git: 80203a27e964 - main - Add sys/_align.h replacing machine/_align.h

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From: Brooks Davis <brooks_at_FreeBSD.org>
Date: Wed, 10 Dec 2025 10:58:07 UTC
The branch main has been updated by brooks:

URL: https://cgit.FreeBSD.org/src/commit/?id=80203a27e964403d1d23907089f5c57c60a15c04

commit 80203a27e964403d1d23907089f5c57c60a15c04
Author:     Brooks Davis <brooks@FreeBSD.org>
AuthorDate: 2025-12-10 10:55:28 +0000
Commit:     Brooks Davis <brooks@FreeBSD.org>
CommitDate: 2025-12-10 10:57:50 +0000

    Add sys/_align.h replacing machine/_align.h
    
    Define _ALIGNBYTES using sizeof(void *) (no functional change on any
    existing architecture) which will allow it to work with CHERI were we
    must align things up to capability alignment.
    
    In _ALIGN, replace integer manipulation which does not preserve pointer
    provenance with a type and provenance preserving builtin.  This requires
    modest changes in code which assumes _ALIGN returns an integer, but
    those are relatively rare.
    
    Reviewed by:    kib, markj
    Effort:         CHERI upstreaming
    Sponsored by:   Innovate UK
    Differential Revision:  https://reviews.freebsd.org/D53947
---
 include/arm/Makefile         |  3 +--
 sys/amd64/include/_align.h   |  5 -----
 sys/amd64/include/param.h    |  2 +-
 sys/arm/include/_align.h     | 51 --------------------------------------------
 sys/arm/include/param.h      |  2 +-
 sys/arm64/include/_align.h   | 47 ----------------------------------------
 sys/arm64/include/param.h    |  2 +-
 sys/i386/include/_align.h    |  5 -----
 sys/i386/include/param.h     |  2 +-
 sys/powerpc/include/_align.h | 51 --------------------------------------------
 sys/powerpc/include/param.h  |  2 +-
 sys/riscv/include/_align.h   | 41 -----------------------------------
 sys/riscv/include/param.h    |  2 +-
 sys/sys/_align.h             | 32 +++++++++++++++++++++++++++
 sys/sys/socket.h             |  2 +-
 sys/x86/include/_align.h     | 51 --------------------------------------------
 16 files changed, 40 insertions(+), 260 deletions(-)

diff --git a/include/arm/Makefile b/include/arm/Makefile
index 27fa8dfb9de3..3e7d73fd911f 100644
--- a/include/arm/Makefile
+++ b/include/arm/Makefile
@@ -2,8 +2,7 @@
 
 .PATH: ${SRCTOP}/sys/arm/include ${SRCTOP}/lib/msun/arm
 
-INCS=	_align.h \
-	_inttypes.h \
+INCS=	_inttypes.h \
 	_limits.h \
 	_stdint.h \
 	_types.h \
diff --git a/sys/amd64/include/_align.h b/sys/amd64/include/_align.h
deleted file mode 100644
index 506bc3c9e7f3..000000000000
--- a/sys/amd64/include/_align.h
+++ /dev/null
@@ -1,5 +0,0 @@
-/*-
- * This file is in the public domain.
- */
-
-#include <x86/_align.h>
diff --git a/sys/amd64/include/param.h b/sys/amd64/include/param.h
index 0654bb9de790..642a031d8841 100644
--- a/sys/amd64/include/param.h
+++ b/sys/amd64/include/param.h
@@ -41,7 +41,7 @@
 #ifndef _AMD64_INCLUDE_PARAM_H_
 #define	_AMD64_INCLUDE_PARAM_H_
 
-#include <machine/_align.h>
+#include <sys/_align.h>
 
 /*
  * Machine dependent constants for AMD64.
diff --git a/sys/arm/include/_align.h b/sys/arm/include/_align.h
deleted file mode 100644
index 1088c2363e9a..000000000000
--- a/sys/arm/include/_align.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/*-
- * SPDX-License-Identifier: BSD-4-Clause
- *
- * Copyright (c) 2001 David E. O'Brien
- * Copyright (c) 1990 The Regents of the University of California.
- * All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * William Jolitz.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *	This product includes software developed by the University of
- *	California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#ifndef _ARM_INCLUDE__ALIGN_H_
-#define	_ARM_INCLUDE__ALIGN_H_
-
-/*
- * Round p (pointer or byte index) up to the hardware-required alignment which
- * is sufficient for any data type, pointer or numeric.  The resulting type
- * is equivelent to arm's uintptr_t (but is purposely spelled "unsigned" here).
- */
-#define	_ALIGNBYTES	(sizeof(int) - 1)
-#define	_ALIGN(p)	(((unsigned)(p) + _ALIGNBYTES) & ~_ALIGNBYTES)
-
-#endif /* !_ARM_INCLUDE__ALIGN_H_ */
diff --git a/sys/arm/include/param.h b/sys/arm/include/param.h
index 79c9bc09c284..fa9737608038 100644
--- a/sys/arm/include/param.h
+++ b/sys/arm/include/param.h
@@ -44,7 +44,7 @@
  * Machine dependent constants for StrongARM
  */
 
-#include <machine/_align.h>
+#include <sys/_align.h>
 
 #define STACKALIGNBYTES	(8 - 1)
 #define STACKALIGN(p)	((u_int)(p) & ~STACKALIGNBYTES)
diff --git a/sys/arm64/include/_align.h b/sys/arm64/include/_align.h
deleted file mode 100644
index b88200e21636..000000000000
--- a/sys/arm64/include/_align.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/*-
- * Copyright (c) 1990 The Regents of the University of California.
- * All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * William Jolitz.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#ifdef __arm__
-#include <arm/_align.h>
-#else /* !__arm__ */
-
-#ifndef _MACHINE__ALIGN_H_
-#define	_MACHINE__ALIGN_H_
-
-/*
- * Round p (pointer or byte index) up to a correctly-aligned value
- * for all data types (int, long, ...).   The result is unsigned int
- * and must be cast to any desired pointer type.
- */
-#define	_ALIGNBYTES	(sizeof(long long) - 1)
-#define	_ALIGN(p)	(((u_long)(p) + _ALIGNBYTES) & ~_ALIGNBYTES)
-
-#endif /* !_MACHINE__ALIGN_H_ */
-
-#endif /* !__arm__ */
diff --git a/sys/arm64/include/param.h b/sys/arm64/include/param.h
index 753035b7775e..f3cdd4e44bc0 100644
--- a/sys/arm64/include/param.h
+++ b/sys/arm64/include/param.h
@@ -38,7 +38,7 @@
  * Machine dependent constants for arm64.
  */
 
-#include <machine/_align.h>
+#include <sys/_align.h>
 
 #define	STACKALIGNBYTES	(16 - 1)
 #define	STACKALIGN(p)	((uint64_t)(p) & ~STACKALIGNBYTES)
diff --git a/sys/i386/include/_align.h b/sys/i386/include/_align.h
deleted file mode 100644
index 506bc3c9e7f3..000000000000
--- a/sys/i386/include/_align.h
+++ /dev/null
@@ -1,5 +0,0 @@
-/*-
- * This file is in the public domain.
- */
-
-#include <x86/_align.h>
diff --git a/sys/i386/include/param.h b/sys/i386/include/param.h
index 657dbcd879bd..9e542038f345 100644
--- a/sys/i386/include/param.h
+++ b/sys/i386/include/param.h
@@ -35,7 +35,7 @@
 #ifndef _I386_INCLUDE_PARAM_H_
 #define	_I386_INCLUDE_PARAM_H_
 
-#include <machine/_align.h>
+#include <sys/_align.h>
 
 /*
  * Machine dependent constants for Intel 386.
diff --git a/sys/powerpc/include/_align.h b/sys/powerpc/include/_align.h
deleted file mode 100644
index 0a7b6039b087..000000000000
--- a/sys/powerpc/include/_align.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/*-
- * SPDX-License-Identifier: BSD-4-Clause
- *
- * Copyright (c) 2001 David E. O'Brien
- * Copyright (c) 1990 The Regents of the University of California.
- * All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * William Jolitz.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *	This product includes software developed by the University of
- *	California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#ifndef _POWERPC_INCLUDE__ALIGN_H_
-#define	_POWERPC_INCLUDE__ALIGN_H_
-
-/*
- * Round p (pointer or byte index) up to a correctly-aligned value
- * for all data types (int, long, ...).   The result is unsigned int
- * and must be cast to any desired pointer type.
- */
-#define	_ALIGNBYTES	(sizeof(register_t) - 1)
-#define	_ALIGN(p)	(((uintptr_t)(p) + _ALIGNBYTES) & ~_ALIGNBYTES)
-
-#endif /* !_POWERPC_INCLUDE__ALIGN_H_ */
diff --git a/sys/powerpc/include/param.h b/sys/powerpc/include/param.h
index e79e92f76ec2..a190f60c02cc 100644
--- a/sys/powerpc/include/param.h
+++ b/sys/powerpc/include/param.h
@@ -44,7 +44,7 @@
  * Machine dependent constants for PowerPC
  */
 
-#include <machine/_align.h>
+#include <sys/_align.h>
 
 #ifndef MACHINE
 #define	MACHINE		"powerpc"
diff --git a/sys/riscv/include/_align.h b/sys/riscv/include/_align.h
deleted file mode 100644
index c588625ce7f9..000000000000
--- a/sys/riscv/include/_align.h
+++ /dev/null
@@ -1,41 +0,0 @@
-/*-
- * Copyright (c) 1990 The Regents of the University of California.
- * All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * William Jolitz.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#ifndef _MACHINE__ALIGN_H_
-#define	_MACHINE__ALIGN_H_
-
-/*
- * Round p (pointer or byte index) up to a correctly-aligned value
- * for all data types (int, long, ...).   The result is unsigned int
- * and must be cast to any desired pointer type.
- */
-#define	_ALIGNBYTES	(sizeof(long long) - 1)
-#define	_ALIGN(p)	(((u_long)(p) + _ALIGNBYTES) & ~_ALIGNBYTES)
-
-#endif /* !_MACHINE__ALIGN_H_ */
diff --git a/sys/riscv/include/param.h b/sys/riscv/include/param.h
index 32b0c7a1e34b..471d8b354b82 100644
--- a/sys/riscv/include/param.h
+++ b/sys/riscv/include/param.h
@@ -34,7 +34,7 @@
  * Machine dependent constants for RISC-V.
  */
 
-#include <machine/_align.h>
+#include <sys/_align.h>
 
 #define	STACKALIGNBYTES	(16 - 1)
 #define	STACKALIGN(p)	((uint64_t)(p) & ~STACKALIGNBYTES)
diff --git a/sys/sys/_align.h b/sys/sys/_align.h
new file mode 100644
index 000000000000..09444bc4afce
--- /dev/null
+++ b/sys/sys/_align.h
@@ -0,0 +1,32 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 SRI International
+ *
+ * This software was developed by SRI International and the University of
+ * Cambridge Computer Laboratory (Department of Computer Science and
+ * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
+ * DARPA SSITH research programme.
+ */
+#ifndef _SYS__ALIGN_H_
+#define	_SYS__ALIGN_H_
+
+/*
+ * Round p up to the alignment of the largest, non-floating point, type
+ * that fits in a register.  In practice this has always been the size
+ * of a pointer (but spelled in a wide varity of ways) and with CHERI
+ * that needs to remain true to support file descriptor passing within
+ * the kernel.
+ *
+ * Unlike historic implementations, _ALIGN macro preserves both the type
+ * and provenance of p.
+ *
+ * These interfaces are ambigiously defined and should be considred
+ * obsolete.  New code that requires alignment adjustments should replace
+ * _ALIGNBYTES with alignof(appropriate type) and _ALIGN with
+ * __align_up(p, alignof(appropriate type)).
+ */
+#define	_ALIGNBYTES	(sizeof(void *) - 1)
+#define	_ALIGN(p)	__align_up((p), _ALIGNBYTES + 1)
+
+#endif /* !_SYS__ALIGN_H_ */
diff --git a/sys/sys/socket.h b/sys/sys/socket.h
index 76a1652644bd..25b6fce75b94 100644
--- a/sys/sys/socket.h
+++ b/sys/sys/socket.h
@@ -36,7 +36,7 @@
 #include <sys/_types.h>
 #include <sys/_iovec.h>
 #include <sys/_timeval.h>
-#include <machine/_align.h>
+#include <sys/_align.h>
 
 /*
  * Definitions related to sockets: types, address families, options.
diff --git a/sys/x86/include/_align.h b/sys/x86/include/_align.h
deleted file mode 100644
index dc2ff4f656f4..000000000000
--- a/sys/x86/include/_align.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/*-
- * SPDX-License-Identifier: BSD-4-Clause
- *
- * Copyright (c) 2001 David E. O'Brien
- * Copyright (c) 1990 The Regents of the University of California.
- * All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * William Jolitz.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *	This product includes software developed by the University of
- *	California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#ifndef _X86_INCLUDE__ALIGN_H_
-#define	_X86_INCLUDE__ALIGN_H_
-
-/*
- * Round p (pointer or byte index) up to a correctly-aligned value
- * for all data types (int, long, ...).   The result is unsigned int
- * and must be cast to any desired pointer type.
- */
-#define	_ALIGNBYTES	(sizeof(__register_t) - 1)
-#define	_ALIGN(p)	(((__uintptr_t)(p) + _ALIGNBYTES) & ~_ALIGNBYTES)
-
-#endif /* !_X86_INCLUDE__ALIGN_H_ */