From ad13baf4569152b00de11949b8c93aaa83c1243f Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Wed, 9 Mar 2022 20:33:21 +0800 Subject: [PATCH] selftests/bpf: Test subprog jit when toggle bpf_jit_harden repeatedly When bpf_jit_harden is toggled between 0 and 2, subprog jit may fail due to inconsistent twice read values of bpf_jit_harden during jit. So add a test to ensure the problem is fixed. Signed-off-by: Hou Tao Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220309123321.2400262-5-houtao1@huawei.com --- .../selftests/bpf/prog_tests/subprogs.c | 77 ++++++++++++++++--- 1 file changed, 68 insertions(+), 9 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/subprogs.c b/tools/testing/selftests/bpf/prog_tests/subprogs.c index 3f3d2ac4dd57..903f35a9e62e 100644 --- a/tools/testing/selftests/bpf/prog_tests/subprogs.c +++ b/tools/testing/selftests/bpf/prog_tests/subprogs.c @@ -1,32 +1,83 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2020 Facebook */ #include -#include #include "test_subprogs.skel.h" #include "test_subprogs_unused.skel.h" -static int duration; +struct toggler_ctx { + int fd; + bool stop; +}; -void test_subprogs(void) +static void *toggle_jit_harden(void *arg) +{ + struct toggler_ctx *ctx = arg; + char two = '2'; + char zero = '0'; + + while (!ctx->stop) { + lseek(ctx->fd, SEEK_SET, 0); + write(ctx->fd, &two, sizeof(two)); + lseek(ctx->fd, SEEK_SET, 0); + write(ctx->fd, &zero, sizeof(zero)); + } + + return NULL; +} + +static void test_subprogs_with_jit_harden_toggling(void) +{ + struct toggler_ctx ctx; + pthread_t toggler; + int err; + unsigned int i, loop = 10; + + ctx.fd = open("/proc/sys/net/core/bpf_jit_harden", O_RDWR); + if (!ASSERT_GE(ctx.fd, 0, "open bpf_jit_harden")) + return; + + ctx.stop = false; + err = pthread_create(&toggler, NULL, toggle_jit_harden, &ctx); + if (!ASSERT_OK(err, "new toggler")) + goto out; + + /* Make toggler thread to run */ + usleep(1); + + for (i = 0; i < loop; i++) { + struct test_subprogs *skel = test_subprogs__open_and_load(); + + if (!ASSERT_OK_PTR(skel, "skel open")) + break; + test_subprogs__destroy(skel); + } + + ctx.stop = true; + pthread_join(toggler, NULL); +out: + close(ctx.fd); +} + +static void test_subprogs_alone(void) { struct test_subprogs *skel; struct test_subprogs_unused *skel2; int err; skel = test_subprogs__open_and_load(); - if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + if (!ASSERT_OK_PTR(skel, "skel_open")) return; err = test_subprogs__attach(skel); - if (CHECK(err, "skel_attach", "failed to attach skeleton: %d\n", err)) + if (!ASSERT_OK(err, "skel attach")) goto cleanup; usleep(1); - CHECK(skel->bss->res1 != 12, "res1", "got %d, exp %d\n", skel->bss->res1, 12); - CHECK(skel->bss->res2 != 17, "res2", "got %d, exp %d\n", skel->bss->res2, 17); - CHECK(skel->bss->res3 != 19, "res3", "got %d, exp %d\n", skel->bss->res3, 19); - CHECK(skel->bss->res4 != 36, "res4", "got %d, exp %d\n", skel->bss->res4, 36); + ASSERT_EQ(skel->bss->res1, 12, "res1"); + ASSERT_EQ(skel->bss->res2, 17, "res2"); + ASSERT_EQ(skel->bss->res3, 19, "res3"); + ASSERT_EQ(skel->bss->res4, 36, "res4"); skel2 = test_subprogs_unused__open_and_load(); ASSERT_OK_PTR(skel2, "unused_progs_skel"); @@ -35,3 +86,11 @@ void test_subprogs(void) cleanup: test_subprogs__destroy(skel); } + +void test_subprogs(void) +{ + if (test__start_subtest("subprogs_alone")) + test_subprogs_alone(); + if (test__start_subtest("subprogs_and_jit_harden")) + test_subprogs_with_jit_harden_toggling(); +}