mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-29 05:44:11 +00:00
Code Issues Releases Wiki Activity
linux-stable/tools/testing/selftests/bpf/prog_tests/tailcalls.c
Daniel Borkmann dbd7eb14e0 bpf, selftests: Replicate tailcall limit test for indirect call case 
The tailcall_3 test program uses bpf_tail_call_static() where the JIT
would patch a direct jump. Add a new tailcall_6 test program replicating
exactly the same test just ensuring that bpf_tail_call() uses a map
index where the verifier cannot make assumptions this time.

In other words, this will now cover both on x86-64 JIT, meaning, JIT
images with emit_bpf_tail_call_direct() emission as well as JIT images
with emit_bpf_tail_call_indirect() emission.

  # echo 1 > /proc/sys/net/core/bpf_jit_enable
  # ./test_progs -t tailcalls
  #136/1 tailcalls/tailcall_1:OK
  #136/2 tailcalls/tailcall_2:OK
  #136/3 tailcalls/tailcall_3:OK
  #136/4 tailcalls/tailcall_4:OK
  #136/5 tailcalls/tailcall_5:OK
  #136/6 tailcalls/tailcall_6:OK
  #136/7 tailcalls/tailcall_bpf2bpf_1:OK
  #136/8 tailcalls/tailcall_bpf2bpf_2:OK
  #136/9 tailcalls/tailcall_bpf2bpf_3:OK
  #136/10 tailcalls/tailcall_bpf2bpf_4:OK
  #136/11 tailcalls/tailcall_bpf2bpf_5:OK
  #136 tailcalls:OK
  Summary: 1/11 PASSED, 0 SKIPPED, 0 FAILED

  # echo 0 > /proc/sys/net/core/bpf_jit_enable
  # ./test_progs -t tailcalls
  #136/1 tailcalls/tailcall_1:OK
  #136/2 tailcalls/tailcall_2:OK
  #136/3 tailcalls/tailcall_3:OK
  #136/4 tailcalls/tailcall_4:OK
  #136/5 tailcalls/tailcall_5:OK
  #136/6 tailcalls/tailcall_6:OK
  [...]

For interpreter, the tailcall_1-6 tests are passing as well. The later
tailcall_bpf2bpf_* are failing due lack of bpf2bpf + tailcall support
in interpreter, so this is expected.

Also, manual inspection shows that both loaded programs from tailcall_3
and tailcall_6 test case emit the expected opcodes:

* tailcall_3 disasm, emit_bpf_tail_call_direct():

  [...]
   b:   push   %rax
   c:   push   %rbx
   d:   push   %r13
   f:   mov    %rdi,%rbx
  12:   movabs $0xffff8d3f5afb0200,%r13
  1c:   mov    %rbx,%rdi
  1f:   mov    %r13,%rsi
  22:   xor    %edx,%edx                 _
  24:   mov    -0x4(%rbp),%eax          |  limit check
  2a:   cmp    $0x20,%eax               |
  2d:   ja     0x0000000000000046       |
  2f:   add    $0x1,%eax                |
  32:   mov    %eax,-0x4(%rbp)          |_
  38:   nopl   0x0(%rax,%rax,1)
  3d:   pop    %r13
  3f:   pop    %rbx
  40:   pop    %rax
  41:   jmpq   0xffffffffffffe377
  [...]

* tailcall_6 disasm, emit_bpf_tail_call_indirect():

  [...]
  47:   movabs $0xffff8d3f59143a00,%rsi
  51:   mov    %edx,%edx
  53:   cmp    %edx,0x24(%rsi)
  56:   jbe    0x0000000000000093        _
  58:   mov    -0x4(%rbp),%eax          |  limit check
  5e:   cmp    $0x20,%eax               |
  61:   ja     0x0000000000000093       |
  63:   add    $0x1,%eax                |
  66:   mov    %eax,-0x4(%rbp)          |_
  6c:   mov    0x110(%rsi,%rdx,8),%rcx
  74:   test   %rcx,%rcx
  77:   je     0x0000000000000093
  79:   pop    %rax
  7a:   mov    0x30(%rcx),%rcx
  7e:   add    $0xb,%rcx
  82:   callq  0x000000000000008e
  87:   pause
  89:   lfence
  8c:   jmp    0x0000000000000087
  8e:   mov    %rcx,(%rsp)
  92:   retq
  [...]

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Acked-by: Paul Chaignon <paul@cilium.io>
Link: https://lore.kernel.org/bpf/CAM1=_QRyRVCODcXo_Y6qOm1iT163HoiSj8U2pZ8Rj3hzMTT=HQ@mail.gmail.com
Link: https://lore.kernel.org/bpf/20210910091900.16119-1-daniel@iogearbox.net
2021-09-13 14:52:22 -07:00

850 lines
23 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include <network_helpers.h>
/* test_tailcall_1 checks basic functionality by patching multiple locations
* in a single program for a single tail call slot with nop->jmp, jmp->nop
* and jmp->jmp rewrites. Also checks for nop->nop.
*/
static void test_tailcall_1(void)
{
int err, map_fd, prog_fd, main_fd, i, j;
struct bpf_map *prog_array;
struct bpf_program *prog;
struct bpf_object *obj;
__u32 retval, duration;
char prog_name[32];
char buff[128] = {};
err = bpf_prog_load("tailcall1.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
&prog_fd);
if (CHECK_FAIL(err))
return;
prog = bpf_object__find_program_by_title(obj, "classifier");
if (CHECK_FAIL(!prog))
goto out;
main_fd = bpf_program__fd(prog);
if (CHECK_FAIL(main_fd < 0))
goto out;
prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
if (CHECK_FAIL(!prog_array))
goto out;
map_fd = bpf_map__fd(prog_array);
if (CHECK_FAIL(map_fd < 0))
goto out;
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
}
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != i, "tailcall",
"err %d errno %d retval %d\n", err, errno, retval);
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
}
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 3, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
}
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
j = bpf_map__def(prog_array)->max_entries - 1 - i;
snprintf(prog_name, sizeof(prog_name), "classifier/%i", j);
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
}
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
j = bpf_map__def(prog_array)->max_entries - 1 - i;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != j, "tailcall",
"err %d errno %d retval %d\n", err, errno, retval);
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
}
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 3, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err >= 0 || errno != ENOENT))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 3, "tailcall",
"err %d errno %d retval %d\n", err, errno, retval);
}
out:
bpf_object__close(obj);
}
/* test_tailcall_2 checks that patching multiple programs for a single
* tail call slot works. It also jumps through several programs and tests
* the tail call limit counter.
*/
static void test_tailcall_2(void)
{
int err, map_fd, prog_fd, main_fd, i;
struct bpf_map *prog_array;
struct bpf_program *prog;
struct bpf_object *obj;
__u32 retval, duration;
char prog_name[32];
char buff[128] = {};
err = bpf_prog_load("tailcall2.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
&prog_fd);
if (CHECK_FAIL(err))
return;
prog = bpf_object__find_program_by_title(obj, "classifier");
if (CHECK_FAIL(!prog))
goto out;
main_fd = bpf_program__fd(prog);
if (CHECK_FAIL(main_fd < 0))
goto out;
prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
if (CHECK_FAIL(!prog_array))
goto out;
map_fd = bpf_map__fd(prog_array);
if (CHECK_FAIL(map_fd < 0))
goto out;
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
}
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 2, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
i = 2;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 1, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
i = 0;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 3, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
out:
bpf_object__close(obj);
}
static void test_tailcall_count(const char *which)
{
int err, map_fd, prog_fd, main_fd, data_fd, i, val;
struct bpf_map *prog_array, *data_map;
struct bpf_program *prog;
struct bpf_object *obj;
__u32 retval, duration;
char buff[128] = {};
err = bpf_prog_load(which, BPF_PROG_TYPE_SCHED_CLS, &obj,
&prog_fd);
if (CHECK_FAIL(err))
return;
prog = bpf_object__find_program_by_title(obj, "classifier");
if (CHECK_FAIL(!prog))
goto out;
main_fd = bpf_program__fd(prog);
if (CHECK_FAIL(main_fd < 0))
goto out;
prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
if (CHECK_FAIL(!prog_array))
goto out;
map_fd = bpf_map__fd(prog_array);
if (CHECK_FAIL(map_fd < 0))
goto out;
prog = bpf_object__find_program_by_title(obj, "classifier/0");
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
i = 0;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 1, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
return;
data_fd = bpf_map__fd(data_map);
if (CHECK_FAIL(map_fd < 0))
return;
i = 0;
err = bpf_map_lookup_elem(data_fd, &i, &val);
CHECK(err || val != 33, "tailcall count", "err %d errno %d count %d\n",
err, errno, val);
i = 0;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
out:
bpf_object__close(obj);
}
/* test_tailcall_3 checks that the count value of the tail call limit
* enforcement matches with expectations. JIT uses direct jump.
*/
static void test_tailcall_3(void)
{
test_tailcall_count("tailcall3.o");
}
/* test_tailcall_6 checks that the count value of the tail call limit
* enforcement matches with expectations. JIT uses indirect jump.
*/
static void test_tailcall_6(void)
{
test_tailcall_count("tailcall6.o");
}
/* test_tailcall_4 checks that the kernel properly selects indirect jump
* for the case where the key is not known. Latter is passed via global
* data to select different targets we can compare return value of.
*/
static void test_tailcall_4(void)
{
int err, map_fd, prog_fd, main_fd, data_fd, i;
struct bpf_map *prog_array, *data_map;
struct bpf_program *prog;
struct bpf_object *obj;
__u32 retval, duration;
static const int zero = 0;
char buff[128] = {};
char prog_name[32];
err = bpf_prog_load("tailcall4.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
&prog_fd);
if (CHECK_FAIL(err))
return;
prog = bpf_object__find_program_by_title(obj, "classifier");
if (CHECK_FAIL(!prog))
goto out;
main_fd = bpf_program__fd(prog);
if (CHECK_FAIL(main_fd < 0))
goto out;
prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
if (CHECK_FAIL(!prog_array))
goto out;
map_fd = bpf_map__fd(prog_array);
if (CHECK_FAIL(map_fd < 0))
goto out;
data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
return;
data_fd = bpf_map__fd(data_map);
if (CHECK_FAIL(map_fd < 0))
return;
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
}
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
err = bpf_map_update_elem(data_fd, &zero, &i, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != i, "tailcall",
"err %d errno %d retval %d\n", err, errno, retval);
}
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
err = bpf_map_update_elem(data_fd, &zero, &i, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 3, "tailcall",
"err %d errno %d retval %d\n", err, errno, retval);
}
out:
bpf_object__close(obj);
}
/* test_tailcall_5 probes similarly to test_tailcall_4 that the kernel generates
* an indirect jump when the keys are const but different from different branches.
*/
static void test_tailcall_5(void)
{
int err, map_fd, prog_fd, main_fd, data_fd, i, key[] = { 1111, 1234, 5678 };
struct bpf_map *prog_array, *data_map;
struct bpf_program *prog;
struct bpf_object *obj;
__u32 retval, duration;
static const int zero = 0;
char buff[128] = {};
char prog_name[32];
err = bpf_prog_load("tailcall5.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
&prog_fd);
if (CHECK_FAIL(err))
return;
prog = bpf_object__find_program_by_title(obj, "classifier");
if (CHECK_FAIL(!prog))
goto out;
main_fd = bpf_program__fd(prog);
if (CHECK_FAIL(main_fd < 0))
goto out;
prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
if (CHECK_FAIL(!prog_array))
goto out;
map_fd = bpf_map__fd(prog_array);
if (CHECK_FAIL(map_fd < 0))
goto out;
data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
return;
data_fd = bpf_map__fd(data_map);
if (CHECK_FAIL(map_fd < 0))
return;
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
}
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
err = bpf_map_update_elem(data_fd, &zero, &key[i], BPF_ANY);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != i, "tailcall",
"err %d errno %d retval %d\n", err, errno, retval);
}
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
err = bpf_map_update_elem(data_fd, &zero, &key[i], BPF_ANY);
if (CHECK_FAIL(err))
goto out;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 3, "tailcall",
"err %d errno %d retval %d\n", err, errno, retval);
}
out:
bpf_object__close(obj);
}
/* test_tailcall_bpf2bpf_1 purpose is to make sure that tailcalls are working
* correctly in correlation with BPF subprograms
*/
static void test_tailcall_bpf2bpf_1(void)
{
int err, map_fd, prog_fd, main_fd, i;
struct bpf_map *prog_array;
struct bpf_program *prog;
struct bpf_object *obj;
__u32 retval, duration;
char prog_name[32];
err = bpf_prog_load("tailcall_bpf2bpf1.o", BPF_PROG_TYPE_SCHED_CLS,
&obj, &prog_fd);
if (CHECK_FAIL(err))
return;
prog = bpf_object__find_program_by_title(obj, "classifier");
if (CHECK_FAIL(!prog))
goto out;
main_fd = bpf_program__fd(prog);
if (CHECK_FAIL(main_fd < 0))
goto out;
prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
if (CHECK_FAIL(!prog_array))
goto out;
map_fd = bpf_map__fd(prog_array);
if (CHECK_FAIL(map_fd < 0))
goto out;
/* nop -> jmp */
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
}
err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
0, &retval, &duration);
CHECK(err || retval != 1, "tailcall",
"err %d errno %d retval %d\n", err, errno, retval);
/* jmp -> nop, call subprog that will do tailcall */
i = 1;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
0, &retval, &duration);
CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
/* make sure that subprog can access ctx and entry prog that
* called this subprog can properly return
*/
i = 0;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
0, &retval, &duration);
CHECK(err || retval != sizeof(pkt_v4) * 2,
"tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
out:
bpf_object__close(obj);
}
/* test_tailcall_bpf2bpf_2 checks that the count value of the tail call limit
* enforcement matches with expectations when tailcall is preceded with
* bpf2bpf call.
*/
static void test_tailcall_bpf2bpf_2(void)
{
int err, map_fd, prog_fd, main_fd, data_fd, i, val;
struct bpf_map *prog_array, *data_map;
struct bpf_program *prog;
struct bpf_object *obj;
__u32 retval, duration;
char buff[128] = {};
err = bpf_prog_load("tailcall_bpf2bpf2.o", BPF_PROG_TYPE_SCHED_CLS,
&obj, &prog_fd);
if (CHECK_FAIL(err))
return;
prog = bpf_object__find_program_by_title(obj, "classifier");
if (CHECK_FAIL(!prog))
goto out;
main_fd = bpf_program__fd(prog);
if (CHECK_FAIL(main_fd < 0))
goto out;
prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
if (CHECK_FAIL(!prog_array))
goto out;
map_fd = bpf_map__fd(prog_array);
if (CHECK_FAIL(map_fd < 0))
goto out;
prog = bpf_object__find_program_by_title(obj, "classifier/0");
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
i = 0;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 1, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
return;
data_fd = bpf_map__fd(data_map);
if (CHECK_FAIL(map_fd < 0))
return;
i = 0;
err = bpf_map_lookup_elem(data_fd, &i, &val);
CHECK(err || val != 33, "tailcall count", "err %d errno %d count %d\n",
err, errno, val);
i = 0;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
&duration, &retval, NULL);
CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
out:
bpf_object__close(obj);
}
/* test_tailcall_bpf2bpf_3 checks that non-trivial amount of stack (up to
* 256 bytes) can be used within bpf subprograms that have the tailcalls
* in them
*/
static void test_tailcall_bpf2bpf_3(void)
{
int err, map_fd, prog_fd, main_fd, i;
struct bpf_map *prog_array;
struct bpf_program *prog;
struct bpf_object *obj;
__u32 retval, duration;
char prog_name[32];
err = bpf_prog_load("tailcall_bpf2bpf3.o", BPF_PROG_TYPE_SCHED_CLS,
&obj, &prog_fd);
if (CHECK_FAIL(err))
return;
prog = bpf_object__find_program_by_title(obj, "classifier");
if (CHECK_FAIL(!prog))
goto out;
main_fd = bpf_program__fd(prog);
if (CHECK_FAIL(main_fd < 0))
goto out;
prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
if (CHECK_FAIL(!prog_array))
goto out;
map_fd = bpf_map__fd(prog_array);
if (CHECK_FAIL(map_fd < 0))
goto out;
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
}
err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
&duration, &retval, NULL);
CHECK(err || retval != sizeof(pkt_v4) * 3,
"tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
i = 1;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
&duration, &retval, NULL);
CHECK(err || retval != sizeof(pkt_v4),
"tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
i = 0;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
&duration, &retval, NULL);
CHECK(err || retval != sizeof(pkt_v4) * 2,
"tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
out:
bpf_object__close(obj);
}
#include "tailcall_bpf2bpf4.skel.h"
/* test_tailcall_bpf2bpf_4 checks that tailcall counter is correctly preserved
* across tailcalls combined with bpf2bpf calls. for making sure that tailcall
* counter behaves correctly, bpf program will go through following flow:
*
* entry -> entry_subprog -> tailcall0 -> bpf_func0 -> subprog0 ->
* -> tailcall1 -> bpf_func1 -> subprog1 -> tailcall2 -> bpf_func2 ->
* subprog2 [here bump global counter] --------^
*
* We go through first two tailcalls and start counting from the subprog2 where
* the loop begins. At the end of the test make sure that the global counter is
* equal to 31, because tailcall counter includes the first two tailcalls
* whereas global counter is incremented only on loop presented on flow above.
*
* The noise parameter is used to insert bpf_map_update calls into the logic
* to force verifier to patch instructions. This allows us to ensure jump
* logic remains correct with instruction movement.
*/
static void test_tailcall_bpf2bpf_4(bool noise)
{
int err, map_fd, prog_fd, main_fd, data_fd, i;
struct tailcall_bpf2bpf4__bss val;
struct bpf_map *prog_array, *data_map;
struct bpf_program *prog;
struct bpf_object *obj;
__u32 retval, duration;
char prog_name[32];
err = bpf_prog_load("tailcall_bpf2bpf4.o", BPF_PROG_TYPE_SCHED_CLS,
&obj, &prog_fd);
if (CHECK_FAIL(err))
return;
prog = bpf_object__find_program_by_title(obj, "classifier");
if (CHECK_FAIL(!prog))
goto out;
main_fd = bpf_program__fd(prog);
if (CHECK_FAIL(main_fd < 0))
goto out;
prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
if (CHECK_FAIL(!prog_array))
goto out;
map_fd = bpf_map__fd(prog_array);
if (CHECK_FAIL(map_fd < 0))
goto out;
for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK_FAIL(!prog))
goto out;
prog_fd = bpf_program__fd(prog);
if (CHECK_FAIL(prog_fd < 0))
goto out;
err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
}
data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
return;
data_fd = bpf_map__fd(data_map);
if (CHECK_FAIL(map_fd < 0))
return;
i = 0;
val.noise = noise;
val.count = 0;
err = bpf_map_update_elem(data_fd, &i, &val, BPF_ANY);
if (CHECK_FAIL(err))
goto out;
err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0,
&duration, &retval, NULL);
CHECK(err || retval != sizeof(pkt_v4) * 3, "tailcall", "err %d errno %d retval %d\n",
err, errno, retval);
i = 0;
err = bpf_map_lookup_elem(data_fd, &i, &val);
CHECK(err || val.count != 31, "tailcall count", "err %d errno %d count %d\n",
err, errno, val.count);
out:
bpf_object__close(obj);
}
void test_tailcalls(void)
{
if (test__start_subtest("tailcall_1"))
test_tailcall_1();
if (test__start_subtest("tailcall_2"))
test_tailcall_2();
if (test__start_subtest("tailcall_3"))
test_tailcall_3();
if (test__start_subtest("tailcall_4"))
test_tailcall_4();
if (test__start_subtest("tailcall_5"))
test_tailcall_5();
if (test__start_subtest("tailcall_6"))
test_tailcall_6();
if (test__start_subtest("tailcall_bpf2bpf_1"))
test_tailcall_bpf2bpf_1();
if (test__start_subtest("tailcall_bpf2bpf_2"))
test_tailcall_bpf2bpf_2();
if (test__start_subtest("tailcall_bpf2bpf_3"))
test_tailcall_bpf2bpf_3();
if (test__start_subtest("tailcall_bpf2bpf_4"))
test_tailcall_bpf2bpf_4(false);
if (test__start_subtest("tailcall_bpf2bpf_5"))
test_tailcall_bpf2bpf_4(true);
}
Reference in a new issue View git blame Copy permalink