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Re: [PATCH] libio: Fix gconv-related memory leak [BZ #24583]
* Florian Weimer:
> * Andreas Schwab:
>
>> On Mai 20 2019, Florian Weimer <fweimer@redhat.com> wrote:
>>
>>> diff --git a/libio/iofclose.c b/libio/iofclose.c
>>> index 8a80dd0b78..f4c7299db3 100644
>>> --- a/libio/iofclose.c
>>> +++ b/libio/iofclose.c
>>> @@ -61,10 +61,10 @@ _IO_new_fclose (FILE *fp)
>>> the conversion functions. */
>>> struct _IO_codecvt *cc = fp->_codecvt;
>>>
>>> - __libc_lock_lock (__gconv_lock);
>>> - __gconv_release_step (cc->__cd_in.__cd.__steps);
>>> - __gconv_release_step (cc->__cd_out.__cd.__steps);
>>> - __libc_lock_unlock (__gconv_lock);
>>> + __gconv_close_transform (cc->__cd_in.__cd.__steps,
>>> + cc->__cd_in.__cd.__nsteps);
>>> + __gconv_close_transform (cc->__cd_out.__cd.__steps,
>>> + cc->__cd_out.__cd.__nsteps);
>>
>> Are the __steps always allocated? In get_gconv_fcts I see them being
>> set to static data.
>
> Correct, this needs to be handled differently. It is difficult to
> reproduce because the test framework disables the gconv cache (even when
> running in a container).
>
> I will try to fix the test framework first.
I've already posted the sbindir patch and the test-in-container fix.
The patch below should fix the memory leak, while avoiding the static
allocation issue you've identified. Ideally, we would use struct
gconv_fcts in libio as well, but I think that's best handled as a
separate cleanup, after the codecvt vtable removal.
Thanks,
Florian
libio: Fix gconv-related memory leak [BZ #24583]
struct gconv_fcts for the C locale is statically allocated,
and __gconv_close_transform deallocates the steps object.
Therefore this commit introduces __wcsmbs_close_conv to avoid
freeing the statically allocated step objects.
2019-05-20 Florian Weimer <fweimer@redhat.com>
[BZ #24583]
* wcsmbs/wcsmbsload.h (__wcsmbs_close_conv): Declare.
* wcsmbs/wcsmbsload.c (__wcsmbs_close_conv): Define.
* libio/iofclose.c (_IO_new_fclose): Call __wcsmbs_close_conv
instead of __gconv_release_step.
* libio/Makefile (tests): Add tst-wfile-gconv.
(tests-container): Add tst-wfile-ascii.
(tst-wfile-gconv-ENV): Enable mtrace.
(generated): Add tst-wfile-gconv.mtrace, tst-wfile-gconv.check.
(tests-special): Add tst-wfile-gconv-mem.out.
(tst-wfile-gconv.out): Depend on locales.
(tst-wfile-gconv-mem.out): Add mtrace rule.
* libio/tst-wfile-ascii.c: New file.
* libio/tst-wfile-gconv.c: Likewise.
diff --git a/libio/Makefile b/libio/Makefile
index a5236c7042..7d53cb06b0 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -66,7 +66,11 @@ tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc \
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-bz24153 \
- tst-wfile-sync
+ tst-wfile-sync tst-wfile-gconv
+
+# This test tests interaction with the gconv cache. Setting
+# GCONV_CACHE during out-of-container testing disables the cache.
+tests-container += tst-wfile-ascii
tests-internal = tst-vtables tst-vtables-interposed tst-readline
@@ -163,10 +167,12 @@ tst_wprintf2-ARGS = "Some Text"
test-fmemopen-ENV = MALLOC_TRACE=$(objpfx)test-fmemopen.mtrace
tst-fopenloc-ENV = MALLOC_TRACE=$(objpfx)tst-fopenloc.mtrace
tst-bz22415-ENV = MALLOC_TRACE=$(objpfx)tst-bz22415.mtrace
+tst-wfile-gconv-ENV = MALLOC_TRACE=$(objpfx)tst-wfile-gconv.mtrace
generated += test-fmemopen.mtrace test-fmemopen.check
generated += tst-fopenloc.mtrace tst-fopenloc.check
generated += tst-bz22415.mtrace tst-bz22415.check
+generated += tst-wfile-gconv.mtrace tst-wfile-gconv.check
aux := fileops genops stdfiles stdio strops
@@ -181,7 +187,8 @@ shared-only-routines = oldiofopen oldiofdopen oldiofclose oldfileops \
ifeq ($(run-built-tests),yes)
tests-special += $(objpfx)test-freopen.out $(objpfx)test-fmemopen-mem.out \
- $(objpfx)tst-bz22415-mem.out
+ $(objpfx)tst-bz22415-mem.out \
+ $(objpfx)tst-wfile-gconv-mem.out
ifeq (yes,$(build-shared))
# Run tst-fopenloc-cmp.out and tst-openloc-mem.out only if shared
# library is enabled since they depend on tst-fopenloc.out.
@@ -214,6 +221,7 @@ $(objpfx)tst-ungetwc2.out: $(gen-locales)
$(objpfx)tst-widetext.out: $(gen-locales)
$(objpfx)tst_wprintf2.out: $(gen-locales)
$(objpfx)tst-wfile-sync.out: $(gen-locales)
+$(objpfx)tst-wfile-gconv.out: $(gen-locales)
endif
$(objpfx)test-freopen.out: test-freopen.sh $(objpfx)test-freopen
@@ -237,3 +245,7 @@ $(objpfx)tst-fopenloc-mem.out: $(objpfx)tst-fopenloc.out
$(objpfx)tst-bz22415-mem.out: $(objpfx)tst-bz22415.out
$(common-objpfx)malloc/mtrace $(objpfx)tst-bz22415.mtrace > $@; \
$(evaluate-test)
+
+$(objpfx)tst-wfile-gconv-mem.out: $(objpfx)tst-wfile-gconv.out
+ $(common-objpfx)malloc/mtrace $(objpfx)tst-wfile-gconv.mtrace > $@; \
+ $(evaluate-test)
diff --git a/libio/iofclose.c b/libio/iofclose.c
index 8a80dd0b78..c03c6cf57c 100644
--- a/libio/iofclose.c
+++ b/libio/iofclose.c
@@ -26,8 +26,8 @@
#include "libioP.h"
#include <stdlib.h>
-#include "../iconv/gconv_int.h"
#include <shlib-compat.h>
+#include <wcsmbs/wcsmbsload.h>
int
_IO_new_fclose (FILE *fp)
@@ -60,11 +60,14 @@ _IO_new_fclose (FILE *fp)
/* This stream has a wide orientation. This means we have to free
the conversion functions. */
struct _IO_codecvt *cc = fp->_codecvt;
-
- __libc_lock_lock (__gconv_lock);
- __gconv_release_step (cc->__cd_in.__cd.__steps);
- __gconv_release_step (cc->__cd_out.__cd.__steps);
- __libc_lock_unlock (__gconv_lock);
+ struct gconv_fcts conv =
+ {
+ .towc = cc->__cd_in.__cd.__steps,
+ .towc_nsteps = cc->__cd_in.__cd.__nsteps,
+ .tomb = cc->__cd_out.__cd.__steps,
+ .tomb_nsteps = cc->__cd_out.__cd.__nsteps,
+ };
+ __wcsmbs_close_conv (&conv);
}
else
{
diff --git a/libio/tst-wfile-ascii.c b/libio/tst-wfile-ascii.c
new file mode 100644
index 0000000000..77272fc125
--- /dev/null
+++ b/libio/tst-wfile-ascii.c
@@ -0,0 +1,51 @@
+/* Test ASCII gconv module followed by cache initialization.
+ 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/>. */
+
+#include <stdlib.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xstdio.h>
+#include <wchar.h>
+
+static int
+do_test (void)
+{
+ /* Create the gconv module cache. iconvconfig is in /sbin, which is
+ not on PATH. */
+ {
+ char *iconvconfig = xasprintf ("%s/iconvconfig", support_sbindir_prefix);
+ TEST_COMPARE (system (iconvconfig), 0);
+ }
+
+ /* Use built-in ASCII gconv module, without triggering cache
+ initialization. */
+ FILE *fp1 = xfopen ("/dev/zero", "r");
+ TEST_COMPARE (fwide (fp1, 1), 1);
+
+ /* Use non-ASCII gconv module and trigger gconv cache
+ initialization. */
+ FILE *fp2 = xfopen ("/dev/zero", "r,ccs=UTF-8");
+ TEST_COMPARE (fwide (fp2, 0), 1);
+
+ xfclose (fp1);
+ xfclose (fp2);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/libio/tst-wfile-gconv.c b/libio/tst-wfile-gconv.c
new file mode 100644
index 0000000000..de603b32d2
--- /dev/null
+++ b/libio/tst-wfile-gconv.c
@@ -0,0 +1,36 @@
+/* Test that non-built-in gconv modules do not cause memory leak (bug 24583).
+ 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/>. */
+
+#include <locale.h>
+#include <mcheck.h>
+#include <support/check.h>
+#include <support/xstdio.h>
+
+static int
+do_test (void)
+{
+ mtrace ();
+
+ TEST_VERIFY_EXIT (setlocale (LC_ALL, "ja_JP.EUC-JP") != NULL);
+ xfclose (xfopen ("/etc/passwd", "r,ccs=UTF-8"));
+ xfclose (xfopen ("/etc/passwd", "r"));
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/wcsmbs/wcsmbsload.c b/wcsmbs/wcsmbsload.c
index 5494d0a23e..cff7ca85f9 100644
--- a/wcsmbs/wcsmbsload.c
+++ b/wcsmbs/wcsmbsload.c
@@ -265,3 +265,17 @@ _nl_cleanup_ctype (struct __locale_data *locale)
free ((char *) data);
}
}
+
+/* Free the specified conversion functions (but not CONV itself). */
+void
+__wcsmbs_close_conv (struct gconv_fcts *conv)
+{
+ /* Nothing to do if both conversions are statically allocated. */
+ if (conv->towc == &to_wc && conv->tomb == &to_mb)
+ return;
+
+ if (conv->towc != &to_wc)
+ __gconv_close_transform (conv->towc, conv->towc_nsteps);
+ if (conv->tomb != &to_mb)
+ __gconv_close_transform (conv->tomb, conv->tomb_nsteps);
+}
diff --git a/wcsmbs/wcsmbsload.h b/wcsmbs/wcsmbsload.h
index 6ccad4b3ba..c2fffbd914 100644
--- a/wcsmbs/wcsmbsload.h
+++ b/wcsmbs/wcsmbsload.h
@@ -51,6 +51,7 @@ extern int __wcsmbs_named_conv (struct gconv_fcts *copy, const char *name)
/* Function used for the `private.cleanup' hook. */
extern void _nl_cleanup_ctype (struct __locale_data *) attribute_hidden;
+extern void __wcsmbs_close_conv (struct gconv_fcts *conv) attribute_hidden;
#include <iconv/gconv_int.h>