/* Test allocation function behavior on allocation failure.

   Copyright (C) 2015-2018 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; see the file COPYING.LIB.  If

   not, see <http://www.gnu.org/licenses/>.  */

/* This test case attempts to trigger various unusual conditions

   related to allocation failures, notably switching to a different

   arena, and falling back to mmap (via sysmalloc).  */

#include <errno.h>

#include <malloc.h>

#include <pthread.h>

#include <stdbool.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <sys/resource.h>

#include <sys/wait.h>

#include <unistd.h>

/* Wrapper for calloc with an optimization barrier.  */

static void *

__attribute__ ((noinline, noclone))

allocate_zeroed (size_t a, size_t b)

{

  return calloc (a, b);

}

/* System page size, as determined by sysconf (_SC_PAGE_SIZE).  */

static unsigned long page_size;

/* Test parameters. */

static size_t allocation_size;

static size_t alignment;

static enum {

  with_malloc,

  with_realloc,

  with_aligned_alloc,

  with_memalign,

  with_posix_memalign,

  with_valloc,

  with_pvalloc,

  with_calloc,

  last_allocation_function = with_calloc

} allocation_function;

/* True if an allocation function uses the alignment test

   parameter.  */

const static bool alignment_sensitive[last_allocation_function + 1] =

  {

    [with_aligned_alloc] = true,

    [with_memalign] = true,

    [with_posix_memalign] = true,

  };

/* Combined pointer/expected alignment result of an allocation

   function.  */

struct allocate_result {

  void *pointer;

  size_t alignment;

};

/* Call the allocation function specified by allocation_function, with

   allocation_size and alignment (if applicable) as arguments.  No

   alignment check.  */

static struct allocate_result

allocate_1 (void)

{

  switch (allocation_function)

    {

    case with_malloc:

      return (struct allocate_result)

        {malloc (allocation_size), _Alignof (max_align_t)};

    case with_realloc:

      {

        void *p = realloc (NULL, 16);

        void *q;

        if (p == NULL)

          q = NULL;

        else

          {

            q = realloc (p, allocation_size);

            if (q == NULL)

              free (p);

          }

        return (struct allocate_result) {q, _Alignof (max_align_t)};

      }

    case with_aligned_alloc:

      {

        void *p = aligned_alloc (alignment, allocation_size);

        return (struct allocate_result) {p, alignment};

      }

    case with_memalign:

      {

        void *p = memalign (alignment, allocation_size);

        return (struct allocate_result) {p, alignment};

      }

    case with_posix_memalign:

      {

        void *p;

        if (posix_memalign (&p, alignment, allocation_size))

          {

            if (errno == ENOMEM)

              p = NULL;

            else

              {

                printf ("error: posix_memalign (p, %zu, %zu): %m\n",

                        alignment, allocation_size);

                abort ();

              }

          }

        return (struct allocate_result) {p, alignment};

      }

    case with_valloc:

      {

        void *p = valloc (allocation_size);

        return (struct allocate_result) {p, page_size};

      }

    case with_pvalloc:

      {

        void *p = pvalloc (allocation_size);

        return (struct allocate_result) {p, page_size};

      }

    case with_calloc:

      {

        char *p = allocate_zeroed (1, allocation_size);

        /* Check for non-zero bytes.  */

        if (p != NULL)

          for (size_t i = 0; i < allocation_size; ++i)

            if (p[i] != 0)

              {

                printf ("error: non-zero byte at offset %zu\n", i);

                abort ();

              }

        return (struct allocate_result) {p, _Alignof (max_align_t)};

      }

    }

  abort ();

}

/* Call allocate_1 and perform the alignment check on the result.  */

static void *

allocate (void)

{

  struct allocate_result r = allocate_1 ();

  if ((((uintptr_t) r.pointer) & (r.alignment - 1)) != 0)

    {

      printf ("error: allocation function %d, size %zu not aligned to %zu\n",

              (int) allocation_function, allocation_size, r.alignment);

      abort ();

    }

  return r.pointer;

}

/* Barriers to synchronize thread creation and termination.  */

static pthread_barrier_t start_barrier;

static pthread_barrier_t end_barrier;

/* Thread function which performs the allocation test.  Called by

   pthread_create and from the main thread.  */

static void *

allocate_thread (void *closure)

{

  /* Wait for the creation of all threads.  */

  {

    int ret = pthread_barrier_wait (&start_barrier);

    if (ret != 0 && ret != PTHREAD_BARRIER_SERIAL_THREAD)

      {

        errno = ret;

        printf ("error: pthread_barrier_wait: %m\n");

        abort ();

      }

  }

  /* Allocate until we run out of memory, creating a single-linked

     list.  */

  struct list {

    struct list *next;

  };

  struct list *head = NULL;

  while (true)

    {

      struct list *e = allocate ();

      if (e == NULL)

        break;

      e->next = head;

      head = e;

    }

  /* Wait for the allocation of all available memory.  */

  {

    int ret = pthread_barrier_wait (&end_barrier);

    if (ret != 0 && ret != PTHREAD_BARRIER_SERIAL_THREAD)

      {

        errno = ret;

        printf ("error: pthread_barrier_wait: %m\n");

        abort ();

      }

  }

  /* Free the allocated memory.  */

  while (head != NULL)

    {

      struct list *next = head->next;

      free (head);

      head = next;

    }

  return NULL;

}

/* Number of threads (plus the main thread.  */

enum { thread_count = 8 };

/* Thread attribute to request creation of threads with a non-default

   stack size which is rather small.  This avoids interfering with the

   configured address space limit.  */

static pthread_attr_t small_stack;

/* Runs one test in multiple threads, all in a subprocess so that

   subsequent tests do not interfere with each other.  */

static void

run_one (void)

{

  /* Isolate the tests in a subprocess, so that we can start over

     from scratch.  */

  pid_t pid = fork ();

  if (pid == 0)

    {

      /* In the child process.  Create the allocation threads.  */

      pthread_t threads[thread_count];

      for (unsigned i = 0; i < thread_count; ++i)

        {

          int ret = pthread_create (threads + i, &small_stack, allocate_thread, NULL);

          if (ret != 0)

            {

              errno = ret;

              printf ("error: pthread_create: %m\n");

              abort ();

            }

        }

      /* Also run the test on the main thread.  */

      allocate_thread (NULL);

      for (unsigned i = 0; i < thread_count; ++i)

        {

          int ret = pthread_join (threads[i], NULL);

          if (ret != 0)

            {

              errno = ret;

              printf ("error: pthread_join: %m\n");

              abort ();

            }

        }

      _exit (0);

    }

  else if (pid < 0)

    {

      printf ("error: fork: %m\n");

      abort ();

    }

  /* In the parent process.  Wait for the child process to exit.  */

  int status;

  if (waitpid (pid, &status, 0) < 0)

    {

      printf ("error: waitpid: %m\n");

      abort ();

    }

  if (status != 0)

    {

      printf ("error: exit status %d from child process\n", status);

      exit (1);

    }

}

/* Run all applicable allocation functions for the current test

   parameters.  */

static void

run_allocation_functions (void)

{

  for (int af = 0; af <= last_allocation_function; ++af)

    {

      /* Run alignment-sensitive functions for non-default

         alignments.  */

      if (alignment_sensitive[af] != (alignment != 0))

        continue;

      allocation_function = af;

      run_one ();

    }

}

int

do_test (void)

{

  /* Limit the number of malloc arenas.  We use a very low number so

     that despute the address space limit configured below, all

     requested arenas a can be created.  */

  if (mallopt (M_ARENA_MAX, 2) == 0)

    {

      printf ("error: mallopt (M_ARENA_MAX) failed\n");

      return 1;

    }

  /* Determine the page size.  */

  {

    long ret = sysconf (_SC_PAGE_SIZE);

    if (ret < 0)

      {

        printf ("error: sysconf (_SC_PAGE_SIZE): %m\n");

        return 1;

      }

    page_size = ret;

  }

  /* Limit the size of the process, so that memory allocation in

     allocate_thread will eventually fail, without impacting the

     entire system.  */

  {

    struct rlimit limit;

    if (getrlimit (RLIMIT_AS, &limit) != 0)

      {

        printf ("getrlimit (RLIMIT_AS) failed: %m\n");

        return 1;

      }

    long target = 200 * 1024 * 1024;

    if (limit.rlim_cur == RLIM_INFINITY || limit.rlim_cur > target)

      {

        limit.rlim_cur = target;

        if (setrlimit (RLIMIT_AS, &limit) != 0)

          {

            printf ("setrlimit (RLIMIT_AS) failed: %m\n");

            return 1;

          }

      }

  }

  /* Initialize thread attribute with a reduced stack size.  */

  {

    int ret = pthread_attr_init (&small_stack);

    if (ret != 0)

      {

        errno = ret;

        printf ("error: pthread_attr_init: %m\n");

        abort ();

      }

    unsigned long stack_size = ((256 * 1024) / page_size) * page_size;

    if (stack_size < 4 * page_size)

      stack_size = 8 * page_size;

    ret = pthread_attr_setstacksize (&small_stack, stack_size);

    if (ret != 0)

      {

        errno = ret;

        printf ("error: pthread_attr_setstacksize: %m\n");

        abort ();

      }

  }

  /* Initialize the barriers.  We run thread_count threads, plus 1 for

     the main thread.  */

  {

    int ret = pthread_barrier_init (&start_barrier, NULL, thread_count + 1);

    if (ret != 0)

      {

        errno = ret;

        printf ("error: pthread_barrier_init: %m\n");

        abort ();

      }

    ret = pthread_barrier_init (&end_barrier, NULL, thread_count + 1);

    if (ret != 0)

      {

        errno = ret;

        printf ("error: pthread_barrier_init: %m\n");

        abort ();

      }

  }

  allocation_size = 144;

  run_allocation_functions ();

  allocation_size = page_size;

  run_allocation_functions ();

  alignment = 128;

  allocation_size = 512;

  run_allocation_functions ();

  allocation_size = page_size;

  run_allocation_functions ();

  allocation_size = 17 * page_size;

  run_allocation_functions ();

  /* Deallocation the barriers and the thread attribute.  */

  {

    int ret = pthread_barrier_destroy (&end_barrier);

    if (ret != 0)

      {

        errno = ret;

        printf ("error: pthread_barrier_destroy: %m\n");

        return 1;

      }

    ret = pthread_barrier_destroy (&start_barrier);

    if (ret != 0)

      {

        errno = ret;

        printf ("error: pthread_barrier_destroy: %m\n");

        return 1;

      }

    ret = pthread_attr_destroy (&small_stack);

    if (ret != 0)

      {

        errno = ret;

        printf ("error: pthread_attr_destroy: %m\n");

        return 1;

      }

  }

  return 0;

}

/* The repeated allocations take some time on slow machines.  */

#define TIMEOUT 100

#define TEST_FUNCTION do_test ()

#include "../test-skeleton.c"