The core part of the selftest, i.e., the je <-> jmp cycle, mimics the
original sched-ext bpf program. The test will fail without the
previous patch.
I tried to create some cases for other potential cycles
(je <-> je, jmp <-> je and jmp <-> jmp) with similar pattern
to the test in this patch, but failed. So this patch
only contains one test for je <-> jmp cycle.
Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/verifier.c | 2 +
.../bpf/progs/verifier_jit_convergence.c | 128 ++++++++++++++++++
2 files changed, 130 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/verifier_jit_convergence.c
diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 80a90c627182..df398e714dff 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
@@ -39,6 +39,7 @@
#include "verifier_int_ptr.skel.h"
#include "verifier_iterating_callbacks.skel.h"
#include "verifier_jeq_infer_not_null.skel.h"
+#include "verifier_jit_convergence.skel.h"
#include "verifier_ld_ind.skel.h"
#include "verifier_ldsx.skel.h"
#include "verifier_leak_ptr.skel.h"
@@ -163,6 +164,7 @@ void test_verifier_helper_value_access(void) { RUN(verifier_helper_value_access
void test_verifier_int_ptr(void) { RUN(verifier_int_ptr); }
void test_verifier_iterating_callbacks(void) { RUN(verifier_iterating_callbacks); }
void test_verifier_jeq_infer_not_null(void) { RUN(verifier_jeq_infer_not_null); }
+void test_verifier_jit_convergence(void) { RUN(verifier_jit_convergence); }
void test_verifier_ld_ind(void) { RUN(verifier_ld_ind); }
void test_verifier_ldsx(void) { RUN(verifier_ldsx); }
void test_verifier_leak_ptr(void) { RUN(verifier_leak_ptr); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_jit_convergence.c b/tools/testing/selftests/bpf/progs/verifier_jit_convergence.c
new file mode 100644
index 000000000000..fdc4ccc83c7d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_jit_convergence.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+#if defined(__TARGET_ARCH_x86)
+
+struct value_t {
+ long long a[32];
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(max_entries, 1);
+ __type(key, long long);
+ __type(value, struct value_t);
+} map_hash SEC(".maps");
+
+SEC("socket")
+__description("bpf_jit_convergence je <-> jmp")
+__success __retval(0)
+__arch_x86_64
+__jited(" pushq %rbp")
+__naked void btf_jit_convergence_je_jmp(void)
+{
+ asm volatile (
+ "call %[bpf_get_prandom_u32];"
+ "if r0 == 0 goto l20_%=;"
+ "if r0 == 1 goto l21_%=;"
+ "if r0 == 2 goto l22_%=;"
+ "if r0 == 3 goto l23_%=;"
+ "if r0 == 4 goto l24_%=;"
+ "call %[bpf_get_prandom_u32];"
+ "call %[bpf_get_prandom_u32];"
+"l20_%=:"
+"l21_%=:"
+"l22_%=:"
+"l23_%=:"
+"l24_%=:"
+ "r1 = 0;"
+ "*(u64 *)(r10 - 8) = r1;"
+ "r2 = r10;"
+ "r2 += -8;"
+ "r1 = %[map_hash] ll;"
+ "call %[bpf_map_lookup_elem];"
+ "if r0 == 0 goto l1_%=;"
+ "r6 = r0;"
+ "call %[bpf_get_prandom_u32];"
+ "r7 = r0;"
+ "r5 = r6;"
+ "if r0 != 0x0 goto l12_%=;"
+ "call %[bpf_get_prandom_u32];"
+ "r1 = r0;"
+ "r2 = r6;"
+ "if r1 == 0x0 goto l0_%=;"
+"l9_%=:"
+ "r2 = *(u64 *)(r6 + 0x0);"
+ "r2 += 0x1;"
+ "*(u64 *)(r6 + 0x0) = r2;"
+ "goto l1_%=;"
+"l12_%=:"
+ "r1 = r7;"
+ "r1 += 0x98;"
+ "r2 = r5;"
+ "r2 += 0x90;"
+ "r2 = *(u32 *)(r2 + 0x0);"
+ "r3 = r7;"
+ "r3 &= 0x1;"
+ "r2 *= 0xa8;"
+ "if r3 == 0x0 goto l2_%=;"
+ "r1 += r2;"
+ "r1 -= r7;"
+ "r1 += 0x8;"
+ "if r1 <= 0xb20 goto l3_%=;"
+ "r1 = 0x0;"
+ "goto l4_%=;"
+"l3_%=:"
+ "r1 += r7;"
+"l4_%=:"
+ "if r1 == 0x0 goto l8_%=;"
+ "goto l9_%=;"
+"l2_%=:"
+ "r1 += r2;"
+ "r1 -= r7;"
+ "r1 += 0x10;"
+ "if r1 <= 0xb20 goto l6_%=;"
+ "r1 = 0x0;"
+ "goto l7_%=;"
+"l6_%=:"
+ "r1 += r7;"
+"l7_%=:"
+ "if r1 == 0x0 goto l8_%=;"
+ "goto l9_%=;"
+"l0_%=:"
+ "r1 = 0x3;"
+ "*(u64 *)(r10 - 0x10) = r1;"
+ "r2 = r1;"
+ "goto l1_%=;"
+"l8_%=:"
+ "r1 = r5;"
+ "r1 += 0x4;"
+ "r1 = *(u32 *)(r1 + 0x0);"
+ "*(u64 *)(r10 - 0x8) = r1;"
+"l1_%=:"
+ "r0 = 0;"
+ "exit;"
+ :
+ : __imm(bpf_get_prandom_u32),
+ __imm(bpf_map_lookup_elem),
+ __imm_addr(map_hash)
+ : __clobber_all);
+}
+
+#else
+
+SEC("socket")
+__description("non-x86 has no jit convergence issue, use a dummy test")
+__success
+int dummy_test(void)
+{
+ return 0;
+}
+
+#endif
+
+char _license[] SEC("license") = "GPL";
--
2.43.5
