1. Summary:

  strerror_r() can use in multi-threaded applications, but
  rarely SIGSEGV occurs in strerror_r() with using setlocale()
  in other threads.

2. hardware dependency:

  none.

3. Description of Problem:

  SIGSEGV occurs in strerror_r().

4. How reproducible:

  rarely, but it happen.

5. Step to Reproduce:
  The following test program can reproduce the problems.
    tst-strerror.tar.gz
  To make reproduction easy, this program executes strerror_r(),
 printf(), setlocale()  at the same time by a lot of threads.

  1) Extract the archive file.
     The following files are extracted.
        Makefile
        tst-strerror.c
  2) Compile the test program.
        # make
  3) Run the test program.
        # ./tst-strerror
     Run the test programs in several times, SIGSEGV occurs.

6. Actual Result:

  SIGSEGV occurs in strerror_r().

7. Expected Result:

 strerror_r() execute normally.

------------------------------
Makefile:

CC=gcc
CFLAGS=-g -Wall -lpthread

PROGS= tst-strerror



all: $(PROGS)

.c:
        $(CC) $(CFLAGS) -o $* $*.c

$(PROGS):

clean:
        rm -f $(PROGS)
-------------------------------
tst-strerror.c:
#include <stdlib.h>
#include <stddef.h>
#include <stdio.h>
#include <unistd.h>
#include <limits.h>
#include <locale.h>
#include <wordexp.h>
#include "pthread.h"
#include <langinfo.h>
#include <string.h>
#include <monetary.h>
#include <string.h>
#include <errno.h>

#define ENVCOUNT_MAX 100
#define MAXTHREAD 100

static int start;

static void *
process_setlocale_1(void *arg)
{
  int i,s;
  char *result;

  while(!start) sched_yield();

  s = 0;
  for (i = 0; ; i++)
    {
        switch (s)
        {
        case 0:
                result = setlocale ( LC_MESSAGES, "el_GR.utf8" );
                s++;
                break;
        case 1:
                result = setlocale ( LC_MESSAGES, "en_CA.iso88591" );
                s++;
                break;
        case 2:
                result = setlocale ( LC_MESSAGES, "es_DO" );
                s++;
                break;
        case 3:
                result = setlocale ( LC_MESSAGES, "et_EE.utf8" );
                s++;
                break;
        default :
                s = 0;
        }

    }
  return NULL;
}
static void *
taikou_strerror(void *arg)
{
  int i;
  char *buf;
  buf = malloc ( 1024 );
  extern int errno;

  while(!start) sched_yield();

  for (i = 0; ; i++)
    {

strerror_r ( errno, buf, 1024 );
printf ( " errno = %d : %s \n ", errno, buf);
    }
  return NULL;
}

int
main (void)
{
  int retcode;
  pthread_t th[MAXTHREAD];
  pthread_attr_t attr[MAXTHREAD];
  char s[MAXTHREAD][7];
  int i;
  void  *result;

  start = 0;


      i = 0;
      pthread_attr_init(&attr[i]);
      pthread_attr_setstacksize(&attr[i],PTHREAD_STACK_MIN);
      sprintf(s[i], "A%05d", i);
      retcode = pthread_create (&th[i], &attr[i], process_setlocale_1, (void
*) s[i]);
      if (retcode != 0)
        {
          fprintf (stderr, "create a failed (wordexp) %d\n", retcode);
        }


  for (i = 1; i < MAXTHREAD; i++)
    {
      pthread_attr_init(&attr[i]);
      pthread_attr_setstacksize(&attr[i],PTHREAD_STACK_MIN);
      sprintf(s[i], "A%05d", i);
      retcode = pthread_create (&th[i], &attr[i], taikou_strerror, (void *)
s[i]);
      if (retcode != 0)
        {
          fprintf (stderr, "create a failed (getenv) %d\n", retcode);
        }
    }
  sleep(0);
  start = 1;
  sleep(0);

  for (i = 0; i < MAXTHREAD ; i++)
    {
      pthread_join(th[i],&result);
    }

  printf("end\n");
  return 0;
}
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