diff mbox series

libio: handle opening a file when all files are closed (bug 31963)

Message ID mvmwmlwgf66.fsf@suse.de
State New
Headers show
Series libio: handle opening a file when all files are closed (bug 31963) | expand

Commit Message

Andreas Schwab July 8, 2024, 1:57 p.m. UTC 
_IO_list_all becomes NULL when all files (including standard files) are
closed.
---
 libio/Makefile       |  1 +
 libio/genops.c       |  3 ++-
 libio/tst-closeall.c | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 libio/tst-closeall.c

Comments

Sam James July 9, 2024, 4:06 a.m. UTC | #1 
Andreas Schwab <schwab@suse.de> writes:

> _IO_list_all becomes NULL when all files (including standard files) are
> closed.

r-b for either patch (yours or H.J's)

> ---
>  libio/Makefile       |  1 +
>  libio/genops.c       |  3 ++-
>  libio/tst-closeall.c | 34 ++++++++++++++++++++++++++++++++++
>  3 files changed, 37 insertions(+), 1 deletion(-)
>  create mode 100644 libio/tst-closeall.c
>
> diff --git a/libio/Makefile b/libio/Makefile
> index 82c7e3ef0b..1f7031066c 100644
> --- a/libio/Makefile
> +++ b/libio/Makefile
> @@ -91,6 +91,7 @@ tests = \
>    tst-bz24051 \
>    tst-bz24153 \
>    tst-bz28828 \
> +  tst-closeall \
>    tst-eof \
>    tst-ext \
>    tst-ext2 \
> diff --git a/libio/genops.c b/libio/genops.c
> index 994ee9c0b1..99f5e80f20 100644
> --- a/libio/genops.c
> +++ b/libio/genops.c
> @@ -119,7 +119,8 @@ _IO_link_in (struct _IO_FILE_plus *fp)
>        if (_IO_vtable_offset ((FILE *) fp) == 0)
>  	{
>  	  fp->file._prevchain = (FILE **) &_IO_list_all;
> -	  _IO_list_all->file._prevchain = &fp->file._chain;
> +	  if (_IO_list_all != NULL)
> +	    _IO_list_all->file._prevchain = &fp->file._chain;
>  	}
>        _IO_list_all = fp;
>  #ifdef _IO_MTSAFE_IO
> diff --git a/libio/tst-closeall.c b/libio/tst-closeall.c
> new file mode 100644
> index 0000000000..34f5246490
> --- /dev/null
> +++ b/libio/tst-closeall.c
> @@ -0,0 +1,34 @@
> +/* Test that opening a file when all files are closed does not crash (bug 31963)
> +   Copyright (C) 2024 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
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <support/check.h>
> +#include <support/xstdio.h>
> +
> +static int
> +do_test (void)
> +{
> +  xfclose (stdin);
> +  xfclose (stdout);
> +  xfclose (stderr);
> +  FILE *f = xfopen ("/dev/null", "w");
> +  fprintf (f, "final\n");
> +  xfclose (f);
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
> -- 
> 2.45.2
Andreas K. Huettel July 9, 2024, 7:56 a.m. UTC | #2 
OK for 2.40 with someone's R-B, either this one or HJL's obviously

Am Montag, 8. Juli 2024, 15:57:05 MESZ schrieb Andreas Schwab:
> _IO_list_all becomes NULL when all files (including standard files) are
> closed.
> ---
>  libio/Makefile       |  1 +
>  libio/genops.c       |  3 ++-
>  libio/tst-closeall.c | 34 ++++++++++++++++++++++++++++++++++
>  3 files changed, 37 insertions(+), 1 deletion(-)
>  create mode 100644 libio/tst-closeall.c
> 
> diff --git a/libio/Makefile b/libio/Makefile
> index 82c7e3ef0b..1f7031066c 100644
> --- a/libio/Makefile
> +++ b/libio/Makefile
> @@ -91,6 +91,7 @@ tests = \
>    tst-bz24051 \
>    tst-bz24153 \
>    tst-bz28828 \
> +  tst-closeall \
>    tst-eof \
>    tst-ext \
>    tst-ext2 \
> diff --git a/libio/genops.c b/libio/genops.c
> index 994ee9c0b1..99f5e80f20 100644
> --- a/libio/genops.c
> +++ b/libio/genops.c
> @@ -119,7 +119,8 @@ _IO_link_in (struct _IO_FILE_plus *fp)
>        if (_IO_vtable_offset ((FILE *) fp) == 0)
>  	{
>  	  fp->file._prevchain = (FILE **) &_IO_list_all;
> -	  _IO_list_all->file._prevchain = &fp->file._chain;
> +	  if (_IO_list_all != NULL)
> +	    _IO_list_all->file._prevchain = &fp->file._chain;
>  	}
>        _IO_list_all = fp;
>  #ifdef _IO_MTSAFE_IO
> diff --git a/libio/tst-closeall.c b/libio/tst-closeall.c
> new file mode 100644
> index 0000000000..34f5246490
> --- /dev/null
> +++ b/libio/tst-closeall.c
> @@ -0,0 +1,34 @@
> +/* Test that opening a file when all files are closed does not crash (bug 31963)
> +   Copyright (C) 2024 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
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <support/check.h>
> +#include <support/xstdio.h>
> +
> +static int
> +do_test (void)
> +{
> +  xfclose (stdin);
> +  xfclose (stdout);
> +  xfclose (stderr);
> +  FILE *f = xfopen ("/dev/null", "w");
> +  fprintf (f, "final\n");
> +  xfclose (f);
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
>
diff mbox series

Patch

diff --git a/libio/Makefile b/libio/Makefile
index 82c7e3ef0b..1f7031066c 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -91,6 +91,7 @@  tests = \
   tst-bz24051 \
   tst-bz24153 \
   tst-bz28828 \
+  tst-closeall \
   tst-eof \
   tst-ext \
   tst-ext2 \
diff --git a/libio/genops.c b/libio/genops.c
index 994ee9c0b1..99f5e80f20 100644
--- a/libio/genops.c
+++ b/libio/genops.c
@@ -119,7 +119,8 @@  _IO_link_in (struct _IO_FILE_plus *fp)
       if (_IO_vtable_offset ((FILE *) fp) == 0)
 	{
 	  fp->file._prevchain = (FILE **) &_IO_list_all;
-	  _IO_list_all->file._prevchain = &fp->file._chain;
+	  if (_IO_list_all != NULL)
+	    _IO_list_all->file._prevchain = &fp->file._chain;
 	}
       _IO_list_all = fp;
 #ifdef _IO_MTSAFE_IO
diff --git a/libio/tst-closeall.c b/libio/tst-closeall.c
new file mode 100644
index 0000000000..34f5246490
--- /dev/null
+++ b/libio/tst-closeall.c
@@ -0,0 +1,34 @@ 
+/* Test that opening a file when all files are closed does not crash (bug 31963)
+   Copyright (C) 2024 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/xstdio.h>
+
+static int
+do_test (void)
+{
+  xfclose (stdin);
+  xfclose (stdout);
+  xfclose (stderr);
+  FILE *f = xfopen ("/dev/null", "w");
+  fprintf (f, "final\n");
+  xfclose (f);
+  return 0;
+}
+
+#include <support/test-driver.c>