1 files changed, 94 insertions, 0 deletions
diff --git a/stdlib/tst-getenv-signal.c b/stdlib/tst-getenv-signal.c
new file mode 100644
index 0000000..03797a5
--- /dev/null
+++ b/stdlib/tst-getenv-signal.c
@@ -0,0 +1,94 @@
+/* Test getenv from a signal handler interrupting environment updates.
+   Copyright (C) 2024-2025 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <array_length.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xthread.h>
+#include <support/xsignal.h>
+
+/* Set to false by the main thread after doing all the setenv
+   calls.  */
+static bool running = true;
+
+/* Used to synchronize the start of signal sending.  */
+static pthread_barrier_t barrier;
+
+/* Identity of the main thread.  */
+static pthread_t main_thread;
+
+/* Send SIGUSR1 signals to main_thread.  */
+static void *
+signal_thread (void *ignored)
+{
+  xpthread_barrier_wait (&barrier);
+  while (__atomic_load_n (&running, __ATOMIC_RELAXED))
+    xpthread_kill (main_thread, SIGUSR1);
+  return NULL;
+}
+
+/* Call getenv from a signal handler.  */
+static void
+signal_handler (int signo)
+{
+  TEST_COMPARE_STRING (getenv ("unset_variable"), NULL);
+  char *value = getenv ("set_variable");
+  TEST_VERIFY (strncmp (value, "value", strlen ("value")) == 0);
+}
+
+static int
+do_test (void)
+{
+  /* Added to the environment using putenv.  */
+  char *variables[30];
+  for (int i = 0; i < array_length (variables); ++i)
+    variables[i] = xasprintf ("v%d=%d", i, i);
+
+  xsignal (SIGUSR1, signal_handler);
+  TEST_COMPARE (setenv ("set_variable", "value", 1), 0);
+  xraise (SIGUSR1);
+  main_thread = pthread_self ();
+  xpthread_barrier_init (&barrier, NULL, 2);
+  pthread_t thr = xpthread_create (NULL, signal_thread, NULL);
+  xpthread_barrier_wait (&barrier);
+
+  for (int i = 0; i < array_length (variables); ++i)
+    {
+      char buf[30];
+      TEST_COMPARE (setenv ("temporary_variable", "1", 1), 0);
+      snprintf (buf, sizeof (buf), "V%d", i);
+      TEST_COMPARE (setenv (buf, buf + 1, 1), 0);
+      TEST_COMPARE (putenv (variables[i]), 0);
+      snprintf (buf, sizeof (buf), "value%d", i);
+      TEST_COMPARE (setenv ("set_variable", buf, 1), 0);
+      TEST_COMPARE (unsetenv ("temporary_variable"), 0);
+    }
+
+  __atomic_store_n (&running, false, __ATOMIC_RELAXED);
+  xpthread_join (thr);
+  xpthread_barrier_destroy (&barrier);
+
+  for (int i = 0; i < array_length (variables); ++i)
+    free (variables[i]);
+  return 0;
+}
+
+#include <support/test-driver.c>