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authorMathieu Desnoyers2018-06-02 08:43:53 -0400
committerThomas Gleixner2018-06-06 11:58:31 +0200
commitb575e837215325544b0dbcef912f13f369de4f3f (patch)
treee05b1dba86d602dfb295a3dbf2cb91fa48866017
parent716a685fdb89942a50c4138141027e38336a895f (diff)
uapi/headers: Provide types_32_64.h
Provide helper macros for fields which represent pointers in kernel-userspace ABI. This facilitates handling of 32-bit user-space by 64-bit kernels by defining those fields as 32-bit 0-padding and 32-bit integer on 32-bit architectures, which allows the kernel to treat those as 64-bit integers. The order of padding and 32-bit integer depends on the endianness. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Joel Fernandes <joelaf@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Watson <davejwatson@fb.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Chris Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Hunter <ahh@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Maurer <bmaurer@fb.com> Cc: linux-api@vger.kernel.org Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20180602124408.8430-2-mathieu.desnoyers@efficios.com
-rw-r--r--include/uapi/linux/types_32_64.h50
1 files changed, 50 insertions, 0 deletions
diff --git a/include/uapi/linux/types_32_64.h b/include/uapi/linux/types_32_64.h
new file mode 100644
index 000000000000..0a87ace34a57
--- /dev/null
+++ b/include/uapi/linux/types_32_64.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+#ifndef _UAPI_LINUX_TYPES_32_64_H
+#define _UAPI_LINUX_TYPES_32_64_H
+
+/*
+ * linux/types_32_64.h
+ *
+ * Integer type declaration for pointers across 32-bit and 64-bit systems.
+ *
+ * Copyright (c) 2015-2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifdef __KERNEL__
+# include <linux/types.h>
+#else
+# include <stdint.h>
+#endif
+
+#include <asm/byteorder.h>
+
+#ifdef __BYTE_ORDER
+# if (__BYTE_ORDER == __BIG_ENDIAN)
+# define LINUX_BYTE_ORDER_BIG_ENDIAN
+# else
+# define LINUX_BYTE_ORDER_LITTLE_ENDIAN
+# endif
+#else
+# ifdef __BIG_ENDIAN
+# define LINUX_BYTE_ORDER_BIG_ENDIAN
+# else
+# define LINUX_BYTE_ORDER_LITTLE_ENDIAN
+# endif
+#endif
+
+#ifdef __LP64__
+# define LINUX_FIELD_u32_u64(field) __u64 field
+# define LINUX_FIELD_u32_u64_INIT_ONSTACK(field, v) field = (intptr_t)v
+#else
+# ifdef LINUX_BYTE_ORDER_BIG_ENDIAN
+# define LINUX_FIELD_u32_u64(field) __u32 field ## _padding, field
+# define LINUX_FIELD_u32_u64_INIT_ONSTACK(field, v) \
+ field ## _padding = 0, field = (intptr_t)v
+# else
+# define LINUX_FIELD_u32_u64(field) __u32 field, field ## _padding
+# define LINUX_FIELD_u32_u64_INIT_ONSTACK(field, v) \
+ field = (intptr_t)v, field ## _padding = 0
+# endif
+#endif
+
+#endif /* _UAPI_LINUX_TYPES_32_64_H */