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selftests/bpf: add verifier cgroup storage tests
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Add the following verifier tests to cover the cgroup storage
functionality:
1) valid access to the cgroup storage
2) invalid access: use regular hashmap instead of cgroup storage map
3) invalid access: use invalid map fd
4) invalid access: try access memory after the cgroup storage
5) invalid access: try access memory before the cgroup storage
6) invalid access: call get_local_storage() with non-zero flags

For tests 2)-6) check returned error strings.

Expected output:
  $ ./test_verifier
  #0/u add+sub+mul OK
  #0/p add+sub+mul OK
  #1/u DIV32 by 0, zero check 1 OK
  ...
  torvalds#280/p valid cgroup storage access OK
  torvalds#281/p invalid cgroup storage access 1 OK
  torvalds#282/p invalid cgroup storage access 2 OK
  torvalds#283/p invalid per-cgroup storage access 3 OK
  torvalds#284/p invalid cgroup storage access 4 OK
  torvalds#285/p invalid cgroup storage access 5 OK
  ...
  torvalds#649/p pass modified ctx pointer to helper, 2 OK
  torvalds#650/p pass modified ctx pointer to helper, 3 OK
  Summary: 901 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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@rgushchin @borkmann
rgushchin authored and borkmann committed Aug 2, 2018
1 parent f42ee09 commit d4c9f57
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Showing 2 changed files with 141 additions and 1 deletion.
2 changes: 2 additions & 0 deletions tools/testing/selftests/bpf/bpf_helpers.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -135,6 +135,8 @@ static int (*bpf_rc_keydown)(void *ctx, unsigned int protocol,
(void *) BPF_FUNC_rc_keydown;
static unsigned long long (*bpf_get_current_cgroup_id)(void) =
(void *) BPF_FUNC_get_current_cgroup_id;
static void *(*bpf_get_local_storage)(void *map, unsigned long long flags) =
(void *) BPF_FUNC_get_local_storage;

/* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions
Expand Down
140 changes: 139 additions & 1 deletion tools/testing/selftests/bpf/test_verifier.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,7 @@

#define MAX_INSNS BPF_MAXINSNS
#define MAX_FIXUPS 8
#define MAX_NR_MAPS 7
#define MAX_NR_MAPS 8
#define POINTER_VALUE 0xcafe4all
#define TEST_DATA_LEN 64

Expand All @@ -70,6 +70,7 @@ struct bpf_test {
int fixup_prog1[MAX_FIXUPS];
int fixup_prog2[MAX_FIXUPS];
int fixup_map_in_map[MAX_FIXUPS];
int fixup_cgroup_storage[MAX_FIXUPS];
const char *errstr;
const char *errstr_unpriv;
uint32_t retval;
Expand Down Expand Up @@ -4630,6 +4631,121 @@ static struct bpf_test tests[] = {
.result = REJECT,
.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
},
{
"valid cgroup storage access",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map1 = { 1 },
.result = REJECT,
.errstr = "cannot pass map_type 1 into func bpf_get_local_storage",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 1),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.result = REJECT,
.errstr = "fd 1 is not pointing to valid bpf_map",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid per-cgroup storage access 3",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 256),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "invalid access to map value, value_size=64 off=256 size=4",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 4",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, -2),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "invalid access to map value, value_size=64 off=-2 size=4",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 5",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 7),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "get_local_storage() doesn't support non-zero flags",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 6",
.insns = {
BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "get_local_storage() doesn't support non-zero flags",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"multiple registers share map_lookup_elem result",
.insns = {
Expand Down Expand Up @@ -12462,6 +12578,19 @@ static int create_map_in_map(void)
return outer_map_fd;
}

static int create_cgroup_storage(void)
{
int fd;

fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_STORAGE,
sizeof(struct bpf_cgroup_storage_key),
TEST_DATA_LEN, 0, 0);
if (fd < 0)
printf("Failed to create array '%s'!\n", strerror(errno));

return fd;
}

static char bpf_vlog[UINT_MAX >> 8];

static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
Expand All @@ -12474,6 +12603,7 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
int *fixup_prog1 = test->fixup_prog1;
int *fixup_prog2 = test->fixup_prog2;
int *fixup_map_in_map = test->fixup_map_in_map;
int *fixup_cgroup_storage = test->fixup_cgroup_storage;

if (test->fill_helper)
test->fill_helper(test);
Expand Down Expand Up @@ -12541,6 +12671,14 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
fixup_map_in_map++;
} while (*fixup_map_in_map);
}

if (*fixup_cgroup_storage) {
map_fds[7] = create_cgroup_storage();
do {
prog[*fixup_cgroup_storage].imm = map_fds[7];
fixup_cgroup_storage++;
} while (*fixup_cgroup_storage);
}
}

static void do_test_single(struct bpf_test *test, bool unpriv,
Expand Down

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