The inflate state machine in zlib uses switch/case fall-through's
extensively, as it sometimes advances the state, and lets the
conveniently placed next case statement handle the new state already.
The pattern here is:
		state->mode = LEN;
	case LEN:

Annotate those occasions with the "fallthrough;" macro, to let compilers
know this is fine when using -Wimplicit-fallthrough.

This mimics the upstream commit 76f70abbc73f:
Author:  Mark Adler <madler@alumni.caltech.edu>
Date:    Sun Mar 27 00:12:38 2022 -0700
Subject: Add fallthrough comments for gcc.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Link: https://github.com/madler/zlib/commit/76f70abbc73f
Reviewed-by: Tom Rini <trini@konsulko.com>

Mark the gunzip code as needed by relocation. This is used to decompress
the next-phase image.

Signed-off-by: Simon Glass <sjg@chromium.org>

Commit 340fdf1303dc ("zlib: Port fix for CVE-2016-9841 to U-Boot")
brings a big performance regression in inflate_fast(), which leads
to watchdog timer reset on powerpc 8xx.

It looks like that commit does more than what it describe, it
especially removed an important optimisation that was doing copies
using halfwords instead of bytes. That unexpected change multiplied
by almost 4 the time spent in inflate_fast() and increased by 40%
the overall time needed to uncompress linux kernel image.

So partially revert that commit but keep post incrementation as it
is the initial purpose of said commit.

[trini: Combine assorted patches in to this one, just restoring the
        performance commit]

Fixes: 340fdf1303dc ("zlib: Port fix for CVE-2016-9841 to U-Boot")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Tom Rini <trini@konsulko.com>

Drop all duplicate newlines. No functional change.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

Now that the release has happened, bring back the update to zlib.

This reverts commit bbacdd3ef7762fbdeab43ceea5205d1fd0f25bbd.

Signed-off-by: Tom Rini <trini@konsulko.com>

This series brings our zlib code more up to date. However, it drops an
important performance improvement that is required on some of our
supported platforms in order to boot Linux before the watchdog resets
the system. Furthermore, the "post increment" version of this
performance loop was not tested, so while we can fix it, it would then
require re-testing all platforms. At this point in time, we will revert
updating zlib (which has had a potential security issue since 2016) and
fix this in the v2024.10 release.

This reverts commit 4914263c9a14315390d3ccc4816cf3a94cfd156d, reversing
changes made to ef8ef5f77c9a998f76a48277a883af1645b54117.

Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Tom Rini <trini@konsulko.com>

Get rid of zlib version which is not correct because of U-Boot related
changes and various CVE backports.

The change in inspired by Linux kernel commit 4f3865fb57a0 ("[PATCH]
zlib_inflate: Upgrade library code to a recent version") which described
ZLIB_VERSION removal as

"This patch also removes ZLIB_VERSION as it no longer has a correct value.
We don't need version checks anyway as the kernel's module handling will
take care of that for us.  This removal is also more in keeping with the
zlib author's wishes (http://www.zlib.net/zlib_faq.html#faq24) and I've
added something to the zlib.h header to note its a modified version."

Author describes wish to follow this guidance at
https://www.zlib.net/zlib_faq.html#faq24:
"The license says that altered source versions must be "plainly marked". So
what exactly do I need to do to meet that requirement?

You need to change the ZLIB_VERSION and ZLIB_VERNUM #defines in zlib.h. In
particular, the final version number needs to be changed to f, and an
identification string should be appended to ZLIB_VERSION. Version numbers
x.x.x.f are reserved for modifications to zlib by others than the zlib
maintainers. For example, if the version of the base zlib you are altering
is 1.2.3.4, then in zlib.h you should change ZLIB_VERNUM to 0x123f, and
ZLIB_VERSION to something like 1.2.3.f-zachary-mods-v3. You can also update
the version strings in deflate.c and inftrees.c."

But U-Boot is not exact version that's why following the same style which
has been used by Linux kernel where ZLIB_VERSION is completely removed.

Signed-off-by: Michal Simek <michal.simek@amd.com>

The patch corresponds to zlib commit at
https://github.com/madler/zlib/commit/9aaec95e82117c1cb0f9624264c3618fc380cecb
which declares that it is fixing CVE-2016-9841.
Here is c&p description from zlib:
"Use post-increment only in inffast.c.

An old inffast.c optimization turns out to not be optimal anymore
with modern compilers, and furthermore was not compliant with the
C standard, for which decrementing a pointer before its allocated
memory is undefined. Per the recommendation of a security audit of
the zlib code by Trail of Bits and TrustInSoft, in support of the
Mozilla Foundation, this "optimization" was removed, in order to
avoid the possibility of undefined behavior."

Origin patch also updates the code when
INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR is present but this code is not
the part of U-Boot hence it is ignored.
Also do not deal with state->sane variable which requires other changes
which are also not the part of zlib.

Commit 92faa8b10918 ("zlib: handle overflow while calculating available
stream input size") is kept in inffast.c too not to break described case.

Signed-off-by: Michal Simek <michal.simek@amd.com>

There is no particular patch/description which described the reason for
this change but it was done as the part of zlib 1.2.3.5 release done by
zlib commit d004b047838a ("zlib 1.2.3.5"). It is preparation for followup
patch.

Signed-off-by: Michal Simek <michal.simek@amd.com>

There is no particular patch/description which described the reason for
this change but it was done as the part of zlib 1.2.3.5 release done by
zlib commit 639be997883d ("zlib 1.2.3.3") It is preparation for followup
patch.

Signed-off-by: Michal Simek <michal.simek@amd.com>