Diagnose Guile subprocess crash on FreeBSD

tests/guile/posix-spawn-freebsd-diagnostics.c

@@ -0,0 +1,134 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <spawn.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+extern char **environ;
+
+static int native_spawn_closefrom_test(void) {
+  posix_spawn_file_actions_t actions;
+  pid_t pid;
+  int status;
+  char *argv[] = { "/usr/bin/true", NULL };
+
+  if (posix_spawn_file_actions_init(&actions) != 0)
+    return 1;
+  if (posix_spawn_file_actions_adddup2(&actions, STDIN_FILENO, STDIN_FILENO) != 0)
+    return 2;
+  if (posix_spawn_file_actions_adddup2(&actions, STDOUT_FILENO, STDOUT_FILENO) != 0)
+    return 3;
+  if (posix_spawn_file_actions_adddup2(&actions, STDERR_FILENO, STDERR_FILENO) != 0)
+    return 4;
+  if (posix_spawn_file_actions_addclosefrom_np(&actions, 3) != 0)
+    return 5;
+  if (posix_spawn(&pid, "/usr/bin/true", &actions, NULL, argv, environ) != 0)
+    return 6;
+  if (waitpid(pid, &status, 0) < 0)
+    return 7;
+  if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+    return 8;
+  return 0;
+}
+
+static int adddup2_invalid_fd_accepted(void) {
+  posix_spawn_file_actions_t actions;
+  if (posix_spawn_file_actions_init(&actions) != 0)
+    return -1;
+  return posix_spawn_file_actions_adddup2(&actions, 10000000, 2) == 0;
+}
+
+static int addopen_invalid_fd_accepted(void) {
+  posix_spawn_file_actions_t actions;
+  if (posix_spawn_file_actions_init(&actions) != 0)
+    return -1;
+  return posix_spawn_file_actions_addopen(&actions, 10000000, "foo", 0, O_RDONLY) == 0;
+}
+
+static int write_script(char *path, size_t size) {
+  int fd;
+  const char script[] = ":\n";
+
+  if (snprintf(path, size, "/tmp/fruix-posix-spawn-script-XXXXXX") >= (int)size)
+    return -1;
+  fd = mkstemp(path);
+  if (fd < 0)
+    return -1;
+  if (write(fd, script, sizeof(script) - 1) != (ssize_t)(sizeof(script) - 1)) {
+    close(fd);
+    unlink(path);
+    return -1;
+  }
+  if (fchmod(fd, 0700) != 0) {
+    close(fd);
+    unlink(path);
+    return -1;
+  }
+  if (close(fd) != 0) {
+    unlink(path);
+    return -1;
+  }
+  return 0;
+}
+
+static int secure_exec_result(int use_path) {
+  char script[128];
+  pid_t child;
+  int err;
+  int status = 0;
+  char *argv[] = { script, NULL };
+  char *env[] = { "PATH=/tmp:/usr/bin:/bin", NULL };
+
+  if (write_script(script, sizeof(script)) != 0)
+    return -1;
+
+  err = use_path
+    ? posix_spawnp(&child, script, NULL, NULL, argv, env)
+    : posix_spawn(&child, script, NULL, NULL, argv, env);
+
+  if (err == ENOEXEC) {
+    unlink(script);
+    return 0;
+  }
+  if (err != 0) {
+    unlink(script);
+    return 1;
+  }
+  while (waitpid(child, &status, 0) != child)
+    ;
+  unlink(script);
+  if (!WIFEXITED(status))
+    return 2;
+  if (WEXITSTATUS(status) != 127)
+    return 3;
+  return 0;
+}
+
+int main(void) {
+  int native_ok = native_spawn_closefrom_test();
+  int dup2_broken = adddup2_invalid_fd_accepted();
+  int addopen_broken = addopen_invalid_fd_accepted();
+  int spawn_secure = secure_exec_result(0);
+  int spawnp_secure = secure_exec_result(1);
+  int issue_profile_match =
+    native_ok == 0 &&
+    dup2_broken == 1 &&
+    addopen_broken == 1 &&
+    spawn_secure == 0 &&
+    spawnp_secure == 3;
+
+  printf("native-spawn-closefrom=%s\n", native_ok == 0 ? "ok" : "fail");
+  printf("adddup2-invalid-fd-accepted=%s\n", dup2_broken == 1 ? "yes" : (dup2_broken == 0 ? "no" : "error"));
+  printf("addopen-invalid-fd-accepted=%s\n", addopen_broken == 1 ? "yes" : (addopen_broken == 0 ? "no" : "error"));
+  printf("posix_spawn-secure-exec-result=%d\n", spawn_secure);
+  printf("posix_spawnp-secure-exec-result=%d\n", spawnp_secure);
+  printf("issue-profile-match=%s\n", issue_profile_match ? "yes" : "no");
+
+  return issue_profile_match ? 0 : 1;
+}

tests/guile/run-subprocess-diagnostics.sh

@@ -0,0 +1,42 @@
+#!/bin/sh
+set -eu
+
+script_dir=$(CDPATH= cd -- "$(dirname "$0")" && pwd)
+repo_root=$(CDPATH= cd -- "$script_dir/../.." && pwd)
+workdir=$(mktemp -d /tmp/fruix-guile-subprocess.XXXXXX)
+trap 'rm -rf "$workdir"' EXIT INT TERM
+
+if command -v guile3 >/dev/null 2>&1; then
+  guile_bin=$(command -v guile3)
+elif command -v guile-3.0 >/dev/null 2>&1; then
+  guile_bin=$(command -v guile-3.0)
+else
+  echo "Unable to find guile3 or guile-3.0 in PATH" >&2
+  exit 1
+fi
+
+ulimit -c 0 || true
+
+cc -Wall -Wextra -O2 "$repo_root/tests/guile/posix-spawn-freebsd-diagnostics.c" \
+  -o "$workdir/posix-spawn-freebsd-diagnostics"
+
+printf '== Native posix_spawn diagnostics ==\n'
+"$workdir/posix-spawn-freebsd-diagnostics"
+
+run_guile_case() {
+  name=$1
+  code=$2
+  set +e
+  "$guile_bin" -c "$code" >/dev/null 2>&1
+  rc=$?
+  set -e
+  printf '%s exit=%s\n' "$name" "$rc"
+  [ "$rc" -eq 139 ]
+}
+
+printf '== Guile subprocess crash repro ==\n'
+run_guile_case system-star '(system* "/usr/bin/true")'
+run_guile_case spawn '(spawn "/usr/bin/true" (list "/usr/bin/true"))'
+run_guile_case open-pipe-star '(use-modules (ice-9 popen)) (open-pipe* OPEN_READ "/usr/bin/true")'
+
+printf 'known FreeBSD Guile subprocess crash profile reproduced\n'