Package: firefox
Version: 117.0-1
Hello,
I am working to get the Firefox build working with LTO on
unstable, i.e. with
DEB_BUILD_MAINT_OPTIONS=optimize=+lto
set in the environment. There are three main issues I encountered, which
are described and addressed below.
1. Webrender / glslopt crash
----begin build log excerpt----
[webrender 0.62.0] cargo:rerun-if-changed=res/brush_yuv_image.glsl
[webrender 0.62.0] cargo:rerun-if-changed=res/cs_conic_gradient.glsl
[webrender 0.62.0] cargo:rerun-if-changed=res/cs_clip_image.glsl
[webrender 0.62.0] Optimizing shader ShaderOptimizationInput { shader_name:
"cs_line_decoration", config: "", gl_version: Gl }
error: failed to run custom build command for `webrender v0.62.0
(/tmp/firefox-117.0/gfx/wr/webrender)`
Caused by:
process didn't exit successfully:
`/tmp/firefox-117.0/build-browser/release/build/webrender-503c370365efbdbf/build-script-build`
(signal: 11, SIGSEGV: invalid memory reference)
----end build log excerpt----
Webrender is invoking "glslopt" here, and the latter has a history of
crashing in multithreaded scenarios. This has supposedly been fixed long
ago, but LTO seems to draw out some unresolved aspect of the issue. I
have filed a bug report on this with the upstream:
https://github.com/jamienicol/glsl-optimizer/issues/9
Here are some historical references, for background:
https://bugzilla.mozilla.org/show_bug.cgi?id=1637148
https://bugzilla.redhat.com/show_bug.cgi?id=1883904
https://github.com/servo/servo/issues/27039
Since this crash does not occur in a non-LTO build, my workaround is
simply to remove LTO flags from the Rust part of the build, by adding
perl -pi -e 's/-flto(=\w+)?//g; s/-ffat-lto-objects//g' \
build-browser/toolkit/library/rust/backend.mk
to the end of the "stamps/configure-$(PRODUCT)::" rule in debian/rules.
2. --param flag syntax
This one had me confused at first:
----begin build log excerpt----
make[3]: Entering directory
'/tmp/firefox-117.0/build-browser/security/sandbox/linux'
security/sandbox/linux/libmozsandbox.so
rm -f libmozsandbox.so
/usr/bin/g++ -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fstack-protector-strong
-Wdate-time -D_FORTIFY_SOURCE=2 -fno-sized-deallocation -fno-aligned-new -O2
-ffile-prefix-map=/tmp/firefox-117.0=. -flto=auto -ffat-lto-objects
-fstack-protector-strong -fstack-clash-protection -Wformat
-Werror=format-security -fcf-protection -fno-exceptions -fPIC -fno-rtti
-ffunction-sections -fdata-sections -fno-exceptions -fno-math-errno -pthread
-pipe -gdwarf-4 -freorder-blocks -O2 -fomit-frame-pointer -funwind-tables
-shared -Wl,-z,defs -Wl,-h,libmozsandbox.so -o libmozsandbox.so safe_sprintf.o
icu_utf.o trap.o syscall_wrappers.o Unified_cpp_sandbox_linux0.o
Unified_cpp_sandbox_linux1.o Unified_cpp_sandbox_linux2.o
Unified_cpp_sandbox_linux3.o -lpthread -flto=auto -ffat-lto-objects
-Wl,-z,relro -Wl,--as-needed -Wl,--reduce-memory-overheads -Wl,--stats
-Wl,-z,pack-relative-relocs -Wl,-z,noexecstack -Wl,-z,text -Wl,-z,relro
-Wl,-z,nocopyreloc -Wl,-Bsymbolic-functions -Wl,--build-id=sha1
-fstack-protector-strong '--param lto-partitions=1'
-Wl,-rpath-link,/tmp/firefox-117.0/build-browser/dist/bin
-Wl,-rpath-link,/usr/lib -lplds4 -lplc4 -lnspr4 -lrt
g++: error: unrecognized command-line option '--param lto-partitions=1'; did
you mean '--param lto-partitions='?
make[3]: *** [/tmp/firefox-117.0/config/rules.mk:526: libmozsandbox.so] Error 1
make[3]: Leaving directory
'/tmp/firefox-117.0/build-browser/security/sandbox/linux'
make[2]: *** [/tmp/firefox-117.0/config/recurse.mk:72:
security/sandbox/linux/target] Error 2
make[2]: Leaving directory '/tmp/firefox-117.0/build-browser'
make[1]: *** [/tmp/firefox-117.0/config/recurse.mk:34: compile] Error 2
make[1]: Leaving directory '/tmp/firefox-117.0/build-browser'
make: *** [/tmp/firefox-117.0/config/rules.mk:361: default] Error 2
----end build log excerpt----
Note that the flag being passed in is '--param lto-partitions=1', as a
single string containing a space. This is incorrect syntax; it needs to
be passed in as '--param' + 'lto-partitions=1'.
Fixed by this source patch:
----begin patch----
--- a/security/sandbox/linux/moz.build
+++ b/security/sandbox/linux/moz.build
@@ -117,7 +117,7 @@ if CONFIG["CC_TYPE"] in ("clang", "gcc")
# forcing there to be only one partition.
for f in CONFIG["OS_CXXFLAGS"]:
if f.startswith("-flto") and CONFIG["CC_TYPE"] != "clang":
- LDFLAGS += ["--param lto-partitions=1"]
+ LDFLAGS += ["--param", "lto-partitions=1"]
DEFINES["NS_NO_XPCOM"] = True
DisableStlWrapping()
----end patch----
This should probably be pushed upstream.
3. dh_dwz unknown opcode error
----begin build log excerpt----
make[2]: Entering directory '/tmp/firefox-117.0'
dh_dwz -X libxul
dwz: debian/firefox/usr/lib/firefox/libmozavcodec.so: Unknown DWARF DW_OP_0
referenced from DIE at [325272]
dwz: debian/firefox/usr/lib/firefox/libmozavutil.so: Unknown DWARF DW_OP_0
referenced from DIE at [3f546]
dwz: debian/firefox/usr/lib/firefox/libmozavutil.so: Unknown DWARF DW_OP_0
referenced from DIE at [3f546]
dwz: debian/firefox/usr/lib/firefox/libmozsqlite3.so: DWARF compression not
beneficial - old size 1647652 new size 1661321
dwz: debian/firefox/usr/lib/firefox/libmozavcodec.so: Unknown DWARF DW_OP_0
referenced from DIE at [325272]
dwz: debian/firefox/usr/lib/firefox/libipcclientcerts.so: DWARF compression not
beneficial - old size 2613256 new size 2630714
dh_dwz: error: dwz
-mdebian/firefox/usr/lib/debug/.dwz/x86_64-linux-gnu/firefox.debug
-M/usr/lib/debug/.dwz/x86_64-linux-gnu/firefox.debug --
debian/firefox/usr/lib/firefox/crashreporter
debian/firefox/usr/lib/firefox/firefox debian/firefox/usr/lib/firefox/glxtest
debian/firefox/usr/lib/firefox/gmp-clearkey/0.1/libclearkey.so
debian/firefox/usr/lib/firefox/libipcclientcerts.so
debian/firefox/usr/lib/firefox/liblgpllibs.so
debian/firefox/usr/lib/firefox/libmozavcodec.so
debian/firefox/usr/lib/firefox/libmozavutil.so
debian/firefox/usr/lib/firefox/libmozgtk.so
debian/firefox/usr/lib/firefox/libmozsandbox.so
debian/firefox/usr/lib/firefox/libmozsqlite3.so
debian/firefox/usr/lib/firefox/libmozwayland.so
debian/firefox/usr/lib/firefox/minidump-analyzer
debian/firefox/usr/lib/firefox/pingsender
debian/firefox/usr/lib/firefox/plugin-container
debian/firefox/usr/lib/firefox/vaapitest returned exit code 1
dh_dwz: error: Aborting due to earlier error
make[2]: *** [debian/rules:321: override_dh_dwz] Error 25
make[2]: Leaving directory '/tmp/firefox-117.0'
make[1]: *** [debian/rules:340: install] Error 2
make[1]: Leaving directory '/tmp/firefox-117.0'
make: *** [debian/rules:340: binary] Error 2
dpkg-buildpackage: error: fakeroot debian/rules binary subprocess returned exit
status 2
----end build log excerpt----
Not sure why those two libraries are causing trouble, but I resolved it
by adding "-X libmozav" to the dh_dwz invocation.
With these three fixes, the Firefox build with LTO enabled completes
successfully.
--Daniel
--
Daniel Richard G. || sk...@iskunk.org
My ASCII-art .sig got a bad case of Times New Roman.
