Add workaround for bad QoI posix_spawn()

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 43 insertions, 36 deletions

diff --git a/src/libstddjb/child_spawn1_internal.c b/src/libstddjb/child_spawn1_internal.c
index be154f0..2fe0ee2 100644
--- 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 ;