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Re: [PATCH v3 6/7] Use PRINTF_FORTIFY instead of _IO_FLAGS2_FORTIFY (bug 11319)
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: "Gabriel F. T. Gomes" <gabriel at inconstante dot eti dot br>
- Cc: libc-alpha at sourceware dot org
- Date: Wed, 5 Dec 2018 16:14:17 -0200
- Subject: Re: [PATCH v3 6/7] Use PRINTF_FORTIFY instead of _IO_FLAGS2_FORTIFY (bug 11319)
- References: <20181115214449.19262-1-gabriel@inconstante.eti.br> <20181115214449.19262-7-gabriel@inconstante.eti.br> <878aa68c-1a30-69d6-ae01-4acd6d80ccaa@linaro.org> <20181204141946.26ba9107@tereshkova> <4eff527e-f466-d778-bc14-00727be3e1b1@linaro.org> <20181204160127.0ca1ec00@tereshkova> <99ffe00c-3fd1-ab6b-0bf4-4531583a87ee@linaro.org> <20181205145337.74d49721@tereshkova>
On 05/12/2018 14:53, Gabriel F. T. Gomes wrote:
> On Tue, 04 Dec 2018, Adhemerval Zanella wrote:
>
>> On 04/12/2018 16:01, Gabriel F. T. Gomes wrote:
>>>
>>> +#ifndef _GNU_SOURCE
>>> +# define _GNU_SOURCE 1
>>> +#endif
>>
>> I think we can define it regardless
>
> OK.
>
>>> +#include <errno.h>
>>> +#include <stdio.h>
>>> +#include <string.h>
>>> +#include <sys/eventfd.h>
>>
>> eventfd is Linux specific, so either we need to move this test to Linux
>> sysdeps or use a platform neutral way to stress this issue.
>
> Oh, indeed.
>
>>> +
>>> +#include <support/check.h>
>>> +
>>> +static int
>>> +do_test (void)
>>> +{
>>> + int ret;
>>> + int fd = eventfd(0, 0);
>>
>> To stress this issue we just need a valid file descriptor that is seekable
>> but fail on a write. Just use a temporary file opened in read-only mode.
>
> Does the following patch look better (thanks for the suggestion)?
>
> From d992bc941921988fee31ff8b3fc13fb406f89b93 Mon Sep 17 00:00:00 2001
> From: "Gabriel F. T. Gomes" <gabriel@inconstante.eti.br>
> Date: Tue, 4 Dec 2018 15:57:57 -0200
> Subject: [PATCH v2] Add test for bug 11319
>
> The commit
>
> commit 7ca890b88e6ab7624afb1742a9fffb37ad5b3fc3
> Author: Ulrich Drepper <drepper@redhat.com>
> Date: Wed Feb 24 16:07:57 2010 -0800
>
> Fix reporting of I/O errors in *dprintf functions.
>
> fixed bug 11319 for dprintf and vdprintf, however, it did not fix it for
> __dprintf_chk and __vdprintf_chk. As a side-effect of the refactoring
> of libio functions, this bug is also fixed for the foritified functions.
> This patch adds a test case to avoid regressions.
>
> Tested for powerpc64le and x86_64.
>
> * stdio-common/Makefile (tests): Add tst-bz11319 and
> tst-bz11319-fortify2.
> (CFLAGS-tst-bz11319-fortify2.c): New macro.
> * stdio-common/tst-bz11319-fortify2.c: New file.
> * stdio-common/tst-bz11319.c: Likewise.
> ---
> stdio-common/Makefile | 6 ++++-
> stdio-common/tst-bz11319-fortify2.c | 1 +
> stdio-common/tst-bz11319.c | 52 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 58 insertions(+), 1 deletion(-)
> create mode 100644 stdio-common/tst-bz11319-fortify2.c
> create mode 100644 stdio-common/tst-bz11319.c
>
> diff --git a/stdio-common/Makefile b/stdio-common/Makefile
> index 84bad1fafe..8978b3fb1f 100644
> --- a/stdio-common/Makefile
> +++ b/stdio-common/Makefile
> @@ -64,7 +64,7 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \
> tst-vfprintf-user-type \
> tst-vfprintf-mbs-prec \
> tst-scanf-round \
> - tst-renameat2 \
> + tst-renameat2 tst-bz11319 tst-bz11319-fortify2 \
>
> test-srcs = tst-unbputc tst-printf tst-printfsz-islongdouble
>
> @@ -164,6 +164,10 @@ CFLAGS-test_rdwr.c += -DOBJPFX=\"$(objpfx)\"
> # tst-gets.c tests a deprecated function.
> CFLAGS-tst-gets.c += -Wno-deprecated-declarations
>
> +# BZ #11319 was first fixed for regular vdprintf, then reopened because
> +# the fortified version had the same bug.
> +CFLAGS-tst-bz11319-fortify2.c += -D_FORTIFY_SOURCE=2
> +
> CPPFLAGS += $(libio-mtsafe)
>
> $(objpfx)tst-setvbuf1.out: /dev/null $(objpfx)tst-setvbuf1
> diff --git a/stdio-common/tst-bz11319-fortify2.c b/stdio-common/tst-bz11319-fortify2.c
> new file mode 100644
> index 0000000000..a8df9a39bd
> --- /dev/null
> +++ b/stdio-common/tst-bz11319-fortify2.c
> @@ -0,0 +1 @@
> +#include <tst-bz11319.c>
> diff --git a/stdio-common/tst-bz11319.c b/stdio-common/tst-bz11319.c
> new file mode 100644
> index 0000000000..29fbd729ab
> --- /dev/null
> +++ b/stdio-common/tst-bz11319.c
> @@ -0,0 +1,52 @@
> +/* Regression test for bug 11319.
> + Copyright (C) 2018 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/>. */
> +
> +#define _GNU_SOURCE 1
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +#include <support/check.h>
> +#include <support/temp_file.h>
> +#include <support/xstdio.h>
> +
> +static int
> +do_test (void)
> +{
> + char *tempfile;
> + int ret;
> + FILE *fp;
> +
> + /* Create a temporary file and open it in read-only mode. */
> + TEST_VERIFY_EXIT (create_temp_file ("tst-bz11319", &tempfile));
> + fp = xfopen (tempfile, "r");
> +
> + /* Try and write to the temporary file to intentionally fail, then
> + check that dprintf (or __dprintf_chk) return EOF. */
> + ret = dprintf (fp->_fileno, "%d", 0);
> + TEST_VERIFY (ret == EOF);
> +
> + /* Clean up. */
> + xfclose (fp);
> + if (tempfile)
> + free (tempfile);
For a lack of a better interface (to create/open read-only temporary files
or memfd_create), I think it would be simpler to:
static int
do_test (void)
{
char *tempfile;
int fd;
/* Create a temporary file and open it in read-only mode. */
TEST_VERIFY_EXIT (create_temp_file ("tst-bz11319", &tempfile));
fd = xopen (tempfile, O_RDONLY, 0660);
/* Try and write to the temporary file to intentionally fail, then
check that dprintf (or __dprintf_chk) return EOF. */
TEST_COMPARE (dprintf (fd, "%d", 0), EOF);
xclose (fd);
free (tempfile);
return 0;
}
> +
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
>