tests: robustify attach-f-p.test against race conditions

Introduce a synchronization mechanism between attach-f-p and strace.

* tests/attach-f-p-cmd.c: New file.
* tests/Makefile.am (check_PROGRAMS): Add attach-f-p-cmd.
* tests/attach-f-p.c: Include <sys/stat.h>.
(main): Write to stdout instead of descriptor 3.  Wait for the peer
writing to stdout.
* tests/attach-f-p.test: Assume that ./attach-f-p-cmd works.
Use $OUT for expected output.  Use attach-f-p-cmd for unlocking $OUT.

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 0cc94e922e5fb72bf3b9a360c738d42d1ebb1715..42f77a731dbede5dd6802d8e701c13404e700c30 100644 (file)
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -77,6 +77,7 @@ check_PROGRAMS = \
        alarm \
        answer \
        attach-f-p \
+       attach-f-p-cmd \
        attach-p-cmd-cmd \
        attach-p-cmd-p \
        bpf \

diff --git a/tests/attach-f-p-cmd.c b/tests/attach-f-p-cmd.c
new file mode 100644 (file)
index 0000000..77594be
--- /dev/null
+++ b/tests/attach-f-p-cmd.c
@@ -0,0 +1,46 @@
+/*
+ * This file is part of attach-f-p strace test.
+ *
+ * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "tests.h"
+#include <stdio.h>
+#include <unistd.h>
+
+int
+main(void)
+{
+       static const char dir[] = "attach-f-p.test cmd";
+       pid_t pid = getpid();
+       int rc = chdir(dir);
+
+       printf("%-5d chdir(\"%s\") = %s\n"
+              "%-5d +++ exited with 0 +++\n",
+              pid, dir, sprintrc(rc), pid);
+
+       return 0;
+}

diff --git a/tests/attach-f-p.c b/tests/attach-f-p.c
index c75deb6fa3b0abb23207ae1bb4c6499615b64bf3..3f9a7e3e030673edc3b5aad3c1cac9aee922e81c 100644 (file)
--- a/tests/attach-f-p.c
+++ b/tests/attach-f-p.c
@@ -33,6 +33,7 @@
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/stat.h>
 #include <asm/unistd.h>
 #include <unistd.h>
 
@@ -71,7 +72,7 @@ main(void)
        pthread_t t[N];
        unsigned int i;
 
-       if (write(3, "", 0) != 0)
+       if (write(1, "", 0) != 0)
                perror_msg_and_fail("write");
 
        for (i = 0; i < N; ++i) {
@@ -83,9 +84,18 @@ main(void)
                        perror_msg_and_fail("pthread_create");
        }
 
-       if (write(3, "\n", 1) != 1)
+       if (write(1, "\n", 1) != 1)
                perror_msg_and_fail("write");
 
+       /* wait for the peer to write to stdout */
+       struct stat st;
+       for (;;) {
+               if (fstat(1, &st))
+                       perror_msg_and_fail("fstat");
+               if (st.st_size >= 103)
+                       break;
+       }
+
        for (i = 0; i < N; ++i) {
                /* sleep a bit to let the tracer catch up */
                sleep(1);
@@ -96,9 +106,9 @@ main(void)
                if (errno)
                        perror_msg_and_fail("pthread_join");
                errno = ENOENT;
-               printf("%-5d chdir(\"%s\") = -1 ENOENT (%m)\n"
+               printf("%-5d chdir(\"%s\") = %s\n"
                       "%-5d +++ exited with 0 +++\n",
-                      retval.pid, child[i], retval.pid);
+                      retval.pid, child[i], sprintrc(-1), retval.pid);
        }
 
        /* sleep a bit more to let the tracer catch up */

diff --git a/tests/attach-f-p.test b/tests/attach-f-p.test
index 030659a200f4031f4738a0cad4cbb7c9794b0971..f41707409a75b8e372fe375992da43640617a3c3 100755 (executable)
--- a/tests/attach-f-p.test
+++ b/tests/attach-f-p.test
@@ -34,16 +34,17 @@
        framework_skip_ '/proc/self/task/ is not available'
 run_prog_skip_if_failed \
        kill -0 $$
-run_prog ./attach-f-p > /dev/null 3>&1
+run_prog ./attach-f-p-cmd > /dev/null
 
-./set_ptracer_any sh -c "exec ./attach-f-p > $EXP 3> $OUT" > /dev/null &
+rm -f "$OUT"
+./set_ptracer_any sh -c "exec ./attach-f-p >> $OUT" > /dev/null &
 tracee_pid=$!
 
 while ! [ -s "$OUT" ]; do
        kill -0 $tracee_pid 2> /dev/null ||
-               fail_ 'set_ptracer_any sleep failed'
+               fail_ 'set_ptracer_any sh failed'
 done
 
-run_strace -a32 -f -echdir -p $tracee_pid
-match_diff "$LOG" "$EXP"
-rm -f "$EXP" "$OUT"
+run_strace -a32 -f -echdir -p $tracee_pid ./attach-f-p-cmd > "$OUT"
+match_diff "$LOG" "$OUT"
+rm -f "$OUT"