[Crash-utility] [PATCH 4/4] 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(a)redhat.com&gt; --- sbitmap.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/sbitmap.c b/sbitmap.c index 94114efc129e..494a1ba85e75 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; -- 2.20.1