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[v3,bpf-next,1/6] selftests/bpf: Fix bind program for big endian systems

Message ID 20240429214529.2644801-2-jrife@google.com
State Accepted
Commit 8e667a065daa6f4c01eadc20f3815f7bf13255bc
Headers show
Series selftests/bpf: Add sockaddr tests for kernel networking | expand

Commit Message

Jordan Rife April 29, 2024, 9:45 p.m. UTC 
Without this fix, the bind4 and bind6 programs will reject bind attempts
on big endian systems. This patch ensures that CI tests pass for the
s390x architecture.

Signed-off-by: Jordan Rife <jrife@google.com>
---
 .../testing/selftests/bpf/progs/bind4_prog.c  | 18 ++++++++++--------
 .../testing/selftests/bpf/progs/bind6_prog.c  | 18 ++++++++++--------
 tools/testing/selftests/bpf/progs/bind_prog.h | 19 +++++++++++++++++++
 3 files changed, 39 insertions(+), 16 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/bind_prog.h
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/progs/bind4_prog.c b/tools/testing/selftests/bpf/progs/bind4_prog.c
index a487f60b73ac4..66005c1a5b367 100644
--- a/tools/testing/selftests/bpf/progs/bind4_prog.c
+++ b/tools/testing/selftests/bpf/progs/bind4_prog.c
@@ -12,6 +12,8 @@ 
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_endian.h>
 
+#include "bind_prog.h"
+
 #define SERV4_IP		0xc0a801feU /* 192.168.1.254 */
 #define SERV4_PORT		4040
 #define SERV4_REWRITE_IP	0x7f000001U /* 127.0.0.1 */
@@ -118,23 +120,23 @@  int bind_v4_prog(struct bpf_sock_addr *ctx)
 
 	// u8 narrow loads:
 	user_ip4 = 0;
-	user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[0] << 0;
-	user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[1] << 8;
-	user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[2] << 16;
-	user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[3] << 24;
+	user_ip4 |= load_byte(ctx->user_ip4, 0, sizeof(user_ip4));
+	user_ip4 |= load_byte(ctx->user_ip4, 1, sizeof(user_ip4));
+	user_ip4 |= load_byte(ctx->user_ip4, 2, sizeof(user_ip4));
+	user_ip4 |= load_byte(ctx->user_ip4, 3, sizeof(user_ip4));
 	if (ctx->user_ip4 != user_ip4)
 		return 0;
 
 	user_port = 0;
-	user_port |= ((volatile __u8 *)&ctx->user_port)[0] << 0;
-	user_port |= ((volatile __u8 *)&ctx->user_port)[1] << 8;
+	user_port |= load_byte(ctx->user_port, 0, sizeof(user_port));
+	user_port |= load_byte(ctx->user_port, 1, sizeof(user_port));
 	if (ctx->user_port != user_port)
 		return 0;
 
 	// u16 narrow loads:
 	user_ip4 = 0;
-	user_ip4 |= ((volatile __u16 *)&ctx->user_ip4)[0] << 0;
-	user_ip4 |= ((volatile __u16 *)&ctx->user_ip4)[1] << 16;
+	user_ip4 |= load_word(ctx->user_ip4, 0, sizeof(user_ip4));
+	user_ip4 |= load_word(ctx->user_ip4, 1, sizeof(user_ip4));
 	if (ctx->user_ip4 != user_ip4)
 		return 0;
 
diff --git a/tools/testing/selftests/bpf/progs/bind6_prog.c b/tools/testing/selftests/bpf/progs/bind6_prog.c
index d62cd9e9cf0ea..9c86c712348cf 100644
--- a/tools/testing/selftests/bpf/progs/bind6_prog.c
+++ b/tools/testing/selftests/bpf/progs/bind6_prog.c
@@ -12,6 +12,8 @@ 
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_endian.h>
 
+#include "bind_prog.h"
+
 #define SERV6_IP_0		0xfaceb00c /* face:b00c:1234:5678::abcd */
 #define SERV6_IP_1		0x12345678
 #define SERV6_IP_2		0x00000000
@@ -129,25 +131,25 @@  int bind_v6_prog(struct bpf_sock_addr *ctx)
 	// u8 narrow loads:
 	for (i = 0; i < 4; i++) {
 		user_ip6 = 0;
-		user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[0] << 0;
-		user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[1] << 8;
-		user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[2] << 16;
-		user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[3] << 24;
+		user_ip6 |= load_byte(ctx->user_ip6[i], 0, sizeof(user_ip6));
+		user_ip6 |= load_byte(ctx->user_ip6[i], 1, sizeof(user_ip6));
+		user_ip6 |= load_byte(ctx->user_ip6[i], 2, sizeof(user_ip6));
+		user_ip6 |= load_byte(ctx->user_ip6[i], 3, sizeof(user_ip6));
 		if (ctx->user_ip6[i] != user_ip6)
 			return 0;
 	}
 
 	user_port = 0;
-	user_port |= ((volatile __u8 *)&ctx->user_port)[0] << 0;
-	user_port |= ((volatile __u8 *)&ctx->user_port)[1] << 8;
+	user_port |= load_byte(ctx->user_port, 0, sizeof(user_port));
+	user_port |= load_byte(ctx->user_port, 1, sizeof(user_port));
 	if (ctx->user_port != user_port)
 		return 0;
 
 	// u16 narrow loads:
 	for (i = 0; i < 4; i++) {
 		user_ip6 = 0;
-		user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[0] << 0;
-		user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[1] << 16;
+		user_ip6 |= load_word(ctx->user_ip6[i], 0, sizeof(user_ip6));
+		user_ip6 |= load_word(ctx->user_ip6[i], 1, sizeof(user_ip6));
 		if (ctx->user_ip6[i] != user_ip6)
 			return 0;
 	}
diff --git a/tools/testing/selftests/bpf/progs/bind_prog.h b/tools/testing/selftests/bpf/progs/bind_prog.h
new file mode 100644
index 0000000000000..e830caa940c35
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bind_prog.h
@@ -0,0 +1,19 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __BIND_PROG_H__
+#define __BIND_PROG_H__
+
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#define load_byte(src, b, s) \
+	(((volatile __u8 *)&(src))[b] << 8 * b)
+#define load_word(src, w, s) \
+	(((volatile __u16 *)&(src))[w] << 16 * w)
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#define load_byte(src, b, s) \
+	(((volatile __u8 *)&(src))[(b) + (sizeof(src) - (s))] << 8 * ((s) - (b) - 1))
+#define load_word(src, w, s) \
+	(((volatile __u16 *)&(src))[w] << 16 * (((s) / 2) - (w) - 1))
+#else
+# error "Fix your compiler's __BYTE_ORDER__?!"
+#endif
+
+#endif