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| author | Johan Almbladh <johan.almbladh@anyfinetworks.com> | 2021-09-14 12:18:41 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 21:16:26 +0300 |
| commit | e1ddaa5dcef63c8083cb2e3a8a4ea14a7fd04bc2 (patch) | |
| tree | ef1ffe29627280d2d68110aebc4a2955927ce534 /lib | |
| parent | 739b92765e0463cbb612d8e0efe3ac0fab70cafb (diff) | |
| download | linux-e1ddaa5dcef63c8083cb2e3a8a4ea14a7fd04bc2.tar.xz | |
bpf/tests: Fix error in tail call limit tests
[ Upstream commit 18935a72eb25525b655262579e1652362a3b29bb ]
This patch fixes an error in the tail call limit test that caused the
test to fail on for x86-64 JIT. Previously, the register R0 was used to
report the total number of tail calls made. However, after a tail call
fall-through, the value of the R0 register is undefined. Now, all tail
call error path tests instead use context state to store the count.
Fixes: 874be05f525e ("bpf, tests: Add tail call test suite")
Reported-by: Paul Chaignon <paul@cilium.io>
Reported-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: https://lore.kernel.org/bpf/20210914091842.4186267-14-johan.almbladh@anyfinetworks.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/test_bpf.c | 37 |
1 files changed, 27 insertions, 10 deletions
diff --git a/lib/test_bpf.c b/lib/test_bpf.c index 830a18ecffc8..68d125b409f2 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -8992,10 +8992,15 @@ static __init int test_bpf(void) struct tail_call_test { const char *descr; struct bpf_insn insns[MAX_INSNS]; + int flags; int result; int stack_depth; }; +/* Flags that can be passed to tail call test cases */ +#define FLAG_NEED_STATE BIT(0) +#define FLAG_RESULT_IN_STATE BIT(1) + /* * Magic marker used in test snippets for tail calls below. * BPF_LD/MOV to R2 and R2 with this immediate value is replaced @@ -9065,32 +9070,38 @@ static struct tail_call_test tail_call_tests[] = { { "Tail call error path, max count reached", .insns = { - BPF_ALU64_IMM(BPF_ADD, R1, 1), - BPF_ALU64_REG(BPF_MOV, R0, R1), + BPF_LDX_MEM(BPF_W, R2, R1, 0), + BPF_ALU64_IMM(BPF_ADD, R2, 1), + BPF_STX_MEM(BPF_W, R1, R2, 0), TAIL_CALL(0), BPF_EXIT_INSN(), }, - .result = MAX_TAIL_CALL_CNT + 1, + .flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE, + .result = (MAX_TAIL_CALL_CNT + 1 + 1) * MAX_TESTRUNS, }, { "Tail call error path, NULL target", .insns = { - BPF_ALU64_IMM(BPF_MOV, R0, -1), + BPF_LDX_MEM(BPF_W, R2, R1, 0), + BPF_ALU64_IMM(BPF_ADD, R2, 1), + BPF_STX_MEM(BPF_W, R1, R2, 0), TAIL_CALL(TAIL_CALL_NULL), - BPF_ALU64_IMM(BPF_MOV, R0, 1), BPF_EXIT_INSN(), }, - .result = 1, + .flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE, + .result = MAX_TESTRUNS, }, { "Tail call error path, index out of range", .insns = { - BPF_ALU64_IMM(BPF_MOV, R0, -1), + BPF_LDX_MEM(BPF_W, R2, R1, 0), + BPF_ALU64_IMM(BPF_ADD, R2, 1), + BPF_STX_MEM(BPF_W, R1, R2, 0), TAIL_CALL(TAIL_CALL_INVALID), - BPF_ALU64_IMM(BPF_MOV, R0, 1), BPF_EXIT_INSN(), }, - .result = 1, + .flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE, + .result = MAX_TESTRUNS, }, }; @@ -9196,6 +9207,8 @@ static __init int test_tail_calls(struct bpf_array *progs) for (i = 0; i < ARRAY_SIZE(tail_call_tests); i++) { struct tail_call_test *test = &tail_call_tests[i]; struct bpf_prog *fp = progs->ptrs[i]; + int *data = NULL; + int state = 0; u64 duration; int ret; @@ -9212,7 +9225,11 @@ static __init int test_tail_calls(struct bpf_array *progs) if (fp->jited) jit_cnt++; - ret = __run_one(fp, NULL, MAX_TESTRUNS, &duration); + if (test->flags & FLAG_NEED_STATE) + data = &state; + ret = __run_one(fp, data, MAX_TESTRUNS, &duration); + if (test->flags & FLAG_RESULT_IN_STATE) + ret = state; if (ret == test->result) { pr_cont("%lld PASS", duration); pass_cnt++; |