diff mbox series

[v1,2/2] nptl: Add a testcase for inputs racey to {w}memcmp{eq} BZ #29863

Message ID 20221219192726.999818-2-goldstein.w.n@gmail.com
State New
Headers
Series [v1,1/2] nptl: Changes tests to be 1/line and sorted |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
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redhat-pt-bot/TryBot-still_applies warning Patch no longer applies to master

Commit Message

Noah Goldstein Dec. 19, 2022, 7:27 p.m. UTC 
  Add test that modifies data as {w}memcmp{eq} runs (creating a race
condition).  Failures from this tests do not inherently mean the
{w}memcmp{eq} implementation is buggy, but is at the very least
something we should be aware of.

Success is no SIGSEGV. Failure is a SIGSEGV.

Verified test failed 10/10 times without:

commit b712be52645282c706a5faa038242504feb06db5
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date:   Wed Dec 14 10:52:10 2022 -0800

    x86: Prevent SIGSEGV in memcmp-sse2 when data is concurrently modified [BZ #29863]

And passes with the fix.
---
 nptl/Makefile            |   7 ++
 nptl/tst-memcmp-race.c   | 149 +++++++++++++++++++++++++++++++++++++++
 nptl/tst-memcmpeq-race.c |  19 +++++
 nptl/tst-wmemcmp-race.c  |  20 ++++++
 4 files changed, 195 insertions(+)
 create mode 100644 nptl/tst-memcmp-race.c
 create mode 100644 nptl/tst-memcmpeq-race.c
 create mode 100644 nptl/tst-wmemcmp-race.c

Comments

Noah Goldstein Dec. 19, 2022, 7:28 p.m. UTC | #1 
On Mon, Dec 19, 2022 at 11:27 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> Add test that modifies data as {w}memcmp{eq} runs (creating a race
> condition).  Failures from this tests do not inherently mean the
> {w}memcmp{eq} implementation is buggy, but is at the very least
> something we should be aware of.
>
> Success is no SIGSEGV. Failure is a SIGSEGV.
>
> Verified test failed 10/10 times without:
>
> commit b712be52645282c706a5faa038242504feb06db5
> Author: Noah Goldstein <goldstein.w.n@gmail.com>
> Date:   Wed Dec 14 10:52:10 2022 -0800
>
>     x86: Prevent SIGSEGV in memcmp-sse2 when data is concurrently modified [BZ #29863]
>
> And passes with the fix.

NB: Forget tag "Co-authored-by: H.J. Lu <hjl.tools@gmail.com>",
will add before commit or next version if more revisions are needed.
> ---
>  nptl/Makefile            |   7 ++
>  nptl/tst-memcmp-race.c   | 149 +++++++++++++++++++++++++++++++++++++++
>  nptl/tst-memcmpeq-race.c |  19 +++++
>  nptl/tst-wmemcmp-race.c  |  20 ++++++
>  4 files changed, 195 insertions(+)
>  create mode 100644 nptl/tst-memcmp-race.c
>  create mode 100644 nptl/tst-memcmpeq-race.c
>  create mode 100644 nptl/tst-wmemcmp-race.c
>
> diff --git a/nptl/Makefile b/nptl/Makefile
> index fc955cd604..5f56bdc80a 100644
> --- a/nptl/Makefile
> +++ b/nptl/Makefile
> @@ -285,6 +285,8 @@ tests = \
>         tst-exec4 \
>         tst-exec5 \
>         tst-initializers1 $(addprefix tst-initializers1-,c89 gnu89 c99 gnu99 c11 gnu11) \
> +       tst-memcmp-race \
> +       tst-memcmpeq-race \
>         tst-minstack-cancel \
>         tst-minstack-exit \
>         tst-minstack-throw \
> @@ -348,8 +350,13 @@ tests = \
>         tst-thread_local1 \
>         tst-tsd3 \
>         tst-tsd4 \
> +       tst-wmemcmp-race \
>  # tests
>
> +CFLAGS-tst-memcmp-race.c += -O0
> +CFLAGS-tst-memcmpeq-race.c += -O0
> +CFLAGS-tst-wmemcmp-race.c += -O0
> +
>  tests-nolibpthread = \
>    tst-pthread_exit-nothreads \
>    tst-pthread_exit-nothreads-static \
> diff --git a/nptl/tst-memcmp-race.c b/nptl/tst-memcmp-race.c
> new file mode 100644
> index 0000000000..56e62b2f7b
> --- /dev/null
> +++ b/nptl/tst-memcmp-race.c
> @@ -0,0 +1,149 @@
> +/* Test case for memcmp with race condition.
> +   Copyright (C) 2022 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/>.  */
> +
> +/* Verify that there is no segfault when one thread is updating the
> +   memory block of memcmp and the other thread is doing memcmp.
> +
> +   NOTE: This test failing does not automatically mean the
> +   {w}memcmp{eq} is incorrect.  This is testing UB and behavior that
> +   is supported.  That being said, users may expect that the mem*
> +   functions never access out of bounds data (even with data races)
> +   and we should be aware of the cases when we do. */
> +
> +#define TEST_MAIN
> +#define MIN_PAGE_SIZE 4096
> +
> +#ifdef TEST_MEMCMPEQ
> +# define MEMCMP __memcmpeq
> +# define TEST_NAME "__memcmpeq"
> +#elif defined WIDE
> +# define MEMCMP wmemcmp
> +# define TEST_NAME "wmemcmp"
> +#else
> +# define MEMCMP memcmp
> +# define TEST_NAME "memcmp"
> +#endif
> +
> +#ifdef WIDE
> +# define MEMSET wmemset
> +# define CHAR wchar_t
> +#else
> +# define MEMSET memset
> +# define CHAR char
> +#endif
> +
> +#include <stdio.h>
> +#include <stdint.h>
> +#include <string.h>
> +#include <string/test-string.h>
> +#include <support/xthread.h>
> +
> +#define NUM_THREADS 2
> +#define LOOP1 10000
> +#define LOOP2 1000000
> +
> +typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
> +
> +IMPL (MEMCMP, 1)
> +
> +struct arg
> +{
> +  proto_t func;
> +  CHAR *a;
> +  CHAR *b;
> +  size_t len;
> +  size_t wpos;
> +  int todo;
> +};
> +
> +static void *
> +childThread (void *tArgs)
> +{
> +  struct arg *args = (struct arg *) tArgs;
> +  int i;
> +  if (0 == args->todo % 2)
> +    {
> +      for (i = 0; i < LOOP1; i++)
> +       {
> +         volatile int result = args->func (args->a, args->b, args->len);
> +      (void)(result);
> +       }
> +    }
> +  else
> +    {
> +      for (i = 0; i < LOOP2; i++)
> +       args->a[args->wpos] = i & 1;
> +      args->a[args->wpos] = 1;
> +    }
> +  return NULL;
> +}
> +
> +static void
> +do_one_test (proto_t func, size_t len)
> +{
> +  int r;
> +  if (len * sizeof (CHAR) > page_size)
> +    return;
> +  for (r = 0; r < 2; ++r)
> +    {
> +      size_t wpos;
> +      for (wpos = 1; wpos < 128 && wpos <= len; wpos = wpos + wpos + 1)
> +       {
> +         int i;
> +         size_t off;
> +         pthread_t threads[NUM_THREADS];
> +         struct arg a[NUM_THREADS];
> +
> +         off = r ? (page_size - len * sizeof (CHAR)) : 0;
> +         for (i = 0; i < NUM_THREADS; ++i)
> +           {
> +             a[i].func = func;
> +             a[i].a = (CHAR *) (buf1 + off);
> +             a[i].b = (CHAR *) (buf2 + off);
> +             a[i].len = len;
> +             a[i].wpos = len - wpos;
> +             a[i].todo = i;
> +             threads[i] = xpthread_create (NULL, childThread, (void *) &a[i]);
> +           }
> +
> +         for (i = 0; i < NUM_THREADS; ++i)
> +           xpthread_join (threads[i]);
> +       }
> +    }
> +}
> +
> +int
> +test_main (void)
> +{
> +  test_init ();
> +
> +  MEMSET ((CHAR *) buf1, 1, page_size / sizeof (CHAR));
> +  MEMSET ((CHAR *) buf2, 1, page_size / sizeof (CHAR));
> +  for (size_t i = 1; i <= 1024; i += i)
> +    {
> +      FOR_EACH_IMPL (impl, 0)
> +       {
> +         do_one_test ((proto_t) impl->fn, i);
> +         do_one_test ((proto_t) impl->fn, i + 1);
> +         do_one_test ((proto_t) impl->fn, i - 1);
> +       }
> +    }
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/nptl/tst-memcmpeq-race.c b/nptl/tst-memcmpeq-race.c
> new file mode 100644
> index 0000000000..7088928f49
> --- /dev/null
> +++ b/nptl/tst-memcmpeq-race.c
> @@ -0,0 +1,19 @@
> +/* Test case for __memcmpeq with race condition.
> +   Copyright (C) 2022 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/>.  */
> +#define TEST_MEMCMPEQ 1
> +#include "tst-memcmp-race.c"
> diff --git a/nptl/tst-wmemcmp-race.c b/nptl/tst-wmemcmp-race.c
> new file mode 100644
> index 0000000000..8278f71842
> --- /dev/null
> +++ b/nptl/tst-wmemcmp-race.c
> @@ -0,0 +1,20 @@
> +/* Test case for wmemcmp with race condition.
> +   Copyright (C) 2022 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 <wchar.h>
> +#define WIDE 1
> +#include "tst-memcmp-race.c"
> --
> 2.34.1
>
Noah Goldstein Dec. 29, 2022, 4:41 p.m. UTC | #2 
On Mon, Dec 19, 2022 at 11:28 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> On Mon, Dec 19, 2022 at 11:27 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > Add test that modifies data as {w}memcmp{eq} runs (creating a race
> > condition).  Failures from this tests do not inherently mean the
> > {w}memcmp{eq} implementation is buggy, but is at the very least
> > something we should be aware of.
> >
> > Success is no SIGSEGV. Failure is a SIGSEGV.
> >
> > Verified test failed 10/10 times without:
> >
> > commit b712be52645282c706a5faa038242504feb06db5
> > Author: Noah Goldstein <goldstein.w.n@gmail.com>
> > Date:   Wed Dec 14 10:52:10 2022 -0800
> >
> >     x86: Prevent SIGSEGV in memcmp-sse2 when data is concurrently modified [BZ #29863]
> >
> > And passes with the fix.
>
> NB: Forget tag "Co-authored-by: H.J. Lu <hjl.tools@gmail.com>",
> will add before commit or next version if more revisions are needed.
> > ---
> >  nptl/Makefile            |   7 ++
> >  nptl/tst-memcmp-race.c   | 149 +++++++++++++++++++++++++++++++++++++++
> >  nptl/tst-memcmpeq-race.c |  19 +++++
> >  nptl/tst-wmemcmp-race.c  |  20 ++++++
> >  4 files changed, 195 insertions(+)
> >  create mode 100644 nptl/tst-memcmp-race.c
> >  create mode 100644 nptl/tst-memcmpeq-race.c
> >  create mode 100644 nptl/tst-wmemcmp-race.c
> >
> > diff --git a/nptl/Makefile b/nptl/Makefile
> > index fc955cd604..5f56bdc80a 100644
> > --- a/nptl/Makefile
> > +++ b/nptl/Makefile
> > @@ -285,6 +285,8 @@ tests = \
> >         tst-exec4 \
> >         tst-exec5 \
> >         tst-initializers1 $(addprefix tst-initializers1-,c89 gnu89 c99 gnu99 c11 gnu11) \
> > +       tst-memcmp-race \
> > +       tst-memcmpeq-race \
> >         tst-minstack-cancel \
> >         tst-minstack-exit \
> >         tst-minstack-throw \
> > @@ -348,8 +350,13 @@ tests = \
> >         tst-thread_local1 \
> >         tst-tsd3 \
> >         tst-tsd4 \
> > +       tst-wmemcmp-race \
> >  # tests
> >
> > +CFLAGS-tst-memcmp-race.c += -O0
> > +CFLAGS-tst-memcmpeq-race.c += -O0
> > +CFLAGS-tst-wmemcmp-race.c += -O0
> > +
> >  tests-nolibpthread = \
> >    tst-pthread_exit-nothreads \
> >    tst-pthread_exit-nothreads-static \
> > diff --git a/nptl/tst-memcmp-race.c b/nptl/tst-memcmp-race.c
> > new file mode 100644
> > index 0000000000..56e62b2f7b
> > --- /dev/null
> > +++ b/nptl/tst-memcmp-race.c
> > @@ -0,0 +1,149 @@
> > +/* Test case for memcmp with race condition.
> > +   Copyright (C) 2022 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/>.  */
> > +
> > +/* Verify that there is no segfault when one thread is updating the
> > +   memory block of memcmp and the other thread is doing memcmp.
> > +
> > +   NOTE: This test failing does not automatically mean the
> > +   {w}memcmp{eq} is incorrect.  This is testing UB and behavior that
> > +   is supported.  That being said, users may expect that the mem*
> > +   functions never access out of bounds data (even with data races)
> > +   and we should be aware of the cases when we do. */
> > +
> > +#define TEST_MAIN
> > +#define MIN_PAGE_SIZE 4096
> > +
> > +#ifdef TEST_MEMCMPEQ
> > +# define MEMCMP __memcmpeq
> > +# define TEST_NAME "__memcmpeq"
> > +#elif defined WIDE
> > +# define MEMCMP wmemcmp
> > +# define TEST_NAME "wmemcmp"
> > +#else
> > +# define MEMCMP memcmp
> > +# define TEST_NAME "memcmp"
> > +#endif
> > +
> > +#ifdef WIDE
> > +# define MEMSET wmemset
> > +# define CHAR wchar_t
> > +#else
> > +# define MEMSET memset
> > +# define CHAR char
> > +#endif
> > +
> > +#include <stdio.h>
> > +#include <stdint.h>
> > +#include <string.h>
> > +#include <string/test-string.h>
> > +#include <support/xthread.h>
> > +
> > +#define NUM_THREADS 2
> > +#define LOOP1 10000
> > +#define LOOP2 1000000
> > +
> > +typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
> > +
> > +IMPL (MEMCMP, 1)
> > +
> > +struct arg
> > +{
> > +  proto_t func;
> > +  CHAR *a;
> > +  CHAR *b;
> > +  size_t len;
> > +  size_t wpos;
> > +  int todo;
> > +};
> > +
> > +static void *
> > +childThread (void *tArgs)
> > +{
> > +  struct arg *args = (struct arg *) tArgs;
> > +  int i;
> > +  if (0 == args->todo % 2)
> > +    {
> > +      for (i = 0; i < LOOP1; i++)
> > +       {
> > +         volatile int result = args->func (args->a, args->b, args->len);
> > +      (void)(result);
> > +       }
> > +    }
> > +  else
> > +    {
> > +      for (i = 0; i < LOOP2; i++)
> > +       args->a[args->wpos] = i & 1;
> > +      args->a[args->wpos] = 1;
> > +    }
> > +  return NULL;
> > +}
> > +
> > +static void
> > +do_one_test (proto_t func, size_t len)
> > +{
> > +  int r;
> > +  if (len * sizeof (CHAR) > page_size)
> > +    return;
> > +  for (r = 0; r < 2; ++r)
> > +    {
> > +      size_t wpos;
> > +      for (wpos = 1; wpos < 128 && wpos <= len; wpos = wpos + wpos + 1)
> > +       {
> > +         int i;
> > +         size_t off;
> > +         pthread_t threads[NUM_THREADS];
> > +         struct arg a[NUM_THREADS];
> > +
> > +         off = r ? (page_size - len * sizeof (CHAR)) : 0;
> > +         for (i = 0; i < NUM_THREADS; ++i)
> > +           {
> > +             a[i].func = func;
> > +             a[i].a = (CHAR *) (buf1 + off);
> > +             a[i].b = (CHAR *) (buf2 + off);
> > +             a[i].len = len;
> > +             a[i].wpos = len - wpos;
> > +             a[i].todo = i;
> > +             threads[i] = xpthread_create (NULL, childThread, (void *) &a[i]);
> > +           }
> > +
> > +         for (i = 0; i < NUM_THREADS; ++i)
> > +           xpthread_join (threads[i]);
> > +       }
> > +    }
> > +}
> > +
> > +int
> > +test_main (void)
> > +{
> > +  test_init ();
> > +
> > +  MEMSET ((CHAR *) buf1, 1, page_size / sizeof (CHAR));
> > +  MEMSET ((CHAR *) buf2, 1, page_size / sizeof (CHAR));
> > +  for (size_t i = 1; i <= 1024; i += i)
> > +    {
> > +      FOR_EACH_IMPL (impl, 0)
> > +       {
> > +         do_one_test ((proto_t) impl->fn, i);
> > +         do_one_test ((proto_t) impl->fn, i + 1);
> > +         do_one_test ((proto_t) impl->fn, i - 1);
> > +       }
> > +    }
> > +  return 0;
> > +}
> > +
> > +#include <support/test-driver.c>
> > diff --git a/nptl/tst-memcmpeq-race.c b/nptl/tst-memcmpeq-race.c
> > new file mode 100644
> > index 0000000000..7088928f49
> > --- /dev/null
> > +++ b/nptl/tst-memcmpeq-race.c
> > @@ -0,0 +1,19 @@
> > +/* Test case for __memcmpeq with race condition.
> > +   Copyright (C) 2022 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/>.  */
> > +#define TEST_MEMCMPEQ 1
> > +#include "tst-memcmp-race.c"
> > diff --git a/nptl/tst-wmemcmp-race.c b/nptl/tst-wmemcmp-race.c
> > new file mode 100644
> > index 0000000000..8278f71842
> > --- /dev/null
> > +++ b/nptl/tst-wmemcmp-race.c
> > @@ -0,0 +1,20 @@
> > +/* Test case for wmemcmp with race condition.
> > +   Copyright (C) 2022 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 <wchar.h>
> > +#define WIDE 1
> > +#include "tst-memcmp-race.c"
> > --
> > 2.34.1
> >
ping.
Noah Goldstein Jan. 10, 2023, 11:03 p.m. UTC | #3 
On Thu, Dec 29, 2022 at 8:41 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> On Mon, Dec 19, 2022 at 11:28 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > On Mon, Dec 19, 2022 at 11:27 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> > >
> > > Add test that modifies data as {w}memcmp{eq} runs (creating a race
> > > condition).  Failures from this tests do not inherently mean the
> > > {w}memcmp{eq} implementation is buggy, but is at the very least
> > > something we should be aware of.
> > >
> > > Success is no SIGSEGV. Failure is a SIGSEGV.
> > >
> > > Verified test failed 10/10 times without:
> > >
> > > commit b712be52645282c706a5faa038242504feb06db5
> > > Author: Noah Goldstein <goldstein.w.n@gmail.com>
> > > Date:   Wed Dec 14 10:52:10 2022 -0800
> > >
> > >     x86: Prevent SIGSEGV in memcmp-sse2 when data is concurrently modified [BZ #29863]
> > >
> > > And passes with the fix.
> >
> > NB: Forget tag "Co-authored-by: H.J. Lu <hjl.tools@gmail.com>",
> > will add before commit or next version if more revisions are needed.
> > > ---
> > >  nptl/Makefile            |   7 ++
> > >  nptl/tst-memcmp-race.c   | 149 +++++++++++++++++++++++++++++++++++++++
> > >  nptl/tst-memcmpeq-race.c |  19 +++++
> > >  nptl/tst-wmemcmp-race.c  |  20 ++++++
> > >  4 files changed, 195 insertions(+)
> > >  create mode 100644 nptl/tst-memcmp-race.c
> > >  create mode 100644 nptl/tst-memcmpeq-race.c
> > >  create mode 100644 nptl/tst-wmemcmp-race.c
> > >
> > > diff --git a/nptl/Makefile b/nptl/Makefile
> > > index fc955cd604..5f56bdc80a 100644
> > > --- a/nptl/Makefile
> > > +++ b/nptl/Makefile
> > > @@ -285,6 +285,8 @@ tests = \
> > >         tst-exec4 \
> > >         tst-exec5 \
> > >         tst-initializers1 $(addprefix tst-initializers1-,c89 gnu89 c99 gnu99 c11 gnu11) \
> > > +       tst-memcmp-race \
> > > +       tst-memcmpeq-race \
> > >         tst-minstack-cancel \
> > >         tst-minstack-exit \
> > >         tst-minstack-throw \
> > > @@ -348,8 +350,13 @@ tests = \
> > >         tst-thread_local1 \
> > >         tst-tsd3 \
> > >         tst-tsd4 \
> > > +       tst-wmemcmp-race \
> > >  # tests
> > >
> > > +CFLAGS-tst-memcmp-race.c += -O0
> > > +CFLAGS-tst-memcmpeq-race.c += -O0
> > > +CFLAGS-tst-wmemcmp-race.c += -O0
> > > +
> > >  tests-nolibpthread = \
> > >    tst-pthread_exit-nothreads \
> > >    tst-pthread_exit-nothreads-static \
> > > diff --git a/nptl/tst-memcmp-race.c b/nptl/tst-memcmp-race.c
> > > new file mode 100644
> > > index 0000000000..56e62b2f7b
> > > --- /dev/null
> > > +++ b/nptl/tst-memcmp-race.c
> > > @@ -0,0 +1,149 @@
> > > +/* Test case for memcmp with race condition.
> > > +   Copyright (C) 2022 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/>.  */
> > > +
> > > +/* Verify that there is no segfault when one thread is updating the
> > > +   memory block of memcmp and the other thread is doing memcmp.
> > > +
> > > +   NOTE: This test failing does not automatically mean the
> > > +   {w}memcmp{eq} is incorrect.  This is testing UB and behavior that
> > > +   is supported.  That being said, users may expect that the mem*
> > > +   functions never access out of bounds data (even with data races)
> > > +   and we should be aware of the cases when we do. */
> > > +
> > > +#define TEST_MAIN
> > > +#define MIN_PAGE_SIZE 4096
> > > +
> > > +#ifdef TEST_MEMCMPEQ
> > > +# define MEMCMP __memcmpeq
> > > +# define TEST_NAME "__memcmpeq"
> > > +#elif defined WIDE
> > > +# define MEMCMP wmemcmp
> > > +# define TEST_NAME "wmemcmp"
> > > +#else
> > > +# define MEMCMP memcmp
> > > +# define TEST_NAME "memcmp"
> > > +#endif
> > > +
> > > +#ifdef WIDE
> > > +# define MEMSET wmemset
> > > +# define CHAR wchar_t
> > > +#else
> > > +# define MEMSET memset
> > > +# define CHAR char
> > > +#endif
> > > +
> > > +#include <stdio.h>
> > > +#include <stdint.h>
> > > +#include <string.h>
> > > +#include <string/test-string.h>
> > > +#include <support/xthread.h>
> > > +
> > > +#define NUM_THREADS 2
> > > +#define LOOP1 10000
> > > +#define LOOP2 1000000
> > > +
> > > +typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
> > > +
> > > +IMPL (MEMCMP, 1)
> > > +
> > > +struct arg
> > > +{
> > > +  proto_t func;
> > > +  CHAR *a;
> > > +  CHAR *b;
> > > +  size_t len;
> > > +  size_t wpos;
> > > +  int todo;
> > > +};
> > > +
> > > +static void *
> > > +childThread (void *tArgs)
> > > +{
> > > +  struct arg *args = (struct arg *) tArgs;
> > > +  int i;
> > > +  if (0 == args->todo % 2)
> > > +    {
> > > +      for (i = 0; i < LOOP1; i++)
> > > +       {
> > > +         volatile int result = args->func (args->a, args->b, args->len);
> > > +      (void)(result);
> > > +       }
> > > +    }
> > > +  else
> > > +    {
> > > +      for (i = 0; i < LOOP2; i++)
> > > +       args->a[args->wpos] = i & 1;
> > > +      args->a[args->wpos] = 1;
> > > +    }
> > > +  return NULL;
> > > +}
> > > +
> > > +static void
> > > +do_one_test (proto_t func, size_t len)
> > > +{
> > > +  int r;
> > > +  if (len * sizeof (CHAR) > page_size)
> > > +    return;
> > > +  for (r = 0; r < 2; ++r)
> > > +    {
> > > +      size_t wpos;
> > > +      for (wpos = 1; wpos < 128 && wpos <= len; wpos = wpos + wpos + 1)
> > > +       {
> > > +         int i;
> > > +         size_t off;
> > > +         pthread_t threads[NUM_THREADS];
> > > +         struct arg a[NUM_THREADS];
> > > +
> > > +         off = r ? (page_size - len * sizeof (CHAR)) : 0;
> > > +         for (i = 0; i < NUM_THREADS; ++i)
> > > +           {
> > > +             a[i].func = func;
> > > +             a[i].a = (CHAR *) (buf1 + off);
> > > +             a[i].b = (CHAR *) (buf2 + off);
> > > +             a[i].len = len;
> > > +             a[i].wpos = len - wpos;
> > > +             a[i].todo = i;
> > > +             threads[i] = xpthread_create (NULL, childThread, (void *) &a[i]);
> > > +           }
> > > +
> > > +         for (i = 0; i < NUM_THREADS; ++i)
> > > +           xpthread_join (threads[i]);
> > > +       }
> > > +    }
> > > +}
> > > +
> > > +int
> > > +test_main (void)
> > > +{
> > > +  test_init ();
> > > +
> > > +  MEMSET ((CHAR *) buf1, 1, page_size / sizeof (CHAR));
> > > +  MEMSET ((CHAR *) buf2, 1, page_size / sizeof (CHAR));
> > > +  for (size_t i = 1; i <= 1024; i += i)
> > > +    {
> > > +      FOR_EACH_IMPL (impl, 0)
> > > +       {
> > > +         do_one_test ((proto_t) impl->fn, i);
> > > +         do_one_test ((proto_t) impl->fn, i + 1);
> > > +         do_one_test ((proto_t) impl->fn, i - 1);
> > > +       }
> > > +    }
> > > +  return 0;
> > > +}
> > > +
> > > +#include <support/test-driver.c>
> > > diff --git a/nptl/tst-memcmpeq-race.c b/nptl/tst-memcmpeq-race.c
> > > new file mode 100644
> > > index 0000000000..7088928f49
> > > --- /dev/null
> > > +++ b/nptl/tst-memcmpeq-race.c
> > > @@ -0,0 +1,19 @@
> > > +/* Test case for __memcmpeq with race condition.
> > > +   Copyright (C) 2022 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/>.  */
> > > +#define TEST_MEMCMPEQ 1
> > > +#include "tst-memcmp-race.c"
> > > diff --git a/nptl/tst-wmemcmp-race.c b/nptl/tst-wmemcmp-race.c
> > > new file mode 100644
> > > index 0000000000..8278f71842
> > > --- /dev/null
> > > +++ b/nptl/tst-wmemcmp-race.c
> > > @@ -0,0 +1,20 @@
> > > +/* Test case for wmemcmp with race condition.
> > > +   Copyright (C) 2022 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 <wchar.h>
> > > +#define WIDE 1
> > > +#include "tst-memcmp-race.c"
> > > --
> > > 2.34.1
> > >
> ping.
ping2.
diff mbox series

Patch

diff --git a/nptl/Makefile b/nptl/Makefile
index fc955cd604..5f56bdc80a 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -285,6 +285,8 @@  tests = \
 	tst-exec4 \
 	tst-exec5 \
 	tst-initializers1 $(addprefix tst-initializers1-,c89 gnu89 c99 gnu99 c11 gnu11) \
+	tst-memcmp-race \
+	tst-memcmpeq-race \
 	tst-minstack-cancel \
 	tst-minstack-exit \
 	tst-minstack-throw \
@@ -348,8 +350,13 @@  tests = \
 	tst-thread_local1 \
 	tst-tsd3 \
 	tst-tsd4 \
+	tst-wmemcmp-race \
 # tests
 
+CFLAGS-tst-memcmp-race.c += -O0
+CFLAGS-tst-memcmpeq-race.c += -O0
+CFLAGS-tst-wmemcmp-race.c += -O0
+
 tests-nolibpthread = \
   tst-pthread_exit-nothreads \
   tst-pthread_exit-nothreads-static \
diff --git a/nptl/tst-memcmp-race.c b/nptl/tst-memcmp-race.c
new file mode 100644
index 0000000000..56e62b2f7b
--- /dev/null
+++ b/nptl/tst-memcmp-race.c
@@ -0,0 +1,149 @@ 
+/* Test case for memcmp with race condition.
+   Copyright (C) 2022 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/>.  */
+
+/* Verify that there is no segfault when one thread is updating the
+   memory block of memcmp and the other thread is doing memcmp.
+
+   NOTE: This test failing does not automatically mean the
+   {w}memcmp{eq} is incorrect.  This is testing UB and behavior that
+   is supported.  That being said, users may expect that the mem*
+   functions never access out of bounds data (even with data races)
+   and we should be aware of the cases when we do. */
+
+#define TEST_MAIN
+#define MIN_PAGE_SIZE 4096
+
+#ifdef TEST_MEMCMPEQ
+# define MEMCMP __memcmpeq
+# define TEST_NAME "__memcmpeq"
+#elif defined WIDE
+# define MEMCMP wmemcmp
+# define TEST_NAME "wmemcmp"
+#else
+# define MEMCMP memcmp
+# define TEST_NAME "memcmp"
+#endif
+
+#ifdef WIDE
+# define MEMSET wmemset
+# define CHAR wchar_t
+#else
+# define MEMSET memset
+# define CHAR char
+#endif
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <string/test-string.h>
+#include <support/xthread.h>
+
+#define NUM_THREADS 2
+#define LOOP1 10000
+#define LOOP2 1000000
+
+typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
+
+IMPL (MEMCMP, 1)
+
+struct arg
+{
+  proto_t func;
+  CHAR *a;
+  CHAR *b;
+  size_t len;
+  size_t wpos;
+  int todo;
+};
+
+static void *
+childThread (void *tArgs)
+{
+  struct arg *args = (struct arg *) tArgs;
+  int i;
+  if (0 == args->todo % 2)
+    {
+      for (i = 0; i < LOOP1; i++)
+	{
+	  volatile int result = args->func (args->a, args->b, args->len);
+      (void)(result);
+	}
+    }
+  else
+    {
+      for (i = 0; i < LOOP2; i++)
+	args->a[args->wpos] = i & 1;
+      args->a[args->wpos] = 1;
+    }
+  return NULL;
+}
+
+static void
+do_one_test (proto_t func, size_t len)
+{
+  int r;
+  if (len * sizeof (CHAR) > page_size)
+    return;
+  for (r = 0; r < 2; ++r)
+    {
+      size_t wpos;
+      for (wpos = 1; wpos < 128 && wpos <= len; wpos = wpos + wpos + 1)
+	{
+	  int i;
+	  size_t off;
+	  pthread_t threads[NUM_THREADS];
+	  struct arg a[NUM_THREADS];
+
+	  off = r ? (page_size - len * sizeof (CHAR)) : 0;
+	  for (i = 0; i < NUM_THREADS; ++i)
+	    {
+	      a[i].func = func;
+	      a[i].a = (CHAR *) (buf1 + off);
+	      a[i].b = (CHAR *) (buf2 + off);
+	      a[i].len = len;
+	      a[i].wpos = len - wpos;
+	      a[i].todo = i;
+	      threads[i] = xpthread_create (NULL, childThread, (void *) &a[i]);
+	    }
+
+	  for (i = 0; i < NUM_THREADS; ++i)
+	    xpthread_join (threads[i]);
+	}
+    }
+}
+
+int
+test_main (void)
+{
+  test_init ();
+
+  MEMSET ((CHAR *) buf1, 1, page_size / sizeof (CHAR));
+  MEMSET ((CHAR *) buf2, 1, page_size / sizeof (CHAR));
+  for (size_t i = 1; i <= 1024; i += i)
+    {
+      FOR_EACH_IMPL (impl, 0)
+	{
+	  do_one_test ((proto_t) impl->fn, i);
+	  do_one_test ((proto_t) impl->fn, i + 1);
+	  do_one_test ((proto_t) impl->fn, i - 1);
+	}
+    }
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/nptl/tst-memcmpeq-race.c b/nptl/tst-memcmpeq-race.c
new file mode 100644
index 0000000000..7088928f49
--- /dev/null
+++ b/nptl/tst-memcmpeq-race.c
@@ -0,0 +1,19 @@ 
+/* Test case for __memcmpeq with race condition.
+   Copyright (C) 2022 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/>.  */
+#define TEST_MEMCMPEQ 1
+#include "tst-memcmp-race.c"
diff --git a/nptl/tst-wmemcmp-race.c b/nptl/tst-wmemcmp-race.c
new file mode 100644
index 0000000000..8278f71842
--- /dev/null
+++ b/nptl/tst-wmemcmp-race.c
@@ -0,0 +1,20 @@ 
+/* Test case for wmemcmp with race condition.
+   Copyright (C) 2022 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 <wchar.h>
+#define WIDE 1
+#include "tst-memcmp-race.c"