From: Dmitry V. Levin <ldv@altlinux.org>
Date: Mon, 29 Jun 2015 11:57:44 +0000 (+0000)
Subject: Fix filtering of <unavailable> syscalls
X-Git-Tag: v4.11~491
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=4b80f34c93b54f2ae79be65e0c727a9d0d094837;p=strace

Fix filtering of <unavailable> syscalls

* syscall.c (trace_syscall_exiting): Skip filtered syscalls also in case
of get_regs or get_syscall_result failure.
* tests/filter-unavailable.c: New file.
* tests/filter-unavailable.expected: Likewise.
* tests/filter-unavailable.test: New test.
* tests/Makefile.am (check_PROGRAMS): Add filter-unavailable.
(filter_unavailable_LDFLAGS): Add -pthread.
(TESTS): Add filter-unavailable.test.
(EXTRA_DIST): Add filter-unavailable.expected.
* tests/.gitignore: Add filter-unavailable.

Reported-by: Bryan Matsuo <bryan.matsuo@gmail.com>
---

diff --git a/syscall.c b/syscall.c
index 0d26b45c..0ab424c1 100644
--- a/syscall.c
+++ b/syscall.c
@@ -873,10 +873,8 @@ trace_syscall_exiting(struct tcb *tcp)
 	update_personality(tcp, tcp->currpers);
 #endif
 	res = (get_regs_error ? -1 : get_syscall_result(tcp));
-	if (res == 1) {
-		if (filtered(tcp) || hide_log_until_execve)
-			goto ret;
-	}
+	if (filtered(tcp) || hide_log_until_execve)
+		goto ret;
 
 	if (cflag) {
 		count_syscall(tcp, &tv);
diff --git a/tests/.gitignore b/tests/.gitignore
index c3eada90..fe19dd89 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -1,5 +1,6 @@
 caps
 fanotify_mark
+filter-unavailable
 getrandom
 inet-accept-connect-send-recv
 ioctl
diff --git a/tests/Makefile.am b/tests/Makefile.am
index f1e88205..32e6e52e 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -11,6 +11,7 @@ AM_CPPFLAGS = -I$(top_builddir)/$(OS)/$(ARCH) \
 check_PROGRAMS = \
 	caps \
 	fanotify_mark \
+	filter-unavailable \
 	getrandom \
 	inet-accept-connect-send-recv \
 	ioctl \
@@ -44,6 +45,7 @@ check_PROGRAMS = \
 	umovestr2 \
 	unix-pair-send-recv
 
+filter_unavailable_LDFLAGS = -pthread
 mmap64_CFLAGS = $(AM_CFLAGS) -D_FILE_OFFSET_BITS=64
 pc_LDADD = $(dl_LIBS)
 stat_CFLAGS = $(AM_CFLAGS) -D_FILE_OFFSET_BITS=64
@@ -59,6 +61,7 @@ TESTS = \
 	caps.test \
 	dumpio.test \
 	fanotify_mark.test \
+	filter-unavailable.test \
 	getdents.test \
 	getrandom.test \
 	ioctl.test \
@@ -107,6 +110,7 @@ EXTRA_DIST = init.sh run.sh match.awk \
 	     caps.awk \
 	     dumpio.expected \
 	     fanotify_mark.expected \
+	     filter-unavailable.expected \
 	     getdents.awk \
 	     getdents.out \
 	     getrandom.awk \
diff --git a/tests/filter-unavailable.c b/tests/filter-unavailable.c
new file mode 100644
index 00000000..6f865e69
--- /dev/null
+++ b/tests/filter-unavailable.c
@@ -0,0 +1,54 @@
+#include <assert.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <sys/wait.h>
+
+#define P 16
+#define T 7
+
+static void *
+thread(void *arg)
+{
+	assert(write(1, "", 1) == 1);
+	pause();
+	return arg;
+}
+
+static int
+process(void)
+{
+	int i;
+	int fds[2];
+	pthread_t t;
+	struct timespec ts = { .tv_nsec = 10000000 };
+
+	(void) close(0);
+	(void) close(1);
+	assert(pipe(fds) == 0 && fds[0] == 0 && fds[1] == 1);
+
+	for (i = 0; i < T; ++i)
+		assert(pthread_create(&t, NULL, thread, NULL) == 0);
+	for (i = 0; i < T; ++i)
+		assert(read(0, fds, 1) == 1);
+
+	(void) nanosleep(&ts, 0);
+	return 0;
+}
+
+int
+main(void)
+{
+	int i, s;
+	pid_t p;
+
+	for (i = 0; i < P; ++i) {
+		assert((p = fork()) >= 0);
+		if (p == 0)
+			return process();
+		assert(waitpid(p, &s, 0) == p && WIFEXITED(s));
+		if (WEXITSTATUS(s))
+			return WEXITSTATUS(s);
+	}
+	return 0;
+}
diff --git a/tests/filter-unavailable.expected b/tests/filter-unavailable.expected
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/filter-unavailable.test b/tests/filter-unavailable.test
new file mode 100755
index 00000000..15a9ad1d
--- /dev/null
+++ b/tests/filter-unavailable.test
@@ -0,0 +1,11 @@
+#!/bin/sh
+
+# check that <unavailable> syscalls are filtered properly
+
+. "${srcdir=.}/init.sh"
+
+run_prog
+run_strace -qq -f -echdir -esignal=none $args
+match_diff
+
+exit 0