kernel/linux.git/lib/zlib_inflate, branch v5.4.107

lib/zlib: remove outdated and incorrect pre-increment optimization

2020-06-24T15:50:39+00:00

[ Upstream commit acaab7335bd6f0c0b54ce3a00bd7f18222ce0f5f ] The zlib inflate code has an old micro-optimization based on the assumption that for pre-increment memory accesses, the compiler will generate code that fits better into the processor's pipeline than what would be generated for post-increment memory accesses. This optimization was already removed in upstream zlib in 2016: https://github.com/madler/zlib/commit/9aaec95e8211 This optimization causes UB according to C99, which says in section 6.5.6 "Additive operators": "If both the pointer operand and the result point to elements of the same array object, or one past the last element of the array object, the evaluation shall not produce an overflow; otherwise, the behavior is undefined". This UB is not only a theoretical concern, but can also cause trouble for future work on compiler-based sanitizers. According to the zlib commit, this optimization also is not optimal anymore with modern compilers. Replace uses of OFF, PUP and UP_UNALIGNED with their definitions in the POSTINC case, and remove the macro definitions, just like in the upstream patch. Signed-off-by: Jann Horn Signed-off-by: Andrew Morton Cc: Mikhail Zaslonko Link: http://lkml.kernel.org/r/20200507123112.252723-1-jannh@google.com Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

lib/zlib_inflate/inflate.c: remove fall through warnings

2018-10-31T15:54:13+00:00

This patch remove all following fall through warnings by adding /* fall through */ markers. Note that we cannot add "__attribute__ ((fallthrough));" due to it is GCC7 only arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:384:25: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:391:25: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:393:16: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:430:25: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:556:25: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:595:25: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:602:25: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:627:25: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:646:25: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:696:25: warning: this statement may fall through [-Wimplicit-fallthrough=] It is easy to see that thoses fall through are needed since in each case state->mode are set to the case value just below. Link: http://lkml.kernel.org/r/1536215920-19955-1-git-send-email-clabbe@baylibre.com Signed-off-by: Corentin Labbe Cc: David Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/zlib_inflate/inftrees.c: fix potential buffer overflow

2017-05-09T00:15:12+00:00

smatch says: WARNING: please, no spaces at the start of a line #30: FILE: lib/zlib_inflate/inftrees.c:112: + for (min = 1; min < MAXBITS; min++)$ total: 0 errors, 1 warnings, 8 lines checked NOTE: For some of the reported defects, checkpatch may be able to mechanically convert to the typical style using --fix or --fix-inplace. ./patches/zlib-inflate-fix-potential-buffer-overflow.patch has style problems, please review. NOTE: If any of the errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

zlib: clean up some dead code

2014-08-07T01:01:24+00:00

Cleanup unused `if 0'-ed functions, which have been dead since 2006 (commits 87c2ce3b9305 ("lib/zlib*: cleanups") by Adrian Bunk and 4f3865fb57a0 ("zlib_inflate: Upgrade library code to a recent version") by Richard Purdie): - zlib_deflateSetDictionary - zlib_deflateParams - zlib_deflateCopy - zlib_inflateSync - zlib_syncsearch - zlib_inflateSetDictionary - zlib_inflatePrime Signed-off-by: Sergey Senozhatsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

inflate_fast: sout is already a short so ptr arith was off by one.

2010-03-12T23:52:44+00:00

inflate_fast() can do either POST INC or PRE INC on its pointers walking the memory to decompress. Default is PRE INC. The sout pointer offset was miscalculated in one case as the calculation assumed sout was a char * This breaks inflate_fast() iff configured to do POST INC. Signed-off-by: Joakim Tjernlund Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

zlib: make new optimized inflate endian independent

2010-03-12T23:52:44+00:00

Commit 6846ee5ca68d81e6baccf0d56221d7a00c1be18b ("zlib: Fix build of powerpc boot wrapper") made the new optimized inflate only available on arch's that define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS. This patch will again enable the optimization for all arch's by defining our own endian independent version of unaligned access. As an added bonus, arch's that define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS do a plain load instead. Signed-off-by: Joakim Tjernlund Cc: Anton Blanchard Cc: Benjamin Herrenschmidt Cc: David Woodhouse Cc: Kumar Gala Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

zlib: Fix build of powerpc boot wrapper

2010-01-14T00:13:39+00:00

Commit ac4c2a3bbe5db5fc570b1d0ee1e474db7cb22585 broke the build of all powerpc boot wrappers. It attempts to add an include of autoconf.h but used the wrong path for it. It also adds -D__KERNEL__ to our boot wrapper, both things that we pretty much didn't do on purpose so far. We want our boot wrapper to remain independent enough of the kernel for various reasons, one of them being that you can "wrap" an existing kernel at distro install time which allows to ship one kernel image and a set of boot wrappers for different platforms, the wrappers don't have to be built out of the same kernel build tree. It's also incorrect to do what the patch does in our boot environment since we may not have a proper alignment exception handler which means we may not be able to fixup the few cases where an unaligned access will need SW emulation (depends on the core variant, could be when crossing page or segment boundaries for example). This patch fixes it by putting the old code back in and using the new "fancy" variant only when CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set, which happens not to be set on powerpc since we don't include autoconf.h. It also reverts the changes to our boot wrapper Makefile. This means that x86 should, afaik, keep the optimisations since its boot wrapper does include autoconf.h and define __KERNEL__ (though I doubt they make that much different outside of slow embedded processors). Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Linus Torvalds

zlib: optimize inffast when copying direct from output

2010-01-11T17:34:04+00:00

JFFS2 uses lesser compression ratio and inflate always ends up in "copy direct from output" case. This patch tries to optimize the direct copy procedure. Uses get_unaligned() but only in one place. The copy loop just above this one can also use this optimization, but I havn't done so as I have not tested if it is a win there too. On my MPC8321 this is about 17% faster on my JFFS2 root FS than the original. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Joakim Tjernlund Cc: Roel Kluin Cc: Richard Purdie Cc: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds