Commit d65f3767 authored by Leon Hwang's avatar Leon Hwang Committed by Alexei Starovoitov
Browse files

bpf: Fix tailcall cases in test_bpf 



Since f663a03c ("bpf, x64: Remove tail call detection"),
tail_call_reachable won't be detected in x86 JIT. And, tail_call_reachable
is provided by verifier.

Therefore, in test_bpf, the tail_call_reachable must be provided in test
cases before running.

Fix and test:

[  174.828662] test_bpf: #0 Tail call leaf jited:1 170 PASS
[  174.829574] test_bpf: #1 Tail call 2 jited:1 244 PASS
[  174.830363] test_bpf: #2 Tail call 3 jited:1 296 PASS
[  174.830924] test_bpf: #3 Tail call 4 jited:1 719 PASS
[  174.831863] test_bpf: #4 Tail call load/store leaf jited:1 197 PASS
[  174.832240] test_bpf: #5 Tail call load/store jited:1 326 PASS
[  174.832240] test_bpf: #6 Tail call error path, max count reached jited:1 2214 PASS
[  174.835713] test_bpf: #7 Tail call count preserved across function calls jited:1 609751 PASS
[  175.446098] test_bpf: #8 Tail call error path, NULL target jited:1 472 PASS
[  175.447597] test_bpf: #9 Tail call error path, index out of range jited:1 206 PASS
[  175.448833] test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed]

Reported-by: default avatarkernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202406251415.c51865bc-oliver.sang@intel.com


Fixes: f663a03c ("bpf, x64: Remove tail call detection")
Signed-off-by: default avatarLeon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20240625145351.40072-1-hffilwlqm@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent c73a9683

lib/test_bpf.c

+10 −0
Original line number Diff line number Diff line
@@ -15198,6 +15198,7 @@ struct tail_call_test { 
	int flags;

	int result;

	int stack_depth;

	bool has_tail_call;

};



/* Flags that can be passed to tail call test cases */
@@ -15273,6 +15274,7 @@ static struct tail_call_test tail_call_tests[] = { 
			BPF_EXIT_INSN(),

		},

		.result = 3,

		.has_tail_call = true,

	},

	{

		"Tail call 3",
@@ -15283,6 +15285,7 @@ static struct tail_call_test tail_call_tests[] = { 
			BPF_EXIT_INSN(),

		},

		.result = 6,

		.has_tail_call = true,

	},

	{

		"Tail call 4",
@@ -15293,6 +15296,7 @@ static struct tail_call_test tail_call_tests[] = { 
			BPF_EXIT_INSN(),

		},

		.result = 10,

		.has_tail_call = true,

	},

	{

		"Tail call load/store leaf",
@@ -15323,6 +15327,7 @@ static struct tail_call_test tail_call_tests[] = { 
		},

		.result = 0,

		.stack_depth = 16,

		.has_tail_call = true,

	},

	{

		"Tail call error path, max count reached",
@@ -15335,6 +15340,7 @@ static struct tail_call_test tail_call_tests[] = { 
		},

		.flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE,

		.result = (MAX_TAIL_CALL_CNT + 1) * MAX_TESTRUNS,

		.has_tail_call = true,

	},

	{

		"Tail call count preserved across function calls",
@@ -15357,6 +15363,7 @@ static struct tail_call_test tail_call_tests[] = { 
		.stack_depth = 8,

		.flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE,

		.result = (MAX_TAIL_CALL_CNT + 1) * MAX_TESTRUNS,

		.has_tail_call = true,

	},

	{

		"Tail call error path, NULL target",
@@ -15369,6 +15376,7 @@ static struct tail_call_test tail_call_tests[] = { 
		},

		.flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE,

		.result = MAX_TESTRUNS,

		.has_tail_call = true,

	},

	{

		"Tail call error path, index out of range",
@@ -15381,6 +15389,7 @@ static struct tail_call_test tail_call_tests[] = { 
		},

		.flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE,

		.result = MAX_TESTRUNS,

		.has_tail_call = true,

	},

};
@@ -15430,6 +15439,7 @@ static __init int prepare_tail_call_tests(struct bpf_array **pprogs) 
		fp->len = len;

		fp->type = BPF_PROG_TYPE_SOCKET_FILTER;

		fp->aux->stack_depth = test->stack_depth;

		fp->aux->tail_call_reachable = test->has_tail_call;

		memcpy(fp->insnsi, test->insns, len * sizeof(struct bpf_insn));



		/* Relocate runtime tail call offsets and addresses */