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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
selftests/bpf: A pro/epilogue test when the main prog jumps back to the 1st insn
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.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240829210833.388152-9-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
authored by
Martin KaFai Lau
and committed by
Alexei Starovoitov
42fdbbde
b191b0fd
+151
+2
tools/testing/selftests/bpf/prog_tests/pro_epilogue.c
+2
tools/testing/selftests/bpf/prog_tests/pro_epilogue.c
···
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#include <test_progs.h>
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#include "pro_epilogue.skel.h"
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#include "epilogue_tailcall.skel.h"
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#include "pro_epilogue_goto_start.skel.h"
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struct st_ops_args {
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__u64 a;
···
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void test_pro_epilogue(void)
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{
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RUN_TESTS(pro_epilogue);
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RUN_TESTS(pro_epilogue_goto_start);
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if (test__start_subtest("tailcall"))
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test_tailcall();
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}
+149
tools/testing/selftests/bpf/progs/pro_epilogue_goto_start.c
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tools/testing/selftests/bpf/progs/pro_epilogue_goto_start.c
···
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// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
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#include <vmlinux.h>
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#include <bpf/bpf_tracing.h>
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#include "bpf_misc.h"
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#include "../bpf_testmod/bpf_testmod.h"
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#include "../bpf_testmod/bpf_testmod_kfunc.h"
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char _license[] SEC("license") = "GPL";
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__success
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/* prologue */
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__xlated("0: r6 = *(u64 *)(r1 +0)")
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__xlated("1: r7 = *(u64 *)(r6 +0)")
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__xlated("2: r7 += 1000")
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__xlated("3: *(u64 *)(r6 +0) = r7")
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/* main prog */
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__xlated("4: if r1 == 0x0 goto pc+5")
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__xlated("5: if r1 == 0x1 goto pc+2")
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__xlated("6: r1 = 1")
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__xlated("7: goto pc-3")
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__xlated("8: r1 = 0")
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__xlated("9: goto pc-6")
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__xlated("10: r0 = 0")
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__xlated("11: exit")
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SEC("struct_ops/test_prologue_goto_start")
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__naked int test_prologue_goto_start(void)
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{
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asm volatile (
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"if r1 == 0 goto +5;"
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"if r1 == 1 goto +2;"
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"r1 = 1;"
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"goto -3;"
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"r1 = 0;"
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"goto -6;"
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"r0 = 0;"
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"exit;"
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::: __clobber_all);
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}
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__success
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/* save __u64 *ctx to stack */
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__xlated("0: *(u64 *)(r10 -8) = r1")
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/* main prog */
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__xlated("1: if r1 == 0x0 goto pc+5")
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__xlated("2: if r1 == 0x1 goto pc+2")
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__xlated("3: r1 = 1")
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__xlated("4: goto pc-3")
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__xlated("5: r1 = 0")
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__xlated("6: goto pc-6")
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__xlated("7: r0 = 0")
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/* epilogue */
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__xlated("8: r1 = *(u64 *)(r10 -8)")
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__xlated("9: r1 = *(u64 *)(r1 +0)")
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__xlated("10: r6 = *(u64 *)(r1 +0)")
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__xlated("11: r6 += 10000")
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__xlated("12: *(u64 *)(r1 +0) = r6")
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__xlated("13: r0 = r6")
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__xlated("14: r0 *= 2")
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__xlated("15: exit")
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SEC("struct_ops/test_epilogue_goto_start")
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__naked int test_epilogue_goto_start(void)
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{
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asm volatile (
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"if r1 == 0 goto +5;"
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"if r1 == 1 goto +2;"
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"r1 = 1;"
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"goto -3;"
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"r1 = 0;"
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"goto -6;"
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"r0 = 0;"
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"exit;"
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::: __clobber_all);
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}
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__success
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/* prologue */
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__xlated("0: r6 = *(u64 *)(r1 +0)")
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__xlated("1: r7 = *(u64 *)(r6 +0)")
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__xlated("2: r7 += 1000")
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__xlated("3: *(u64 *)(r6 +0) = r7")
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/* save __u64 *ctx to stack */
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__xlated("4: *(u64 *)(r10 -8) = r1")
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/* main prog */
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__xlated("5: if r1 == 0x0 goto pc+5")
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__xlated("6: if r1 == 0x1 goto pc+2")
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__xlated("7: r1 = 1")
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__xlated("8: goto pc-3")
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__xlated("9: r1 = 0")
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__xlated("10: goto pc-6")
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__xlated("11: r0 = 0")
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/* epilogue */
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__xlated("12: r1 = *(u64 *)(r10 -8)")
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__xlated("13: r1 = *(u64 *)(r1 +0)")
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__xlated("14: r6 = *(u64 *)(r1 +0)")
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__xlated("15: r6 += 10000")
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__xlated("16: *(u64 *)(r1 +0) = r6")
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__xlated("17: r0 = r6")
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__xlated("18: r0 *= 2")
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__xlated("19: exit")
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SEC("struct_ops/test_pro_epilogue_goto_start")
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__naked int test_pro_epilogue_goto_start(void)
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{
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asm volatile (
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"if r1 == 0 goto +5;"
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"if r1 == 1 goto +2;"
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"r1 = 1;"
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"goto -3;"
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"r1 = 0;"
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"goto -6;"
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"r0 = 0;"
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"exit;"
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::: __clobber_all);
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}
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SEC(".struct_ops.link")
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struct bpf_testmod_st_ops epilogue_goto_start = {
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.test_prologue = (void *)test_prologue_goto_start,
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.test_epilogue = (void *)test_epilogue_goto_start,
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.test_pro_epilogue = (void *)test_pro_epilogue_goto_start,
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};
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SEC("syscall")
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__retval(0)
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int syscall_prologue_goto_start(void *ctx)
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{
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struct st_ops_args args = {};
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return bpf_kfunc_st_ops_test_prologue(&args);
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}
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SEC("syscall")
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__retval(20000) /* (EPILOGUE_A [10000]) * 2 */
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int syscall_epilogue_goto_start(void *ctx)
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{
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struct st_ops_args args = {};
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return bpf_kfunc_st_ops_test_epilogue(&args);
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}
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SEC("syscall")
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__retval(22000) /* (PROLOGUE_A [1000] + EPILOGUE_A [10000]) * 2 */
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int syscall_pro_epilogue_goto_start(void *ctx)
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{
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struct st_ops_args args = {};
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return bpf_kfunc_st_ops_test_pro_epilogue(&args);
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}