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Revision 467d12f5c7842896d2de3ced74e4147ee29e97c8 authored by Christian Borntraeger on 21 February 2020, 04:04:03 UTC, committed by Linus Torvalds on 21 February 2020, 19:22:15 UTC 
include/uapi/linux/swab.h: fix userspace breakage, use __BITS_PER_LONG for swap
 
QEMU has a funny new build error message when I use the upstream kernel
headers:

      CC      block/file-posix.o
    In file included from /home/cborntra/REPOS/qemu/include/qemu/timer.h:4,
                     from /home/cborntra/REPOS/qemu/include/qemu/timed-average.h:29,
                     from /home/cborntra/REPOS/qemu/include/block/accounting.h:28,
                     from /home/cborntra/REPOS/qemu/include/block/block_int.h:27,
                     from /home/cborntra/REPOS/qemu/block/file-posix.c:30:
    /usr/include/linux/swab.h: In function `__swab':
    /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:34: error: "sizeof" is not defined, evaluates to 0 [-Werror=undef]
       20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
          |                                  ^~~~~~
    /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:41: error: missing binary operator before token "("
       20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
          |                                         ^
    cc1: all warnings being treated as errors
    make: *** [/home/cborntra/REPOS/qemu/rules.mak:69: block/file-posix.o] Error 1
    rm tests/qemu-iotests/socket_scm_helper.o

This was triggered by commit d5767057c9a ("uapi: rename ext2_swab() to
swab() and share globally in swab.h").  That patch is doing

  #include <asm/bitsperlong.h>

but it uses BITS_PER_LONG.

The kernel file asm/bitsperlong.h provide only __BITS_PER_LONG.

Let us use the __ variant in swap.h

Link: http://lkml.kernel.org/r/20200213142147.17604-1-borntraeger@de.ibm.com
Fixes: d5767057c9a ("uapi: rename ext2_swab() to swab() and share globally in swab.h")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Joe Perches <joe@perches.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent edf28f4
Raw File
gcc-ld 
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# run gcc with ld options
# used as a wrapper to execute link time optimizations
# yes virginia, this is not pretty

ARGS="-nostdlib"

while [ "$1" != "" ] ; do
	case "$1" in
	-save-temps|-m32|-m64) N="$1" ;;
	-r) N="$1" ;;
	-[Wg]*) N="$1" ;;
	-[olv]|-[Ofd]*|-nostdlib) N="$1" ;;
	--end-group|--start-group)
		 N="-Wl,$1" ;;
	-[RTFGhIezcbyYu]*|\
--script|--defsym|-init|-Map|--oformat|-rpath|\
-rpath-link|--sort-section|--section-start|-Tbss|-Tdata|-Ttext|\
--version-script|--dynamic-list|--version-exports-symbol|--wrap|-m)
		A="$1" ; shift ; N="-Wl,$A,$1" ;;
	-[m]*) N="$1" ;;
	-*) N="-Wl,$1" ;;
	*)  N="$1" ;;
	esac
	ARGS="$ARGS $N"
	shift
done

exec $CC $ARGS
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