linux-stable.git/tools/objtool/Makefile, branch v4.19.321

tools: Factor HOSTCC, HOSTLD, HOSTAR definitions

2021-01-30T12:32:13+00:00

commit c8a950d0d3b926a02c7b2e713850d38217cec3d1 upstream.

Several Makefiles in tools/ need to define the host toolchain variables.
Move their definition to tools/scripts/Makefile.include

Signed-off-by: Jean-Philippe Brucker 
Signed-off-by: Andrii Nakryiko 
Acked-by: Jiri Olsa 
Acked-by: Rafael J. Wysocki 
Link: https://lore.kernel.org/bpf/20201110164310.2600671-2-jean-philippe@linaro.org
Cc: Alistair Delva 
Signed-off-by: Greg Kroah-Hartman

kbuild: support LLVM=1 to switch the default tools to Clang/LLVM

2020-09-26T16:01:32+00:00

commit a0d1c951ef08ed24f35129267e3595d86f57f5d3 upstream.

As Documentation/kbuild/llvm.rst implies, building the kernel with a
full set of LLVM tools gets very verbose and unwieldy.

Provide a single switch LLVM=1 to use Clang and LLVM tools instead
of GCC and Binutils. You can pass it from the command line or as an
environment variable.

Please note LLVM=1 does not turn on the integrated assembler. You need
to pass LLVM_IAS=1 to use it. When the upstream kernel is ready for the
integrated assembler, I think we can make it default.

We discussed what we need, and we agreed to go with a simple boolean
flag that switches both target and host tools:

  https://lkml.org/lkml/2020/3/28/494
  https://lkml.org/lkml/2020/4/3/43

Some items discussed, but not adopted:

- LLVM_DIR

  When multiple versions of LLVM are installed, I just thought supporting
  LLVM_DIR=/path/to/my/llvm/bin/ might be useful.

  CC      = $(LLVM_DIR)clang
  LD      = $(LLVM_DIR)ld.lld
    ...

  However, we can handle this by modifying PATH. So, we decided to not do
  this.

- LLVM_SUFFIX

  Some distributions (e.g. Debian) package specific versions of LLVM with
  naming conventions that use the version as a suffix.

  CC      = clang$(LLVM_SUFFIX)
  LD      = ld.lld(LLVM_SUFFIX)
    ...

  will allow a user to pass LLVM_SUFFIX=-11 to use clang-11 etc.,
  but the suffixed versions in /usr/bin/ are symlinks to binaries in
  /usr/lib/llvm-#/bin/, so this can also be handled by PATH.

Signed-off-by: Masahiro Yamada 
Reviewed-by: Nathan Chancellor 
Tested-by: Nathan Chancellor  # build
Tested-by: Nick Desaulniers 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Nick Desaulniers 
[nd: conflict in exported vars list from not backporting commit
 e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
[nd: hunk against Documentation/kbuild/kbuild.rst dropped due to not backporting
 commit cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to *.rst")]
Signed-off-by: Greg Kroah-Hartman

objtool: Clobber user CFLAGS variable

2019-10-01T06:26:07+00:00

commit f73b3cc39c84220e6dccd463b5c8279b03514646 upstream.

If the build user has the CFLAGS variable set in their environment,
objtool blindly appends to it, which can cause unexpected behavior.

Clobber CFLAGS to ensure consistent objtool compilation behavior.

Reported-by: Valdis Kletnieks 
Tested-by: Valdis Kletnieks 
Signed-off-by: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: https://lkml.kernel.org/r/83a276df209962e6058fcb6c615eef9d401c21bc.1567121311.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar 
CC: Nathan Chancellor 
Signed-off-by: Greg Kroah-Hartman

objtool: Allow AR to be overridden with HOSTAR

2019-05-25T16:23:33+00:00

commit 8ea58f1e8b11cca3087b294779bf5959bf89cc10 upstream.

Currently, this Makefile hardcodes GNU ar, meaning that if it is not
available, there is no way to supply a different one and the build will
fail.

  $ make AR=llvm-ar CC=clang LD=ld.lld HOSTAR=llvm-ar HOSTCC=clang \
         HOSTLD=ld.lld HOSTLDFLAGS=-fuse-ld=lld defconfig modules_prepare
  ...
    AR       /out/tools/objtool/libsubcmd.a
  /bin/sh: 1: ar: not found
  ...

Follow the logic of HOST{CC,LD} and allow the user to specify a
different ar tool via HOSTAR (which is used elsewhere in other
tools/ Makefiles).

Signed-off-by: Nathan Chancellor 
Signed-off-by: Josh Poimboeuf 
Reviewed-by: Nick Desaulniers 
Reviewed-by: Mukesh Ojha 
Cc: 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/80822a9353926c38fd7a152991c6292491a9d0e8.1558028966.git.jpoimboe@redhat.com
Link: https://github.com/ClangBuiltLinux/linux/issues/481
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

objtool: Query pkg-config for libelf location

2019-04-03T04:26:28+00:00

commit 056d28d135bca0b1d0908990338e00e9dadaf057 upstream.

If it is not in the default location, compilation fails at several points.

Signed-off-by: Rolf Eike Beer 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/91a25e992566a7968fedc89ec80e7f4c83ad0548.1553622500.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman

kbuild: Rename HOSTLDFLAGS to KBUILD_HOSTLDFLAGS

2018-07-17T16:18:05+00:00

In preparation for enabling command line LDFLAGS, re-name HOSTLDFLAGS
to KBUILD_HOSTLDFLAGS as the internal use only flags. This should not
have any visible effects.

Signed-off-by: Laura Abbott 
Signed-off-by: Masahiro Yamada

kbuild: Rename HOSTCFLAGS to KBUILD_HOSTCFLAGS

2018-07-17T16:18:05+00:00

In preparation for enabling command line CFLAGS, re-name HOSTCFLAGS to
KBUILD_HOSTCFLAGS as the internal use only flags. This should not have
any visible effects.

Signed-off-by: Laura Abbott 
Signed-off-by: Masahiro Yamada

objtool: Support HOSTCFLAGS and HOSTLDFLAGS

2018-04-17T05:59:42+00:00

It may be useful to compile host programs with different flags (e.g.
hardening). Ensure that objtool picks up the appropriate flags.

Signed-off-by: Laura Abbott 
Signed-off-by: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Masahiro Yamada 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/05a360681176f1423cb2fde8faae3a0a0261afc5.1523560825.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar

Kbuild: fix # escaping in .cmd files for future Make

2018-04-10T15:03:02+00:00

I tried building using a freshly built Make (4.2.1-69-g8a731d1), but
already the objtool build broke with

orc_dump.c: In function ‘orc_dump’:
orc_dump.c:106:2: error: ‘elf_getshnum’ is deprecated [-Werror=deprecated-declarations]
  if (elf_getshdrnum(elf, &nr_sections)) {

Turns out that with that new Make, the backslash was not removed, so cpp
didn't see a #include directive, grep found nothing, and
-DLIBELF_USE_DEPRECATED was wrongly put in CFLAGS.

Now, that new Make behaviour is documented in their NEWS file:

  * WARNING: Backward-incompatibility!
    Number signs (#) appearing inside a macro reference or function invocation
    no longer introduce comments and should not be escaped with backslashes:
    thus a call such as:
      foo := $(shell echo '#')
    is legal.  Previously the number sign needed to be escaped, for example:
      foo := $(shell echo '\#')
    Now this latter will resolve to "\#".  If you want to write makefiles
    portable to both versions, assign the number sign to a variable:
      C := \#
      foo := $(shell echo '$C')
    This was claimed to be fixed in 3.81, but wasn't, for some reason.
    To detect this change search for 'nocomment' in the .FEATURES variable.

This also fixes up the two make-cmd instances to replace # with $(pound)
rather than with \#. There might very well be other places that need
similar fixup in preparation for whatever future Make release contains
the above change, but at least this builds an x86_64 defconfig with the
new make.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=197847
Cc: Randy Dunlap 
Signed-off-by: Rasmus Villemoes 
Signed-off-by: Masahiro Yamada

tools/objtool/Makefile: don't assume sync-check.sh is executable

2018-01-13T18:42:48+00:00

patch(1) loses the x bit.  So if a user follows our patching
instructions in Documentation/admin-guide/README.rst, their kernel will
not compile.

Fixes: 3bd51c5a371de ("objtool: Move kernel headers/code sync check to a script")
Reported-by: Nicolas Bock 
Reported-by Joakim Tjernlund 
Cc: Ingo Molnar 
Cc: Josh Poimboeuf 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds