Replace the libc environment with a thread-safe emulation

putenv(3) and friends aren't thread-safe regardless of how you slice
it; a global lock around all environment operations (like before)
keeps things safe as far as our own operations go, but we have
absolutely no control over what libc or a library dragged in by a
driver/NIF does -- they're free to call getenv(3) or putenv(3)
without honoring our lock.

This commit solves this by setting up an "emulated" environment which
can't be touched without going through our interfaces. Third-party
libraries can still shoot themselves in the foot but benign uses of
os:putenv/2 will no longer risk crashing the emulator.

1 files changed, 1 insertions, 1 deletions

diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 64639e157b..9aafab86c0 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -1754,7 +1754,7 @@ static int check_if_xml(void)
 {
     char buf[1];
     size_t bufsz = sizeof(buf);
-    return erts_sys_getenv_raw("VALGRIND_LOG_XML", buf, &bufsz) >= 0;
+    return erts_sys_explicit_8bit_getenv("VALGRIND_LOG_XML", buf, &bufsz) >= 0;
 }
 #else
 #define check_if_xml() 0