Adding upstream version 5.4.1.upstream/5.4.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 165 insertions, 0 deletions

diff --git a/src/liblzma/validate_map.sh b/src/liblzma/validate_map.sh
new file mode 100644
index 0000000..2bf6f8b
--- /dev/null
+++ b/src/liblzma/validate_map.sh
@@ -0,0 +1,165 @@
+#!/bin/sh
+
+###############################################################################
+#
+# Check liblzma_*.map for certain types of errors.
+#
+# liblzma_generic.map is for FreeBSD and Solaris and possibly others
+# except GNU/Linux.
+#
+# liblzma_linux.map is for GNU/Linux only. This and the matching extra code
+# in the .c files make liblzma >= 5.2.7 compatible with binaries that were
+# linked against ill-patched liblzma in RHEL/CentOS 7. By providing the
+# compatibility in official XZ Utils release will hopefully prevent people
+# from further copying the broken patch to other places when they want
+# compatibility with binaries linked on RHEL/CentOS 7. The long version
+# of the story:
+#
+#     RHEL/CentOS 7 shipped with 5.1.2alpha, including the threaded
+#     encoder that is behind #ifdef LZMA_UNSTABLE in the API headers.
+#     In 5.1.2alpha these symbols are under XZ_5.1.2alpha in liblzma.map.
+#     API/ABI compatibility tracking isn't done between development
+#     releases so newer releases didn't have XZ_5.1.2alpha anymore.
+#
+#     Later RHEL/CentOS 7 updated xz to 5.2.2 but they wanted to keep
+#     the exported symbols compatible with 5.1.2alpha. After checking
+#     the ABI changes it turned out that >= 5.2.0 ABI is backward
+#     compatible with the threaded encoder functions from 5.1.2alpha
+#     (but not vice versa as fixes and extensions to these functions
+#     were made between 5.1.2alpha and 5.2.0).
+#
+#     In RHEL/CentOS 7, XZ Utils 5.2.2 was patched with
+#     xz-5.2.2-compat-libs.patch to modify liblzma.map:
+#
+#       - XZ_5.1.2alpha was added with lzma_stream_encoder_mt and
+#         lzma_stream_encoder_mt_memusage. This matched XZ Utils 5.1.2alpha.
+#
+#       - XZ_5.2 was replaced with XZ_5.2.2. It is clear that this was
+#         an error; the intention was to keep using XZ_5.2 (XZ_5.2.2
+#         has never been used in XZ Utils). So XZ_5.2.2 lists all
+#         symbols that were listed under XZ_5.2 before the patch.
+#         lzma_stream_encoder_mt and _mt_memusage are included too so
+#         they are listed both here and under XZ_5.1.2alpha.
+#
+#     The patch didn't add any __asm__(".symver ...") lines to the .c
+#     files. Thus the resulting liblzma.so exports the threaded encoder
+#     functions under XZ_5.1.2alpha only. Listing the two functions
+#     also under XZ_5.2.2 in liblzma.map has no effect without
+#     matching .symver lines.
+#
+#     The lack of XZ_5.2 in RHEL/CentOS 7 means that binaries linked
+#     against unpatched XZ Utils 5.2.x won't run on RHEL/CentOS 7.
+#     This is unfortunate but this alone isn't too bad as the problem
+#     is contained within RHEL/CentOS 7 and doesn't affect users
+#     of other distributions. It could also be fixed internally in
+#     RHEL/CentOS 7.
+#
+#     The second problem is more serious: In XZ Utils 5.2.2 the API
+#     headers don't have #ifdef LZMA_UNSTABLE for obvious reasons.
+#     This is true in RHEL/CentOS 7 version too. Thus now programs
+#     using new APIs can be compiled without an extra #define. However,
+#     the programs end up depending on symbol version XZ_5.1.2alpha
+#     (and possibly also XZ_5.2.2) instead of XZ_5.2 as they would
+#     with an unpatched XZ Utils 5.2.2. This means that such binaries
+#     won't run on other distributions shipping XZ Utils >= 5.2.0 as
+#     they don't provide XZ_5.1.2alpha or XZ_5.2.2; they only provide
+#     XZ_5.2 (and XZ_5.0). (This includes RHEL/CentOS 8 as the patch
+#     luckily isn't included there anymore with XZ Utils 5.2.4.)
+#
+#     Binaries built by RHEL/CentOS 7 users get distributed and then
+#     people wonder why they don't run on some other distribution.
+#     Seems that people have found out about the patch and been copying
+#     it to some build scripts, seemingly curing the symptoms but
+#     actually spreading the illness further and outside RHEL/CentOS 7.
+#     Adding compatibility in an official XZ Utils release should work
+#     as a vaccine against this ill patch and stop it from spreading.
+#     The vaccine is kept GNU/Linux-only as other OSes should be immune
+#     (hopefully it hasn't spread via some build script to other OSes).
+#
+# Author: Lasse Collin
+#
+# This file has been put into the public domain.
+# You can do whatever you want with this file.
+#
+###############################################################################
+
+LC_ALL=C
+export LC_ALL
+
+STATUS=0
+
+cd "$(dirname "$0")"
+
+# Get the list of symbols that aren't defined in liblzma_generic.map.
+SYMS=$(sed -n 's/^extern LZMA_API([^)]*) \([a-z0-9_]*\)(.*$/\1;/p' \
+		api/lzma/*.h \
+	| sort \
+	| grep -Fve "$(sed '/[{}:*]/d;/^$/d;s/^	//' liblzma_generic.map)")
+
+# Check that there are no old alpha or beta versions listed.
+VER=$(cd ../.. && sh build-aux/version.sh)
+NAMES=
+case $VER in
+	*alpha | *beta)
+		NAMES=$(sed -n 's/^.*XZ_\([^ ]*\)\(alpha\|beta\) .*$/\1\2/p' \
+			liblzma_generic.map | grep -Fv "$VER")
+		;;
+esac
+
+# Check for duplicate lines. It can catch missing dependencies.
+DUPS=$(sort liblzma_generic.map | sed '/^$/d;/^global:$/d' | uniq -d)
+
+# Check that liblzma_linux.map is in sync with liblzma_generic.map.
+# The RHEL/CentOS 7 compatibility symbols are in a fixed location
+# so it makes it easy to remove them for comparison with liblzma_generic.map.
+#
+# NOTE: Putting XZ_5.2 before the compatibility symbols XZ_5.1.2alpha
+# and XZ_5.2.2 in liblzma_linux.map is important: If liblzma_linux.map is
+# incorrectly used without #define HAVE_SYMBOL_VERSIONS_LINUX, only the first
+# occurrence of each function name will be used from liblzma_linux.map;
+# the rest are ignored by the linker. Thus having XZ_5.2 before the
+# compatibility symbols means that @@XZ_5.2 will be used for the symbols
+# listed under XZ_5.2 {...} and the same function names later in
+# the file under XZ_5.1.2alpha {...} and XZ_5.2.2 {...} will be
+# ignored (@XZ_5.1.2alpha or @XZ_5.2.2 won't be added at all when
+# the #define HAVE_SYMBOL_VERSIONS_LINUX isn't used).
+IN_SYNC=
+if ! sed '109,123d' liblzma_linux.map \
+		| cmp -s - liblzma_generic.map; then
+	IN_SYNC=no
+fi
+
+# Print error messages if needed.
+if test -n "$SYMS$NAMES$DUPS$IN_SYNC"; then
+	echo
+	echo 'validate_map.sh found problems from liblzma_*.map:'
+	echo
+
+	if test -n "$SYMS"; then
+		echo 'liblzma_generic.map lacks the following symbols:'
+		echo "$SYMS"
+		echo
+	fi
+
+	if test -n "$NAMES"; then
+		echo 'Obsolete alpha or beta version names:'
+		echo "$NAMES"
+		echo
+	fi
+
+	if test -n "$DUPS"; then
+		echo 'Duplicate lines:'
+		echo "$DUPS"
+		echo
+	fi
+
+	if test -n "$IN_SYNC"; then
+		echo "liblzma_generic.map and liblzma_linux.map aren't in sync"
+		echo
+	fi
+
+	STATUS=1
+fi
+
+# Exit status is 1 if problems were found, 0 otherwise.
+exit "$STATUS"