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	Richard reports that since772dd03427("mm: enumerate all gfp flags"), gfp-translate is broken, as the bit numbers are implicit, leaving the shell script unable to extract them. Even more, some bits are now at a variable location, making it double extra hard to parse using a simple shell script. Use a brute-force approach to the problem by generating a small C stub that will use the enum to dump the interesting bits. As an added bonus, we are now able to identify invalid bits for a given configuration. As an added drawback, we cannot parse include files that predate this change anymore. Tough luck. Link: https://lkml.kernel.org/r/20240823163850.3791201-1-maz@kernel.org Fixes:772dd03427("mm: enumerate all gfp flags") Signed-off-by: Marc Zyngier <maz@kernel.org> Reported-by: Richard Weinberger <richard@nod.at> Cc: Petr Tesařík <petr@tesarici.cz> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
		
			
				
	
	
		
			118 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable file
		
	
	
	
	
			
		
		
	
	
			118 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable file
		
	
	
	
	
#!/bin/bash
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# SPDX-License-Identifier: GPL-2.0-only
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# Translate the bits making up a GFP mask
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# (c) 2009, Mel Gorman <mel@csn.ul.ie>
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SOURCE=
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GFPMASK=none
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# Helper function to report failures and exit
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die() {
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	echo ERROR: $@
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	if [ "$TMPFILE" != "" ]; then
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		rm -f $TMPFILE
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	fi
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	exit -1
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}
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usage() {
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	echo "usage: gfp-translate [-h] [ --source DIRECTORY ] gfpmask"
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	exit 0
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}
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# Parse command-line arguments
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while [ $# -gt 0 ]; do
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	case $1 in
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		--source)
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			SOURCE=$2
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			shift 2
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			;;
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		-h)
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			usage
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			;;
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		--help)
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			usage
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			;;
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		*)
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			GFPMASK=$1
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			shift
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			;;
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	esac
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done
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# Guess the kernel source directory if it's not set. Preference is in order of
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# o current directory
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# o /usr/src/linux
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if [ "$SOURCE" = "" ]; then
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	if [ -r "/usr/src/linux/Makefile" ]; then
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		SOURCE=/usr/src/linux
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	fi
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	if [ -r "`pwd`/Makefile" ]; then
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		SOURCE=`pwd`
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	fi
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fi
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# Confirm that a source directory exists
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if [ ! -r "$SOURCE/Makefile" ]; then
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	die "Could not locate kernel source directory or it is invalid"
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fi
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# Confirm that a GFP mask has been specified
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if [ "$GFPMASK" = "none" ]; then
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	usage
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fi
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# Extract GFP flags from the kernel source
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TMPFILE=`mktemp -t gfptranslate-XXXXXX.c` || exit 1
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echo Source: $SOURCE
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echo Parsing: $GFPMASK
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(
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    cat <<EOF
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#include <stdint.h>
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#include <stdio.h>
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// Try to fool compiler.h into not including extra stuff
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#define __ASSEMBLY__	1
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#include <generated/autoconf.h>
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#include <linux/gfp_types.h>
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static const char *masks[] = {
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EOF
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    sed -nEe 's/^[[:space:]]+(___GFP_.*)_BIT,.*$/\1/p' $SOURCE/include/linux/gfp_types.h |
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	while read b; do
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	    cat <<EOF
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#if defined($b) && ($b > 0)
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	[${b}_BIT]	= "$b",
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#endif
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EOF
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	done
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    cat <<EOF
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};
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int main(int argc, char *argv[])
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{
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	unsigned long long mask = $GFPMASK;
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	for (int i = 0; i < sizeof(mask) * 8; i++) {
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		unsigned long long bit = 1ULL << i;
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		if (mask & bit)
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			printf("\t%-25s0x%llx\n",
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			       (i < ___GFP_LAST_BIT && masks[i]) ?
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					masks[i] : "*** INVALID ***",
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			       bit);
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	}
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	return 0;
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}
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EOF
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) > $TMPFILE
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${CC:-gcc} -Wall -o ${TMPFILE}.bin -I $SOURCE/include $TMPFILE && ${TMPFILE}.bin
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rm -f $TMPFILE ${TMPFILE}.bin
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exit 0
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