configure: add CONFIG_HAVE_ARC4RANDOM

glibc 2.36 added arc4random(), which breaks
the SPDK iSCSI build since it always implements its
own arc4random() implementation on non-FreeBSD OS
(meaning always on Linux).

So instead add a CONFIG_HAVE_ARC4RANDOM and remove
the explicit FreeBSD dependency - this will work on
FreeBSD as well as Linux with >= glibc 2.36.

Also fix check_format.sh, so that it does not
enforce spdk/stdinc.h checks on code snippets in
the configure file.

Fixes issue #2637.

Reported-by: Karl Bonde Torp <k.torp@samsung.com>
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/14028 (master)

(cherry picked from commit 43a3984)
Change-Id: Iab9da8ae30d62a56869530846372ffddf7138eed
Signed-off-by: Krzysztof Karas <krzysztof.karas@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15750
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <smatsumoto@nvidia.com>

CONFIG

@@ -195,3 +195,6 @@ CONFIG_USDT=n
 # Build with IDXD kernel support.
 # In this mode, SPDK shares the DSA device with the kernel.
 CONFIG_IDXD_KERNEL=n
+
+# arc4random is available in stdlib.h
+CONFIG_HAVE_ARC4RANDOM=n

configure

@@ -850,6 +850,11 @@ if [[ "${CONFIG[TSAN]}" = "y" ]]; then
 	fi
 fi
 
+if echo -e '#include <stdlib.h>\nint main(void) { arc4random(); return 0; }\n' \
+	| "${BUILD_CMD[@]}" - 2> /dev/null; then
+	CONFIG[HAVE_ARC4RANDOM]="y"
+fi
+
 if [[ "${CONFIG[OCF]}" = "y" ]]; then
 	# If OCF_PATH is a file, assume it is a library and use it to compile with
 	if [ -f ${CONFIG[OCF_PATH]} ]; then

lib/iscsi/iscsi.c

@@ -62,7 +62,6 @@
 
 #ifdef __FreeBSD__
 #define HAVE_SRANDOMDEV 1
-#define HAVE_ARC4RANDOM 1
 #endif
 
 struct spdk_iscsi_globals g_iscsi = {
@@ -97,7 +96,7 @@ srandomdev(void)
 }
 #endif /* HAVE_SRANDOMDEV */
 
-#ifndef HAVE_ARC4RANDOM
+#ifndef SPDK_CONFIG_HAVE_ARC4RANDOM
 static int g_arc4random_initialized = 0;
 
 static uint32_t
@@ -115,7 +114,7 @@ arc4random(void)
 	r = (r1 << 16) | r2;
 	return r;
 }
-#endif /* HAVE_ARC4RANDOM */
+#endif /* SPDK_CONFIG_HAVE_ARC4RANDOM */
 
 static void
 gen_random(uint8_t *buf, size_t len)

scripts/check_format.sh

@@ -270,7 +270,7 @@ function check_posix_includes() {
 	local rc=0
 
 	echo -n "Checking for POSIX includes..."
-	git grep -I -i -f scripts/posix.txt -- './*' ':!include/spdk/stdinc.h' ':!include/linux/**' ':!lib/rte_vhost*/**' ':!scripts/posix.txt' ':!*.patch' > scripts/posix.log || true
+	git grep -I -i -f scripts/posix.txt -- './*' ':!include/spdk/stdinc.h' ':!include/linux/**' ':!lib/rte_vhost*/**' ':!scripts/posix.txt' ':!*.patch' ':!configure' > scripts/posix.log || true
 	if [ -s scripts/posix.log ]; then
 		echo "POSIX includes detected. Please include spdk/stdinc.h instead."
 		cat scripts/posix.log