83 lines
2.6 KiB
C
83 lines
2.6 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2021 Facebook */
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#define _GNU_SOURCE
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#include <sched.h>
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#include <test_progs.h>
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#include <time.h>
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#include <sys/mman.h>
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#include <sys/syscall.h>
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#include "fexit_sleep.lskel.h"
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static int do_sleep(void *skel)
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{
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struct fexit_sleep_lskel *fexit_skel = skel;
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struct timespec ts1 = { .tv_nsec = 1 };
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struct timespec ts2 = { .tv_sec = 10 };
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fexit_skel->bss->pid = getpid();
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(void)syscall(__NR_nanosleep, &ts1, NULL);
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(void)syscall(__NR_nanosleep, &ts2, NULL);
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return 0;
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}
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#define STACK_SIZE (1024 * 1024)
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static char child_stack[STACK_SIZE];
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void test_fexit_sleep(void)
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{
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struct fexit_sleep_lskel *fexit_skel = NULL;
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int wstatus, duration = 0;
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pid_t cpid;
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int err, fexit_cnt;
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fexit_skel = fexit_sleep_lskel__open_and_load();
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if (CHECK(!fexit_skel, "fexit_skel_load", "fexit skeleton failed\n"))
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goto cleanup;
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err = fexit_sleep_lskel__attach(fexit_skel);
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if (CHECK(err, "fexit_attach", "fexit attach failed: %d\n", err))
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goto cleanup;
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cpid = clone(do_sleep, child_stack + STACK_SIZE, CLONE_FILES | SIGCHLD, fexit_skel);
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if (CHECK(cpid == -1, "clone", "%s\n", strerror(errno)))
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goto cleanup;
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/* wait until first sys_nanosleep ends and second sys_nanosleep starts */
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while (READ_ONCE(fexit_skel->bss->fentry_cnt) != 2);
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fexit_cnt = READ_ONCE(fexit_skel->bss->fexit_cnt);
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if (CHECK(fexit_cnt != 1, "fexit_cnt", "%d", fexit_cnt))
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goto cleanup;
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/* close progs and detach them. That will trigger two nop5->jmp5 rewrites
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* in the trampolines to skip nanosleep_fexit prog.
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* The nanosleep_fentry prog will get detached first.
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* The nanosleep_fexit prog will get detached second.
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* Detaching will trigger freeing of both progs JITed images.
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* There will be two dying bpf_tramp_image-s, but only the initial
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* bpf_tramp_image (with both _fentry and _fexit progs will be stuck
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* waiting for percpu_ref_kill to confirm). The other one
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* will be freed quickly.
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*/
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close(fexit_skel->progs.nanosleep_fentry.prog_fd);
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close(fexit_skel->progs.nanosleep_fexit.prog_fd);
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fexit_sleep_lskel__detach(fexit_skel);
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/* kill the thread to unwind sys_nanosleep stack through the trampoline */
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kill(cpid, 9);
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if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", "%s\n", strerror(errno)))
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goto cleanup;
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if (CHECK(WEXITSTATUS(wstatus) != 0, "exitstatus", "failed"))
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goto cleanup;
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/* The bypassed nanosleep_fexit prog shouldn't have executed.
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* Unlike progs the maps were not freed and directly accessible.
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*/
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fexit_cnt = READ_ONCE(fexit_skel->bss->fexit_cnt);
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if (CHECK(fexit_cnt != 1, "fexit_cnt", "%d", fexit_cnt))
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goto cleanup;
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cleanup:
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fexit_sleep_lskel__destroy(fexit_skel);
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}
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