--- a/auto/unix
+++ b/auto/unix
@@ -33,12 +33,12 @@ ngx_feature_run=no
 ngx_feature_incs="#include <poll.h>"
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="int  n, dp; struct pollfd  pl;
-                  dp = 0;
+ngx_feature_test="int  n; struct pollfd  pl;
                   pl.fd = 0;
                   pl.events = 0;
                   pl.revents = 0;
-                  n = poll(&pl, 1, 0)"
+                  n = poll(&pl, 1, 0);
+                  if (n == -1) return 1"
 . auto/feature
 
 if [ $ngx_found = no ]; then
@@ -57,7 +57,8 @@ ngx_feature_test="int  n, dp; struct dvp
                   dvp.dp_fds = NULL;
                   dvp.dp_nfds = 0;
                   dvp.dp_timeout = 0;
-                  n = ioctl(dp, DP_POLL, &dvp)"
+                  n = ioctl(dp, DP_POLL, &dvp);
+                  if (n == -1) return 1"
 . auto/feature
 
 if [ $ngx_found = yes ]; then
@@ -237,7 +238,7 @@ ngx_feature_incs="$NGX_INCLUDE_SYS_PARAM
 ngx_feature_path=
 ngx_feature_libs=
 ngx_feature_test="struct statfs  fs;
-                  statfs(NULL, &fs);"
+                  statfs(\".\", &fs);"
 . auto/feature
 
 
@@ -249,7 +250,7 @@ ngx_feature_incs="#include <sys/types.h>
 ngx_feature_path=
 ngx_feature_libs=
 ngx_feature_test="struct statvfs  fs;
-                  statvfs(NULL, &fs);"
+                  statvfs(\".\", &fs);"
 . auto/feature
 
 
@@ -343,6 +344,24 @@ ngx_feature_test="setsockopt(0, IPPROTO_
 . auto/feature
 
 
+ngx_feature="TCP_INFO"
+ngx_feature_name="NGX_HAVE_TCP_INFO"
+ngx_feature_run=no
+ngx_feature_incs="#include <sys/socket.h>
+                  #include <netinet/in.h>
+                  #include <netinet/tcp.h>"
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="socklen_t optlen = sizeof(struct tcp_info);
+                  struct tcp_info ti;
+                  ti.tcpi_rtt = 0;
+                  ti.tcpi_rttvar = 0;
+                  ti.tcpi_snd_cwnd = 0;
+                  ti.tcpi_rcv_space = 0;
+                  getsockopt(0, IPPROTO_TCP, TCP_INFO, &ti, &optlen)"
+. auto/feature
+
+
 ngx_feature="accept4()"
 ngx_feature_name="NGX_HAVE_ACCEPT4"
 ngx_feature_run=no
@@ -481,7 +500,7 @@ fi
 ngx_feature="setproctitle()"
 ngx_feature_name="NGX_HAVE_SETPROCTITLE"
 ngx_feature_run=no
-ngx_feature_incs=
+ngx_feature_incs="#include <stdlib.h>"
 ngx_feature_path=
 ngx_feature_libs=$NGX_SETPROCTITLE_LIB
 ngx_feature_test="setproctitle(\"test\");"
@@ -494,7 +513,8 @@ ngx_feature_run=no
 ngx_feature_incs=
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="char buf[1]; ssize_t n; n = pread(0, buf, 1, 0)"
+ngx_feature_test="char buf[1]; ssize_t n; n = pread(0, buf, 1, 0);
+                  if (n == -1) return 1"
 . auto/feature
 
 
@@ -504,7 +524,8 @@ ngx_feature_run=no
 ngx_feature_incs=
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="char buf[1]; ssize_t n; n = pwrite(1, buf, 1, 0)"
+ngx_feature_test="char buf[1]; ssize_t n; n = pwrite(1, buf, 1, 0);
+                  if (n == -1) return 1"
 . auto/feature
 
 
@@ -578,17 +599,20 @@ ngx_feature_run=no
 ngx_feature_incs="#include <stdlib.h>"
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="void *p; int n; n = posix_memalign(&p, 4096, 4096)"
+ngx_feature_test="void *p; int n; n = posix_memalign(&p, 4096, 4096);
+                  if (n != 0) return 1"
 . auto/feature
 
 
 ngx_feature="memalign()"
 ngx_feature_name="NGX_HAVE_MEMALIGN"
 ngx_feature_run=no
-ngx_feature_incs="#include <stdlib.h>"
+ngx_feature_incs="#include <stdlib.h>
+                  #include <malloc.h>"
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="void *p; p = memalign(4096, 4096)"
+ngx_feature_test="void *p; p = memalign(4096, 4096);
+                  if (p == NULL) return 1"
 . auto/feature
 
 
@@ -675,10 +699,12 @@ fi
 ngx_feature="struct msghdr.msg_control"
 ngx_feature_name="NGX_HAVE_MSGHDR_MSG_CONTROL"
 ngx_feature_run=no
-ngx_feature_incs="#include <sys/socket.h>"
+ngx_feature_incs="#include <sys/socket.h>
+                  #include <stdio.h>"
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="struct msghdr  msg; msg.msg_control = NULL"
+ngx_feature_test="struct msghdr  msg;
+                  printf(\"%d\", (int) sizeof(msg.msg_control))"
 . auto/feature
 
 
@@ -686,40 +712,47 @@ ngx_feature="ioctl(FIONBIO)"
 ngx_feature_name="NGX_HAVE_FIONBIO"
 ngx_feature_run=no
 ngx_feature_incs="#include <sys/ioctl.h>
+                  #include <stdio.h>
                   $NGX_INCLUDE_SYS_FILIO_H"
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="int i; i = FIONBIO"
+ngx_feature_test="int i = FIONBIO; printf(\"%d\", i)"
 . auto/feature
 
 
 ngx_feature="struct tm.tm_gmtoff"
 ngx_feature_name="NGX_HAVE_GMTOFF"
 ngx_feature_run=no
-ngx_feature_incs="#include <time.h>"
+ngx_feature_incs="#include <time.h>
+                  #include <stdio.h>"
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="struct tm  tm; tm.tm_gmtoff = 0"
+ngx_feature_test="struct tm  tm; tm.tm_gmtoff = 0;
+                  printf(\"%d\", (int) tm.tm_gmtoff)"
 . auto/feature
 
 
 ngx_feature="struct dirent.d_namlen"
 ngx_feature_name="NGX_HAVE_D_NAMLEN"
 ngx_feature_run=no
-ngx_feature_incs="#include <dirent.h>"
+ngx_feature_incs="#include <dirent.h>
+                  #include <stdio.h>"
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="struct dirent  dir; dir.d_namlen = 0"
+ngx_feature_test="struct dirent  dir; dir.d_namlen = 0;
+                  printf(\"%d\", (int) dir.d_namlen)"
 . auto/feature
 
 
 ngx_feature="struct dirent.d_type"
 ngx_feature_name="NGX_HAVE_D_TYPE"
 ngx_feature_run=no
-ngx_feature_incs="#include <dirent.h>"
+ngx_feature_incs="#include <dirent.h>
+                  #include <stdio.h>"
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="struct dirent  dir; dir.d_type = DT_REG"
+ngx_feature_test="struct dirent  dir; dir.d_type = DT_REG;
+                  printf(\"%d\", (int) dir.d_type)"
 . auto/feature