This reverts commit 310afefe71 as the LTO
feature causes merge issues with 5.8-rc1. So remove it for now and
allow the developer to add the latest version of the patches later on.
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I4f30d8544545860dd1a70bd18a63b9a1673c6c6a
This reverts commit c4fa71e251 as the LTO
feature causes merge issues with 5.8-rc1. So remove it for now and
allow the developer to add the latest version of the patches later on.
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Id688d5e1e8b69b13aeb49da2716bfe45415e7c39
This reverts commit 2d939f16c3 as the LTO
feature causes merge issues with 5.8-rc1. So remove it for now and
allow the developer to add the latest version of the patches later on.
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I36ab73538f0ea727b82b52edb2a3c049d440aaed
Makefile.modpost was split to Makefile.modfinal in 5.4. This file
doesn't include include/config/auto.conf, which breaks checking
for kernel configuration. This change adds the missing include and
cleans up the LTO build rule.
Bug: 145296861
Fixes: 310afefe71 ("ANDROID: kbuild: add support for Clang LTO")
Change-Id: I3e6f676e841eed730ce8cccdfbd312f63660c293
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
With CONFIG_LTO_CLANG enabled, LLVM IR won't be compiled into object
files until modpost_link. This change postpones calls to recordmcount
until after this step.
In order to exclude ftrace_process_locs from inspection, we add a new
code section .text..ftrace, which we tell recordmcount to ignore, and
a __norecordmcount attribute for moving functions to this section.
Bug: 145210207
Change-Id: Ib77f7c431fce54243c46d584b55761ed2342965c
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
This change adds the configuration option CONFIG_LTO_CLANG, and
build system support for Clang's Link Time Optimization (LTO). In
preparation for LTO support with other compilers, potentially common
parts of the changes are gated behind CONFIG_LTO instead.
With -flto, instead of object files, Clang produces LLVM bitcode,
which is compiled into a native object at link time, allowing the
final binary to be optimized globally. For more details, see:
https://llvm.org/docs/LinkTimeOptimization.html
While the kernel normally uses GNU ld for linking, LLVM supports LTO
only with LLD or GNU gold linkers. This change assumes LLD is used.
Bug: 145210207
Change-Id: If1164ff33d073358ee7d4bba84cbb06c349c4a88
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Makefile.lib is included by Makefile.modfinal as well as Makefile.build.
Move modkern_cflags to Makefile.lib in order to simplify cmd_cc_o_c
in Makefile.modfinal. Move modkern_cflags as well for consistency.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
I think splitting the modpost and linking modules into separate
Makefiles will be useful especially when more complex build steps
come in. The main motivation of this commit is to integrate the
proposed klp-convert feature cleanly.
I moved the logging 'Building modules, stage 2.' to Makefile.modpost
to avoid the code duplication although I do not know whether or not
this message is needed in the first place.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
