On Wed, Aug 28, 2019 at 6:22 AM Ilya Leoshkevich <iii@xxxxxxxxxxxxx> wrote:
>
> 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.
>
> Also, sometimes tests fail because sysctl() unexpectedly succeeds with
> an inappropriate "Unexpected failure" message and a random errno. Zero
> out errno before calling sysctl() and replace the message with
> "Unexpected success".
>
> 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@xxxxxxxxxxxxx>
> ---
> tools/testing/selftests/bpf/test_sysctl.c | 130 ++++++++++++++--------
> 1 file changed, 85 insertions(+), 45 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/test_sysctl.c b/tools/testing/selftests/bpf/test_sysctl.c
> index a3bebd7c68dd..b8c6e31645cb 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"
> @@ -100,7 +101,7 @@ static struct sysctl_test tests[] = {
> .descr = "ctx:write sysctl:write read ok",
> .insns = {
> /* If (write) */
> - BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_1,
> + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
I didn't find explanation for this change in the commit log. Is this a typo, or
a real fix?
> offsetof(struct bpf_sysctl, write)),
> BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 1, 2),
>
> @@ -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 = {};
This change doesn't match the description in the changelog.
> 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;
> }
> @@ -1499,6 +1538,7 @@ static int run_test_case(int cgfd, struct sysctl_test *test)
> goto err;
> }
>
> + errno = 0;
> if (access_sysctl(sysctl_path, test) == -1) {
> if (test->result == OP_EPERM && errno == EPERM)
> goto out;
> @@ -1507,7 +1547,7 @@ static int run_test_case(int cgfd, struct sysctl_test *test)
> }
>
> if (test->result != SUCCESS) {
> - log_err("Unexpected failure");
> + log_err("Unexpected success");
> goto err;
> }
>
> --
> 2.21.0
>
