linux-IllusionX/scripts/gfp-translate
Marc Zyngier a3f6a89c83 scripts: fix gfp-translate after ___GFP_*_BITS conversion to an enum
Richard reports that since 772dd03427 ("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>
2024-09-01 17:59:01 -07:00

118 lines
2.1 KiB
Bash
Executable file

#!/bin/bash
# SPDX-License-Identifier: GPL-2.0-only
# Translate the bits making up a GFP mask
# (c) 2009, Mel Gorman <mel@csn.ul.ie>
SOURCE=
GFPMASK=none
# Helper function to report failures and exit
die() {
echo ERROR: $@
if [ "$TMPFILE" != "" ]; then
rm -f $TMPFILE
fi
exit -1
}
usage() {
echo "usage: gfp-translate [-h] [ --source DIRECTORY ] gfpmask"
exit 0
}
# Parse command-line arguments
while [ $# -gt 0 ]; do
case $1 in
--source)
SOURCE=$2
shift 2
;;
-h)
usage
;;
--help)
usage
;;
*)
GFPMASK=$1
shift
;;
esac
done
# Guess the kernel source directory if it's not set. Preference is in order of
# o current directory
# o /usr/src/linux
if [ "$SOURCE" = "" ]; then
if [ -r "/usr/src/linux/Makefile" ]; then
SOURCE=/usr/src/linux
fi
if [ -r "`pwd`/Makefile" ]; then
SOURCE=`pwd`
fi
fi
# Confirm that a source directory exists
if [ ! -r "$SOURCE/Makefile" ]; then
die "Could not locate kernel source directory or it is invalid"
fi
# Confirm that a GFP mask has been specified
if [ "$GFPMASK" = "none" ]; then
usage
fi
# Extract GFP flags from the kernel source
TMPFILE=`mktemp -t gfptranslate-XXXXXX.c` || exit 1
echo Source: $SOURCE
echo Parsing: $GFPMASK
(
cat <<EOF
#include <stdint.h>
#include <stdio.h>
// Try to fool compiler.h into not including extra stuff
#define __ASSEMBLY__ 1
#include <generated/autoconf.h>
#include <linux/gfp_types.h>
static const char *masks[] = {
EOF
sed -nEe 's/^[[:space:]]+(___GFP_.*)_BIT,.*$/\1/p' $SOURCE/include/linux/gfp_types.h |
while read b; do
cat <<EOF
#if defined($b) && ($b > 0)
[${b}_BIT] = "$b",
#endif
EOF
done
cat <<EOF
};
int main(int argc, char *argv[])
{
unsigned long long mask = $GFPMASK;
for (int i = 0; i < sizeof(mask) * 8; i++) {
unsigned long long bit = 1ULL << i;
if (mask & bit)
printf("\t%-25s0x%llx\n",
(i < ___GFP_LAST_BIT && masks[i]) ?
masks[i] : "*** INVALID ***",
bit);
}
return 0;
}
EOF
) > $TMPFILE
${CC:-gcc} -Wall -o ${TMPFILE}.bin -I $SOURCE/include $TMPFILE && ${TMPFILE}.bin
rm -f $TMPFILE ${TMPFILE}.bin
exit 0