From 4db23c74550f4dc3b46cc9120d1ccf52cf6ab259 Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Wed, 5 Jun 2019 23:37:50 +0000
Subject: [PATCH] Use parse_integer to avoid sign extension.

Coverity warned about gdb_write_mem sign extending the result of
parse_byte shifted left by 24 bits when generating a 32-bit memory
write value for MMIO.  Simplify the code by using parse_integer
instead of unrolled parse_byte calls.

CID:		1401600
Reviewed by:	cem
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D20508
---
 usr.sbin/bhyve/gdb.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/usr.sbin/bhyve/gdb.c b/usr.sbin/bhyve/gdb.c
index 3571a4e2b604..2de639022c8b 100644
--- a/usr.sbin/bhyve/gdb.c
+++ b/usr.sbin/bhyve/gdb.c
@@ -32,6 +32,7 @@ __FBSDID("$FreeBSD$");
 #ifndef WITHOUT_CAPSICUM
 #include <sys/capsicum.h>
 #endif
+#include <sys/endian.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/socket.h>
@@ -953,14 +954,10 @@ gdb_write_mem(const uint8_t *data, size_t len)
 					val = parse_byte(data);
 				} else if (gpa & 2 || todo == 2) {
 					bytes = 2;
-					val = parse_byte(data) |
-					    (parse_byte(data + 2) << 8);
+					val = be16toh(parse_integer(data, 4));
 				} else {
 					bytes = 4;
-					val = parse_byte(data) |
-					    (parse_byte(data + 2) << 8) |
-					    (parse_byte(data + 4) << 16) |
-					    (parse_byte(data + 6) << 24);
+					val = be32toh(parse_integer(data, 8));
 				}
 				error = write_mem(ctx, cur_vcpu, gpa, val,
 				    bytes);