* [committed 2.37 1/5] support: Add FAIL test failure helper
2024-08-30 15:28 [committed 2.37 0/5] vfscanf test case and ungetc fix Siddhesh Poyarekar
@ 2024-08-30 15:28 ` Siddhesh Poyarekar
2024-08-30 15:28 ` [committed 2.37 2/5] stdio-common: Add test for vfscanf with matches longer than INT_MAX [BZ #27650] Siddhesh Poyarekar
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2024-08-30 15:28 UTC (permalink / raw)
To: libc-stable; +Cc: Maciej W. Rozycki, DJ Delorie
From: "Maciej W. Rozycki" <macro@redhat.com>
Add a FAIL test failure helper analogous to FAIL_RET, that does not
cause the current function to return, providing a standardized way to
report a test failure with a message supplied while permitting the
caller to continue executing, for further reporting, cleaning up, etc.
Update existing test cases that provide a conflicting definition of FAIL
by removing the local FAIL definition and then as follows:
- tst-fortify-syslog: provide a meaningful message in addition to the
file name already added by <support/check.h>; 'support_record_failure'
is already called by 'support_print_failure_impl' invoked by the new
FAIL test failure helper.
- tst-ctype: no update to FAIL calls required, with the name of the file
and the line number within of the failure site additionally included
by the new FAIL test failure helper, and error counting plus count
reporting upon test program termination also already provided by
'support_record_failure' and 'support_report_failure' respectively,
called by 'support_print_failure_impl' and 'adjust_exit_status' also
respectively. However in a number of places 'printf' is called and
the error count adjusted by hand, so update these places to make use
of FAIL instead. And last but not least adjust the final summary just
to report completion, with any error count following as reported by
the test driver.
- test-tgmath2: no update to FAIL calls required, with the name of the
file of the failure site additionally included by the new FAIL test
failure helper. Also there is no need to track the return status by
hand as any call to FAIL will eventually cause the test case to return
an unsuccesful exit status regardless of the return status from the
test function, via a call to 'adjust_exit_status' made by the test
driver.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 1b97a9f23bf605ca608162089c94187573fb2a9e)
(cherry picked from commit 28f358bc4209ab0425170cdccf65bb1fe861148f)
---
localedata/tst-ctype.c | 40 +++++++++-------------------------------
math/test-tgmath2.c | 13 +++----------
support/check.h | 5 +++++
3 files changed, 17 insertions(+), 41 deletions(-)
diff --git a/localedata/tst-ctype.c b/localedata/tst-ctype.c
index 098bf51335..355b666866 100644
--- a/localedata/tst-ctype.c
+++ b/localedata/tst-ctype.c
@@ -21,6 +21,8 @@
#include <stdio.h>
#include <string.h>
+#include <support/check.h>
+
static const char lower[] = "abcdefghijklmnopqrstuvwxyz";
static const char upper[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
@@ -53,19 +55,11 @@ static struct classes
#define nclasses (sizeof (classes) / sizeof (classes[0]))
-#define FAIL(str, args...) \
- { \
- printf (" " str "\n", ##args); \
- ++errors; \
- }
-
-
static int
do_test (void)
{
const char *cp;
const char *cp2;
- int errors = 0;
char *inpline = NULL;
size_t inplinelen = 0;
char *resline = NULL;
@@ -394,11 +388,8 @@ punct = %04x alnum = %04x\n",
{
if (((__ctype_b[(unsigned int) *inp] & classes[n].mask) != 0)
!= (*resp != '0'))
- {
- printf (" is%s('%c' = '\\x%02x') %s true\n", inpline,
- *inp, *inp, *resp == '1' ? "not" : "is");
- ++errors;
- }
+ FAIL (" is%s('%c' = '\\x%02x') %s true\n", inpline,
+ *inp, *inp, *resp == '1' ? "not" : "is");
++inp;
++resp;
}
@@ -408,11 +399,8 @@ punct = %04x alnum = %04x\n",
while (*inp != '\0')
{
if (tolower (*inp) != *resp)
- {
- printf (" tolower('%c' = '\\x%02x') != '%c'\n",
- *inp, *inp, *resp);
- ++errors;
- }
+ FAIL (" tolower('%c' = '\\x%02x') != '%c'\n",
+ *inp, *inp, *resp);
++inp;
++resp;
}
@@ -422,11 +410,8 @@ punct = %04x alnum = %04x\n",
while (*inp != '\0')
{
if (toupper (*inp) != *resp)
- {
- printf (" toupper('%c' = '\\x%02x') != '%c'\n",
- *inp, *inp, *resp);
- ++errors;
- }
+ FAIL (" toupper('%c' = '\\x%02x') != '%c'\n",
+ *inp, *inp, *resp);
++inp;
++resp;
}
@@ -436,14 +421,7 @@ punct = %04x alnum = %04x\n",
}
- if (errors != 0)
- {
- printf (" %d error%s for `%s' locale\n\n\n", errors,
- errors == 1 ? "" : "s", setlocale (LC_ALL, NULL));
- return 1;
- }
-
- printf (" No errors for `%s' locale\n\n\n", setlocale (LC_ALL, NULL));
+ printf ("Completed testing for `%s' locale\n\n\n", setlocale (LC_ALL, NULL));
return 0;
}
diff --git a/math/test-tgmath2.c b/math/test-tgmath2.c
index 6dd0d64da5..deba439e0c 100644
--- a/math/test-tgmath2.c
+++ b/math/test-tgmath2.c
@@ -24,6 +24,8 @@
#include <string.h>
#include <tgmath.h>
+#include <support/check.h>
+
//#define DEBUG
typedef complex float cfloat;
@@ -87,13 +89,6 @@ enum
int count;
int counts[Tlast][C_last];
-#define FAIL(str) \
- do \
- { \
- printf ("%s failure on line %d\n", (str), __LINE__); \
- result = 1; \
- } \
- while (0)
#define TEST_TYPE_ONLY(expr, rettype) \
do \
{ \
@@ -133,8 +128,6 @@ int counts[Tlast][C_last];
int
test_cos (const int Vint4, const long long int Vllong4)
{
- int result = 0;
-
TEST (cos (vfloat1), float, cos);
TEST (cos (vdouble1), double, cos);
TEST (cos (vldouble1), ldouble, cos);
@@ -152,7 +145,7 @@ test_cos (const int Vint4, const long long int Vllong4)
TEST (cos (Vcdouble1), cdouble, cos);
TEST (cos (Vcldouble1), cldouble, cos);
- return result;
+ return 0;
}
int
diff --git a/support/check.h b/support/check.h
index e6ae39f1a1..0a9fff484f 100644
--- a/support/check.h
+++ b/support/check.h
@@ -24,6 +24,11 @@
__BEGIN_DECLS
+/* Record a test failure, print the failure message to standard output
+ and pass the result of 1 through. */
+#define FAIL(...) \
+ support_print_failure_impl (__FILE__, __LINE__, __VA_ARGS__)
+
/* Record a test failure, print the failure message to standard output
and return 1. */
#define FAIL_RET(...) \
--
2.45.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [committed 2.37 2/5] stdio-common: Add test for vfscanf with matches longer than INT_MAX [BZ #27650]
2024-08-30 15:28 [committed 2.37 0/5] vfscanf test case and ungetc fix Siddhesh Poyarekar
2024-08-30 15:28 ` [committed 2.37 1/5] support: Add FAIL test failure helper Siddhesh Poyarekar
@ 2024-08-30 15:28 ` Siddhesh Poyarekar
2024-08-30 15:28 ` [committed 2.37 3/5] Make tst-ungetc use libsupport Siddhesh Poyarekar
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2024-08-30 15:28 UTC (permalink / raw)
To: libc-stable; +Cc: Maciej W. Rozycki, DJ Delorie
From: "Maciej W. Rozycki" <macro@redhat.com>
Complement commit b03e4d7bd25b ("stdio: fix vfscanf with matches longer
than INT_MAX (bug 27650)") and add a test case for the issue, inspired
by the reproducer provided with the bug report.
This has been verified to succeed as from the commit referred and fail
beforehand.
As the test requires 2GiB of data to be passed around its performance
has been evaluated using a choice of systems and the execution time
determined to be respectively in the range of 9s for POWER9@2.166GHz,
24s for FU740@1.2GHz, and 40s for 74Kf@950MHz. As this is on the verge
of and beyond the default timeout it has been increased by the factor of
8. Regardless, following recent practice the test has been added to the
standard rather than extended set.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 89cddc8a7096f3d9225868304d2bc0a1aaf07d63)
(cherry picked from commit 99ffa84bdcdc3d81e82f448279f0c8278dd30964)
---
stdio-common/Makefile | 5 ++
stdio-common/tst-scanf-bz27650.c | 108 +++++++++++++++++++++++++++++++
2 files changed, 113 insertions(+)
create mode 100644 stdio-common/tst-scanf-bz27650.c
diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index fdc49f32ea..eb1f2791ac 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -214,6 +214,7 @@ tests := \
tst-put-error \
tst-renameat2 \
tst-rndseek \
+ tst-scanf-bz27650 \
tst-scanf-round \
tst-setvbuf1 \
tst-sprintf \
@@ -274,6 +275,7 @@ generated += \
tst-printf-fp-free.mtrace \
tst-printf-fp-leak-mem.out \
tst-printf-fp-leak.mtrace \
+ tst-scanf-bz27650.mtrace \
tst-vfprintf-width-prec-mem.out \
tst-vfprintf-width-prec.mtrace \
# generated
@@ -358,6 +360,9 @@ tst-printf-fp-free-ENV = \
tst-printf-fp-leak-ENV = \
MALLOC_TRACE=$(objpfx)tst-printf-fp-leak.mtrace \
LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
+tst-scanf-bz27650-ENV = \
+ MALLOC_TRACE=$(objpfx)tst-scanf-bz27650.mtrace \
+ LD_PRELOAD=$(common-objpfx)malloc/libc_malloc_debug.so
$(objpfx)tst-unbputc.out: tst-unbputc.sh $(objpfx)tst-unbputc
$(SHELL) $< $(common-objpfx) '$(test-program-prefix)'; \
diff --git a/stdio-common/tst-scanf-bz27650.c b/stdio-common/tst-scanf-bz27650.c
new file mode 100644
index 0000000000..3a742bc865
--- /dev/null
+++ b/stdio-common/tst-scanf-bz27650.c
@@ -0,0 +1,108 @@
+/* Test for BZ #27650, formatted input matching beyond INT_MAX.
+ 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 <error.h>
+#include <errno.h>
+#include <limits.h>
+#include <mcheck.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <sys/types.h>
+
+#include <support/check.h>
+#include <support/test-driver.h>
+
+/* Produce a stream of more than INT_MAX characters via buffer BUF of
+ size SIZE according to bookkeeping in COOKIE and then return EOF. */
+
+static ssize_t
+io_read (void *cookie, char *buf, size_t size)
+{
+ unsigned int *written = cookie;
+ unsigned int w = *written;
+
+ if (w > INT_MAX)
+ return 0;
+
+ memset (buf, 'a', size);
+ *written = w + size;
+ return size;
+}
+
+/* Consume a stream of more than INT_MAX characters from an artificial
+ input stream of which none is the new line character. The call to
+ fscanf is supposed to complete upon the EOF condition of input,
+ however in the presence of BZ #27650 it will terminate prematurely
+ with characters still outstanding in input. Diagnose the condition
+ and return status accordingly. */
+
+int
+do_test (void)
+{
+ static cookie_io_functions_t io_funcs = { .read = io_read };
+ unsigned int written = 0;
+ FILE *in;
+ int v;
+
+ mtrace ();
+
+ in = fopencookie (&written, "r", io_funcs);
+ if (in == NULL)
+ {
+ FAIL ("fopencookie: %m");
+ goto out;
+ }
+
+ v = fscanf (in, "%*[^\n]");
+ if (ferror (in))
+ {
+ FAIL ("fscanf: input failure, at %u: %m", written);
+ goto out_close;
+ }
+ else if (v == EOF)
+ {
+ FAIL ("fscanf: unexpected end of file, at %u", written);
+ goto out_close;
+ }
+
+ if (!feof (in))
+ {
+ v = fgetc (in);
+ if (ferror (in))
+ FAIL ("fgetc: input failure: %m");
+ else if (v == EOF)
+ FAIL ("fgetc: unexpected end of file after missing end of file");
+ else if (v == '\n')
+ FAIL ("unexpected new line character received");
+ else
+ FAIL ("character received after end of file expected: \\x%02x", v);
+ }
+
+out_close:
+ if (fclose (in) != 0)
+ FAIL ("fclose: %m");
+
+out:
+ return EXIT_SUCCESS;
+}
+
+#define TIMEOUT (DEFAULT_TIMEOUT * 8)
+#include <support/test-driver.c>
--
2.45.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [committed 2.37 3/5] Make tst-ungetc use libsupport
2024-08-30 15:28 [committed 2.37 0/5] vfscanf test case and ungetc fix Siddhesh Poyarekar
2024-08-30 15:28 ` [committed 2.37 1/5] support: Add FAIL test failure helper Siddhesh Poyarekar
2024-08-30 15:28 ` [committed 2.37 2/5] stdio-common: Add test for vfscanf with matches longer than INT_MAX [BZ #27650] Siddhesh Poyarekar
@ 2024-08-30 15:28 ` Siddhesh Poyarekar
2024-08-30 15:29 ` [committed 2.37 4/5] ungetc: Fix uninitialized read when putting into unused streams [BZ #27821] Siddhesh Poyarekar
2024-08-30 15:29 ` [committed 2.37 5/5] ungetc: Fix backup buffer leak on program exit " Siddhesh Poyarekar
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2024-08-30 15:28 UTC (permalink / raw)
To: libc-stable; +Cc: Carlos O'Donell
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 3f7df7e757f4efec38e45d4068e5492efcac4856)
(cherry picked from commit 87a1968a72e4b4e5436f3e2be1ed8a8d5a5862c7)
---
stdio-common/tst-ungetc.c | 112 +++++++++++++++++++-------------------
1 file changed, 57 insertions(+), 55 deletions(-)
diff --git a/stdio-common/tst-ungetc.c b/stdio-common/tst-ungetc.c
index 1344b2b591..5c808f0734 100644
--- a/stdio-common/tst-ungetc.c
+++ b/stdio-common/tst-ungetc.c
@@ -1,70 +1,72 @@
-/* Test for ungetc bugs. */
+/* Test for ungetc bugs.
+ Copyright (C) 1996-2024 Free Software Foundation, Inc.
+ Copyright The GNU Toolchain Authors.
+ 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 <stdio.h>
#include <stdlib.h>
-#include <unistd.h>
-
-#undef assert
-#define assert(x) \
- if (!(x)) \
- { \
- fputs ("test failed: " #x "\n", stderr); \
- retval = 1; \
- goto the_end; \
- }
+#include <support/check.h>
+#include <support/support.h>
+#include <support/temp_file.h>
+#include <support/xstdio.h>
+#include <support/xunistd.h>
-int
-main (int argc, char *argv[])
+static int
+do_test (void)
{
- char name[] = "/tmp/tst-ungetc.XXXXXX";
+ char *name = NULL;
FILE *fp = NULL;
- int retval = 0;
int c;
char buffer[64];
- int fd = mkstemp (name);
+ int fd = create_temp_file ("tst-ungetc.", &name);
if (fd == -1)
- {
- printf ("mkstemp failed: %m\n");
- return 1;
- }
- close (fd);
- fp = fopen (name, "w");
- assert (fp != NULL)
- fputs ("bla", fp);
- fclose (fp);
- fp = NULL;
+ FAIL_EXIT1 ("cannot create temporary file: %m");
+ xclose (fd);
- fp = fopen (name, "r");
- assert (fp != NULL);
- assert (ungetc ('z', fp) == 'z');
- assert (getc (fp) == 'z');
- assert (getc (fp) == 'b');
- assert (getc (fp) == 'l');
- assert (ungetc ('m', fp) == 'm');
- assert (getc (fp) == 'm');
- assert ((c = getc (fp)) == 'a');
- assert (getc (fp) == EOF);
- assert (ungetc (c, fp) == c);
- assert (feof (fp) == 0);
- assert (getc (fp) == c);
- assert (getc (fp) == EOF);
- fclose (fp);
- fp = NULL;
+ fp = xfopen (name, "w");
+ fputs ("bla", fp);
+ xfclose (fp);
- fp = fopen (name, "r");
- assert (fp != NULL);
- assert (getc (fp) == 'b');
- assert (getc (fp) == 'l');
- assert (ungetc ('b', fp) == 'b');
- assert (fread (buffer, 1, 64, fp) == 2);
- assert (buffer[0] == 'b');
- assert (buffer[1] == 'a');
+ fp = xfopen (name, "r");
+ TEST_VERIFY_EXIT (ungetc ('z', fp) == 'z');
+ TEST_VERIFY_EXIT (getc (fp) == 'z');
+ TEST_VERIFY_EXIT (getc (fp) == 'b');
+ TEST_VERIFY_EXIT (getc (fp) == 'l');
+ TEST_VERIFY_EXIT (ungetc ('m', fp) == 'm');
+ TEST_VERIFY_EXIT (getc (fp) == 'm');
+ TEST_VERIFY_EXIT ((c = getc (fp)) == 'a');
+ TEST_VERIFY_EXIT (getc (fp) == EOF);
+ TEST_VERIFY_EXIT (ungetc (c, fp) == c);
+ TEST_VERIFY_EXIT (feof (fp) == 0);
+ TEST_VERIFY_EXIT (getc (fp) == c);
+ TEST_VERIFY_EXIT (getc (fp) == EOF);
+ xfclose (fp);
-the_end:
- if (fp != NULL)
- fclose (fp);
- unlink (name);
+ fp = xfopen (name, "r");
+ TEST_VERIFY_EXIT (getc (fp) == 'b');
+ TEST_VERIFY_EXIT (getc (fp) == 'l');
+ TEST_VERIFY_EXIT (ungetc ('b', fp) == 'b');
+ TEST_VERIFY_EXIT (fread (buffer, 1, 64, fp) == 2);
+ TEST_VERIFY_EXIT (buffer[0] == 'b');
+ TEST_VERIFY_EXIT (buffer[1] == 'a');
+ xfclose (fp);
- return retval;
+ return 0;
}
+
+#include <support/test-driver.c>
--
2.45.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [committed 2.37 4/5] ungetc: Fix uninitialized read when putting into unused streams [BZ #27821]
2024-08-30 15:28 [committed 2.37 0/5] vfscanf test case and ungetc fix Siddhesh Poyarekar
` (2 preceding siblings ...)
2024-08-30 15:28 ` [committed 2.37 3/5] Make tst-ungetc use libsupport Siddhesh Poyarekar
@ 2024-08-30 15:29 ` Siddhesh Poyarekar
2024-08-30 15:29 ` [committed 2.37 5/5] ungetc: Fix backup buffer leak on program exit " Siddhesh Poyarekar
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2024-08-30 15:29 UTC (permalink / raw)
To: libc-stable; +Cc: Carlos O'Donell
When ungetc is called on an unused stream, the backup buffer is
allocated without the main get area being present. This results in
every subsequent ungetc (as the stream remains in the backup area)
checking uninitialized memory in the backup buffer when trying to put a
character back into the stream.
Avoid comparing the input character with buffer contents when in backup
to avoid this uninitialized read. The uninitialized read is harmless in
this context since the location is promptly overwritten with the input
character, thus fulfilling ungetc functionality.
Also adjust wording in the manual to drop the paragraph that says glibc
cannot do multiple ungetc back to back since with this change, ungetc
can actually do this.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit cdf0f88f97b0aaceb894cc02b21159d148d7065c)
(cherry picked from commit 804d3c8db79db204154dcf5e11a76f14fdddc570)
---
libio/genops.c | 2 +-
manual/stdio.texi | 8 +++-----
stdio-common/tst-ungetc.c | 2 ++
3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/libio/genops.c b/libio/genops.c
index 7c45052aa2..cc1b9dcac5 100644
--- a/libio/genops.c
+++ b/libio/genops.c
@@ -635,7 +635,7 @@ _IO_sputbackc (FILE *fp, int c)
{
int result;
- if (fp->_IO_read_ptr > fp->_IO_read_base
+ if (fp->_IO_read_ptr > fp->_IO_read_base && !_IO_in_backup (fp)
&& (unsigned char)fp->_IO_read_ptr[-1] == (unsigned char)c)
{
fp->_IO_read_ptr--;
diff --git a/manual/stdio.texi b/manual/stdio.texi
index d7eab1843a..2b65485997 100644
--- a/manual/stdio.texi
+++ b/manual/stdio.texi
@@ -1474,11 +1474,9 @@ program; usually @code{ungetc} is used only to unread a character that
was just read from the same stream. @Theglibc{} supports this
even on files opened in binary mode, but other systems might not.
-@Theglibc{} only supports one character of pushback---in other
-words, it does not work to call @code{ungetc} twice without doing input
-in between. Other systems might let you push back multiple characters;
-then reading from the stream retrieves the characters in the reverse
-order that they were pushed.
+@Theglibc{} supports pushing back multiple characters; subsequently
+reading from the stream retrieves the characters in the reverse order
+that they were pushed.
Pushing back characters doesn't alter the file; only the internal
buffering for the stream is affected. If a file positioning function
diff --git a/stdio-common/tst-ungetc.c b/stdio-common/tst-ungetc.c
index 5c808f0734..388b202493 100644
--- a/stdio-common/tst-ungetc.c
+++ b/stdio-common/tst-ungetc.c
@@ -48,6 +48,8 @@ do_test (void)
TEST_VERIFY_EXIT (getc (fp) == 'b');
TEST_VERIFY_EXIT (getc (fp) == 'l');
TEST_VERIFY_EXIT (ungetc ('m', fp) == 'm');
+ TEST_VERIFY_EXIT (ungetc ('n', fp) == 'n');
+ TEST_VERIFY_EXIT (getc (fp) == 'n');
TEST_VERIFY_EXIT (getc (fp) == 'm');
TEST_VERIFY_EXIT ((c = getc (fp)) == 'a');
TEST_VERIFY_EXIT (getc (fp) == EOF);
--
2.45.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [committed 2.37 5/5] ungetc: Fix backup buffer leak on program exit [BZ #27821]
2024-08-30 15:28 [committed 2.37 0/5] vfscanf test case and ungetc fix Siddhesh Poyarekar
` (3 preceding siblings ...)
2024-08-30 15:29 ` [committed 2.37 4/5] ungetc: Fix uninitialized read when putting into unused streams [BZ #27821] Siddhesh Poyarekar
@ 2024-08-30 15:29 ` Siddhesh Poyarekar
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2024-08-30 15:29 UTC (permalink / raw)
To: libc-stable; +Cc: Carlos O'Donell
If a file descriptor is left unclosed and is cleaned up by _IO_cleanup
on exit, its backup buffer remains unfreed, registering as a leak in
valgrind. This is not strictly an issue since (1) the program should
ideally be closing the stream once it's not in use and (2) the program
is about to exit anyway, so keeping the backup buffer around a wee bit
longer isn't a real problem. Free it anyway to keep valgrind happy
when the streams in question are the standard ones, i.e. stdout, stdin
or stderr.
Also, the _IO_have_backup macro checks for _IO_save_base,
which is a roundabout way to check for a backup buffer instead of
directly looking for _IO_backup_base. The roundabout check breaks when
the main get area has not been used and user pushes a char into the
backup buffer with ungetc. Fix this to use the _IO_backup_base
directly.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 3e1d8d1d1dca24ae90df2ea826a8916896fc7e77)
(cherry picked from commit b9f72bd5de931eac39219018c2fa319a449bb2cf)
---
libio/genops.c | 6 ++++++
libio/libioP.h | 4 ++--
stdio-common/Makefile | 7 +++++++
stdio-common/tst-ungetc-leak.c | 32 ++++++++++++++++++++++++++++++++
4 files changed, 47 insertions(+), 2 deletions(-)
create mode 100644 stdio-common/tst-ungetc-leak.c
diff --git a/libio/genops.c b/libio/genops.c
index cc1b9dcac5..5530ebc403 100644
--- a/libio/genops.c
+++ b/libio/genops.c
@@ -796,6 +796,12 @@ _IO_unbuffer_all (void)
legacy = 1;
#endif
+ /* Free up the backup area if it was ever allocated. */
+ if (_IO_have_backup (fp))
+ _IO_free_backup_area (fp);
+ if (fp->_mode > 0 && _IO_have_wbackup (fp))
+ _IO_free_wbackup_area (fp);
+
if (! (fp->_flags & _IO_UNBUFFERED)
/* Iff stream is un-orientated, it wasn't used. */
&& (legacy || fp->_mode != 0))
diff --git a/libio/libioP.h b/libio/libioP.h
index a5f00822ab..635783bf9e 100644
--- a/libio/libioP.h
+++ b/libio/libioP.h
@@ -530,8 +530,8 @@ extern void _IO_old_init (FILE *fp, int flags) __THROW;
((__fp)->_wide_data->_IO_write_base \
= (__fp)->_wide_data->_IO_write_ptr = __p, \
(__fp)->_wide_data->_IO_write_end = (__ep))
-#define _IO_have_backup(fp) ((fp)->_IO_save_base != NULL)
-#define _IO_have_wbackup(fp) ((fp)->_wide_data->_IO_save_base != NULL)
+#define _IO_have_backup(fp) ((fp)->_IO_backup_base != NULL)
+#define _IO_have_wbackup(fp) ((fp)->_wide_data->_IO_backup_base != NULL)
#define _IO_in_backup(fp) ((fp)->_flags & _IO_IN_BACKUP)
#define _IO_have_markers(fp) ((fp)->_markers != NULL)
#define _IO_blen(fp) ((fp)->_IO_buf_end - (fp)->_IO_buf_base)
diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index eb1f2791ac..110e690d1b 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -226,6 +226,7 @@ tests := \
tst-swscanf \
tst-tmpnam \
tst-ungetc \
+ tst-ungetc-leak \
tst-unlockedio \
tst-vfprintf-mbs-prec \
tst-vfprintf-user-type \
@@ -262,6 +263,7 @@ tests-special += \
$(objpfx)tst-printfsz-islongdouble.out \
$(objpfx)tst-setvbuf1-cmp.out \
$(objpfx)tst-unbputc.out \
+ $(objpfx)tst-ungetc-leak-mem.out \
$(objpfx)tst-vfprintf-width-prec-mem.out \
# tests-special
@@ -276,6 +278,8 @@ generated += \
tst-printf-fp-leak-mem.out \
tst-printf-fp-leak.mtrace \
tst-scanf-bz27650.mtrace \
+ tst-ungetc-leak-mem.out \
+ tst-ungetc-leak.mtrace \
tst-vfprintf-width-prec-mem.out \
tst-vfprintf-width-prec.mtrace \
# generated
@@ -363,6 +367,9 @@ tst-printf-fp-leak-ENV = \
tst-scanf-bz27650-ENV = \
MALLOC_TRACE=$(objpfx)tst-scanf-bz27650.mtrace \
LD_PRELOAD=$(common-objpfx)malloc/libc_malloc_debug.so
+tst-ungetc-leak-ENV = \
+ MALLOC_TRACE=$(objpfx)tst-ungetc-leak.mtrace \
+ LD_PRELOAD=$(common-objpfx)malloc/libc_malloc_debug.so
$(objpfx)tst-unbputc.out: tst-unbputc.sh $(objpfx)tst-unbputc
$(SHELL) $< $(common-objpfx) '$(test-program-prefix)'; \
diff --git a/stdio-common/tst-ungetc-leak.c b/stdio-common/tst-ungetc-leak.c
new file mode 100644
index 0000000000..6c5152b43f
--- /dev/null
+++ b/stdio-common/tst-ungetc-leak.c
@@ -0,0 +1,32 @@
+/* Test for memory leak with ungetc when stream is unused.
+ Copyright The GNU Toolchain Authors.
+ 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 <stdio.h>
+#include <mcheck.h>
+#include <support/check.h>
+#include <support/support.h>
+
+static int
+do_test (void)
+{
+ mtrace ();
+ TEST_COMPARE (ungetc('y', stdin), 'y');
+ return 0;
+}
+
+#include <support/test-driver.c>
--
2.45.1
^ permalink raw reply [flat|nested] 6+ messages in thread