Make getentropy available from <unistd.h>
getentropy is originally an OpenBSD-ism, where it was in <unistd.h> from
day one:
https://man.openbsd.org/OpenBSD-5.6/getentropy
FreeBSD's and Linux's current man pages also document it this way:
https://man7.org/linux/man-pages/man3/getentropy.3.html
https://man.freebsd.org/cgi/man.cgi?query=getentropy&sektion=3&format=html
The man7.org URL is even cited by bionic itself in the comments, though
glibc originally put it in <sys/random.h> and added to <unistd.h> very
shortly afterwards:
https://sourceware.org/bugzilla/show_bug.cgi?id=17252#c9
The cited man page (maintained separately from glibc) originally
documented <sys/random.h>...
https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/man3/getentropy.3?id=b0265728162cdcafb8e7d7f1372e8de1a4c963ed
But similarly fixed it to <unistd.h> three months later:
https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/man3/getentropy.3?id=9cf011f94b56e8832c5a5d8cf66d4a115d34b9cc
musl matches the BSDs in putting it in <unistd.h>, but not
<sys/random.h>.
https://git.musl-libc.org/cgit/musl/tree/include/unistd.h?id=25e6fee27f4a293728dd15b659170e7b9c7db9bc#n183
POSIX will likely place it there too:
https://www.austingroupbugs.net/view.php?id=1134
macOS and Fuchsia place it in <sys/random.h> and not <unistd.h>, though
given the rest of this precedent, they're clearly outliers. (Note iOS
does *not* have getentropy, just macOS. The system has it, but it's not
exposed as public API. See https://dev.gnupg.org/T5375 and
https://github.com/openssl/openssl/pull/15924.)
Use the more standard location in bionic and put getentropy in
<unistd.h>. This will improve portability and avoid needing workarounds
in BoringSSL. For compatibility, keep it also available in
<sys/random.h> by using a <bits/getentropy.h> header.
BYPASS_INCLUSIVE_LANGUAGE_REASON=Above URLs are not hosted by Android and reference the name of a command-line utility, short for 'manual', as in instruction manual
Bug: 290898063
Test: treehugger
Change-Id: Id2d6b6ea09d814e5ba2cb117a7af2c74861148fb
diff --git a/libc/include/sys/random.h b/libc/include/sys/random.h
index 0251176..2ff5349 100644
--- a/libc/include/sys/random.h
+++ b/libc/include/sys/random.h
@@ -38,19 +38,9 @@
#include <linux/random.h>
-__BEGIN_DECLS
+#include <bits/getentropy.h>
-/**
- * [getentropy(3)](http://man7.org/linux/man-pages/man3/getentropy.3.html) fills the given buffer
- * with random bytes.
- *
- * Returns 0 on success, and returns -1 and sets `errno` on failure.
- *
- * Available since API level 28.
- *
- * See also arc4random_buf() which is available in all API levels.
- */
-int getentropy(void* _Nonnull __buffer, size_t __buffer_size) __wur __INTRODUCED_IN(28);
+__BEGIN_DECLS
/**
* [getrandom(2)](http://man7.org/linux/man-pages/man2/getrandom.2.html) fills the given buffer