U << 31) for one of the
  * parameters, and 0 for the other.
  */
 static void
@@ -358,10 +358,10 @@ __fpu_execute(struct utrapframe *uf, struct fpemu *fe, u_int32_t insn,
 		__fpu_mov(fe, type, rd, rs2, 0, 0);
 		return (0);
 	case FOP(INS2_FPop1, INSFP1_FNEG):
-		__fpu_mov(fe, type, rd, rs2, 0, (1 << 31));
+		__fpu_mov(fe, type, rd, rs2, 0, (1U << 31));
 		return (0);
 	case FOP(INS2_FPop1, INSFP1_FABS):
-		__fpu_mov(fe, type, rd, rs2, (1 << 31), 0);
+		__fpu_mov(fe, type, rd, rs2, (1U << 31), 0);
 		return (0);
 	case FOP(INS2_FPop1, INSFP1_FSQRT):
 		__fpu_explode(fe, &fe->fe_f1, type, rs2);
diff --git a/lib/libc/sparc64/fpu/fpu_sqrt.c b/lib/libc/sparc64/fpu/fpu_sqrt.c
index 364384b41f69..52290f2b90c4 100644
--- a/lib/libc/sparc64/fpu/fpu_sqrt.c
+++ b/lib/libc/sparc64/fpu/fpu_sqrt.c
@@ -257,7 +257,7 @@ __fpu_sqrt(fe)
 	 * double x correctly while doing the `known q=1.0'.
 	 *
 	 * We do this one mantissa-word at a time, as noted above, to
-	 * save work.  To avoid `(1 << 31) << 1', we also do the top bit
+	 * save work.  To avoid `(1U << 31) << 1', we also do the top bit
 	 * outside of each per-word loop.
 	 *
 	 * The calculation `t = y + bit' breaks down into `t0 = y0, ...,
diff --git a/lib/libc/xdr/xdr_rec.c b/lib/libc/xdr/xdr_rec.c
index dc4aa18f14bf..4c94acbd61a8 100644
--- a/lib/libc/xdr/xdr_rec.c
+++ b/lib/libc/xdr/xdr_rec.c
@@ -106,7 +106,7 @@ static const struct  xdr_ops xdrrec_ops = {
  * meet the needs of xdr and rpc based on tcp.
  */
 
-#define LAST_FRAG ((u_int32_t)(1 << 31))
+#define LAST_FRAG ((u_int32_t)(1U << 31))
 
 typedef struct rec_strm {
 	char *tcp_handle;