* [merged mm-nonmm-stable] lib-xz-use-size_t-instead-of-uint32_t-in-a-few-places.patch removed from -mm tree
@ 2026-08-13 22:42 Andrew Morton
0 siblings, 0 replies; only message in thread
From: Andrew Morton @ 2026-08-13 22:42 UTC (permalink / raw)
To: mm-commits, thorsten.blum, nathan, david.laight.linux,
lasse.collin, akpm
The quilt patch titled
Subject: lib/xz: use size_t instead of uint32_t in a few places
has been removed from the -mm tree. Its filename was
lib-xz-use-size_t-instead-of-uint32_t-in-a-few-places.patch
This patch was dropped because it was merged into the mm-nonmm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Lasse Collin <lasse.collin@tukaani.org>
Subject: lib/xz: use size_t instead of uint32_t in a few places
Date: Sun, 14 Jun 2026 19:05:17 +0300
Reduce the number of uint32_t <-> size_t conversions a little.
Eliminating such conversions entirely would require changing almost all
uint32_t to size_t, which would look confusing and increase the sizes of
the structs even more. Going the other way, converting everything to
uint32_t, isn't possible because the input and output buffers use size_t
in struct xz_buf.
Now both arguments to min() have the same type. This is required to for
compatibility with PowerPC boot code[1] whose min() is strict like
include/linux/minmax.h was before the commit d03eba99f5bf ("minmax: allow
min()/max()/clamp() if the arguments have the same signedness.").
Swap the order of the "state" and "len" in struct lzma_dec to avoid
padding in the middle of the struct when size_t is 64 bits. The
reordering doesn't change the size of the struct; the padding just appears
at the end instead.
dict_flush() used to truncate size_t to uint32_t when returning. This
wasn't a bug; the value is always small enough.
Link: https://lore.kernel.org/20260614160521.924710-1-lasse.collin@tukaani.org
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/lkml/20260610232323.GA1071374@ax162/ [1]
Reviewed-by: Thorsten Blum <thorsten.blum@linux.dev>
Cc: David Laight <david.laight.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
lib/xz/xz_dec_lzma2.c | 40 ++++++++++++++++++++--------------------
lib/xz/xz_lzma2.h | 2 +-
2 files changed, 21 insertions(+), 21 deletions(-)
--- a/lib/xz/xz_dec_lzma2.c~lib-xz-use-size_t-instead-of-uint32_t-in-a-few-places
+++ a/lib/xz/xz_dec_lzma2.c
@@ -135,14 +135,16 @@ struct lzma_dec {
uint32_t rep2;
uint32_t rep3;
- /* Types of the most recently seen LZMA symbols */
- enum lzma_state state;
-
/*
* Length of a match. This is updated so that dict_repeat can
- * be called again to finish repeating the whole match.
+ * be called again to finish repeating the whole match. This is
+ * size_t because a pointer to this is passed to dict_repeat,
+ * and there it's nicer to have size_t instead of uint32_t.
*/
- uint32_t len;
+ size_t len;
+
+ /* Types of the most recently seen LZMA symbols */
+ enum lzma_state state;
/*
* LZMA properties or related bit masks (number of literal
@@ -228,13 +230,13 @@ struct lzma2_dec {
enum lzma2_seq next_sequence;
/* Uncompressed size of LZMA chunk (2 MiB at maximum) */
- uint32_t uncompressed;
+ size_t uncompressed;
/*
* Compressed size of LZMA chunk or compressed/uncompressed
* size of uncompressed chunk (64 KiB at maximum)
*/
- uint32_t compressed;
+ size_t compressed;
/*
* True if dictionary reset is needed. This is false before
@@ -273,7 +275,7 @@ struct xz_dec_lzma2 {
* decoder calls. See lzma2_lzma() for details.
*/
struct {
- uint32_t size;
+ size_t size;
uint8_t buf[3 * LZMA_IN_REQUIRED];
} temp;
};
@@ -320,7 +322,7 @@ static inline bool dict_has_space(const
* still empty. This special case is needed for single-call decoding to
* avoid writing a '\0' to the end of the destination buffer.
*/
-static inline uint32_t dict_get(const struct dictionary *dict, uint32_t dist)
+static inline uint32_t dict_get(const struct dictionary *dict, size_t dist)
{
size_t offset = dict->pos - dist - 1;
@@ -346,10 +348,10 @@ static inline void dict_put(struct dicti
* invalid, false is returned. On success, true is returned and *len is
* updated to indicate how many bytes were left to be repeated.
*/
-static bool dict_repeat(struct dictionary *dict, uint32_t *len, uint32_t dist)
+static bool dict_repeat(struct dictionary *dict, size_t *len, size_t dist)
{
size_t back;
- uint32_t left;
+ size_t left;
if (dist >= dict->full || dist >= dict->size)
return false;
@@ -375,7 +377,7 @@ static bool dict_repeat(struct dictionar
/* Copy uncompressed data as is from input to dictionary and output buffers. */
static void dict_uncompressed(struct dictionary *dict, struct xz_buf *b,
- uint32_t *left)
+ size_t *left)
{
size_t copy_size;
@@ -433,7 +435,7 @@ static void dict_uncompressed(struct dic
* enough space in b->out. This is guaranteed because caller uses dict_limit()
* before decoding data into the dictionary.
*/
-static uint32_t dict_flush(struct dictionary *dict, struct xz_buf *b)
+static size_t dict_flush(struct dictionary *dict, struct xz_buf *b)
{
size_t copy_size = dict->pos - dict->start;
@@ -878,7 +880,7 @@ static bool lzma_props(struct xz_dec_lzm
static bool lzma2_lzma(struct xz_dec_lzma2 *s, struct xz_buf *b)
{
size_t in_avail;
- uint32_t tmp;
+ size_t tmp;
in_avail = b->in_size - b->in_pos;
if (s->temp.size > 0 || s->lzma2.compressed == 0) {
@@ -1046,25 +1048,23 @@ enum xz_ret xz_dec_lzma2_run(struct xz_d
case SEQ_UNCOMPRESSED_1:
s->lzma2.uncompressed
- += (uint32_t)b->in[b->in_pos++] << 8;
+ += (size_t)b->in[b->in_pos++] << 8;
s->lzma2.sequence = SEQ_UNCOMPRESSED_2;
break;
case SEQ_UNCOMPRESSED_2:
s->lzma2.uncompressed
- += (uint32_t)b->in[b->in_pos++] + 1;
+ += (size_t)b->in[b->in_pos++] + 1;
s->lzma2.sequence = SEQ_COMPRESSED_0;
break;
case SEQ_COMPRESSED_0:
- s->lzma2.compressed
- = (uint32_t)b->in[b->in_pos++] << 8;
+ s->lzma2.compressed = (size_t)b->in[b->in_pos++] << 8;
s->lzma2.sequence = SEQ_COMPRESSED_1;
break;
case SEQ_COMPRESSED_1:
- s->lzma2.compressed
- += (uint32_t)b->in[b->in_pos++] + 1;
+ s->lzma2.compressed += (size_t)b->in[b->in_pos++] + 1;
s->lzma2.sequence = s->lzma2.next_sequence;
break;
--- a/lib/xz/xz_lzma2.h~lib-xz-use-size_t-instead-of-uint32_t-in-a-few-places
+++ a/lib/xz/xz_lzma2.h
@@ -143,7 +143,7 @@ static inline bool lzma_state_is_literal
* Get the index of the appropriate probability array for decoding
* the distance slot.
*/
-static inline uint32_t lzma_get_dist_state(uint32_t len)
+static inline size_t lzma_get_dist_state(size_t len)
{
return len < DIST_STATES + MATCH_LEN_MIN
? len - MATCH_LEN_MIN : DIST_STATES - 1;
_
Patches currently in -mm which might be from lasse.collin@tukaani.org are
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2026-08-13 22:42 [merged mm-nonmm-stable] lib-xz-use-size_t-instead-of-uint32_t-in-a-few-places.patch removed from -mm tree Andrew Morton
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