scripts-fix-gfp-translate-after-_gfpbits-conversion-to-an-enum.patch removed from -mm tree

merged mm-hotfixes-stable Andrew Morton 1 participant 1 message Sep 2, 2024

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Andrew Morton

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2024-09-02 00:59 UTC #0 lore raw

The quilt patch titled
Subject: scripts: fix gfp-translate after ___GFP_*_BITS conversion to an enum
has been removed from the -mm tree. Its filename was
scripts-fix-gfp-translate-after-___gfp__bits-conversion-to-an-enum.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Marc Zyngier <[email protected]>
Subject: scripts: fix gfp-translate after ___GFP_*_BITS conversion to an enum
Date: Fri, 23 Aug 2024 17:38:50 +0100

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/[email protected] open here

Fixes 772dd0342727 ("mm: enumerate all gfp flags")

Signed-off-by Marc Zyngier <[email protected]>

Reported-by Richard Weinberger <[email protected]>

Cc Petr Tesařík <[email protected]>

Cc Suren Baghdasaryan <[email protected]>

Signed-off-by Andrew Morton <[email protected]>

---

 scripts/gfp-translate |   66 +++++++++++++++++++++++++++++-----------
 1 file changed, 49 insertions(+), 17 deletions(-)

scripts/gfp-translate renamed from scripts/gfp-translate~scripts-fix-gfp-translate-after-___gfp__bits-conversion-to-an-enum +49 ~~-17~~

@@ -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

Patches currently in -mm which might be from [email protected] are