linux-toradex.git/lib/zstd/common, branch v6.17-rc3

Merge tag 'zstd-linus-v6.15-rc1' of https://github.com/terrelln/linux

2025-03-27T04:35:28+00:00

Pull zstd updates from Nick Terrell:
 "Update zstd to the latest upstream release v1.5.7.

  The two major motivations for updating Zstandard are to keep the code
  up to date, and to expose API's needed by Intel for the QAT
  compression accelerator.

  Imported cleanly from the upstream tag v1.5.7-kernel, which is signed
  by upstream's signing key EF8FE99528B52FFD"

Link: https://github.com/facebook/zstd/releases/tag/v1.5.7
Link: https://github.com/facebook/zstd/releases/tag/v1.5.7-kernel
Link: https://keyserver.ubuntu.com/pks/lookup?search=EF8FE99528B52FFD&fingerprint=on&op=index

* tag 'zstd-linus-v6.15-rc1' of https://github.com/terrelln/linux:
  zstd: Import upstream v1.5.7

zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault

2025-03-21T07:38:43+00:00

Due to pending percpu improvements in -next, GCC9 and GCC10 are
crashing during the build with:

    lib/zstd/compress/huf_compress.c:1033:1: internal compiler error: Segmentation fault
     1033 | {
          | ^
    Please submit a full bug report,
    with preprocessed source if appropriate.
    See  for instructions.

The DYNAMIC_BMI2 feature is a known-challenging feature of
the ZSTD library, with an existing GCC quirk turning it off
for GCC versions below 4.8.

Increase the DYNAMIC_BMI2 version cutoff to GCC 11.0 - GCC 10.5
is the last version known to crash.

Reported-by: Michael Kelley 
Debugged-by: Ard Biesheuvel 
Signed-off-by: Ingo Molnar 
Cc: https://lore.kernel.org/r/SN6PR02MB415723FBCD79365E8D72CA5FD4D82@SN6PR02MB4157.namprd02.prod.outlook.com
Cc: Linus Torvalds

zstd: Import upstream v1.5.7

2025-03-13T20:25:58+00:00

In addition to keeping the kernel's copy of zstd up to date, this update
was requested by Intel to expose upstream's APIs that allow QAT to accelerate
the LZ match finding stage of Zstd.

This patch is imported from the upstream tag v1.5.7-kernel [0], which is signed
with upstream's signing key EF8FE99528B52FFD [1]. It was imported from upstream
using this command:

  export ZSTD=/path/to/repo/zstd/
  export LINUX=/path/to/repo/linux/
  cd "$ZSTD/contrib/linux-kernel"
  git checkout v1.5.7-kernel
  make import LINUX="$LINUX"

This patch has been tested on x86-64, and has been boot tested with
a zstd compressed kernel & initramfs on i386 and aarch64. I benchmarked
the patch on x86-64 with gcc-14.2.1 on an Intel i9-9900K by measruing the
performance of compressed filesystem reads and writes.

Component,  Level,  Size delta, C. time delta,  D. time delta
Btrfs    ,      1,      +0.00%,         -6.1%,          +1.4%
Btrfs    ,      3,      +0.00%,         -9.8%,          +3.0%
Btrfs    ,      5,      +0.00%,         +1.7%,          +1.4%
Btrfs    ,      7,      +0.00%,         -1.9%,          +2.7%
Btrfs    ,      9,      +0.00%,         -3.4%,          +3.7%
Btrfs    ,     15,      +0.00%,         -0.3%,          +3.6%
SquashFS ,      1,      +0.00%,           N/A,          +1.9%

The major changes that impact the kernel use cases for each version are:

v1.5.7: https://github.com/facebook/zstd/releases/tag/v1.5.7
* Add zstd_compress_sequences_and_literals() for use by Intel's QAT driver
  to implement Zstd compression acceleration in the kernel.
* Fix an underflow bug in 32-bit builds that can cause data corruption when
  processing more than 4GB of data with a single `ZSTD_CCtx` object, when an
  input crosses the 4GB boundry. I don't believe this impacts any current kernel
  use cases, because the `ZSTD_CCtx` is typically reconstructed between
  compressions.
* Levels 1-4 see 5-10% compression speed improvements for inputs smaller than
  128KB.

v1.5.6: https://github.com/facebook/zstd/releases/tag/v1.5.6
* Improved compression ratio for the highest compression levels. I don't expect
  these see much use however, due to their slow speeds.

v1.5.5: https://github.com/facebook/zstd/releases/tag/v1.5.5
* Fix a rare corruption bug that can trigger on levels 13 and above.
* Improve compression speed of levels 5-11 on incompressible data.

v1.5.4: https://github.com/facebook/zstd/releases/tag/v1.5.4
* Improve copmression speed of levels 5-11 on ARM.
* Improve dictionary compression speed.

Signed-off-by: Nick Terrell

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23+00:00

asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

zstd: Fix array-index-out-of-bounds UBSAN warning

2023-11-15T01:12:52+00:00

Zstd used an array of length 1 to mean a flexible array for C89
compatibility. Switch to a C99 flexible array to fix the UBSAN warning.

Tested locally by booting the kernel and writing to and reading from a
BtrFS filesystem with zstd compression enabled. I was unable to reproduce
the issue before the fix, however it is a trivial change.

Link: https://lkml.kernel.org/r/20231012213428.1390905-1-nickrterrell@gmail.com
Reported-by: syzbot+1f2eb3e8cd123ffce499@syzkaller.appspotmail.com
Reported-by: Eric Biggers 
Reported-by: Kees Cook 
Signed-off-by: Nick Terrell 
Reviewed-by: Kees Cook

add intptr_t

2023-06-10T00:44:13+00:00

Add signed intptr_t given that a) it is standard type and b) uintptr_t is
in tree.

Link: https://lkml.kernel.org/r/ed66b9e4-1fb7-45be-9bb9-d4bc291c691f@p183
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton

zstd: Fix definition of assert()

2023-03-06T23:54:54+00:00

assert(x) should emit a warning if x is false. WARN_ON(x) emits a
warning if x is true. Thus, assert(x) should be defined as WARN_ON(!x)
rather than WARN_ON(x).

Signed-off-by: Jonathan Neuschäfer 
Signed-off-by: Nick Terrell

zstd: import usptream v1.5.2

2022-10-24T19:12:32+00:00

Updates the kernel's zstd library to v1.5.2, the latest zstd release.
The upstream tag it is updated to is `v1.5.2-kernel`, which contains
several cherry-picked commits on top of the v1.5.2 release which are
required for the kernel update. I will create this tag once the PR is
ready to merge, until then reference the temporary upstream branch
`v1.5.2-kernel-cherrypicks`.

I plan to submit this patch as part of the v6.2 merge window.

I've done basic build testing & testing on x86-64, i386, and aarch64.
I'm merging these patches into my `zstd-next` branch, which is pulled
into `linux-next` for further testing.

I've benchmarked BtrFS with zstd compression on a x86-64 machine, and
saw these results. Decompression speed is a small win across the board.
The lower compression levels 1-4 see both compression speed and
compression ratio wins. The higher compression levels see a small
compression speed loss and about neutral ratio. I expect the lower
compression levels to be used much more heavily than the high
compression levels, so this should be a net win.

Level	CTime	DTime	Ratio
1	-2.95%	-1.1%	-0.7%
3	-3.5%	-1.2%	-0.5%
5	+3.7%	-1.0%	+0.0%
7	+3.2%	-0.9%	+0.0%
9	-4.3%	-0.8%	+0.1%

Signed-off-by: Nick Terrell

zstd: Move zstd-common module exports to zstd_common_module.c

2022-10-24T19:12:26+00:00

The zstd codebase is imported from the upstream zstd repo, and is over-written on
every update. Upstream keeps the kernel specific code separate from the main
library. So the module definition is moved into the zstd_common_module.c file.
This matches the pattern followed by the zstd-compress and zstd-decompress files.

I've done build and boot testing on x86-64, i386, and aarch64. I've
verified that zstd built both as modules and built-in build and boot.

Signed-off-by: Nick Terrell

zstd: Fixing mixed module-builtin objects

2022-10-02T18:52:58+00:00

With CONFIG_ZSTD_COMPRESS=m and CONFIG_ZSTD_DECOMPRESS=y we end up in
a situation when files from lib/zstd/common/ are compiled once to be
linked later for ZSTD_DECOMPRESS (build-in) and ZSTD_COMPRESS (module)
even though CFLAGS are different for builtins and modules.
So far somehow this was not a problem but enabling LLVM LTO exposes
the problem as:

ld.lld: error: linking module flags 'Code Model': IDs have conflicting values in 'lib/built-in.a(zstd_common.o at 5868)' and 'ld-temp.o'

This particular conflict is caused by KBUILD_CFLAGS=-mcmodel=medium vs.
KBUILD_CFLAGS_MODULE=-mcmodel=large , modules use the large model on
POWERPC as explained at
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/Makefile?h=v5.18-rc4#n127
but the current use of common files is wrong anyway.

This works around the issue by introducing a zstd_common module with
shared code.

Signed-off-by: Alexey Kardashevskiy 
Signed-off-by: Masahiro Yamada