From 3ec2a0ed3fec4ec8b27d9b71fdcbc1c30d1542d3 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 30 Aug 2019 13:07:32 +0200 Subject: [PATCH] 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 Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_sysctl.c | 125 ++++++++++++++-------- 1 file 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 #include +#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; } -- 2.30.2