From a33747a902b57d353127a4648ce8dccf30173aae Mon Sep 17 00:00:00 2001 From: "Dmitry V. Levin" Date: Sun, 3 Dec 2017 00:25:43 +0000 Subject: [PATCH] tests: robustify attach-p-cmd.test against buggy kernels From time to time various kernels, old and new, just go nuts and fail attach-p-cmd.test with the following diagnostics: 12345 --- SIGALRM {si_signo=SIGALRM, si_code=SI_KERNEL} --- -12345 chdir("attach-p-cmd.test -p") = -1 ENOENT (No such file or directory) +12345 syscall_4294967295(0xffe60934, 0x1c0, 0xffe60934, 0x1, 0xffe609b4, 0xffe60a58) = -1 (errno 38) +12345 chdir("attach-p-cmd.test -p") = -1 ENOSYS (Function not implemented) Let's workaround this kernel madness by rewriting the test without use of SIGALRM. * tests/attach-p-cmd.h: New file. * tests/Makefile.am (EXTRA_DIST): Add attach-p-cmd.h. * tests/attach-p-cmd-cmd.c: Include "attach-p-cmd.h". (write_pidfile, wait_for_peer_invocation): New functions. (main): Use them. * tests/attach-p-cmd-p.c: Include and "attach-p-cmd.h". (wait_for_peer_invocation, wait_for_peer_termination): New functions. (main): Use them. Do not raise SIGALRM, use nanosleep after peer termination. --- tests/Makefile.am | 1 + tests/attach-p-cmd-cmd.c | 32 ++++++++++++++++---- tests/attach-p-cmd-p.c | 65 +++++++++++++++++++++++++--------------- tests/attach-p-cmd.h | 2 ++ 4 files changed, 71 insertions(+), 29 deletions(-) create mode 100644 tests/attach-p-cmd.h diff --git a/tests/Makefile.am b/tests/Makefile.am index f2109fd4..7bc2872f 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -316,6 +316,7 @@ VALGRIND_FLAGS = --quiet VALGRIND_SUPPRESSIONS_FILES = $(abs_srcdir)/strace.supp EXTRA_DIST = \ + attach-p-cmd.h \ caps-abbrev.awk \ caps.awk \ clock.in \ diff --git a/tests/attach-p-cmd-cmd.c b/tests/attach-p-cmd-cmd.c index d0f824e9..70e3a2de 100644 --- a/tests/attach-p-cmd-cmd.c +++ b/tests/attach-p-cmd-cmd.c @@ -1,7 +1,7 @@ /* * This file is part of attach-p-cmd strace test. * - * Copyright (c) 2016 Dmitry V. Levin + * Copyright (c) 2016-2017 Dmitry V. Levin * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -32,19 +32,41 @@ #include #include #include +#include "attach-p-cmd.h" -int -main(void) +static void +write_pidfile(const pid_t pid) +{ + FILE *fp = fopen(pidfile, "w"); + if (!fp) + perror_msg_and_fail("fopen: %s", pidfile); + + if (fprintf(fp, "%d", pid) < 0) + perror_msg_and_fail("fprintf: %s", pidfile); + + if (fclose(fp)) + perror_msg_and_fail("fclose: %s", pidfile); +} + +static void +wait_for_peer_invocation(void) { - static const char lockdir[] = "attach-p-cmd.test-lock"; /* wait for the lock directory to be created by peer */ while (rmdir(lockdir)) { if (ENOENT != errno) perror_msg_and_fail("rmdir: %s", lockdir); } +} + +int +main(void) +{ + const pid_t pid = getpid(); + write_pidfile(pid); + + wait_for_peer_invocation(); static const char dir[] = "attach-p-cmd.test cmd"; - pid_t pid = getpid(); int rc = chdir(dir); printf("%-5d chdir(\"%s\") = %s\n" diff --git a/tests/attach-p-cmd-p.c b/tests/attach-p-cmd-p.c index 254d19ae..843db957 100644 --- a/tests/attach-p-cmd-p.c +++ b/tests/attach-p-cmd-p.c @@ -1,7 +1,7 @@ /* * This file is part of attach-p-cmd strace test. * - * Copyright (c) 2016 Dmitry V. Levin + * Copyright (c) 2016-2017 Dmitry V. Levin * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -33,27 +33,14 @@ #include #include #include +#include #include +#include "attach-p-cmd.h" static void -handler(int signo) +wait_for_peer_invocation(void) { -} - -int -main(void) -{ - const struct sigaction act = { .sa_handler = handler }; - if (sigaction(SIGALRM, &act, NULL)) - perror_msg_and_fail("sigaction"); - - sigset_t mask = {}; - sigaddset(&mask, SIGALRM); - if (sigprocmask(SIG_UNBLOCK, &mask, NULL)) - perror_msg_and_fail("sigprocmask"); - - static const char lockdir[] = "attach-p-cmd.test-lock"; - /* create a lock directory */ + /* create the lock directory */ if (mkdir(lockdir, 0700)) perror_msg_and_fail("mkdir: %s", lockdir); @@ -63,21 +50,51 @@ main(void) perror_msg_and_fail("mkdir: %s", lockdir); } - /* remove the lock directory */ + /* cleanup the lock directory */ if (rmdir(lockdir)) perror_msg_and_fail("rmdir: %s", lockdir); +} - alarm(1); - pause(); +static void +wait_for_peer_termination(void) +{ + FILE *fp = fopen(pidfile, "r"); + if (!fp) + perror_msg_and_fail("fopen: %s", pidfile); + + pid_t pid; + if (fscanf(fp, "%d", &pid) < 0) + perror_msg_and_fail("fscanf: %s", pidfile); + if (pid < 0) + error_msg_and_fail("pid = %d", pid); + + if (fclose(fp)) + perror_msg_and_fail("fclose: %s", pidfile); + + if (unlink(pidfile)) + perror_msg_and_fail("unlink: %s", pidfile); + + while (kill(pid, 0) == 0) + ; +} + +int +main(void) +{ + wait_for_peer_invocation(); + wait_for_peer_termination(); + + static const struct timespec ts = { .tv_nsec = 123456789 }; + if (nanosleep(&ts, NULL)) + perror_msg_and_fail("nanosleep"); static const char dir[] = "attach-p-cmd.test -p"; pid_t pid = getpid(); int rc = chdir(dir); - printf("%-5d --- SIGALRM {si_signo=SIGALRM, si_code=SI_KERNEL} ---\n" - "%-5d chdir(\"%s\") = %d %s (%m)\n" + printf("%-5d chdir(\"%s\") = %s\n" "%-5d +++ exited with 0 +++\n", - pid, pid, dir, rc, errno2name(), pid); + pid, dir, sprintrc(rc), pid); return 0; } diff --git a/tests/attach-p-cmd.h b/tests/attach-p-cmd.h new file mode 100644 index 00000000..e04af38f --- /dev/null +++ b/tests/attach-p-cmd.h @@ -0,0 +1,2 @@ +static const char lockdir[] = "attach-p-cmd.test-lock"; +static const char pidfile[] = "attach-p-cmd.test-pid";