[PATCH net-next v2] selftests: mptcp: Mark xerror __noreturn

[Ankit Khushwaha]

Compiler reports potential uses of uninitialized variables in
mptcp_connect.c when xerror() is called from failure paths.

mptcp_connect.c:1262:11: warning: variable 'raw_addr' is used
      uninitialized whenever 'if' condition is false
      [-Wsometimes-uninitialized]

xerror() terminates execution by calling exit(), but it is not visible
to the compiler & assumes control flow may continue past the call.

Annotate xerror() with __noreturn so the compiler can correctly reason
about control flow and avoid false-positive uninitialized variable
warnings.

Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux@xxxxxxxxx>
---
changelog:
v2: 
- annotate 'xerror()' with __noreturn
- remove defining 'raw_addr' to NULL

v1: https://lore.kernel.org/all/20251126163046.58615-1-ankitkhushwaha.linux@xxxxxxxxx/
---
 tools/testing/selftests/net/mptcp/Makefile        | 4 ++++
 tools/testing/selftests/net/mptcp/mptcp_connect.c | 3 ++-
 tools/testing/selftests/net/mptcp/mptcp_inq.c     | 3 ++-
 tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 3 ++-
 4 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/Makefile b/tools/testing/selftests/net/mptcp/Makefile
index 15d144a25d82..4c94c01b893a 100644
--- a/tools/testing/selftests/net/mptcp/Makefile
+++ b/tools/testing/selftests/net/mptcp/Makefile
@@ -35,3 +35,7 @@ TEST_INCLUDES := ../lib.sh $(wildcard ../lib/sh/*.sh)
 EXTRA_CLEAN := *.pcap

 include ../../lib.mk
+
+$(OUTPUT)/mptcp_connect: CFLAGS += -I$(top_srcdir)/tools/include
+$(OUTPUT)/mptcp_sockopt: CFLAGS += -I$(top_srcdir)/tools/include
+$(OUTPUT)/mptcp_inq: CFLAGS += -I$(top_srcdir)/tools/include
diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/testing/selftests/net/mptcp/mptcp_connect.c
index 404a77bf366a..10f6f99cfd4e 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c
@@ -33,6 +33,7 @@
 #include <linux/tcp.h>
 #include <linux/time_types.h>
 #include <linux/sockios.h>
+#include <linux/compiler.h>

 extern int optind;

@@ -140,7 +141,7 @@ static void die_usage(void)
 	exit(1);
 }

-static void xerror(const char *fmt, ...)
+static void __noreturn xerror(const char *fmt, ...)
 {
 	va_list ap;

diff --git a/tools/testing/selftests/net/mptcp/mptcp_inq.c b/tools/testing/selftests/net/mptcp/mptcp_inq.c
index 8e8f6441ad8b..d4a729814662 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_inq.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_inq.c
@@ -28,6 +28,7 @@

 #include <linux/tcp.h>
 #include <linux/sockios.h>
+#include <linux/compiler.h>

 #ifndef IPPROTO_MPTCP
 #define IPPROTO_MPTCP 262
@@ -52,7 +53,7 @@ static void die_usage(int r)
 	exit(r);
 }

-static void xerror(const char *fmt, ...)
+static void __noreturn xerror(const char *fmt, ...)
 {
 	va_list ap;

diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
index 286164f7246e..15cea5e919b5 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
@@ -25,6 +25,7 @@
 #include <netinet/in.h>

 #include <linux/tcp.h>
+#include <linux/compiler.h>

 static int pf = AF_INET;

@@ -139,7 +140,7 @@ static void die_usage(int r)
 	exit(r);
 }

-static void xerror(const char *fmt, ...)
+static void __noreturn xerror(const char *fmt, ...)
 {
 	va_list ap;

--
2.52.0