89 lines · c
1// SPDX-License-Identifier: GPL-2.02/* Copyright (c) 2021 Facebook */3#define _GNU_SOURCE4#include <sched.h>5#include <test_progs.h>6#include <time.h>7#include <sys/mman.h>8#include <sys/syscall.h>9#include "fexit_sleep.lskel.h"10 11static int do_sleep(void *skel)12{13 struct fexit_sleep_lskel *fexit_skel = skel;14 struct timespec ts1 = { .tv_nsec = 1 };15 struct timespec ts2 = { .tv_sec = 10 };16 17 fexit_skel->bss->pid = getpid();18 (void)syscall(__NR_nanosleep, &ts1, NULL);19 (void)syscall(__NR_nanosleep, &ts2, NULL);20 return 0;21}22 23#define STACK_SIZE (1024 * 1024)24 25void test_fexit_sleep(void)26{27 struct fexit_sleep_lskel *fexit_skel = NULL;28 int wstatus, duration = 0;29 pid_t cpid;30 char *child_stack = NULL;31 int err, fexit_cnt;32 33 fexit_skel = fexit_sleep_lskel__open_and_load();34 if (CHECK(!fexit_skel, "fexit_skel_load", "fexit skeleton failed\n"))35 goto cleanup;36 37 err = fexit_sleep_lskel__attach(fexit_skel);38 if (CHECK(err, "fexit_attach", "fexit attach failed: %d\n", err))39 goto cleanup;40 41 child_stack = mmap(NULL, STACK_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE |42 MAP_ANONYMOUS | MAP_STACK, -1, 0);43 if (!ASSERT_NEQ(child_stack, MAP_FAILED, "mmap"))44 goto cleanup;45 46 cpid = clone(do_sleep, child_stack + STACK_SIZE, CLONE_FILES | SIGCHLD, fexit_skel);47 if (CHECK(cpid == -1, "clone", "%s\n", strerror(errno)))48 goto cleanup;49 50 /* wait until first sys_nanosleep ends and second sys_nanosleep starts */51 while (READ_ONCE(fexit_skel->bss->fentry_cnt) != 2);52 fexit_cnt = READ_ONCE(fexit_skel->bss->fexit_cnt);53 if (CHECK(fexit_cnt != 1, "fexit_cnt", "%d", fexit_cnt))54 goto cleanup;55 56 /* close progs and detach them. That will trigger two nop5->jmp5 rewrites57 * in the trampolines to skip nanosleep_fexit prog.58 * The nanosleep_fentry prog will get detached first.59 * The nanosleep_fexit prog will get detached second.60 * Detaching will trigger freeing of both progs JITed images.61 * There will be two dying bpf_tramp_image-s, but only the initial62 * bpf_tramp_image (with both _fentry and _fexit progs will be stuck63 * waiting for percpu_ref_kill to confirm). The other one64 * will be freed quickly.65 */66 close(fexit_skel->progs.nanosleep_fentry.prog_fd);67 close(fexit_skel->progs.nanosleep_fexit.prog_fd);68 fexit_sleep_lskel__detach(fexit_skel);69 70 /* kill the thread to unwind sys_nanosleep stack through the trampoline */71 kill(cpid, 9);72 73 if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", "%s\n", strerror(errno)))74 goto cleanup;75 if (CHECK(WEXITSTATUS(wstatus) != 0, "exitstatus", "failed"))76 goto cleanup;77 78 /* The bypassed nanosleep_fexit prog shouldn't have executed.79 * Unlike progs the maps were not freed and directly accessible.80 */81 fexit_cnt = READ_ONCE(fexit_skel->bss->fexit_cnt);82 if (CHECK(fexit_cnt != 1, "fexit_cnt", "%d", fexit_cnt))83 goto cleanup;84 85cleanup:86 munmap(child_stack, STACK_SIZE);87 fexit_sleep_lskel__destroy(fexit_skel);88}89