[v3,2/7] xz: fix XZ_DYNALLOC to avoid useless memory reallocations

Commit Message

Jan Beulich March 3, 2022, 10:05 a.m. UTC

From: Lasse Collin <[e-mail]>

s->dict.allocated was initialized to 0 but never set after a successful
allocation, thus the code always thought that the dictionary buffer has
to be reallocated.

Link: http://lkml.kernel.org/r/[e-mail]
Reported-by: Yu Sun <[e-mail]>
Signed-off-by: Lasse Collin <[e-mail]>
Acked-by: Daniel Walker <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>
[Linux commit: 8e20ba2e53fc6198cbfbcc700e9f884157052a8d]
Signed-off-by: Jan Beulich <[e-mail]>
Reviewed-by: Luca Fancellu <[e-mail]>
---
v3: Retain all Linux side S-o-b, as per 5e326b61693c.

Patch

--- a/xen/common/xz/dec_lzma2.c
+++ b/xen/common/xz/dec_lzma2.c
@@ -1146,6 +1146,7 @@  XZ_EXTERN enum xz_ret __init xz_dec_lzma
 
 		if (DEC_IS_DYNALLOC(s->dict.mode)) {
 			if (s->dict.allocated < s->dict.size) {
+				s->dict.allocated = s->dict.size;
 				large_free(s->dict.buf);
 				s->dict.buf = large_malloc(s->dict.size);
 				if (s->dict.buf == NULL) {