[PATCH v7 04/14] linux/termios/powerpc: deal with powerpc-unique ioctl emulation

H. Peter Anvin hpa@zytor.com
Sun Jun 8 02:19:07 GMT 2025


From: "H. Peter Anvin (Intel)" <hpa@zytor.com>

The powerpc architecture, only, emulates the termios ioctls using the
glibc termios structure. Export the real kernel ones as the termios2
interface; although the kernel doesn't call it termios2, it is exactly
the termios2 interface, and it avoids the namespace clash between the
emulated ioctls and the real kernel ioctls.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
---
 sysdeps/unix/sysv/linux/powerpc/bits/ioctls.h | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 sysdeps/unix/sysv/linux/powerpc/bits/ioctls.h

diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/ioctls.h b/sysdeps/unix/sysv/linux/powerpc/bits/ioctls.h
new file mode 100644
index 000000000000..e1921dfb86c0
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/bits/ioctls.h
@@ -0,0 +1,36 @@
+/* Copyright (C) 1996-2025 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/>.  */
+
+#ifndef _SYS_IOCTL_H
+# error "Never use <bits/ioctls.h> directly; include <sys/ioctl.h> instead."
+#endif
+
+/* Use the definitions from the kernel header files.  */
+#include <asm/ioctls.h>
+
+/* PowerPC quirk: on PowerPC only, ioctl() emulates the TCGETS/TCSETS*
+   ioctls with tcgetattr/tcsetattr using the glibc struct termios.
+   As struct termios2 is the same as the kernel struct termios on PowerPC,
+   simply consider the kernel ones as the termios2 interface, even
+   though the kernel doesn't call it that. */
+
+#define TCGETS2	 _IOR ('t', 19, struct termios2)
+#define TCSETS2	 _IOW ('t', 20, struct termios2)
+#define TCSETSW2 _IOW ('t', 21, struct termios2)
+#define TCSETSF2 _IOW ('t', 22, struct termios2)
+
+#include <linux/sockios.h>
-- 
2.49.0



More information about the Libc-alpha mailing list