From 3750803f6ae5f5ad071f86ca916dbbb17b7a83a5 Mon Sep 17 00:00:00 2001

From: Lianbo Jiang <lijiang@redhat.com>

Date: Mon, 23 May 2022 18:04:16 +0800

Subject: [PATCH 04/15] sbitmapq: fix invalid offset for "sbitmap_word_depth"

 on Linux v5.18-rc1

Kernel commit 3301bc53358a ("lib/sbitmap: kill 'depth' from sbitmap_word")

removed the depth member from struct sbitmap_word.  Without the patch, the

sbitmapq will fail:

  crash> sbitmapq 0xffff8e99d0dc8010

  sbitmapq: invalid structure member offset: sbitmap_word_depth

          FILE: sbitmap.c  LINE: 84  FUNCTION: __sbitmap_weight()

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>

---

 sbitmap.c | 19 +++++++++++--------

 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/sbitmap.c b/sbitmap.c

index 7b318b533702..e8ebd62fe01c 100644

--- a/sbitmap.c

+++ b/sbitmap.c

@@ -78,10 +78,16 @@ static unsigned long bitmap_weight(unsigned long bitmap, unsigned int bits)

 	return w;

 }

+static inline unsigned int __map_depth(const struct sbitmap_context *sc, int index)

+{

+       if (index == sc->map_nr - 1)

+               return sc->depth - (index << sc->shift);

+       return 1U << sc->shift;

+}

+

 static unsigned int __sbitmap_weight(const struct sbitmap_context *sc, bool set)

 {

 	const ulong sbitmap_word_size = SIZE(sbitmap_word);

-	const ulong w_depth_off = OFFSET(sbitmap_word_depth);

 	const ulong w_word_off = OFFSET(sbitmap_word_word);

 	const ulong w_cleared_off = OFFSET(sbitmap_word_cleared);

@@ -99,7 +105,7 @@ static unsigned int __sbitmap_weight(const struct sbitmap_context *sc, bool set)

 			error(FATAL, "cannot read sbitmap_word\n");

 		}

-		depth = ULONG(sbitmap_word_buf + w_depth_off);

+		depth = __map_depth(sc, i);

 		if (set) {

 			word = ULONG(sbitmap_word_buf + w_word_off);

@@ -142,7 +148,6 @@ static void sbitmap_emit_byte(unsigned int offset, uint8_t byte)

 static void sbitmap_bitmap_show(const struct sbitmap_context *sc)

 {

 	const ulong sbitmap_word_size = SIZE(sbitmap_word);

-	const ulong w_depth_off = OFFSET(sbitmap_word_depth);

 	const ulong w_word_off = OFFSET(sbitmap_word_word);

 	const ulong w_cleared_off = OFFSET(sbitmap_word_cleared);

@@ -165,7 +170,7 @@ static void sbitmap_bitmap_show(const struct sbitmap_context *sc)

 		word = ULONG(sbitmap_word_buf + w_word_off);

 		cleared = ULONG(sbitmap_word_buf + w_cleared_off);

-		word_bits = ULONG(sbitmap_word_buf + w_depth_off);

+		word_bits = __map_depth(sc, i);

 		word &= ~cleared;

@@ -213,7 +218,6 @@ static void __sbitmap_for_each_set(const struct sbitmap_context *sc,

 		unsigned int start, sbitmap_for_each_fn fn, void *data)

 {

 	const ulong sbitmap_word_size = SIZE(sbitmap_word);

-	const ulong w_depth_off = OFFSET(sbitmap_word_depth);

 	const ulong w_word_off = OFFSET(sbitmap_word_word);

 	const ulong w_cleared_off = OFFSET(sbitmap_word_cleared);

@@ -232,7 +236,7 @@ static void __sbitmap_for_each_set(const struct sbitmap_context *sc,

 	while (scanned < sc->depth) {

 		unsigned long w_addr = sc->map_addr + (sbitmap_word_size * index);

-		unsigned long w_depth, w_word, w_cleared;

+		unsigned long w_word, w_cleared;

 		unsigned long word, depth;

 		if (!readmem(w_addr, KVADDR, sbitmap_word_buf, sbitmap_word_size, "sbitmap_word", RETURN_ON_ERROR)) {

@@ -240,11 +244,10 @@ static void __sbitmap_for_each_set(const struct sbitmap_context *sc,

 			error(FATAL, "cannot read sbitmap_word\n");

 		}

-		w_depth = ULONG(sbitmap_word_buf + w_depth_off);

 		w_word = ULONG(sbitmap_word_buf + w_word_off);

 		w_cleared = ULONG(sbitmap_word_buf + w_cleared_off);

-		depth = min(w_depth - nr, sc->depth - scanned);

+		depth = min(__map_depth(sc, index) - nr, sc->depth - scanned);

 		scanned += depth;

 		word = w_word & ~w_cleared;

-- 

2.30.2