kern/97921: close() socket deadlocks blocked threads

[Kurt Miller]

>Number:         97921
>Category:       kern
>Synopsis:       close() socket deadlocks blocked threads
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu May 25 17:40:17 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Kurt Miller
>Release:        6.1-release
>Organization:
Intricate Software
>Environment:
FreeBSD freebsd6-1.zonesville.com 6.1-RELEASE FreeBSD 6.1-RELEASE #0: Sun May  7 04:42:56 UTC 2006     root at opus.cse.buffalo.edu:/usr/obj/usr/src/sys/SMP  i386
>Description:
When a thread is blocked waiting for data on a socket and another thread closes the socket, the blocked thread remains blocked indefinitely. Both kse and thr have this issue. c_r returns with -1 errno==EBADF. Solaris
returns with -1 errno==0.

I originally posted this on the freebsd-threads list. Daniel Eischen replied indicating this is not a thread library issue.
>How-To-Repeat:
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <sys/param.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <pthread.h>

static void *
start_routine(void *arg)
{
  int sock1 = (int)arg;
  struct sockaddr remote_addr;
  char readBuf;
  int n, remote_addr_len = sizeof(struct sockaddr);

  n = recvfrom(sock1, &readBuf, 1, 0, &remote_addr, &remote_addr_len);

  if (n == -1) {
    printf("unblocked with errno = %d\n", errno);
  }

  return (0);
}

void
buildAddr4(struct sockaddr_in *addr4, int address, short port) {
  memset((char *) addr4, 0, sizeof(struct sockaddr_in));
  addr4->sin_port = htons(port);
  addr4->sin_addr.s_addr = (uint32_t) htonl(address);
  addr4->sin_family = AF_INET;
}

int
main() {
  int sock1;
  struct sockaddr addr;
  pthread_t thread1;
  void *value_ptr;

  buildAddr4((struct sockaddr_in *)&addr, 0, 0);

  if ((sock1 = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
    exit(1);
  if (bind(sock1, (struct sockaddr *)&addr, sizeof(struct sockaddr_in)) != 0)
    exit(1);

  pthread_create(&thread1, NULL, start_routine, (void *)sock1);
  sleep(1);

  close(sock1);
  pthread_join(thread1, &value_ptr);

  return (0);
}
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: