6.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Marc Zyngier <maz@xxxxxxxxxx>
[ Upstream commit a3f6a89c834a4cba0f881da21307b26de3796133 ]
Richard reports that since 772dd0342727c ("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@xxxxxxxxxx
Fixes: 772dd0342727 ("mm: enumerate all gfp flags")
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Reported-by: Richard Weinberger <richard@xxxxxx>
Cc: Petr Tesařík <petr@xxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
scripts/gfp-translate | 66 ++++++++++++++++++++++++++++++++-----------
1 file changed, 49 insertions(+), 17 deletions(-)
diff --git a/scripts/gfp-translate b/scripts/gfp-translate
index 6c9aed17cf56..8385ae0d5af9 100755
--- a/scripts/gfp-translate
+++ b/scripts/gfp-translate
@@ -62,25 +62,57 @@ if [ "$GFPMASK" = "none" ]; then
fi
# Extract GFP flags from the kernel source
-TMPFILE=`mktemp -t gfptranslate-XXXXXX` || exit 1
-grep -q ___GFP $SOURCE/include/linux/gfp_types.h
-if [ $? -eq 0 ]; then
- grep "^#define ___GFP" $SOURCE/include/linux/gfp_types.h | sed -e 's/u$//' | grep -v GFP_BITS > $TMPFILE
-else
- grep "^#define __GFP" $SOURCE/include/linux/gfp_types.h | sed -e 's/(__force gfp_t)//' | sed -e 's/u)/)/' | grep -v GFP_BITS | sed -e 's/)\//) \//' > $TMPFILE
-fi
+TMPFILE=`mktemp -t gfptranslate-XXXXXX.c` || exit 1
-# Parse the flags
-IFS="
-"
echo Source: $SOURCE
echo Parsing: $GFPMASK
-for LINE in `cat $TMPFILE`; do
- MASK=`echo $LINE | awk '{print $3}'`
- if [ $(($GFPMASK&$MASK)) -ne 0 ]; then
- echo $LINE
- fi
-done
-rm -f $TMPFILE
+(
+ cat <<EOF
+#include <stdint.h>
+#include <stdio.h>
+
+// Try to fool compiler.h into not including extra stuff
+#define __ASSEMBLY__ 1
+
+#include <generated/autoconf.h>
+#include <linux/gfp_types.h>
+
+static const char *masks[] = {
+EOF
+
+ sed -nEe 's/^[[:space:]]+(___GFP_.*)_BIT,.*$/\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
--
2.43.0
