spawn: note we do not use absolute paths within our code

[public-inbox.git] / lib / PublicInbox / Spawn.pm

diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index 23f303fbe182ee7968f6ca6ff6c1486498fe1f61..66dce3353e3bd872fad51838a53200bf94f50632 100644 (file)
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -24,6 +24,8 @@ my $vfork_spawn = <<'VFORK_SPAWN';
 #include <sys/uio.h>
 #include <unistd.h>
 #include <alloca.h>
+#include <signal.h>
+#include <assert.h>
 
 #define AV_ALLOCA(av, max) alloca((max = (av_len((av)) + 1)) * sizeof(char *))
 
@@ -81,6 +83,8 @@ int public_inbox_fork_exec(int in, int out, int err,
        pid_t pid;
        char **argv, **envp;
        I32 max;
+       sigset_t set, old;
+       int ret;
 
        argv = AV_ALLOCA(cmd, max);
        av2c_copy(argv, cmd, max);
@@ -88,14 +92,26 @@ int public_inbox_fork_exec(int in, int out, int err,
        envp = AV_ALLOCA(env, max);
        av2c_copy(envp, env, max);
 
+       ret = sigfillset(&set);
+       assert(ret == 0 && "BUG calling sigfillset");
+       ret = sigprocmask(SIG_SETMASK, &set, &old);
+       assert(ret == 0 && "BUG calling sigprocmask to block");
        pid = vfork();
        if (pid == 0) {
+               int sig;
+
                REDIR(in, 0);
                REDIR(out, 1);
                REDIR(err, 2);
+               for (sig = 1; sig < NSIG; sig++)
+                       signal(sig, SIG_DFL); /* ignore errorrs on signals */
+               ret = sigprocmask(SIG_SETMASK, &old, NULL);
+               if (ret != 0) xerr("sigprocmask failed in vfork child");
                execve(filename, argv, envp);
                xerr("execve failed");
        }
+       ret = sigprocmask(SIG_SETMASK, &old, NULL);
+       assert(ret == 0 && "BUG calling sigprocmask to restore");
 
        return (int)pid;
 }
@@ -111,7 +127,7 @@ if (defined $vfork_spawn) {
                my $f = "$inline_dir/.public-inbox.lock";
                open my $fh, '>', $f or die "failed to open $f: $!\n";
                flock($fh, LOCK_EX) or die "LOCK_EX failed on $f: $!\n";
-               eval 'use Inline C => $vfork_spawn';
+               eval 'use Inline C => $vfork_spawn'; #, BUILD_NOISY => 1';
                my $err = $@;
                flock($fh, LOCK_UN) or die "LOCK_UN failed on $f: $!\n";
                die $err if $err;
@@ -128,6 +144,7 @@ unless (defined $vfork_spawn) {
        *public_inbox_fork_exec = *PublicInbox::SpawnPP::public_inbox_fork_exec
 }
 
+# n.b. we never use absolute paths with this
 sub which ($) {
        my ($file) = @_;
        foreach my $p (split(':', $ENV{PATH})) {