commit 28e09b5eb76919122f8baf57899154b3dd5fdaa0
parent d64a3751ca805c08bfda6a330d73a09e87e993c0
Author: Laurent Bercot <ska-skaware@skarnet.org>
Date: Wed, 28 Jun 2023 21:27:29 +0000
Add workaround for bad QoI posix_spawn()
Signed-off-by: Laurent Bercot <ska@appnovation.com>
Diffstat:
10 files changed, 462 insertions(+), 276 deletions(-)
diff --git a/configure b/configure
@@ -47,8 +47,10 @@ $package options:
Sysdeps autodetection override:
--with-sysdep-K=V assume sysdep K has the value V [autodetected]
-List of mandatory K for cross-compiling: devurandom (V=yes|no)
-
+
+List of mandatory sysdeps for cross-compiling:
+ devurandom (yes|no): =yes if you have a working /dev/urandom
+ posixspawnearlyreturn (yes|no): =yes if you have an old glibc or otherwise bad posix_spawn
EOF
exit 0
}
@@ -641,6 +643,7 @@ choose cl chroot 'chroot()'
# Here are the evil irreducible run-time sysdeps.
choose clr devurandom '/dev/urandom'
+choose clr posixspawnearlyreturn 'posix_spawn() returning early'
# Finally, produce config.mak and config.h
diff --git a/package/deps.mak b/package/deps.mak
@@ -63,6 +63,7 @@ src/libstdcrypto/sha1-internal.h: src/include/skalibs/sha1.h
src/libstdcrypto/sha256-internal.h: src/include/skalibs/sha256.h
src/libstdcrypto/sha512-internal.h: src/include/skalibs/sha512.h
src/libstddjb/cdb-internal.h: src/include/skalibs/cdb.h src/include/skalibs/gccattributes.h
+src/libstddjb/child_spawn-internal.h: src/include/skalibs/sysdeps.h
src/libstddjb/djbtime-internal.h: src/include/skalibs/uint64.h
src/libstddjb/fmtscan-internal.h: src/include/skalibs/fmtscan.h src/include/skalibs/uint64.h
src/libunixonacid/skaclient-internal.h: src/include/skalibs/kolbak.h src/include/skalibs/skaclient.h src/include/skalibs/unixmessage.h
@@ -236,7 +237,7 @@ src/libstddjb/buffer_2.o src/libstddjb/buffer_2.lo: src/libstddjb/buffer_2.c src
src/libstddjb/buffer_fill.o src/libstddjb/buffer_fill.lo: src/libstddjb/buffer_fill.c src/include/skalibs/buffer.h
src/libstddjb/buffer_flush.o src/libstddjb/buffer_flush.lo: src/libstddjb/buffer_flush.c src/include/skalibs/buffer.h src/include/skalibs/cbuffer.h
src/libstddjb/buffer_flush1read.o src/libstddjb/buffer_flush1read.lo: src/libstddjb/buffer_flush1read.c src/include/skalibs/allreadwrite.h src/include/skalibs/buffer.h
-src/libstddjb/buffer_get.o src/libstddjb/buffer_get.lo: src/libstddjb/buffer_get.c src/include/skalibs/buffer.h
+src/libstddjb/buffer_get.o src/libstddjb/buffer_get.lo: src/libstddjb/buffer_get.c src/include/skalibs/allreadwrite.h src/include/skalibs/buffer.h
src/libstddjb/buffer_getall.o src/libstddjb/buffer_getall.lo: src/libstddjb/buffer_getall.c src/include/skalibs/allreadwrite.h src/include/skalibs/buffer.h
src/libstddjb/buffer_getallnf.o src/libstddjb/buffer_getallnf.lo: src/libstddjb/buffer_getallnf.c src/include/skalibs/buffer.h
src/libstddjb/buffer_getfd.o src/libstddjb/buffer_getfd.lo: src/libstddjb/buffer_getfd.c src/include/skalibs/buffer.h
@@ -293,13 +294,14 @@ src/libstddjb/cdb_p.o src/libstddjb/cdb_p.lo: src/libstddjb/cdb_p.c src/libstddj
src/libstddjb/cdb_traverse_next.o src/libstddjb/cdb_traverse_next.lo: src/libstddjb/cdb_traverse_next.c src/libstddjb/cdb-internal.h src/include/skalibs/cdb.h src/include/skalibs/uint32.h
src/libstddjb/cdb_zero.o src/libstddjb/cdb_zero.lo: src/libstddjb/cdb_zero.c src/include/skalibs/cdb.h
src/libstddjb/cdbmake.o src/libstddjb/cdbmake.lo: src/libstddjb/cdbmake.c src/include/skalibs/buffer.h src/libstddjb/cdb-internal.h src/include/skalibs/cdbmake.h src/include/skalibs/diuint32.h src/include/skalibs/genalloc.h src/include/skalibs/uint32.h
-src/libstddjb/child_spawn.o src/libstddjb/child_spawn.lo: src/libstddjb/child_spawn.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/env.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/strerr.h src/include/skalibs/sysdeps.h src/include/skalibs/types.h
-src/libstddjb/child_spawn0.o src/libstddjb/child_spawn0.lo: src/libstddjb/child_spawn0.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/strerr.h src/include/skalibs/sysdeps.h
-src/libstddjb/child_spawn1_internal.o src/libstddjb/child_spawn1_internal.lo: src/libstddjb/child_spawn1_internal.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/strerr.h src/include/skalibs/sysdeps.h
+src/libstddjb/child_spawn.o src/libstddjb/child_spawn.lo: src/libstddjb/child_spawn.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/env.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/sysdeps.h src/include/skalibs/types.h
+src/libstddjb/child_spawn0.o src/libstddjb/child_spawn0.lo: src/libstddjb/child_spawn0.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/sysdeps.h
+src/libstddjb/child_spawn1_internal.o src/libstddjb/child_spawn1_internal.lo: src/libstddjb/child_spawn1_internal.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/sysdeps.h
src/libstddjb/child_spawn1_pipe.o src/libstddjb/child_spawn1_pipe.lo: src/libstddjb/child_spawn1_pipe.c src/libstddjb/djbunix-internal.h src/include/skalibs/djbunix.h
src/libstddjb/child_spawn1_socket.o src/libstddjb/child_spawn1_socket.lo: src/libstddjb/child_spawn1_socket.c src/libstddjb/djbunix-internal.h src/include/skalibs/djbunix.h src/include/skalibs/socket.h
-src/libstddjb/child_spawn2.o src/libstddjb/child_spawn2.lo: src/libstddjb/child_spawn2.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/strerr.h src/include/skalibs/sysdeps.h
-src/libstddjb/child_spawn3.o src/libstddjb/child_spawn3.lo: src/libstddjb/child_spawn3.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/env.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/strerr.h src/include/skalibs/sysdeps.h src/include/skalibs/types.h
+src/libstddjb/child_spawn2.o src/libstddjb/child_spawn2.lo: src/libstddjb/child_spawn2.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/sysdeps.h
+src/libstddjb/child_spawn3.o src/libstddjb/child_spawn3.lo: src/libstddjb/child_spawn3.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/env.h src/include/skalibs/exec.h src/include/skalibs/sig.h src/include/skalibs/sysdeps.h src/include/skalibs/types.h
+src/libstddjb/child_spawn_workaround.o src/libstddjb/child_spawn_workaround.lo: src/libstddjb/child_spawn_workaround.c src/include/skalibs/allreadwrite.h src/libstddjb/child_spawn-internal.h src/include/skalibs/djbunix.h src/include/skalibs/sysdeps.h
src/libstddjb/coe.o src/libstddjb/coe.lo: src/libstddjb/coe.c src/include/skalibs/djbunix.h
src/libstddjb/deepsleepuntil.o src/libstddjb/deepsleepuntil.lo: src/libstddjb/deepsleepuntil.c src/include/skalibs/iopause.h src/include/skalibs/tai.h
src/libstddjb/devino_cmp.o src/libstddjb/devino_cmp.lo: src/libstddjb/devino_cmp.c src/include/skalibs/devino.h
diff --git a/src/libstddjb/child_spawn-internal.h b/src/libstddjb/child_spawn-internal.h
@@ -0,0 +1,16 @@
+/* ISC license. */
+
+#ifndef CHILD_SPAWN_INTERNAL_H
+#define CHILD_SPAWN_INTERNAL_H
+
+#include <skalibs/sysdeps.h>
+
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+
+#include <sys/types.h>
+
+extern pid_t child_spawn_workaround (pid_t, int const *) ; /* closes the pipe */
+
+#endif
+
+#endif
diff --git a/src/libstddjb/child_spawn.c b/src/libstddjb/child_spawn.c
@@ -3,58 +3,48 @@
/* MT-unsafe */
#include <skalibs/sysdeps.h>
+
#include <string.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <sys/wait.h>
-#include <unistd.h>
#include <errno.h>
-#include <signal.h>
+#include <unistd.h>
+
+#include <skalibs/types.h>
+#include <skalibs/djbunix.h>
#ifdef SKALIBS_HASPOSIXSPAWN
+#include <signal.h>
#include <stdlib.h>
#include <spawn.h>
-#include <skalibs/config.h>
-
-#else
-
-#include <skalibs/sig.h>
-#include <skalibs/strerr.h>
-#include <skalibs/exec.h>
-
-#endif
-#include <skalibs/types.h>
-#include <skalibs/allreadwrite.h>
+#include <skalibs/config.h>
#include <skalibs/env.h>
-#include <skalibs/djbunix.h>
- /*
- If n = 0 : child's stdin and stdout are the same as the parent's
- If n >= 1 : pipes between parent and child.
- Parent reads on even ones, writes on odd ones.
- */
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+# include "child_spawn-internal.h"
+#endif
pid_t child_spawn (char const *prog, char const *const *argv, char const *const *envp, int *fds, unsigned int n)
{
pid_t pid ;
-#ifdef SKALIBS_HASPOSIXSPAWN
posix_spawn_file_actions_t actions ;
posix_spawnattr_t attr ;
+ sigset_t set ;
int e ;
-#else
- int syncpipe[2] ;
-#endif
int p[n ? n : 1][2] ;
size_t m = sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
unsigned int i = 0 ;
char modifs[m + 1 + n * UINT_FMT] ;
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ int syncpipe[2] ;
+ if (pipecoe(syncpipe) == -1) return 0 ;
+#endif
+
memcpy(modifs, SKALIBS_CHILD_SPAWN_FDS_ENVVAR "=", sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR)) ;
for (; i < n ; i++)
{
- if (pipe(p[i]) < 0) goto errpi ;
- if ((ndelay_on(p[i][i & 1]) < 0) || (coe(p[i][i & 1]) < 0))
+ if (pipe(p[i]) == -1) goto errpi ;
+ if ((ndelay_on(p[i][i & 1]) == -1) || (coe(p[i][i & 1]) == -1))
{
i++ ; goto errpi ;
}
@@ -66,18 +56,13 @@ pid_t child_spawn (char const *prog, char const *const *argv, char const *const
}
modifs[m++] = 0 ;
-#ifdef SKALIBS_HASPOSIXSPAWN
-
e = posix_spawnattr_init(&attr) ;
if (e) goto erre ;
- {
- sigset_t set ;
- sigemptyset(&set) ;
- e = posix_spawnattr_setsigmask(&attr, &set) ;
- if (e) goto errattr ;
- e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
- if (e) goto errattr ;
- }
+ sigemptyset(&set) ;
+ e = posix_spawnattr_setsigmask(&attr, &set) ;
+ if (e) goto errattr ;
+ e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
+ if (e) goto errattr ;
e = posix_spawn_file_actions_init(&actions) ;
if (e) goto errattr ;
if (n >= 2 && p[1][0])
@@ -110,53 +95,104 @@ pid_t child_spawn (char const *prog, char const *const *argv, char const *const
posix_spawn_file_actions_destroy(&actions) ;
posix_spawnattr_destroy(&attr) ;
+ for (i = 0 ; i < n ; i++) fd_close(p[i][!(i & 1)]) ;
+
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ pid = child_spawn_workaround(pid, syncpipe) ;
+ if (!pid)
+ {
+ for (i = 0 ; i < n ; i++) fd_close(p[i][i & 1]) ;
+ return 0 ;
+ }
+#endif
+ for (i = 0 ; i < n ; i++) fds[i] = p[i][i & 1] ;
+ return pid ;
+
+ erractions:
+ posix_spawn_file_actions_destroy(&actions) ;
+ errattr:
+ posix_spawnattr_destroy(&attr) ;
+ erre:
+ errno = e ;
+ i = n ;
+ errpi:
+ while (i--)
+ {
+ fd_close(p[i][1]) ;
+ fd_close(p[i][0]) ;
+ }
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ fd_close(syncpipe[1]) ;
+ fd_close(syncpipe[0]) ;
+#endif
+ return 0 ;
+}
#else
+
+#include <skalibs/allreadwrite.h>
+#include <skalibs/sig.h>
+#include <skalibs/exec.h>
+
+pid_t child_spawn (char const *prog, char const *const *argv, char const *const *envp, int *fds, unsigned int n)
+{
+ pid_t pid ;
+ int syncpipe[2] ;
+ int p[n ? n : 1][2] ;
+ size_t m = sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
+ unsigned int i = 0 ;
+ char modifs[m + 1 + n * UINT_FMT] ;
+ char c ;
+
+ memcpy(modifs, SKALIBS_CHILD_SPAWN_FDS_ENVVAR "=", sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR)) ;
+ for (; i < n ; i++)
+ {
+ if (pipe(p[i]) == -1) goto errpi ;
+ if ((ndelay_on(p[i][i & 1]) == -1) || (coe(p[i][i & 1]) == -1))
+ {
+ i++ ; goto errpi ;
+ }
+ }
+ for (i = 2 ; i < n ; i++)
+ {
+ m += uint_fmt(modifs + m, p[i][!(i & 1)]) ;
+ if (i+1 < n) modifs[m++] = ',' ;
+ }
+ modifs[m++] = 0 ;
+
if (pipecoe(syncpipe) < 0) goto errp ;
pid = fork() ;
if (pid < 0) goto errsp ;
else if (!pid)
{
- size_t len = strlen(PROG) ;
- char name[len + 9] ;
- memcpy(name, PROG, len) ;
- memcpy(name + len, " (child)", 9) ;
- PROG = name ;
if (n >= 2)
{
- if (fd_move2(0, p[1][0], 1, p[0][1]) < 0) goto syncdie ;
+ if (fd_move2(0, p[1][0], 1, p[0][1]) == -1) goto syncdie ;
}
else if (n)
{
- if (fd_move(1, p[0][1]) < 0) goto syncdie ;
+ if (fd_move(1, p[0][1]) == -1) goto syncdie ;
}
sig_blocknone() ;
mexec_aen(prog, argv, envp, modifs, m, 1) ;
-
syncdie:
- {
- unsigned char c = errno ;
- fd_write(syncpipe[1], (char *)&c, 1) ;
- }
+ c = errno ;
+ fd_write(syncpipe[1], &c, 1) ;
_exit(127) ;
}
fd_close(syncpipe[1]) ;
+ syncpipe[1] = fd_read(syncpipe[0], &c, 1) ;
+ if (syncpipe[1])
{
- unsigned char c ;
- syncpipe[1] = fd_read(syncpipe[0], (char *)&c, 1) ;
- if (syncpipe[1])
- {
- int e = c ;
- if (syncpipe[1] < 0) e = errno ;
- if (wait_pid(pid, &syncpipe[1]) < 0) e = errno ;
- errno = e ;
- goto errsp0 ;
- }
+ int e = (unsigned char)c ;
+ if (syncpipe[1] == -1) e = errno ;
+ if (wait_pid(pid, 0) == -1) e = errno ;
+ errno = e ;
+ goto errsp0 ;
}
fd_close(syncpipe[0]) ;
-#endif
for (i = n ; i ; i--)
{
@@ -165,21 +201,11 @@ pid_t child_spawn (char const *prog, char const *const *argv, char const *const
}
return pid ;
-#ifdef SKALIBS_HASPOSIXSPAWN
- erractions:
- posix_spawn_file_actions_destroy(&actions) ;
- errattr:
- posix_spawnattr_destroy(&attr) ;
- erre:
- errno = e ;
-#endif
-#ifndef SKALIBS_HASPOSIXSPAWN
errsp:
fd_close(syncpipe[1]) ;
errsp0:
fd_close(syncpipe[0]) ;
errp:
-#endif
i = n ;
errpi:
while (i--)
@@ -189,3 +215,5 @@ pid_t child_spawn (char const *prog, char const *const *argv, char const *const
}
return 0 ;
}
+
+#endif
diff --git a/src/libstddjb/child_spawn0.c b/src/libstddjb/child_spawn0.c
@@ -1,42 +1,59 @@
/* ISC license. */
#include <skalibs/sysdeps.h>
+
#include <errno.h>
#ifdef SKALIBS_HASPOSIXSPAWN
#include <signal.h>
-#include <spawn.h>
#include <stdlib.h>
+#include <spawn.h>
#include <skalibs/config.h>
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+# include <skalibs/djbunix.h>
+# include "child_spawn-internal.h"
+#endif
+
pid_t child_spawn0 (char const *prog, char const *const *argv, char const *const *envp)
{
pid_t pid ;
posix_spawnattr_t attr ;
+ sigset_t set ;
int e ;
int nopath = !getenv("PATH") ;
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ int p[2] ;
+ if (pipecoe(p) == -1) return 0 ;
+#endif
e = posix_spawnattr_init(&attr) ;
if (e) goto err ;
- {
- sigset_t set ;
- sigemptyset(&set) ;
- e = posix_spawnattr_setsigmask(&attr, &set) ;
- if (e) goto errattr ;
- e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
- if (e) goto errattr ;
- }
+ sigemptyset(&set) ;
+ e = posix_spawnattr_setsigmask(&attr, &set) ;
+ if (e) goto errattr ;
+ e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
+ if (e) goto errattr ;
if (nopath && (setenv("PATH", SKALIBS_DEFAULTPATH, 0) < 0)) { e = errno ; goto errattr ; }
e = posix_spawnp(&pid, prog, 0, &attr, (char *const *)argv, (char *const *)envp) ;
if (nopath) unsetenv("PATH") ;
+ if (e) goto errattr ;
+
posix_spawnattr_destroy(&attr) ;
- if (e) goto err ;
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ return child_spawn_workaround(pid, p) ;
+#else
return pid ;
+#endif
errattr:
posix_spawnattr_destroy(&attr) ;
err:
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ fd_close(p[1]) ;
+ fd_close(p[0]) ;
+#endif
errno = e ;
return 0 ;
}
@@ -44,10 +61,8 @@ pid_t child_spawn0 (char const *prog, char const *const *argv, char const *const
#else
#include <unistd.h>
-#include <string.h>
#include <skalibs/allreadwrite.h>
-#include <skalibs/strerr.h>
#include <skalibs/sig.h>
#include <skalibs/djbunix.h>
#include <skalibs/exec.h>
@@ -56,8 +71,9 @@ pid_t child_spawn0 (char const *prog, char const *const *argv, char const *const
{
pid_t pid ;
int p[2] ;
- unsigned char c ;
- if (pipecoe(p) < 0) return 0 ;
+ char c ;
+
+ if (pipecoe(p) == -1) return 0 ;
pid = fork() ;
if (pid < 0)
{
@@ -67,20 +83,14 @@ pid_t child_spawn0 (char const *prog, char const *const *argv, char const *const
}
if (!pid)
{
- size_t len = strlen(PROG) ;
- char name[len + 9] ;
- memcpy(name, PROG, len) ;
- memcpy(name + len, " (child)", 9) ;
- PROG = name ;
- fd_close(p[0]) ;
sig_blocknone() ;
exec_ae(prog, argv, envp) ;
c = errno ;
- fd_write(p[1], (char *)&c, 1) ;
+ fd_write(p[1], &c, 1) ;
_exit(127) ;
}
fd_close(p[1]) ;
- p[1] = fd_read(p[0], (char *)&c, 1) ;
+ p[1] = fd_read(p[0], &c, 1) ;
if (p[1] < 0)
{
fd_close(p[0]) ;
@@ -90,7 +100,7 @@ pid_t child_spawn0 (char const *prog, char const *const *argv, char const *const
if (p[1])
{
wait_pid(pid, &p[0]) ;
- errno = c ;
+ errno = (unsigned char)c ;
return 0 ;
}
return pid ;
diff --git a/src/libstddjb/child_spawn1_internal.c b/src/libstddjb/child_spawn1_internal.c
@@ -1,9 +1,11 @@
/* ISC license. */
#include <skalibs/sysdeps.h>
-#include <unistd.h>
+
#include <errno.h>
+#include <skalibs/djbunix.h>
+
#ifdef SKALIBS_HASPOSIXSPAWN
#include <signal.h>
@@ -11,26 +13,33 @@
#include <stdlib.h>
#include <skalibs/config.h>
-#include <skalibs/djbunix.h>
+
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+# include "child_spawn-internal.h"
+#endif
pid_t child_spawn1_internal (char const *prog, char const *const *argv, char const *const *envp, int *p, int to)
{
pid_t pid ;
posix_spawn_file_actions_t actions ;
posix_spawnattr_t attr ;
+ sigset_t set ;
int e ;
int nopath = !getenv("PATH") ;
- if (coe(p[!(to & 1)]) < 0) goto err ;
+
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ int syncpipe[2] ;
+ if (pipecoe(syncpipe) == -1) goto err ;
+#endif
+
+ if (coe(p[!(to & 1)]) == -1) goto errp ;
e = posix_spawnattr_init(&attr) ;
if (e) goto erre ;
- {
- sigset_t set ;
- sigemptyset(&set) ;
- e = posix_spawnattr_setsigmask(&attr, &set) ;
- if (e) goto errattr ;
- e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
- if (e) goto errattr ;
- }
+ sigemptyset(&set) ;
+ e = posix_spawnattr_setsigmask(&attr, &set) ;
+ if (e) goto errattr ;
+ e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
+ if (e) goto errattr ;
e = posix_spawn_file_actions_init(&actions) ;
if (e) goto errattr ;
if (p[to & 1] != (to & 1))
@@ -49,10 +58,16 @@ pid_t child_spawn1_internal (char const *prog, char const *const *argv, char con
e = posix_spawnp(&pid, prog, &actions, &attr, (char *const *)argv, (char *const *)envp) ;
if (nopath) unsetenv("PATH") ;
if (e) goto erractions ;
+
posix_spawn_file_actions_destroy(&actions) ;
posix_spawnattr_destroy(&attr) ;
fd_close(p[to & 1]) ;
+
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ return child_spawn_workaround(pid, syncpipe) ;
+#else
return pid ;
+#endif
erractions:
posix_spawn_file_actions_destroy(&actions) ;
@@ -60,7 +75,12 @@ pid_t child_spawn1_internal (char const *prog, char const *const *argv, char con
posix_spawnattr_destroy(&attr) ;
erre:
errno = e ;
+ errp:
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ fd_close(syncpipe[1]) ;
+ fd_close(syncpipe[0]) ;
err:
+#endif
fd_close(p[1]) ;
fd_close(p[0]) ;
return 0 ;
@@ -68,59 +88,46 @@ pid_t child_spawn1_internal (char const *prog, char const *const *argv, char con
#else
-#include <string.h>
+#include <unistd.h>
#include <skalibs/allreadwrite.h>
-#include <skalibs/strerr.h>
#include <skalibs/sig.h>
-#include <skalibs/djbunix.h>
#include <skalibs/exec.h>
pid_t child_spawn1_internal (char const *prog, char const *const *argv, char const *const *envp, int *p, int to)
{
pid_t pid ;
int syncpipe[2] ;
+ char c ;
+
if (coe(p[0]) < 0 || pipecoe(syncpipe) < 0) goto err ;
pid = fork() ;
if (pid < 0) goto errsp ;
if (!pid)
{
- size_t len = strlen(PROG) ;
- char name[len + 9] ;
- memcpy(name, PROG, len) ;
- memcpy(name + len, " (child)", 9) ;
- PROG = name ;
fd_close(p[!(to & 1)]) ;
if (fd_move(to & 1, p[to & 1]) < 0) goto syncdie ;
if ((to & 2) && (fd_copy(!(to & 1), to & 1) < 0)) goto syncdie ;
sig_blocknone() ;
exec_ae(prog, argv, envp) ;
-
syncdie:
- {
- unsigned char c = errno ;
- fd_write(syncpipe[1], (char *)&c, 1) ;
- }
+ c = errno ;
+ fd_write(syncpipe[1], &c, 1) ;
_exit(127) ;
}
fd_close(syncpipe[1]) ;
-
+ syncpipe[1] = fd_read(syncpipe[0], &c, 1) ;
+ if (syncpipe[1])
{
- unsigned char c ;
- syncpipe[1] = fd_read(syncpipe[0], (char *)&c, 1) ;
- if (syncpipe[1])
- {
- int e = c ;
- if (syncpipe[1] < 0) e = errno ;
- if (wait_pid(pid, &syncpipe[1]) < 0) e = errno ;
- errno = e ;
- goto errsp0 ;
- }
+ int e = (unsigned char)c ;
+ if (syncpipe[1] == -1) e = errno ;
+ if (wait_pid(pid, 0) == -1) e = errno ;
+ errno = e ;
+ goto errsp0 ;
}
fd_close(syncpipe[0]) ;
-
fd_close(p[to & 1]) ;
return pid ;
diff --git a/src/libstddjb/child_spawn2.c b/src/libstddjb/child_spawn2.c
@@ -3,58 +3,48 @@
/* MT-unsafe */
#include <skalibs/sysdeps.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <sys/wait.h>
+
#include <unistd.h>
#include <errno.h>
-#include <signal.h>
+
+#include <skalibs/djbunix.h>
#ifdef SKALIBS_HASPOSIXSPAWN
+#include <signal.h>
#include <stdlib.h>
#include <spawn.h>
-#include <skalibs/config.h>
-#else
-
-#include <string.h>
-#include <skalibs/allreadwrite.h>
-#include <skalibs/sig.h>
-#include <skalibs/strerr.h>
-#include <skalibs/exec.h>
+#include <skalibs/config.h>
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+# include "child_spawn-internal.h"
#endif
-#include <skalibs/djbunix.h>
-
pid_t child_spawn2 (char const *prog, char const *const *argv, char const *const *envp, int *fds)
{
pid_t pid ;
-#ifdef SKALIBS_HASPOSIXSPAWN
posix_spawn_file_actions_t actions ;
posix_spawnattr_t attr ;
+ int p[2][2] ;
int e ;
-#else
+ int nopath = !getenv("PATH") ;
+ sigset_t set ;
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
int syncpipe[2] ;
+ if (pipecoe(syncpipe) == -1) return 0 ;
#endif
- int p[2][2] ;
- if (pipe(p[0]) < 0) return 0 ;
- if (ndelay_on(p[0][0]) < 0 || coe(p[0][0]) < 0 || pipe(p[1]) < 0) goto errp ;
- if (ndelay_on(p[1][1]) < 0 || coe(p[1][1]) < 0) goto errp1 ;
-
-#ifdef SKALIBS_HASPOSIXSPAWN
+ if (pipe(p[0]) == -1) goto err ;
+ if (ndelay_on(p[0][0]) == -1 || coe(p[0][0]) == -1 || pipe(p[1]) == -1) goto errp ;
+ if (ndelay_on(p[1][1]) == -1 || coe(p[1][1]) == -1) goto errp1 ;
e = posix_spawnattr_init(&attr) ;
if (e) goto erre ;
- {
- sigset_t set ;
- sigemptyset(&set) ;
- e = posix_spawnattr_setsigmask(&attr, &set) ;
- if (e) goto errattr ;
- e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
- if (e) goto errattr ;
- }
+ sigemptyset(&set) ;
+ e = posix_spawnattr_setsigmask(&attr, &set) ;
+ if (e) goto errattr ;
+ e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
+ if (e) goto errattr ;
e = posix_spawn_file_actions_init(&actions) ;
if (e) goto errattr ;
if (p[1][0] != fds[0])
@@ -71,78 +61,105 @@ pid_t child_spawn2 (char const *prog, char const *const *argv, char const *const
e = posix_spawn_file_actions_addclose(&actions, p[0][1]) ;
if (e) goto erractions ;
}
+ if (nopath && (setenv("PATH", SKALIBS_DEFAULTPATH, 0) == -1))
{
- int nopath = !getenv("PATH") ;
- if (nopath && (setenv("PATH", SKALIBS_DEFAULTPATH, 0) < 0))
- {
- e = errno ; goto erractions ;
- }
- e = posix_spawnp(&pid, prog, &actions, &attr, (char *const *)argv, (char *const *)envp) ;
- if (nopath) unsetenv("PATH") ;
- if (e) goto erractions ;
+ e = errno ; goto erractions ;
+ }
+ e = posix_spawnp(&pid, prog, &actions, &attr, (char *const *)argv, (char *const *)envp) ;
+ if (nopath) unsetenv("PATH") ;
+ if (e) goto erractions ;
+
+ posix_spawn_file_actions_destroy(&actions) ;
+ posix_spawnattr_destroy(&attr) ;
+ fd_close(p[0][1]) ;
+ fd_close(p[1][0]) ;
+
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ pid = child_spawn_workaround(pid, syncpipe) ;
+ if (!pid)
+ {
+ fd_close(p[1][1]) ;
+ fd_close(p[0][0]) ;
+ return 0 ;
}
+#endif
+ fds[0] = p[0][0] ;
+ fds[1] = p[1][1] ;
+ return pid ;
+ erractions:
posix_spawn_file_actions_destroy(&actions) ;
+ errattr:
posix_spawnattr_destroy(&attr) ;
+ erre:
+ errno = e ;
+ errp1:
+ fd_close(p[1][1]) ;
+ fd_close(p[1][0]) ;
+ errp:
+ fd_close(p[0][1]) ;
+ fd_close(p[0][0]) ;
+ err:
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ fd_close(syncpipe[1]) ;
+ fd_close(syncpipe[0]) ;
+#endif
+ return 0 ;
+}
#else
+
+#include <skalibs/allreadwrite.h>
+#include <skalibs/sig.h>
+#include <skalibs/exec.h>
+
+pid_t child_spawn2 (char const *prog, char const *const *argv, char const *const *envp, int *fds)
+{
+ pid_t pid ;
+ int syncpipe[2] ;
+ int p[2][2] ;
+ char c ;
+
+ if (pipe(p[0]) < 0) return 0 ;
+ if (ndelay_on(p[0][0]) < 0 || coe(p[0][0]) < 0 || pipe(p[1]) < 0) goto errp ;
+ if (ndelay_on(p[1][1]) < 0 || coe(p[1][1]) < 0) goto errp1 ;
if (pipecoe(syncpipe) < 0) goto errp1 ;
pid = fork() ;
- if (pid < 0) goto errsp ;
+ if (pid == -1) goto errsp ;
else if (!pid)
{
- size_t len = strlen(PROG) ;
- char name[len + 9] ;
- memcpy(name, PROG, len) ;
- memcpy(name + len, " (child)", 9) ;
- PROG = name ;
if (fd_move2(fds[0], p[1][0], fds[1], p[0][1]) < 0) goto syncdie ;
sig_blocknone() ;
exec_ae(prog, argv, envp) ;
-
- syncdie:
- {
- unsigned char c = errno ;
- fd_write(syncpipe[1], (char *)&c, 1) ;
- }
+ syncdie:
+ c = errno ;
+ fd_write(syncpipe[1], &c, 1) ;
_exit(127) ;
}
fd_close(syncpipe[1]) ;
+ syncpipe[1] = fd_read(syncpipe[0], &c, 1) ;
+ if (syncpipe[1])
{
- unsigned char c ;
- syncpipe[1] = fd_read(syncpipe[0], (char *)&c, 1) ;
- if (syncpipe[1])
- {
- int e = c ;
- if (syncpipe[1] < 0) e = errno ;
- if (wait_pid(pid, &syncpipe[1]) < 0) e = errno ;
- errno = e ;
- goto errsp0 ;
- }
+ int e = (unsigned char)c ;
+ if (syncpipe[1] == -1) e = errno ;
+ if (wait_pid(pid, &syncpipe[1]) == -1) e = errno ;
+ errno = e ;
+ goto errsp0 ;
}
fd_close(syncpipe[0]) ;
-#endif
+ fd_close(p[0][1]) ;
+ fd_close(p[1][0]) ;
- fd_close(p[0][1]) ; fds[0] = p[0][0] ;
- fd_close(p[1][0]) ; fds[1] = p[1][1] ;
+ fds[0] = p[0][0] ;
+ fds[1] = p[1][1] ;
return pid ;
-#ifdef SKALIBS_HASPOSIXSPAWN
- erractions:
- posix_spawn_file_actions_destroy(&actions) ;
- errattr:
- posix_spawnattr_destroy(&attr) ;
- erre:
- errno = e ;
-#endif
-#ifndef SKALIBS_HASPOSIXSPAWN
errsp:
fd_close(syncpipe[1]) ;
errsp0:
fd_close(syncpipe[0]) ;
-#endif
errp1:
fd_close(p[1][1]) ;
fd_close(p[1][0]) ;
@@ -151,3 +168,5 @@ pid_t child_spawn2 (char const *prog, char const *const *argv, char const *const
fd_close(p[0][0]) ;
return 0 ;
}
+
+#endif
diff --git a/src/libstddjb/child_spawn3.c b/src/libstddjb/child_spawn3.c
@@ -3,64 +3,54 @@
/* MT-unsafe */
#include <skalibs/sysdeps.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <sys/wait.h>
+
#include <unistd.h>
#include <errno.h>
-#include <signal.h>
+
+#include <skalibs/types.h>
+#include <skalibs/djbunix.h>
#ifdef SKALIBS_HASPOSIXSPAWN
+#include <signal.h>
#include <stdlib.h>
#include <spawn.h>
-#include <skalibs/config.h>
-
-#else
-#include <string.h>
-#include <skalibs/sig.h>
-#include <skalibs/strerr.h>
-#include <skalibs/exec.h>
+#include <skalibs/config.h>
+#include <skalibs/env.h>
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+# include "child_spawn-internal.h"
#endif
-#include <skalibs/types.h>
-#include <skalibs/allreadwrite.h>
-#include <skalibs/env.h>
-#include <skalibs/djbunix.h>
-
pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const *envp, int *fds)
{
pid_t pid ;
-#ifdef SKALIBS_HASPOSIXSPAWN
posix_spawn_file_actions_t actions ;
posix_spawnattr_t attr ;
+ sigset_t set ;
int e ;
-#else
- int syncpipe[2] ;
-#endif
int p[3][2] ;
size_t m = sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
char modifs[sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) + UINT_FMT] = SKALIBS_CHILD_SPAWN_FDS_ENVVAR "=" ;
- if (pipe(p[0]) < 0 || ndelay_on(p[0][0]) < 0 || coe(p[0][0]) < 0) return 0 ;
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ int syncpipe[2] ;
+ if (pipecoe(syncpipe) == -1) return 0 ;
+#endif
+
+ if (pipe(p[0]) < 0 || ndelay_on(p[0][0]) < 0 || coe(p[0][0]) < 0) goto err ;
if (pipe(p[1]) < 0 || ndelay_on(p[1][1]) < 0 || coe(p[1][1]) < 0) goto errp0 ;
if (pipe(p[2]) < 0 || ndelay_on(p[2][0]) < 0 || coe(p[2][0]) < 0) goto errp1 ;
m += uint_fmt(modifs + sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR), p[2][1]) ;
modifs[m++] = 0 ;
-#ifdef SKALIBS_HASPOSIXSPAWN
-
e = posix_spawnattr_init(&attr) ;
if (e) goto erre ;
- {
- sigset_t set ;
- sigemptyset(&set) ;
- e = posix_spawnattr_setsigmask(&attr, &set) ;
- if (e) goto errattr ;
- e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
- if (e) goto errattr ;
- }
+ sigemptyset(&set) ;
+ e = posix_spawnattr_setsigmask(&attr, &set) ;
+ if (e) goto errattr ;
+ e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
+ if (e) goto errattr ;
e = posix_spawn_file_actions_init(&actions) ;
if (e) goto errattr ;
if (p[1][0] != fds[0])
@@ -77,7 +67,7 @@ pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const
e = posix_spawn_file_actions_addclose(&actions, p[0][1]) ;
if (e) goto erractions ;
}
- {
+ {
int nopath = !getenv("PATH") ;
size_t envlen = env_len(envp) ;
char const *newenv[envlen + 2] ;
@@ -93,46 +83,93 @@ pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const
posix_spawn_file_actions_destroy(&actions) ;
posix_spawnattr_destroy(&attr) ;
+ fd_close(p[2][1]) ;
+ fd_close(p[1][0]) ;
+ fd_close(p[0][1]) ;
+
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ pid = child_spawn_workaround(pid, syncpipe) ;
+ if (!pid)
+ {
+ fd_close(p[2][0]) ;
+ fd_close(p[1][1]) ;
+ fd_close(p[0][0]) ;
+ return 0 ;
+ }
+#endif
+ fds[0] = p[0][0] ;
+ fds[1] = p[1][1] ;
+ fds[2] = p[2][0] ;
+ return pid ;
+
+ erractions:
+ posix_spawn_file_actions_destroy(&actions) ;
+ errattr:
+ posix_spawnattr_destroy(&attr) ;
+ erre:
+ errno = e ;
+ fd_close(p[2][1]) ;
+ fd_close(p[2][0]) ;
+ errp1:
+ fd_close(p[1][1]) ;
+ fd_close(p[1][0]) ;
+ errp0:
+ fd_close(p[0][1]) ;
+ fd_close(p[0][0]) ;
+ err:
+#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
+ fd_close(syncpipe[1]) ;
+ fd_close(syncpipe[0]) ;
+#endif
+ return 0 ;
+}
#else
+
+#include <skalibs/allreadwrite.h>
+#include <skalibs/sig.h>
+#include <skalibs/exec.h>
+
+pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const *envp, int *fds)
+{
+ pid_t pid ;
+ int syncpipe[2] ;
+ int p[3][2] ;
+ size_t m = sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
+ char modifs[sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) + UINT_FMT] = SKALIBS_CHILD_SPAWN_FDS_ENVVAR "=" ;
+ char c ;
+
+ if (pipe(p[0]) == -1 || ndelay_on(p[0][0]) == -1 || coe(p[0][0]) == -1) return 0 ;
+ if (pipe(p[1]) == -1 || ndelay_on(p[1][1]) == -1 || coe(p[1][1]) == -1) goto errp0 ;
+ if (pipe(p[2]) == -1 || ndelay_on(p[2][0]) == -1 || coe(p[2][0]) == -1) goto errp1 ;
+ m += uint_fmt(modifs + sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR), p[2][1]) ;
+ modifs[m++] = 0 ;
if (pipecoe(syncpipe) < 0) goto errp2 ;
pid = fork() ;
if (pid < 0) goto errsp ;
else if (!pid)
{
- size_t len = strlen(PROG) ;
- char name[len + 9] ;
- memcpy(name, PROG, len) ;
- memcpy(name + len, " (child)", 9) ;
- PROG = name ;
- if (fd_move2(fds[0], p[1][0], fds[1], p[0][1]) < 0) goto syncdie ;
+ if (fd_move2(fds[0], p[1][0], fds[1], p[0][1]) == -1) goto syncdie ;
sig_blocknone() ;
mexec_aen(prog, argv, envp, modifs, m, 1) ;
-
- syncdie:
- {
- unsigned char c = errno ;
- fd_write(syncpipe[1], (char *)&c, 1) ;
- }
+ syncdie:
+ c = errno ;
+ fd_write(syncpipe[1], &c, 1) ;
_exit(127) ;
}
fd_close(syncpipe[1]) ;
+ syncpipe[1] = fd_read(syncpipe[0], &c, 1) ;
+ if (syncpipe[1])
{
- unsigned char c ;
- syncpipe[1] = fd_read(syncpipe[0], (char *)&c, 1) ;
- if (syncpipe[1])
- {
- int e = c ;
- if (syncpipe[1] < 0) e = errno ;
- if (wait_pid(pid, &syncpipe[1]) < 0) e = errno ;
- errno = e ;
- goto errsp0 ;
- }
+ int e = (unsigned char)c ;
+ if (syncpipe[1] == -1) e = errno ;
+ if (wait_pid(pid, &syncpipe[1]) == -1) e = errno ;
+ errno = e ;
+ goto errsp0 ;
}
fd_close(syncpipe[0]) ;
-#endif
fd_close(p[2][1]) ;
fd_close(p[1][0]) ;
@@ -142,21 +179,11 @@ pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const
fds[2] = p[2][0] ;
return pid ;
-#ifdef SKALIBS_HASPOSIXSPAWN
- erractions:
- posix_spawn_file_actions_destroy(&actions) ;
- errattr:
- posix_spawnattr_destroy(&attr) ;
- erre:
- errno = e ;
-#endif
-#ifndef SKALIBS_HASPOSIXSPAWN
errsp:
fd_close(syncpipe[1]) ;
errsp0:
fd_close(syncpipe[0]) ;
errp2:
-#endif
fd_close(p[2][1]) ;
fd_close(p[2][0]) ;
errp1:
@@ -167,3 +194,5 @@ pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const
fd_close(p[0][0]) ;
return 0 ;
}
+
+#endif
diff --git a/src/libstddjb/child_spawn_workaround.c b/src/libstddjb/child_spawn_workaround.c
@@ -0,0 +1,48 @@
+/* ISC license. */
+
+#include <skalibs/sysdeps.h>
+
+#if defined(SKALIBS_HASPOSIXSPAWN) && defined(SKALIBS_HASPOSIXSPAWNEARLYRETURN)
+
+#include <errno.h>
+#include <signal.h>
+#include <sys/wait.h>
+
+#include <skalibs/allreadwrite.h>
+#include <skalibs/djbunix.h>
+#include "child_spawn-internal.h"
+
+pid_t child_spawn_workaround (pid_t pid, int const *p)
+{
+ siginfo_t si ;
+ int e ;
+ ssize_t r ;
+ char c ;
+
+ fd_close(p[1]) ;
+ r = fd_read(p[0], &c, 1) ;
+ fd_close(p[0]) ;
+ if (r == -1) return 0 ;
+ if (r) return (errno = EILSEQ, 0) ; /* child wrote, wtf */
+
+ do e = waitid(P_PID, pid, &si, WNOHANG | WNOWAIT) ;
+ while (e == -1 && errno == EINTR) ;
+ if (e == -1) return pid ; /* we're in trouble, but don't leak a child */
+ if (!si.si_pid) return pid ; /* child is running */
+ if (si.si_code != CLD_EXITED || si.si_status != 127) return pid ; /* child died after execve(), let caller handle it */
+ /*
+ child exited 127, so either execve() failed, which is what we want to catch,
+ or it raced like a mofo, execve()d and then exited 127 on its own, in which
+ case, tough luck, it never existed.
+ */
+ wait_pid(pid, 0) ;
+ return (errno = 0, 0) ;
+}
+
+#else
+
+ /* avoid empty TUs */
+
+extern int skalibs_child_spawn_workaround_dummy_ ;
+
+#endif
diff --git a/src/sysdeps/tryposixspawnearlyreturn.c b/src/sysdeps/tryposixspawnearlyreturn.c
@@ -0,0 +1,24 @@
+/* ISC license. */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <spawn.h>
+
+int main (void)
+{
+ posix_spawnattr_t attr ;
+ int e ;
+ char tmp[40] = "./tryposixspawnearlyreturn child:XXXXXX" ;
+ char *argv[2] = { tmp, 0 } ;
+ char *env = 0 ;
+ int fd = mkstemp(tmp) ;
+ if (fd == -1) return 111 ;
+ e = posix_spawnattr_init(&attr) ;
+ if (e) return 111 ;
+ e = posix_spawnattr_setflags(&attr, 0) ;
+ if (e) return 111 ;
+ if (close(fd) == -1 || unlink(tmp) == -1) return 111 ;
+ e = posix_spawn(0, argv[0], 0, &attrp, argv, &env) ;
+ return e ? e == ENOENT ? 1 : 111 : 0 ;
+}
