libc: Add getenv_r() function.

This is a calque of the NetBSD function of the same name.

MFC after:	never
Relontes:	yes
Sponsored by:	Klara, Inc.
Reviewed by:	kevans
Differential Revision:	https://reviews.freebsd.org/D49979

2 files changed, 7 insertions, 0 deletions

diff --git a/include/ssp/stdlib.h b/include/ssp/stdlib.h
index f595ecbcbc0a..0a87be9f17d9 100644
--- a/include/ssp/stdlib.h
+++ b/include/ssp/stdlib.h
@@ -38,6 +38,10 @@ __BEGIN_DECLS
 __ssp_redirect(void, arc4random_buf, (void *__buf, size_t __len),
     (__buf, __len));
 
+__ssp_redirect(int, getenv_r,
+    (const char *name, char * _Nonnull __buf, size_t __len),
+    (name, __buf, __len));
+
 __ssp_redirect_raw_impl(char *, realpath, realpath,
     (const char *__restrict path, char *__restrict buf))
 {
diff --git a/include/stdlib.h b/include/stdlib.h
index 162031ab393d..ba0cf4b5e88e 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -95,6 +95,9 @@ div_t	 div(int, int) __pure2;
 _Noreturn void	 exit(int);
 void	 free(void *);
 char	*getenv(const char *);
+#if __BSD_VISIBLE
+int	 getenv_r(const char *, char * _Nonnull, size_t);
+#endif
 long	 labs(long) __pure2;
 ldiv_t	 ldiv(long, long) __pure2;
 void	*malloc(size_t) __malloc_like __result_use_check __alloc_size(1);