[08/12] Add a test for swapcontext with a wrapper

  Check swapcontext works with a wrapper.

	* stdlib/Makefile (tests): Add tst-swapcontext1.
	* stdlib/tst-swapcontext1.c: New test.
---
 stdlib/Makefile           |  3 +-
 stdlib/tst-swapcontext1.c | 92 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+), 1 deletion(-)
 create mode 100644 stdlib/tst-swapcontext1.c
  

On 07/21/2018 10:20 AM, H.J. Lu wrote:
> Check swapcontext works with a wrapper.
> 
> 	* stdlib/Makefile (tests): Add tst-swapcontext1.
> 	* stdlib/tst-swapcontext1.c: New test.

OK for 2.28 if you can answer the licensing question.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

> ---
>  stdlib/Makefile           |  3 +-
>  stdlib/tst-swapcontext1.c | 92 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 94 insertions(+), 1 deletion(-)
>  create mode 100644 stdlib/tst-swapcontext1.c
> 
> diff --git a/stdlib/Makefile b/stdlib/Makefile
> index b5e55b0a55..bc8929f2b9 100644
> --- a/stdlib/Makefile
> +++ b/stdlib/Makefile
> @@ -84,7 +84,8 @@ tests		:= tst-strtol tst-strtod testmb testrand testsort testdiv   \
>  		   tst-cxa_atexit tst-on_exit test-atexit-race 		    \
>  		   test-at_quick_exit-race test-cxa_atexit-race             \
>  		   test-on_exit-race test-dlclose-exit-race 		    \
> -		   tst-makecontext-align test-bz22786 tst-strtod-nan-sign
> +		   tst-makecontext-align test-bz22786 tst-strtod-nan-sign \
> +		   tst-swapcontext1

OK.

>  
>  tests-internal	:= tst-strtod1i tst-strtod3 tst-strtod4 tst-strtod5i \
>  		   tst-tls-atexit tst-tls-atexit-nodelete
> diff --git a/stdlib/tst-swapcontext1.c b/stdlib/tst-swapcontext1.c
> new file mode 100644
> index 0000000000..6dd52f22a6
> --- /dev/null
> +++ b/stdlib/tst-swapcontext1.c
> @@ -0,0 +1,92 @@
> +/* Check swapcontext wrapper.
> +   Modified from c-c++-common/asan/swapcontext-test-1.c in GCC testsuite.

I'm not sure we can relicense a test like this or copy the test.

> +   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/>.  */
> +
> +#include <stdio.h>
> +#include <ucontext.h>
> +#include <unistd.h>
> +
> +__attribute__((noinline, noclone))
> +__INDIRECT_RETURN
> +int
> +myswapcontext (ucontext_t *oucp, ucontext_t *ucp)
> +{
> +  int res = swapcontext (oucp, ucp);
> +  return res;
> +}
> +
> +ucontext_t orig_context;
> +ucontext_t child_context;
> +
> +void
> +Child (int mode)
> +{
> +  char x[32] = {0};  /* Stack gets poisoned. */
> +  printf("Child: %p\n", x);
> +  /* (a) Do nothing, just return to parent function.
> +     (b) Jump into the original function. Stack remains poisoned unless we do
> +     something. */
> +  if (mode == 1)
> +    {
> +      if (myswapcontext (&child_context, &orig_context) < 0)
> +	{
> +	  perror ("swapcontext");
> +	  _exit (0);
> +	}
> +    }

OK.

> +}
> +
> +int
> +Run (int arg, int mode)
> +{
> +  int i;
> +  const int kStackSize = 1 << 20;
> +  char child_stack[kStackSize + 1];
> +  printf ("Child stack: %p\n", child_stack);
> +  /* Setup child context. */
> +  getcontext (&child_context);
> +  child_context.uc_stack.ss_sp = child_stack;
> +  child_context.uc_stack.ss_size = kStackSize / 2;
> +  if (mode == 0)
> +    child_context.uc_link = &orig_context;
> +  makecontext (&child_context, (void (*)(void))Child, 1, mode);
> +  if (myswapcontext (&orig_context, &child_context) < 0)
> +    {
> +      perror("swapcontext");
> +      return 0;
> +    }
> +  /* Touch childs's stack to make sure it's unpoisoned. */
> +  for (i = 0; i < kStackSize; i++)
> +    child_stack[i] = i;
> +  return child_stack[arg];

OK.

> +}
> +
> +volatile int zero = 0;
> +
> +static int
> +do_test (void)
> +{
> +  int ret = 0;
> +  ret += Run (zero, 0);
> +  fprintf (stderr, "Test1 passed\n");
> +  ret += Run (zero, 1);
> +  fprintf (stderr, "Test2 passed\n");
> +  return ret;
> +}

OK.

> +
> +#include <support/test-driver.c>
> 

OK.
  

On Tue, Jul 24, 2018 at 11:27:04PM -0400, Carlos O'Donell wrote:
> On 07/21/2018 10:20 AM, H.J. Lu wrote:
> > Check swapcontext works with a wrapper.
> > 
> > 	* stdlib/Makefile (tests): Add tst-swapcontext1.
> > 	* stdlib/tst-swapcontext1.c: New test.
> 
> OK for 2.28 if you can answer the licensing question.
> 

I am dropping this for now.

H.J.