selftests/bpf: fix endianness issues in test_sysctl

A lot of test_sysctl sub-tests fail due to handling strings as a bunch
of immediate values in a little-endian-specific manner.

Fix by wrapping all immediates in bpf_ntohl and the new bpf_be64_to_cpu.

fixup_sysctl_value() dynamically writes an immediate, and thus should be
endianness-aware.  Implement this by simply memcpy()ing the raw
user-provided value, since testcase endianness and bpf program
endianness match.

Fixes: 1f5fa9ab6e2e ("selftests/bpf: Test BPF_CGROUP_SYSCTL")
Fixes: 9a1027e52535 ("selftests/bpf: Test file_pos field in bpf_sysctl ctx")
Fixes: 6041c67f28d8 ("selftests/bpf: Test bpf_sysctl_get_name helper")
Fixes: 11ff34f74e32 ("selftests/bpf: Test sysctl_get_current_value helper")
Fixes: 786047dd08de ("selftests/bpf: Test bpf_sysctl_{get,set}_new_value helpers")
Fixes: 8549ddc832d6 ("selftests/bpf: Test bpf_strtol and bpf_strtoul helpers")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 82 insertions, 43 deletions

diff --git a/tools/testing/selftests/bpf/test_sysctl.c b/tools/testing/selftests/bpf/test_sysctl.c
index 106644f7e73e..fc33ae36b760 100644
--- a/tools/testing/selftests/bpf/test_sysctl.c
+++ b/tools/testing/selftests/bpf/test_sysctl.c
@@ -13,6 +13,7 @@
 #include <bpf/bpf.h>
 #include <bpf/libbpf.h>
 
+#include "bpf_endian.h"
 #include "bpf_rlimit.h"
 #include "bpf_util.h"
 #include "cgroup_helpers.h"
@@ -214,7 +215,8 @@ static struct sysctl_test tests[] = {
 			/* if (ret == expected && */
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, sizeof("tcp_mem") - 1, 6),
 			/*     buf == "tcp_mem\0") */
-			BPF_LD_IMM64(BPF_REG_8, 0x006d656d5f706374ULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x7463705f6d656d00ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 2),
 
@@ -255,7 +257,8 @@ static struct sysctl_test tests[] = {
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 6),
 
 			/*     buf[0:7] == "tcp_me\0") */
-			BPF_LD_IMM64(BPF_REG_8, 0x00656d5f706374ULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x7463705f6d650000ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 2),
 
@@ -298,12 +301,14 @@ static struct sysctl_test tests[] = {
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 16, 14),
 
 			/*     buf[0:8] == "net/ipv4" && */
-			BPF_LD_IMM64(BPF_REG_8, 0x347670692f74656eULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x6e65742f69707634ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 10),
 
 			/*     buf[8:16] == "/tcp_mem" && */
-			BPF_LD_IMM64(BPF_REG_8, 0x6d656d5f7063742fULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x2f7463705f6d656dULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 8),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 6),
 
@@ -350,12 +355,14 @@ static struct sysctl_test tests[] = {
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 10),
 
 			/*     buf[0:8] == "net/ipv4" && */
-			BPF_LD_IMM64(BPF_REG_8, 0x347670692f74656eULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x6e65742f69707634ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 6),
 
 			/*     buf[8:16] == "/tcp_me\0") */
-			BPF_LD_IMM64(BPF_REG_8, 0x00656d5f7063742fULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x2f7463705f6d6500ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 8),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 2),
 
@@ -396,7 +403,8 @@ static struct sysctl_test tests[] = {
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 6),
 
 			/*     buf[0:8] == "net/ip\0") */
-			BPF_LD_IMM64(BPF_REG_8, 0x000070692f74656eULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x6e65742f69700000ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 2),
 
@@ -431,7 +439,8 @@ static struct sysctl_test tests[] = {
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 6, 6),
 
 			/*     buf[0:6] == "Linux\n\0") */
-			BPF_LD_IMM64(BPF_REG_8, 0x000a78756e694cULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x4c696e75780a0000ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 2),
 
@@ -469,7 +478,8 @@ static struct sysctl_test tests[] = {
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 6, 6),
 
 			/*     buf[0:6] == "Linux\n\0") */
-			BPF_LD_IMM64(BPF_REG_8, 0x000a78756e694cULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x4c696e75780a0000ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 2),
 
@@ -507,7 +517,8 @@ static struct sysctl_test tests[] = {
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 6),
 
 			/*     buf[0:6] == "Linux\0") */
-			BPF_LD_IMM64(BPF_REG_8, 0x000078756e694cULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x4c696e7578000000ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 2),
 
@@ -650,7 +661,8 @@ static struct sysctl_test tests[] = {
 
 			/*     buf[0:4] == "606\0") */
 			BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_7, 0),
-			BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 0x00363036, 2),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_9,
+				    bpf_ntohl(0x36303600), 2),
 
 			/* return DENY; */
 			BPF_MOV64_IMM(BPF_REG_0, 0),
@@ -685,17 +697,20 @@ static struct sysctl_test tests[] = {
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 23, 14),
 
 			/*     buf[0:8] == "3000000 " && */
-			BPF_LD_IMM64(BPF_REG_8, 0x2030303030303033ULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x3330303030303020ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 10),
 
 			/*     buf[8:16] == "4000000 " && */
-			BPF_LD_IMM64(BPF_REG_8, 0x2030303030303034ULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x3430303030303020ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 8),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 6),
 
 			/*     buf[16:24] == "6000000\0") */
-			BPF_LD_IMM64(BPF_REG_8, 0x0030303030303036ULL),
+			BPF_LD_IMM64(BPF_REG_8,
+				     bpf_be64_to_cpu(0x3630303030303000ULL)),
 			BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 16),
 			BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 2),
 
@@ -735,7 +750,8 @@ static struct sysctl_test tests[] = {
 
 			/*     buf[0:3] == "60\0") */
 			BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_7, 0),
-			BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 0x003036, 2),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_9,
+				    bpf_ntohl(0x36300000), 2),
 
 			/* return DENY; */
 			BPF_MOV64_IMM(BPF_REG_0, 0),
@@ -757,7 +773,8 @@ static struct sysctl_test tests[] = {
 			/* sysctl_set_new_value arg2 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, 0x00303036),
+			BPF_MOV64_IMM(BPF_REG_0,
+				      bpf_ntohl(0x36303000)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
@@ -791,7 +808,7 @@ static struct sysctl_test tests[] = {
 			/* sysctl_set_new_value arg2 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, FIXUP_SYSCTL_VALUE),
+			BPF_LD_IMM64(BPF_REG_0, FIXUP_SYSCTL_VALUE),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
@@ -825,8 +842,9 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, 0x00303036),
-			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+			BPF_MOV64_IMM(BPF_REG_0,
+				      bpf_ntohl(0x36303000)),
+			BPF_STX_MEM(BPF_W, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
 
@@ -869,7 +887,8 @@ static struct sysctl_test tests[] = {
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
 			/* "600 602\0" */
-			BPF_LD_IMM64(BPF_REG_0, 0x0032303620303036ULL),
+			BPF_LD_IMM64(BPF_REG_0,
+				     bpf_be64_to_cpu(0x3630302036303200ULL)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
 
@@ -937,7 +956,8 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, 0x00303036),
+			BPF_MOV64_IMM(BPF_REG_0,
+				      bpf_ntohl(0x36303000)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
@@ -969,8 +989,9 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, 0x00373730),
-			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+			BPF_MOV64_IMM(BPF_REG_0,
+				      bpf_ntohl(0x30373700)),
+			BPF_STX_MEM(BPF_W, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
 
@@ -1012,7 +1033,8 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, 0x00303036),
+			BPF_MOV64_IMM(BPF_REG_0,
+				      bpf_ntohl(0x36303000)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
@@ -1052,7 +1074,8 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, 0x090a0c0d),
+			BPF_MOV64_IMM(BPF_REG_0,
+				      bpf_ntohl(0x0d0c0a09)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
@@ -1092,7 +1115,9 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, 0x00362d0a), /* " -6\0" */
+			/* " -6\0" */
+			BPF_MOV64_IMM(BPF_REG_0,
+				      bpf_ntohl(0x0a2d3600)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
@@ -1132,8 +1157,10 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, 0x00362d0a), /* " -6\0" */
-			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+			/* " -6\0" */
+			BPF_MOV64_IMM(BPF_REG_0,
+				      bpf_ntohl(0x0a2d3600)),
+			BPF_STX_MEM(BPF_W, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
 
@@ -1175,8 +1202,10 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
-			BPF_MOV64_IMM(BPF_REG_0, 0x65667830), /* "0xfe" */
-			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+			/* "0xfe" */
+			BPF_MOV64_IMM(BPF_REG_0,
+				      bpf_ntohl(0x30786665)),
+			BPF_STX_MEM(BPF_W, BPF_REG_7, BPF_REG_0, 0),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
 
@@ -1218,11 +1247,14 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) 9223372036854775807 */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -24),
-			BPF_LD_IMM64(BPF_REG_0, 0x3032373333323239ULL),
+			BPF_LD_IMM64(BPF_REG_0,
+				     bpf_be64_to_cpu(0x3932323333373230ULL)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
-			BPF_LD_IMM64(BPF_REG_0, 0x3537373435383633ULL),
+			BPF_LD_IMM64(BPF_REG_0,
+				     bpf_be64_to_cpu(0x3336383534373735ULL)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 8),
-			BPF_LD_IMM64(BPF_REG_0, 0x0000000000373038ULL),
+			BPF_LD_IMM64(BPF_REG_0,
+				     bpf_be64_to_cpu(0x3830370000000000ULL)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 16),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
@@ -1266,11 +1298,14 @@ static struct sysctl_test tests[] = {
 			/* arg1 (buf) 9223372036854775808 */
 			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -24),
-			BPF_LD_IMM64(BPF_REG_0, 0x3032373333323239ULL),
+			BPF_LD_IMM64(BPF_REG_0,
+				     bpf_be64_to_cpu(0x3932323333373230ULL)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
-			BPF_LD_IMM64(BPF_REG_0, 0x3537373435383633ULL),
+			BPF_LD_IMM64(BPF_REG_0,
+				     bpf_be64_to_cpu(0x3336383534373735ULL)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 8),
-			BPF_LD_IMM64(BPF_REG_0, 0x0000000000383038ULL),
+			BPF_LD_IMM64(BPF_REG_0,
+				     bpf_be64_to_cpu(0x3830380000000000ULL)),
 			BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 16),
 
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
@@ -1344,20 +1379,24 @@ static size_t probe_prog_length(const struct bpf_insn *fp)
 static int fixup_sysctl_value(const char *buf, size_t buf_len,
 			      struct bpf_insn *prog, size_t insn_num)
 {
-	uint32_t value_num = 0;
+	union {
+		uint8_t raw[sizeof(uint64_t)];
+		uint64_t num;
+	} value = {};
 	uint8_t c, i;
 
-	if (buf_len > sizeof(value_num)) {
+	if (buf_len > sizeof(value)) {
 		log_err("Value is too big (%zd) to use in fixup", buf_len);
 		return -1;
 	}
-
-	for (i = 0; i < buf_len; ++i) {
-		c = buf[i];
-		value_num |= (c << i * 8);
+	if (prog[insn_num].code != (BPF_LD | BPF_DW | BPF_IMM)) {
+		log_err("Can fixup only BPF_LD_IMM64 insns");
+		return -1;
 	}
 
-	prog[insn_num].imm = value_num;
+	memcpy(value.raw, buf, buf_len);
+	prog[insn_num].imm = (uint32_t)value.num;
+	prog[insn_num + 1].imm = (uint32_t)(value.num >> 32);
 
 	return 0;
 }