diff mbox series

[v3,1/2] asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch

Message ID 1687443219-11946-2-git-send-email-yangtiezhu@loongson.cn
State Accepted
Commit 8386f58f8deda81110283798a387fb53ec21957c
Headers show
Series Unify uapi bitsperlong.h | expand

Commit Message

Tiezhu Yang June 22, 2023, 2:13 p.m. UTC 
Now we specify the minimal version of GCC as 5.1 and Clang/LLVM as 11.0.0
in Documentation/process/changes.rst, __CHAR_BIT__ and __SIZEOF_LONG__ are
usable, it is probably fine to unify the definition of __BITS_PER_LONG as
(__CHAR_BIT__ * __SIZEOF_LONG__) in asm-generic uapi bitsperlong.h.

In order to keep safe and avoid regression, only unify uapi bitsperlong.h
for some archs such as arm64, riscv and loongarch which are using newer
toolchains that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__.

Suggested-by: Xi Ruoyao <xry111@xry111.site>
Link: https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-arch/a3a4f48a-07d4-4ed9-bc53-5d383428bdd2@app.fastmail.com/
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 arch/arm64/include/uapi/asm/bitsperlong.h          | 24 ----------------------
 arch/loongarch/include/uapi/asm/bitsperlong.h      |  9 --------
 arch/riscv/include/uapi/asm/bitsperlong.h          | 14 -------------
 include/uapi/asm-generic/bitsperlong.h             | 13 +++++++++++-
 tools/arch/arm64/include/uapi/asm/bitsperlong.h    | 24 ----------------------
 .../arch/loongarch/include/uapi/asm/bitsperlong.h  |  9 --------
 tools/arch/riscv/include/uapi/asm/bitsperlong.h    | 14 -------------
 tools/include/uapi/asm-generic/bitsperlong.h       | 14 ++++++++++++-
 tools/include/uapi/asm/bitsperlong.h               |  6 ------
 9 files changed, 25 insertions(+), 102 deletions(-)
 delete mode 100644 arch/arm64/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/loongarch/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/riscv/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/arm64/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/loongarch/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/riscv/include/uapi/asm/bitsperlong.h

Comments

Arnd Bergmann July 28, 2023, 11 a.m. UTC | #1 
On Thu, Jul 27, 2023, at 23:36, Nathan Chancellor wrote:
> Hi Tiezhu and Arnd,
>
> On Thu, Jun 22, 2023 at 10:13:38PM +0800, Tiezhu Yang wrote:
>> Now we specify the minimal version of GCC as 5.1 and Clang/LLVM as 11.0.0
>> in Documentation/process/changes.rst, __CHAR_BIT__ and __SIZEOF_LONG__ are
>> usable, it is probably fine to unify the definition of __BITS_PER_LONG as
>> (__CHAR_BIT__ * __SIZEOF_LONG__) in asm-generic uapi bitsperlong.h.
>> 
>> In order to keep safe and avoid regression, only unify uapi bitsperlong.h
>> for some archs such as arm64, riscv and loongarch which are using newer
>> toolchains that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__.
>> 
>> Suggested-by: Xi Ruoyao <xry111@xry111.site>
>> Link: https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/
>> Suggested-by: Arnd Bergmann <arnd@arndb.de>
>> Link: https://lore.kernel.org/linux-arch/a3a4f48a-07d4-4ed9-bc53-5d383428bdd2@app.fastmail.com/
>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>> ---

>
> I think this change has backwards compatibility concerns, as it breaks
> building certain host tools on the stable releases (at least 6.4 and
> 6.1, as that is where I noticed this). I see the following error on my
> aarch64 system:
>
>   $ make -skj"$(nproc)" ARCH=x86_64 CROSS_COMPILE=x86_64-linux- 
> mrproper defconfig prepare
>   In file included from /usr/include/asm/bitsperlong.h:1,
>                    from /usr/include/asm-generic/int-ll64.h:12,
>                    from /usr/include/asm-generic/types.h:7,
>                    from /usr/include/asm/types.h:1,
>                    from tools/include/linux/types.h:13,
>                    from tools/arch/x86/include/asm/orc_types.h:9,
>                    from scripts/sorttable.h:96,
>                    from scripts/sorttable.c:201:
>   tools/include/asm-generic/bitsperlong.h:14:2: error: #error 
> Inconsistent word size. Check asm/bitsperlong.h
>      14 | #error Inconsistent word size. Check asm/bitsperlong.h
>         |  ^~~~~

Thanks for the report. I'm still struggling to figure out what
exactly is going wrong here, and if this is a bug in the patch
I merged, or an existing bug that now causes a build failure instead
of some other problem.

> A reverse bisect of 6.4 to 6.5-rc1 points to this patch. This Fedora
> rawhide container has kernel-headers 6.5.0-0.rc2.git0.1.fc39 and the
> error disappears when I downgrade to 6.4.0-0.rc7.git0.1.fc39. I have not
> done a ton of triage/debugging so far, as I am currently hunting down
> other regressions, but I figured I would get an initial report out,
> since I noticed it when validating LLVM from the new release/17.x
> branch. If there is any additional information I can provide or patches
> I can test, I am more than happy to do so.

One thing I think is going wrong here is that scripts/sorttable.c is
meant to run on the host (arm64) but includes the target (x86)
orc_Types.h header and the kernel-internal asm/bitsperlong.h instead
of the uapi version. The sanity check in the kernel-side header
is intended to cross-check the CONFIG_64BIT value against the
__BITS_PER_LONG constant from the header.

My first guess would be that this only worked by accident if the headers
defaulted to "#define __BITS_PER_LONG 32" in and #undef CONFIG_64BIT"
when include/generated/autoconf.h, but now the __BITS_PER_LONG value
is actually correct.

       Arnd
diff mbox series

Patch

diff --git a/arch/arm64/include/uapi/asm/bitsperlong.h b/arch/arm64/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 485d60be..0000000
--- a/arch/arm64/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,24 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_BITSPERLONG_H
-#define __ASM_BITSPERLONG_H
-
-#define __BITS_PER_LONG 64
-
-#include <asm-generic/bitsperlong.h>
-
-#endif	/* __ASM_BITSPERLONG_H */
diff --git a/arch/loongarch/include/uapi/asm/bitsperlong.h b/arch/loongarch/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 00b4ba1..0000000
--- a/arch/loongarch/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_LOONGARCH_BITSPERLONG_H
-#define __ASM_LOONGARCH_BITSPERLONG_H
-
-#define __BITS_PER_LONG (__SIZEOF_LONG__ * 8)
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_LOONGARCH_BITSPERLONG_H */
diff --git a/arch/riscv/include/uapi/asm/bitsperlong.h b/arch/riscv/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 7d0b32e..0000000
--- a/arch/riscv/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,14 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
-/*
- * Copyright (C) 2012 ARM Ltd.
- * Copyright (C) 2015 Regents of the University of California
- */
-
-#ifndef _UAPI_ASM_RISCV_BITSPERLONG_H
-#define _UAPI_ASM_RISCV_BITSPERLONG_H
-
-#define __BITS_PER_LONG (__SIZEOF_POINTER__ * 8)
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* _UAPI_ASM_RISCV_BITSPERLONG_H */
diff --git a/include/uapi/asm-generic/bitsperlong.h b/include/uapi/asm-generic/bitsperlong.h
index 693d9a4..352cb81 100644
--- a/include/uapi/asm-generic/bitsperlong.h
+++ b/include/uapi/asm-generic/bitsperlong.h
@@ -2,6 +2,17 @@ 
 #ifndef _UAPI__ASM_GENERIC_BITS_PER_LONG
 #define _UAPI__ASM_GENERIC_BITS_PER_LONG
 
+#ifndef __BITS_PER_LONG
+/*
+ * In order to keep safe and avoid regression, only unify uapi
+ * bitsperlong.h for some archs which are using newer toolchains
+ * that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__.
+ * See the following link for more info:
+ * https://lore.kernel.org/linux-arch/b9624545-2c80-49a1-ac3c-39264a591f7b@app.fastmail.com/
+ */
+#if defined(__CHAR_BIT__) && defined(__SIZEOF_LONG__)
+#define __BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__)
+#else
 /*
  * There seems to be no way of detecting this automatically from user
  * space, so 64 bit architectures should override this in their
@@ -9,8 +20,8 @@ 
  * both 32 and 64 bit user space must not rely on CONFIG_64BIT
  * to decide it, but rather check a compiler provided macro.
  */
-#ifndef __BITS_PER_LONG
 #define __BITS_PER_LONG 32
 #endif
+#endif
 
 #endif /* _UAPI__ASM_GENERIC_BITS_PER_LONG */
diff --git a/tools/arch/arm64/include/uapi/asm/bitsperlong.h b/tools/arch/arm64/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 485d60be..0000000
--- a/tools/arch/arm64/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,24 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_BITSPERLONG_H
-#define __ASM_BITSPERLONG_H
-
-#define __BITS_PER_LONG 64
-
-#include <asm-generic/bitsperlong.h>
-
-#endif	/* __ASM_BITSPERLONG_H */
diff --git a/tools/arch/loongarch/include/uapi/asm/bitsperlong.h b/tools/arch/loongarch/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 00b4ba1..0000000
--- a/tools/arch/loongarch/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_LOONGARCH_BITSPERLONG_H
-#define __ASM_LOONGARCH_BITSPERLONG_H
-
-#define __BITS_PER_LONG (__SIZEOF_LONG__ * 8)
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_LOONGARCH_BITSPERLONG_H */
diff --git a/tools/arch/riscv/include/uapi/asm/bitsperlong.h b/tools/arch/riscv/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 0b9b58b..0000000
--- a/tools/arch/riscv/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,14 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2012 ARM Ltd.
- * Copyright (C) 2015 Regents of the University of California
- */
-
-#ifndef _UAPI_ASM_RISCV_BITSPERLONG_H
-#define _UAPI_ASM_RISCV_BITSPERLONG_H
-
-#define __BITS_PER_LONG (__SIZEOF_POINTER__ * 8)
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* _UAPI_ASM_RISCV_BITSPERLONG_H */
diff --git a/tools/include/uapi/asm-generic/bitsperlong.h b/tools/include/uapi/asm-generic/bitsperlong.h
index 23e6c41..352cb81 100644
--- a/tools/include/uapi/asm-generic/bitsperlong.h
+++ b/tools/include/uapi/asm-generic/bitsperlong.h
@@ -1,6 +1,18 @@ 
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
 #ifndef _UAPI__ASM_GENERIC_BITS_PER_LONG
 #define _UAPI__ASM_GENERIC_BITS_PER_LONG
 
+#ifndef __BITS_PER_LONG
+/*
+ * In order to keep safe and avoid regression, only unify uapi
+ * bitsperlong.h for some archs which are using newer toolchains
+ * that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__.
+ * See the following link for more info:
+ * https://lore.kernel.org/linux-arch/b9624545-2c80-49a1-ac3c-39264a591f7b@app.fastmail.com/
+ */
+#if defined(__CHAR_BIT__) && defined(__SIZEOF_LONG__)
+#define __BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__)
+#else
 /*
  * There seems to be no way of detecting this automatically from user
  * space, so 64 bit architectures should override this in their
@@ -8,8 +20,8 @@ 
  * both 32 and 64 bit user space must not rely on CONFIG_64BIT
  * to decide it, but rather check a compiler provided macro.
  */
-#ifndef __BITS_PER_LONG
 #define __BITS_PER_LONG 32
 #endif
+#endif
 
 #endif /* _UAPI__ASM_GENERIC_BITS_PER_LONG */
diff --git a/tools/include/uapi/asm/bitsperlong.h b/tools/include/uapi/asm/bitsperlong.h
index da52065..c65267a 100644
--- a/tools/include/uapi/asm/bitsperlong.h
+++ b/tools/include/uapi/asm/bitsperlong.h
@@ -1,8 +1,6 @@ 
 /* SPDX-License-Identifier: GPL-2.0 */
 #if defined(__i386__) || defined(__x86_64__)
 #include "../../../arch/x86/include/uapi/asm/bitsperlong.h"
-#elif defined(__aarch64__)
-#include "../../../arch/arm64/include/uapi/asm/bitsperlong.h"
 #elif defined(__powerpc__)
 #include "../../../arch/powerpc/include/uapi/asm/bitsperlong.h"
 #elif defined(__s390__)
@@ -13,12 +11,8 @@ 
 #include "../../../arch/mips/include/uapi/asm/bitsperlong.h"
 #elif defined(__ia64__)
 #include "../../../arch/ia64/include/uapi/asm/bitsperlong.h"
-#elif defined(__riscv)
-#include "../../../arch/riscv/include/uapi/asm/bitsperlong.h"
 #elif defined(__alpha__)
 #include "../../../arch/alpha/include/uapi/asm/bitsperlong.h"
-#elif defined(__loongarch__)
-#include "../../../arch/loongarch/include/uapi/asm/bitsperlong.h"
 #else
 #include <asm-generic/bitsperlong.h>
 #endif