git: 6789b9f63023 - stable/14 - libc: Fix getentropy POSIX 2024 conformance issues

The branch stable/14 has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=6789b9f630236a9bc0e7b4f2b930c1048c5312ef

commit 6789b9f630236a9bc0e7b4f2b930c1048c5312ef
Author:     Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2024-11-16 15:14:21 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2025-02-20 14:13:25 +0000

    libc: Fix getentropy POSIX 2024 conformance issues
    
    GETENTROPY_MAX should be defined in limits.h.  EINVAL is the return
    value for buflen > GETENTROPY_MAX.
    
    PR:             282783
    Reviewed by:    markj, asomers, jhb
    Sponsored by:   The FreeBSD Foundation
    Differential Revision: https://reviews.freebsd.org/D47689
---
 include/limits.h          |  4 ++++
 lib/libc/gen/getentropy.3 | 14 ++++----------
 lib/libc/gen/getentropy.c |  5 +++--
 3 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/include/limits.h b/include/limits.h
index 73036ca3ad7b..1a3c872b1ffb 100644
--- a/include/limits.h
+++ b/include/limits.h
@@ -139,6 +139,10 @@
 
 #define	MB_LEN_MAX		6	/* 31-bit UTF-8 */
 
+#if __POSIX_VISIBLE >= 202405
+#define GETENTROPY_MAX		256
+#endif
+
 #include <sys/limits.h>
 
 #if __POSIX_VISIBLE
diff --git a/lib/libc/gen/getentropy.3 b/lib/libc/gen/getentropy.3
index 5bbbc80e2414..5f7ee32ebbfc 100644
--- a/lib/libc/gen/getentropy.3
+++ b/lib/libc/gen/getentropy.3
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd November 20, 2024
+.Dd January 17, 2025
 .Dt GETENTROPY 3
 .Os
 .Sh NAME
@@ -60,8 +60,8 @@ The
 .Fa buf
 parameter points to an
 invalid address.
-.It Bq Er EIO
-Too many bytes requested, or some other fatal error occurred.
+.It Bq Er EINVAL
+Too many bytes requested.
 .El
 .Sh SEE ALSO
 .Xr getrandom 2 ,
@@ -69,7 +69,7 @@ Too many bytes requested, or some other fatal error occurred.
 .Xr random 4
 .Sh STANDARDS
 .Fn getentropy
-nearly conforms to
+conforms to
 .St -p1003.1-2024 .
 .Sh HISTORY
 The
@@ -80,9 +80,3 @@ The
 .Fx
 libc compatibility shim first appeared in
 .Fx 12.0 .
-.Sh BUGS
-.In limits.h
-does not define
-.Dv GETENTROPY_MAX .
-Some error values do not match
-.St -p1003.1-2024 .
diff --git a/lib/libc/gen/getentropy.c b/lib/libc/gen/getentropy.c
index 060c2760bfad..5dffd91c6dee 100644
--- a/lib/libc/gen/getentropy.c
+++ b/lib/libc/gen/getentropy.c
@@ -31,6 +31,7 @@
 #include <sys/sysctl.h>
 
 #include <errno.h>
+#include <limits.h>
 #include <signal.h>
 #include <stdbool.h>
 #include <stdlib.h>
@@ -110,8 +111,8 @@ getentropy(void *buf, size_t buflen)
 	ssize_t rd;
 	bool have_getrandom;
 
-	if (buflen > 256) {
-		errno = EIO;
+	if (buflen > GETENTROPY_MAX) {
+		errno = EINVAL;
 		return (-1);
 	}