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[PATCH] libio: Use stdin consistently for input functions [BZ #24153]
- From: Florian Weimer <fweimer at redhat dot com>
- To: libc-alpha at sourceware dot org
- Date: Fri, 01 Feb 2019 13:58:01 +0100
- Subject: [PATCH] libio: Use stdin consistently for input functions [BZ #24153]
The internal _IO_stdin_ variable is not updated when the application
assigns to stdin, which is a GNU extension.
2019-02-01 Florian Weimer <fweimer@redhat.com>
[BZ #24153]
* debug/gets_chk.c (__gets_chk): Use stdin instead of _IO_stdin.
* libio/getchar.c (getchar): Likewise.
* libio/getchar_u.c (getchar_unlocked): Likewise.
* libio/getwchar.c (getwchar): Likewise.
* libio/getwchar_u.c (getwchar_unlocked): Likewise.
* libio/iogets.c (_IO_gets): Likewise.
* libio/vscanf.c (_IO_vscanf): Likewise.
* libio/vwscanf.c (__vwscanf): Likewise.
* libio/tst-bz24153.c: New file.
* libio/Makefile (tests): Add it.
diff --git a/debug/gets_chk.c b/debug/gets_chk.c
index 4b5e13d6a6..fc6557a7f7 100644
--- a/debug/gets_chk.c
+++ b/debug/gets_chk.c
@@ -37,8 +37,8 @@ __gets_chk (char *buf, size_t size)
if (size == 0)
__chk_fail ();
- _IO_acquire_lock (_IO_stdin);
- ch = _IO_getc_unlocked (_IO_stdin);
+ _IO_acquire_lock (stdin);
+ ch = _IO_getc_unlocked (stdin);
if (ch == EOF)
{
retval = NULL;
@@ -51,24 +51,24 @@ __gets_chk (char *buf, size_t size)
/* This is very tricky since a file descriptor may be in the
non-blocking mode. The error flag doesn't mean much in this
case. We return an error only when there is a new error. */
- int old_error = _IO_stdin->_flags & _IO_ERR_SEEN;
- _IO_stdin->_flags &= ~_IO_ERR_SEEN;
+ int old_error = stdin->_flags & _IO_ERR_SEEN;
+ stdin->_flags &= ~_IO_ERR_SEEN;
buf[0] = (char) ch;
- count = _IO_getline (_IO_stdin, buf + 1, size - 1, '\n', 0) + 1;
- if (_IO_stdin->_flags & _IO_ERR_SEEN)
+ count = _IO_getline (stdin, buf + 1, size - 1, '\n', 0) + 1;
+ if (stdin->_flags & _IO_ERR_SEEN)
{
retval = NULL;
goto unlock_return;
}
else
- _IO_stdin->_flags |= old_error;
+ stdin->_flags |= old_error;
}
if (count >= size)
__chk_fail ();
buf[count] = 0;
retval = buf;
unlock_return:
- _IO_release_lock (_IO_stdin);
+ _IO_release_lock (stdin);
return retval;
}
diff --git a/libio/Makefile b/libio/Makefile
index dbeba88fc0..95b91084dd 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -65,7 +65,7 @@ tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc \
tst-setvbuf1 tst-popen1 tst-fgetwc bug-wsetpos tst-fseek \
tst-fwrite-error tst-ftell-partial-wide tst-ftell-active-handler \
tst-ftell-append tst-fputws tst-bz22415 tst-fgetc-after-eof \
- tst-sprintf-ub tst-sprintf-chk-ub tst-bz24051
+ tst-sprintf-ub tst-sprintf-chk-ub tst-bz24051 tst-bz24153
tests-internal = tst-vtables tst-vtables-interposed tst-readline
diff --git a/libio/getchar.c b/libio/getchar.c
index 7e385305ff..90dea38ddb 100644
--- a/libio/getchar.c
+++ b/libio/getchar.c
@@ -33,11 +33,11 @@ int
getchar (void)
{
int result;
- if (!_IO_need_lock (_IO_stdin))
- return _IO_getc_unlocked (_IO_stdin);
- _IO_acquire_lock (_IO_stdin);
- result = _IO_getc_unlocked (_IO_stdin);
- _IO_release_lock (_IO_stdin);
+ if (!_IO_need_lock (stdin))
+ return _IO_getc_unlocked (stdin);
+ _IO_acquire_lock (stdin);
+ result = _IO_getc_unlocked (stdin);
+ _IO_release_lock (stdin);
return result;
}
diff --git a/libio/getchar_u.c b/libio/getchar_u.c
index 9af50be717..a933d9aad0 100644
--- a/libio/getchar_u.c
+++ b/libio/getchar_u.c
@@ -32,5 +32,5 @@
int
getchar_unlocked (void)
{
- return _IO_getc_unlocked (_IO_stdin);
+ return _IO_getc_unlocked (stdin);
}
diff --git a/libio/getwchar.c b/libio/getwchar.c
index baac916fdd..b6155fa276 100644
--- a/libio/getwchar.c
+++ b/libio/getwchar.c
@@ -33,8 +33,8 @@ wint_t
getwchar (void)
{
wint_t result;
- _IO_acquire_lock (_IO_stdin);
- result = _IO_getwc_unlocked (_IO_stdin);
- _IO_release_lock (_IO_stdin);
+ _IO_acquire_lock (stdin);
+ result = _IO_getwc_unlocked (stdin);
+ _IO_release_lock (stdin);
return result;
}
diff --git a/libio/getwchar_u.c b/libio/getwchar_u.c
index 1490bbe79f..23fa18b007 100644
--- a/libio/getwchar_u.c
+++ b/libio/getwchar_u.c
@@ -32,5 +32,5 @@
wint_t
getwchar_unlocked (void)
{
- return _IO_getwc_unlocked (_IO_stdin);
+ return _IO_getwc_unlocked (stdin);
}
diff --git a/libio/iogets.c b/libio/iogets.c
index 2525056781..6691e4c0fc 100644
--- a/libio/iogets.c
+++ b/libio/iogets.c
@@ -34,8 +34,8 @@ _IO_gets (char *buf)
int ch;
char *retval;
- _IO_acquire_lock (_IO_stdin);
- ch = _IO_getc_unlocked (_IO_stdin);
+ _IO_acquire_lock (stdin);
+ ch = _IO_getc_unlocked (stdin);
if (ch == EOF)
{
retval = NULL;
@@ -48,22 +48,22 @@ _IO_gets (char *buf)
/* This is very tricky since a file descriptor may be in the
non-blocking mode. The error flag doesn't mean much in this
case. We return an error only when there is a new error. */
- int old_error = _IO_stdin->_flags & _IO_ERR_SEEN;
- _IO_stdin->_flags &= ~_IO_ERR_SEEN;
+ int old_error = stdin->_flags & _IO_ERR_SEEN;
+ stdin->_flags &= ~_IO_ERR_SEEN;
buf[0] = (char) ch;
- count = _IO_getline (_IO_stdin, buf + 1, INT_MAX, '\n', 0) + 1;
- if (_IO_stdin->_flags & _IO_ERR_SEEN)
+ count = _IO_getline (stdin, buf + 1, INT_MAX, '\n', 0) + 1;
+ if (stdin->_flags & _IO_ERR_SEEN)
{
retval = NULL;
goto unlock_return;
}
else
- _IO_stdin->_flags |= old_error;
+ stdin->_flags |= old_error;
}
buf[count] = 0;
retval = buf;
unlock_return:
- _IO_release_lock (_IO_stdin);
+ _IO_release_lock (stdin);
return retval;
}
diff --git a/libio/tst-bz24153.c b/libio/tst-bz24153.c
new file mode 100644
index 0000000000..85ad1415df
--- /dev/null
+++ b/libio/tst-bz24153.c
@@ -0,0 +1,114 @@
+/* Test that assigning to stdin redirects input (bug 24153).
+ Copyright (C) 2019 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+/* Prevent getchar -> getc inline expansion. */
+#define __NO_INLINE__
+#pragma GCC optimize ("O0")
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/temp_file.h>
+#include <support/xstdio.h>
+#include <support/xunistd.h>
+#include <wchar.h>
+
+static int
+call_vscanf (const char *format, ...)
+{
+ va_list ap;
+ va_start (ap, format);
+ int ret = vscanf (format, ap);
+ va_end (ap);
+ return ret;
+}
+
+static int
+call_vwscanf (const wchar_t *format, ...)
+{
+ va_list ap;
+ va_start (ap, format);
+ int ret = vwscanf (format, ap);
+ va_end (ap);
+ return ret;
+}
+
+static void
+narrow (const char *path)
+{
+ FILE *old_stdin = stdin;
+ stdin = xfopen (path, "r");
+
+ TEST_COMPARE (getchar (), 'a');
+ TEST_COMPARE (getchar_unlocked (), 'b');
+ char ch = 1;
+ TEST_COMPARE (scanf ("%c", &ch), 1);
+ TEST_COMPARE (ch, 'c');
+ TEST_COMPARE (call_vscanf ("%c", &ch), 1);
+ TEST_COMPARE (ch, 'd');
+ char buf[8];
+ memset (buf, 'X', sizeof (buf));
+
+ /* Legacy interface. */
+ extern char *gets (char *);
+ TEST_VERIFY (gets (buf) == buf);
+ TEST_COMPARE_BLOB (buf, sizeof (buf), "ef\0XXXXX", sizeof (buf));
+
+ fclose (stdin);
+ stdin = old_stdin;
+}
+
+static void
+wide (const char *path)
+{
+ FILE *old_stdin = stdin;
+ stdin = xfopen (path, "r");
+
+ TEST_COMPARE (getwchar (), L'a');
+ TEST_COMPARE (getwchar_unlocked (), L'b');
+ wchar_t ch = 1;
+ TEST_COMPARE (wscanf (L"%c", &ch), 1);
+ TEST_COMPARE (ch, L'c');
+ TEST_COMPARE (call_vwscanf (L"%c", &ch), 1);
+ TEST_COMPARE (ch, L'd');
+
+ fclose (stdin);
+ stdin = old_stdin;
+}
+
+static int
+do_test (void)
+{
+ char *path;
+ {
+ int fd = create_temp_file ("tst-bz24153-", &path);
+ TEST_VERIFY_EXIT (fd >= 0);
+ xwrite (fd, "abcdef", strlen ("abcdef"));
+ xclose (fd);
+ }
+
+ narrow (path);
+ wide (path);
+
+ free (path);
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/libio/vscanf.c b/libio/vscanf.c
index 342dc3effc..526d486399 100644
--- a/libio/vscanf.c
+++ b/libio/vscanf.c
@@ -37,6 +37,6 @@
int
_IO_vscanf (const char *format, va_list args)
{
- return __vfscanf_internal (_IO_stdin, format, args, 0);
+ return __vfscanf_internal (stdin, format, args, 0);
}
ldbl_weak_alias (_IO_vscanf, vscanf)
diff --git a/libio/vwscanf.c b/libio/vwscanf.c
index 696e4c5c99..7b1903c71d 100644
--- a/libio/vwscanf.c
+++ b/libio/vwscanf.c
@@ -35,6 +35,6 @@
int
__vwscanf (const wchar_t *format, va_list args)
{
- return __vfwscanf_internal (_IO_stdin, format, args, 0);
+ return __vfwscanf_internal (stdin, format, args, 0);
}
ldbl_strong_alias (__vwscanf, vwscanf)