From: Martin KaFai Lau <martin.lau@linux.dev>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Eduard Zingerman <eddyz87@gmail.com>,
Yonghong Song <yonghong.song@linux.dev>,
Amery Hung <ameryhung@gmail.com>,
kernel-team@meta.com
Subject: [PATCH v3 bpf-next 8/9] selftests/bpf: A pro/epilogue test when the main prog jumps back to the 1st insn
Date: Tue, 27 Aug 2024 11:16:44 -0700 [thread overview]
Message-ID: <20240827181647.847890-9-martin.lau@linux.dev> (raw)
In-Reply-To: <20240827181647.847890-1-martin.lau@linux.dev>
From: Martin KaFai Lau <martin.lau@kernel.org>
This patch adds a pro/epilogue test when the main prog has a goto insn
that goes back to the very first instruction of the prog. It is
to test the correctness of the adjust_jmp_off(prog, 0, delta)
after the verifier has applied the prologue and/or epilogue patch.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
.../selftests/bpf/prog_tests/pro_epilogue.c | 2 +
.../bpf/progs/pro_epilogue_goto_start.c | 149 ++++++++++++++++++
2 files changed, 151 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/pro_epilogue_goto_start.c
diff --git a/tools/testing/selftests/bpf/prog_tests/pro_epilogue.c b/tools/testing/selftests/bpf/prog_tests/pro_epilogue.c
index 98de677c55a9..b2e467cf15fe 100644
--- a/tools/testing/selftests/bpf/prog_tests/pro_epilogue.c
+++ b/tools/testing/selftests/bpf/prog_tests/pro_epilogue.c
@@ -5,6 +5,7 @@
#include "pro_epilogue_subprog.skel.h"
#include "pro_epilogue_kfunc.skel.h"
#include "epilogue_tailcall.skel.h"
+#include "pro_epilogue_goto_start.skel.h"
struct st_ops_args {
int a;
@@ -45,6 +46,7 @@ void test_pro_epilogue(void)
{
RUN_TESTS(pro_epilogue_subprog);
RUN_TESTS(pro_epilogue_kfunc);
+ RUN_TESTS(pro_epilogue_goto_start);
if (test__start_subtest("tailcall"))
test_tailcall();
}
diff --git a/tools/testing/selftests/bpf/progs/pro_epilogue_goto_start.c b/tools/testing/selftests/bpf/progs/pro_epilogue_goto_start.c
new file mode 100644
index 000000000000..0ddc646cc24b
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/pro_epilogue_goto_start.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
+
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include "bpf_misc.h"
+#include "../bpf_testmod/bpf_testmod.h"
+#include "../bpf_testmod/bpf_testmod_kfunc.h"
+
+char _license[] SEC("license") = "GPL";
+
+__success
+/* prologue */
+__xlated("0: r6 = *(u64 *)(r1 +0)")
+__xlated("1: r7 = *(u32 *)(r6 +0)")
+__xlated("2: w7 += 1000")
+__xlated("3: *(u32 *)(r6 +0) = r7")
+/* main prog */
+__xlated("4: if r1 == 0x0 goto pc+5")
+__xlated("5: if r1 == 0x1 goto pc+2")
+__xlated("6: r1 = 1")
+__xlated("7: goto pc-3")
+__xlated("8: r1 = 0")
+__xlated("9: goto pc-6")
+__xlated("10: r0 = 0")
+__xlated("11: exit")
+SEC("struct_ops/test_prologue_goto_start")
+__naked int test_prologue_goto_start(void)
+{
+ asm volatile (
+ "if r1 == 0 goto +5;"
+ "if r1 == 1 goto +2;"
+ "r1 = 1;"
+ "goto -3;"
+ "r1 = 0;"
+ "goto -6;"
+ "r0 = 0;"
+ "exit;"
+ ::: __clobber_all);
+}
+
+__success
+/* save __u64 *ctx to stack */
+__xlated("0: *(u64 *)(r10 -8) = r1")
+/* main prog */
+__xlated("1: if r1 == 0x0 goto pc+5")
+__xlated("2: if r1 == 0x1 goto pc+2")
+__xlated("3: r1 = 1")
+__xlated("4: goto pc-3")
+__xlated("5: r1 = 0")
+__xlated("6: goto pc-6")
+__xlated("7: r0 = 0")
+/* epilogue */
+__xlated("8: r1 = *(u64 *)(r10 -8)")
+__xlated("9: r1 = *(u64 *)(r1 +0)")
+__xlated("10: r6 = *(u32 *)(r1 +0)")
+__xlated("11: w6 += 10000")
+__xlated("12: *(u32 *)(r1 +0) = r6")
+__xlated("13: w0 = w6")
+__xlated("14: w0 *= 2")
+__xlated("15: exit")
+SEC("struct_ops/test_epilogue_goto_start")
+__naked int test_epilogue_goto_start(void)
+{
+ asm volatile (
+ "if r1 == 0 goto +5;"
+ "if r1 == 1 goto +2;"
+ "r1 = 1;"
+ "goto -3;"
+ "r1 = 0;"
+ "goto -6;"
+ "r0 = 0;"
+ "exit;"
+ ::: __clobber_all);
+}
+
+__success
+/* prologue */
+__xlated("0: r6 = *(u64 *)(r1 +0)")
+__xlated("1: r7 = *(u32 *)(r6 +0)")
+__xlated("2: w7 += 1000")
+__xlated("3: *(u32 *)(r6 +0) = r7")
+/* save __u64 *ctx to stack */
+__xlated("4: *(u64 *)(r10 -8) = r1")
+/* main prog */
+__xlated("5: if r1 == 0x0 goto pc+5")
+__xlated("6: if r1 == 0x1 goto pc+2")
+__xlated("7: r1 = 1")
+__xlated("8: goto pc-3")
+__xlated("9: r1 = 0")
+__xlated("10: goto pc-6")
+__xlated("11: r0 = 0")
+/* epilogue */
+__xlated("12: r1 = *(u64 *)(r10 -8)")
+__xlated("13: r1 = *(u64 *)(r1 +0)")
+__xlated("14: r6 = *(u32 *)(r1 +0)")
+__xlated("15: w6 += 10000")
+__xlated("16: *(u32 *)(r1 +0) = r6")
+__xlated("17: w0 = w6")
+__xlated("18: w0 *= 2")
+__xlated("19: exit")
+SEC("struct_ops/test_pro_epilogue_goto_start")
+__naked int test_pro_epilogue_goto_start(void)
+{
+ asm volatile (
+ "if r1 == 0 goto +5;"
+ "if r1 == 1 goto +2;"
+ "r1 = 1;"
+ "goto -3;"
+ "r1 = 0;"
+ "goto -6;"
+ "r0 = 0;"
+ "exit;"
+ ::: __clobber_all);
+}
+
+SEC(".struct_ops.link")
+struct bpf_testmod_st_ops epilogue_goto_start = {
+ .test_prologue = (void *)test_prologue_goto_start,
+ .test_epilogue = (void *)test_epilogue_goto_start,
+ .test_pro_epilogue = (void *)test_pro_epilogue_goto_start,
+};
+
+SEC("syscall")
+__retval(0)
+int syscall_prologue_goto_start(void *ctx)
+{
+ struct st_ops_args args = {};
+
+ return bpf_kfunc_st_ops_test_prologue(&args);
+}
+
+SEC("syscall")
+__retval(20000) /* (EPILOGUE_A [10000]) * 2 */
+int syscall_epilogue_goto_start(void *ctx)
+{
+ struct st_ops_args args = {};
+
+ return bpf_kfunc_st_ops_test_epilogue(&args);
+}
+
+SEC("syscall")
+__retval(22000) /* (PROLOGUE_A [1000] + EPILOGUE_A [10000]) * 2 */
+int syscall_pro_epilogue_goto_start(void *ctx)
+{
+ struct st_ops_args args = {};
+
+ return bpf_kfunc_st_ops_test_pro_epilogue(&args);
+}
--
2.43.5
next prev parent reply other threads:[~2024-08-27 18:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-27 18:16 [PATCH v3 bpf-next 0/9] bpf: Add gen_epilogue to bpf_verifier_ops Martin KaFai Lau
2024-08-27 18:16 ` [PATCH v3 bpf-next 1/9] bpf: Move insn_buf[16] to bpf_verifier_env Martin KaFai Lau
2024-08-27 18:16 ` [PATCH v3 bpf-next 2/9] bpf: Adjust BPF_JMP that jumps to the 1st insn of the prologue Martin KaFai Lau
2024-08-27 18:16 ` [PATCH v3 bpf-next 3/9] bpf: Add gen_epilogue to bpf_verifier_ops Martin KaFai Lau
2024-08-27 19:19 ` Martin KaFai Lau
2024-08-27 18:16 ` [PATCH v3 bpf-next 4/9] bpf: Export bpf_base_func_proto Martin KaFai Lau
2024-08-27 18:16 ` [PATCH v3 bpf-next 5/9] selftests/bpf: attach struct_ops maps before test prog runs Martin KaFai Lau
2024-08-27 18:16 ` [PATCH v3 bpf-next 6/9] selftests/bpf: Test gen_prologue and gen_epilogue Martin KaFai Lau
2024-08-27 18:16 ` Martin KaFai Lau [this message]
2024-08-27 18:16 ` [PATCH v3 bpf-next 9/9] selftests/bpf: Test epilogue patching when the main prog has multiple BPF_EXIT Martin KaFai Lau
2024-08-27 18:29 ` [PATCH v3 bpf-next 7/9] selftests/bpf: Add tailcall epilogue test Martin KaFai Lau
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