The patch titled
Subject: lib/zlib: DFLTCC not writing header bits when avail_out == 0
has been added to the -mm mm-nonmm-unstable branch. Its filename is
lib-zlib-dfltcc-not-writing-header-bits-when-avail_out-==-0.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-zlib-dfltcc-not-writing-header-bits-when-avail_out-==-0.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Mikhail Zaslonko <zaslonko@xxxxxxxxxxxxx>
Subject: lib/zlib: DFLTCC not writing header bits when avail_out == 0
Date: Thu, 26 Jan 2023 14:14:25 +0100
This commit is based on:
https://github.com/zlib-ng/zlib-ng/commit/ce409c6
Link: https://lkml.kernel.org/r/20230126131428.1222214-6-zaslonko@xxxxxxxxxxxxx
Signed-off-by: Mikhail Zaslonko <zaslonko@xxxxxxxxxxxxx>
Acked-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/zlib_dfltcc/dfltcc_deflate.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
--- a/lib/zlib_dfltcc/dfltcc_deflate.c~lib-zlib-dfltcc-not-writing-header-bits-when-avail_out-==-0
+++ a/lib/zlib_dfltcc/dfltcc_deflate.c
@@ -170,13 +170,18 @@ again:
param->bcf = 0;
dfltcc_state->block_threshold =
strm->total_in + dfltcc_state->block_size;
- if (strm->avail_out == 0) {
- *result = need_more;
- return 1;
- }
}
}
+ /* No space for compressed data. If we proceed, dfltcc_cmpr() will return
+ * DFLTCC_CC_OP1_TOO_SHORT without buffering header bits, but we will still
+ * set BCF=1, which is wrong. Avoid complications and return early.
+ */
+ if (strm->avail_out == 0) {
+ *result = need_more;
+ return 1;
+ }
+
/* The caller gave us too much data. Pass only one block worth of
* uncompressed data to DFLTCC and mask the rest, so that on the next
* iteration we start a new block.
_
Patches currently in -mm which might be from zaslonko@xxxxxxxxxxxxx are
lib-zlib-adjust-offset-calculation-for-dfltcc_state.patch
lib-zlib-implement-switching-between-dfltcc-and-software.patch
lib-zlib-fix-dfltcc-not-flushing-eobs-when-creating-raw-streams.patch
lib-zlib-fix-dfltcc-ignoring-flush-modes-when-avail_in-==-0.patch
lib-zlib-dfltcc-not-writing-header-bits-when-avail_out-==-0.patch
lib-zlib-split-deflate-and-inflate-states-for-dfltcc.patch
lib-zlib-dfltcc-support-inflate-with-small-window.patch
lib-zlib-dfltcc-always-switch-to-software-inflate-for-z_packet_flush-option.patch
