Commit Graph

187 Commits

Author SHA1 Message Date
Masahiro Yamada 9f69a496f1 kbuild: split out *.mod out of {single,multi}-used-m rules
Currently, *.mod is created as a side-effect of obj-m.

Split out *.mod as a dedicated build rule, which allows to unify
the %.c -> %.o rule, and remove the single-used-m rule.

This also makes the incremental build of allmodconfig faster because
it saves $(NM) invocation when there is no change in the module.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-18 02:19:31 +09:00
Masahiro Yamada 60ae1b194b kbuild: remove the first line of *.mod files
The current format of *.mod is like this:

  line 1: directory path to the .ko file
  line 2: a list of objects linked into this module
  line 3: unresolved symbols (only when CONFIG_TRIM_UNUSED_KSYMS=y)

Now that *.mod and *.ko are created in the same directory, the line 1
provides no valuable information. It can be derived by replacing the
extension .mod with .ko. In fact, nobody uses the first line any more.

Cut down the first line.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-18 02:19:31 +09:00
Masahiro Yamada b7dca6dd1e kbuild: create *.mod with full directory path and remove MODVERDIR
While descending directories, Kbuild produces objects for modules,
but do not link final *.ko files; it is done in the modpost.

To keep track of modules, Kbuild creates a *.mod file in $(MODVERDIR)
for every module it is building. Some post-processing steps read the
necessary information from *.mod files. This avoids descending into
directories again. This mechanism was introduced in 2003 or so.

Later, commit 551559e13a ("kbuild: implement modules.order") added
modules.order. So, we can simply read it out to know all the modules
with directory paths. This is easier than parsing the first line of
*.mod files.

$(MODVERDIR) has a flat directory structure, that is, *.mod files
are named only with base names. This is based on the assumption that
the module name is unique across the tree. This assumption is really
fragile.

Stephen Rothwell reported a race condition caused by a module name
conflict:

  https://lkml.org/lkml/2019/5/13/991

In parallel building, two different threads could write to the same
$(MODVERDIR)/*.mod simultaneously.

Non-unique module names are the source of all kind of troubles, hence
commit 3a48a91901 ("kbuild: check uniqueness of module names")
introduced a new checker script.

However, it is still fragile in the build system point of view because
this race happens before scripts/modules-check.sh is invoked. If it
happens again, the modpost will emit unclear error messages.

To fix this issue completely, create *.mod with full directory path
so that two threads never attempt to write to the same file.

$(MODVERDIR) is no longer needed.

Since modules with directory paths are listed in modules.order, Kbuild
is still able to find *.mod files without additional descending.

I also killed cmd_secanalysis; scripts/mod/sumversion.c computes MD4 hash
for modules with MODULE_VERSION(). When CONFIG_DEBUG_SECTION_MISMATCH=y,
it occurs not only in the modpost stage, but also during directory
descending, where sumversion.c may parse stale *.mod files. It would emit
'No such file or directory' warning when an object consisting a module is
renamed, or when a single-obj module is turned into a multi-obj module or
vice versa.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
2019-07-18 02:19:31 +09:00
Masahiro Yamada e0e1b1ec39 kbuild: remove duplication from modules.order in sub-directories
Currently, only the top-level modules.order drops duplicated entries.

The modules.order files in sub-directories potentially contain
duplication. To list out the paths of all modules, I want to use
modules.order instead of parsing *.mod files in $(MODVERDIR).

To achieve this, I want to rip off duplication from modules.order
of external modules too.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17 22:39:27 +09:00
Masahiro Yamada 1bd9a46801 kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin}
Removing the 'kernel/' prefix will make our life easier because we can
simply do 'cat modules.order' to get all built modules with full paths.

Currently, we parse the first line of '*.mod' files in $(MODVERDIR).
Since we have duplicated functionality here, I plan to remove MODVERDIR
entirely.

In fact, modules.order is generated also for external modules in a
broken format. It adds the 'kernel/' prefix to the absolute path of
the module, like this:

  kernel//path/to/your/external/module/foo.ko

This is fine for now since modules.order is not used for external
modules. However, I want to sanitize the format everywhere towards
the goal of removing MODVERDIR.

We cannot change the format of installed module.{order,builtin}.
So, 'make modules_install' will add the 'kernel/' prefix while copying
them to $(MODLIB)/.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17 22:39:27 +09:00
Masahiro Yamada 7e13191879 kbuild: do not create empty modules.order in the prepare stage
Currently, $(objtree)/modules.order is touched in two places.

In the 'prepare0' rule, scripts/Makefile.build creates an empty
modules.order while processing 'obj=.'

In the 'modules' rule, the top-level Makefile overwrites it with
the correct list of modules.

While this might be a good side-effect that modules.order is made
empty every time (probably this is not intended functionality),
I personally do not like this behavior.

Create modules.order only when it is sensible to do so.

This avoids creating the following pointless files:

  scripts/basic/modules.order
  scripts/dtc/modules.order
  scripts/gcc-plugins/modules.order
  scripts/genksyms/modules.order
  scripts/mod/modules.order
  scripts/modules.order
  scripts/selinux/genheaders/modules.order
  scripts/selinux/mdp/modules.order
  scripts/selinux/modules.order

Going forward, $(objtree)/modules.order lists the modules that
was built in the last successful build.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17 22:39:27 +09:00
Masahiro Yamada 4bd01de8f2 kbuild: compile-test headers listed in header-test-m as well
It will be useful to control the header-test by a tristate option.

If CONFIG_FOO is a tristate option, you can write like this:

  header-test-$(CONFIG_FOO) += foo.h

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17 22:37:51 +09:00
Masahiro Yamada 051f278e9d kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree
Commit 25b146c5b8 ("kbuild: allow Kbuild to start from any directory")
deprecated KBUILD_SRCTREE.

It is only used in tools/testing/selftest/ to distinguish out-of-tree
build. Replace it with a new boolean flag, building_out_of_srctree.

I also replaced the conditional ($(srctree),.) because the next commit
will allow an absolute path to be used for $(srctree) even when building
in the source tree.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-11 00:05:09 +09:00
Masahiro Yamada c93a0368aa kbuild: do not create wrappers for header-test-y
header-test-y does not work with headers in sub-directories.

For example, you may want to write a Makefile, like this:

include/linux/Kbuild:

  header-test-y += mtd/nand.h

This entry will create a wrapper include/linux/mtd/nand.hdrtest.c
with the following content:

  #include "mtd/nand.h"

To make this work, we need to add $(srctree)/include/linux to the
header search path. It would be tedious to add ccflags-y.

Instead, we could change the *.hdrtest.c rule to wrap:

  #include "nand.h"

This works for in-tree build since #include "..." searches in the
relative path from the header with this directive. For O=... build,
we need to add $(srctree)/include/linux/mtd to the header search path,
which will be even more tedious.

After all, I thought it would be handier to compile headers directly
without creating wrappers.

I added a new build rule to compile %.h into %.h.s

The target is %.h.s instead of %.h.o because it is slightly faster.
Also, as for GCC, an empty assembly is smaller than an empty object.

I wrote the build rule:

  $(CC) $(c_flags) -S -o $@ -x c /dev/null -include $<

instead of:

  $(CC) $(c_flags) -S -o $@ -x c $<

Both work fine with GCC, but the latter is bad for Clang.

This comes down to the difference in the -Wunused-function policy.
GCC does not warn about unused 'static inline' functions at all.
Clang does not warn about the ones in included headers, but does
about the ones in the source. So, we should handle headers as
headers, not as source files.

In fact, this has been hidden since commit abb2ea7dfd ("compiler,
clang: suppress warning for unused static inline functions"), but we
should not rely on that.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Jani Nikula <jani.nikula@intel.com>
2019-07-09 10:10:27 +09:00
Jani Nikula e846f0dc57 kbuild: add support for ensuring headers are self-contained
Sometimes it's useful to be able to explicitly ensure certain headers
remain self-contained, i.e. that they are compilable as standalone
units, by including and/or forward declaring everything they depend on.

Add special target header-test-y where individual Makefiles can add
headers to be tested if CONFIG_HEADER_TEST is enabled. This will
generate a dummy C file per header that gets built as part of extra-y.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-15 19:57:02 +09:00
Linus Torvalds 2646719a48 Kbuild updates for v5.2
- allow users to invoke 'make' out of the source tree
 
 - refactor scripts/mkmakefile
 
 - deprecate KBUILD_SRC, which was used to track the source tree
   location for O= build.
 
 - fix recordmcount.pl in case objdump output is localized
 
 - turn unresolved symbols in external modules to errors from warnings
   by default; pass KBUILD_MODPOST_WARN=1 to get them back to warnings
 
 - generate modules.builtin.modinfo to collect .modinfo data from
   built-in modules
 
 - misc Makefile cleanups
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJc0upmAAoJED2LAQed4NsGreoP/jkKQojVdzTjM/nn/Xe9FrE9
 elQ59Wu/gW/q7jouN733WTJ2fRPAEVaGPw/CT/cCRWjNJjd6MM4voDKVxifZE+u4
 qz5XUGq4Mjozd0MJdU1LA1dIRJrEaPofOj7E0JEIerEdLPKpv4kjCCbbHOZwN2Kl
 YrpPFJkYspCRVG+txEWY8YaZeU/+OAdNckJnMkX8hnUwsNplAlPw4L/5Y12Uncuz
 7g/3T1f701pJhStoO4OPR/+Rivi0EX5AP7TZyv2/FOwTO+Oau5G1rF0j1BT0+ceg
 d+bApuaHLR4ocZ6GvWfACMYhH7ais0BUgAwi6HY/b78SGMmNB6xlD5biVqcklx6c
 mjrPNaj6WJEQIflZ3yr83tRNhTu7xXRKZkrGHHUjOGNsRULuD8RFrXtusl06A22S
 hA3vt2SF4FuLBabPw5yFkKNOTX+P5dG79BC1fWIQjglBGoYqWTRQNYoottr/7t2T
 Si+E6J2lAD0EDNuc/EFKWfrgONfatgcdgQuTibwCcE2KfYnMG/C+9DvxRV4lAQtn
 fYpap9gws+0AisbVx0m1W088NMFiwrMbN3n3KITGY/15XDmeySEA1QgPKFN8JHJd
 Do0duaMx8BHjkA5ms/Bf0AZd0tWUkWVdt0epwU2KafWNGK7VaPnhKxn5eQOGkWV+
 gT3J3XZc3b7OEOQ4XX3Z
 =zj9w
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - allow users to invoke 'make' out of the source tree

 - refactor scripts/mkmakefile

 - deprecate KBUILD_SRC, which was used to track the source tree
   location for O= build.

 - fix recordmcount.pl in case objdump output is localized

 - turn unresolved symbols in external modules to errors from warnings
   by default; pass KBUILD_MODPOST_WARN=1 to get them back to warnings

 - generate modules.builtin.modinfo to collect .modinfo data from
   built-in modules

 - misc Makefile cleanups

* tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (21 commits)
  .gitignore: add more all*.config patterns
  moduleparam: Save information about built-in modules in separate file
  Remove MODULE_ALIAS() calls that take undefined macro
  .gitignore: add leading and trailing slashes to generated directories
  scripts/tags.sh: fix direct execution of scripts/tags.sh
  scripts: override locale from environment when running recordmcount.pl
  samples: kobject: allow CONFIG_SAMPLE_KOBJECT to become y
  samples: seccomp: turn CONFIG_SAMPLE_SECCOMP into a bool option
  kbuild: move Documentation to vmlinux-alldirs
  kbuild: move samples/ to KBUILD_VMLINUX_OBJS
  modpost: make KBUILD_MODPOST_WARN also configurable for external modules
  kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build
  kbuild: remove unneeded dependency for include/config/kernel.release
  memory: squash drivers/memory/Makefile.asm-offsets
  kbuild: use $(srctree) instead of KBUILD_SRC to check out-of-tree build
  kbuild: mkmakefile: generate a simple wrapper of top Makefile
  kbuild: mkmakefile: do not check the generated Makefile marker
  kbuild: allow Kbuild to start from any directory
  kbuild: pass $(MAKECMDGOALS) to sub-make as is
  kbuild: fix warning "overriding recipe for target 'Makefile'"
  ...
2019-05-08 12:25:12 -07:00
Peter Zijlstra ea24213d80 objtool: Add UACCESS validation
It is important that UACCESS regions are as small as possible;
furthermore the UACCESS state is not scheduled, so doing anything that
might directly call into the scheduler will cause random code to be
ran with UACCESS enabled.

Teach objtool too track UACCESS state and warn about any CALL made
while UACCESS is enabled. This very much includes the __fentry__()
and __preempt_schedule() calls.

Note that exceptions _do_ save/restore the UACCESS state, and therefore
they can drive preemption. This also means that all exception handlers
must have an otherwise redundant UACCESS disable instruction;
therefore ignore this warning for !STT_FUNC code (exception handlers
are not normal functions).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-03 11:02:24 +02:00
Masahiro Yamada a9a49c2ad9 kbuild: use $(srctree) instead of KBUILD_SRC to check out-of-tree build
KBUILD_SRC was conventionally used for some different purposes:
 [1] To remember the source tree path
 [2] As a flag to check if sub-make is already done
 [3] As a flag to check if Kbuild runs out of tree

For [1], we do not need to remember it because the top Makefile
can compute it by $(realpath $(dir $(lastword $(MAKEFILE_LIST))))

[2] has been replaced with self-commenting 'sub_make_done'.

For [3], we can distinguish in-tree/out-of-tree by comparing
$(srctree) and '.'

This commit converts [3] to prepare for the KBUILD_SRC removal.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-04-02 23:28:04 +09:00
Joe Lawrence 1a49b2fd8f kbuild: strip whitespace in cmd_record_mcount findstring
CC_FLAGS_FTRACE may contain trailing whitespace that interferes with
findstring.

For example, commit 6977f95e63 ("powerpc: avoid -mno-sched-epilog on
GCC 4.9 and newer") introduced a change such that on my ppc64le box,
CC_FLAGS_FTRACE="-pg -mprofile-kernel ".  (Note the trailing space.)
When cmd_record_mcount is now invoked, findstring fails as the ftrace
flags were found at very end of _c_flags, without the trailing space.

  _c_flags=" ... -pg -mprofile-kernel"
  CC_FLAGS_FTRACE="-pg -mprofile-kernel "
                                       ^
    findstring is looking for this extra space

Remove the redundant whitespaces from CC_FLAGS_FTRACE in
cmd_record_mcount to avoid this problem.

[masahiro.yamada: This issue only happens in the released versions
of GNU Make. CC_FLAGS_FTRACE will not contain the trailing space if
you use the latest GNU Make, which contains commit b90fabc8d6f3
("* NEWS: Do not insert a space during '+=' if the value is empty.") ]

Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> (refactoring)
Fixes: 6977f95e63 ("powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer").
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-28 23:46:55 +09:00
Masahiro Yamada 898f5a009f kbuild: move archive command to scripts/Makefile.lib
scripts/Makefile.build and arch/s390/boot/Makefile use the same
command (thin archiving with symbol table creation).

Avoid the code duplication, and move it to scripts/Makefile.lib.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-14 02:39:10 +09:00
Masahiro Yamada 88110713ca kbuild: hardcode genksyms path and remove GENKSYMS variable
The genksyms source was integrated into the kernel tree in 2003.

I do not expect anybody still using the external /sbin/genksyms.
Kbuild does not need to provide the ability to override GENKSYMS.

Let's remove the GENKSYMS variable, and use the hardcoded path.

Since it occurred in the pre-git era, I attached the commit message
in case somebody is interested in the historical background.

  | Author: Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de>
  | Date:   Wed Feb 19 04:17:28 2003 -0600
  |
  | kbuild: [PATCH] put genksyms in scripts dir
  |
  | This puts genksyms into scripts/genksyms/.
  |
  | genksyms used to be maintained externally, though the only possible user
  | was the kernel build. Moving it into the kernel sources makes it easier to
  | keep it uptodate, like for example updating it to generate linker scripts
  | directly instead of postprocessing the generated header file fragments
  | with sed, as we do currently.
  |
  | Also, genksyms does not handle __typeof__, which needs to be fixed since
  | some of the exported symbol in the kernel are defined using __typeof__.
  |
  | (Rusty Russell/me)

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-02-27 21:41:26 +09:00
Masahiro Yamada 1d8001ef35 kbuild: generate modules.order only when CONFIG_MODULES=y
Do not generate pointless modules.order when the module support is
disabled.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-02-20 09:42:46 +09:00
Masahiro Yamada 1e88e415eb kbuild: Disable extra debugging info in .s output
Modern gcc adds view assignments, reset assertion checking in .loc
directives and a couple more additional debug markers, which clutters
the asm output unnecessarily:

For example:

  bsp_resume:
  .LFB3466:
          .loc 1 1868 1 is_stmt 1 view -0
          .cfi_startproc
          .loc 1 1869 2 view .LVU73
  # arch/x86/kernel/cpu/common.c:1869:    if (this_cpu->c_bsp_resume)
          .loc 1 1869 14 is_stmt 0 view .LVU74
          movq    this_cpu(%rip), %rax    # this_cpu, this_cpu
          movq    64(%rax), %rax  # this_cpu.94_1->c_bsp_resume, _2
  # arch/x86/kernel/cpu/common.c:1869:    if (this_cpu->c_bsp_resume)
          .loc 1 1869 5 view .LVU75
          testq   %rax, %rax      # _2
          je      .L8     #,
          .loc 1 1870 3 is_stmt 1 view .LVU76
          movq    $boot_cpu_data, %rdi    #,
          jmp     __x86_indirect_thunk_rax

or
        .loc 2 57 9 view .LVU478
        .loc 2 57 9 view .LVU479
        .loc 2 57 9 view .LVU480
        .loc 2 57 9 view .LVU481
  .LBB1385:
  .LBB1383:
  .LBB1379:
  .LBB1377:
  .LBB1375:
        .loc 2 57 9 view .LVU482
        .loc 2 57 9 view .LVU483
        movl	%edi, %edx	# cpu, cpu
  .LVL87:
        .loc 2 57 9 is_stmt 0 view .LVU484

That MOV in there is drowned in debugging information and latter makes
it hard to follow the asm. And that DWARF info is not really needed for
asm output staring.

Disable the debug information generation which clutters the asm output
unnecessarily:

  bsp_resume:
  # arch/x86/kernel/cpu/common.c:1869:    if (this_cpu->c_bsp_resume)
          movq    this_cpu(%rip), %rax    # this_cpu, this_cpu
          movq    64(%rax), %rax  # this_cpu.94_1->c_bsp_resume, _2
  # arch/x86/kernel/cpu/common.c:1869:    if (this_cpu->c_bsp_resume)
          testq   %rax, %rax      # _2
          je      .L8     #,
  # arch/x86/kernel/cpu/common.c:1870:            this_cpu->c_bsp_resume(&boot_cpu_data);
          movq    $boot_cpu_data, %rdi    #,
          jmp     __x86_indirect_thunk_rax
  .L8:
  # arch/x86/kernel/cpu/common.c:1871: }
          rep ret
          .size   bsp_resume, .-bsp_resume

  [ bp: write commit message. ]

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
2019-02-20 09:39:39 +09:00
Masahiro Yamada b79c6aa6a1 kbuild: remove unnecessary in-subshell execution
The commands surrounded by ( ) are executed in a subshell, but in
most cases, we do not need to spawn an extra subshell.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-01-28 09:11:17 +09:00
Masahiro Yamada afa974b771 kbuild: add real-prereqs shorthand for $(filter-out FORCE,$^)
In Kbuild, if_changed and friends must have FORCE as a prerequisite.

Hence, $(filter-out FORCE,$^) or $(filter-out $(PHONY),$^) is a common
idiom to get the names of all the prerequisites except phony targets.

Add real-prereqs as a shorthand.

Note:
We cannot replace $(filter %.o,$^) in cmd_link_multi-m because $^ may
include auto-generated dependencies from the .*.cmd file when a single
object module is changed into a multi object module. Refer to commit
69ea912fda ("kbuild: remove unneeded link_multi_deps"). I added some
comment to avoid accidental breakage.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Rob Herring <robh@kernel.org>
2019-01-28 09:11:17 +09:00
Masahiro Yamada dee9495303 kbuild: remove top-level built-in.a
The symbol table in the final archive is unneeded; the linker does not
require the symbol table after the --whole-archive option. Every object
file in the archive is included in the link anyway.

Pass thin archives from subdirectories directly to the linker, and
remove the final archiving step.

Fix up the document and comments as well.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
2019-01-28 09:11:17 +09:00
Linus Torvalds 668c35f69c Kbuild updates for v4.21
Kbuild core:
  - remove unneeded $(call cc-option,...) switches
  - consolidate Clang compiler flags into CLANG_FLAGS
  - announce the deprecation of SUBDIRS
  - fix single target build for external module
  - simplify the dependencies of 'prepare' stage targets
  - allow fixdep to directly write to .*.cmd files
  - simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS
  - change if_changed_rule to accept multi-line recipe
  - move .SECONDARY special target to scripts/Kbuild.include
  - remove redundant 'set -e'
  - improve parallel execution for CONFIG_HEADERS_CHECK
  - misc cleanups
 
 Treewide fixes and cleanups
  - set Clang flags correctly for PowerPC boot images
  - fix UML build error with CONFIG_GCC_PLUGINS
  - remove unneeded patterns from .gitignore files
  - refactor firmware/Makefile
  - remove unneeded rules for *offsets.s
  - avoid unneeded regeneration of intermediate .s files
  - clean up ./Kbuild
 
 Modpost:
  - remove unused -M, -K options
  - fix false positive warnings about section mismatch
  - use simple devtable lookup instead of linker magic
  - misc cleanups
 
 Coccinelle:
  - relax boolinit.cocci checks for overall consistency
  - fix warning messages of boolinit.cocci
 
 Other tools:
  - improve -dirty check of scripts/setlocalversion
  - add a tool to generate compile_commands.json from .*.cmd files
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJcJiVeAAoJED2LAQed4NsGXEMP/1fdkBfZGxYlxp4w1tEBeRKZ
 GInxxMfHiHZlu7nFPQ3k1mncczZjeLbnKcLaybnPmqBSfQe1F7tN0ux1sHtWkVfI
 DvqoKaHObZ3lEMEVxCHXQ2bKrN/j9nB2xSxzr4dvc9DscW8dwKElZuKVE7nHKdhl
 z70xsalxHGEGY6hptJrucbv8KTBOSleZ8Gaat79sEDkDSLCTjxXB3WcVMWqDT0M/
 IqN5QCwiPjZC3UCwuqq6+vnG1gyvDUORcbrVgHrBIKxLYAABYzugB5IlLpi8B31C
 ZUDmijSTandHd4SG5gw5uZoyYuK4YhZeI7g4yNyXSqnPurmcJxrGdpiuwRcE7xet
 5yB2uaNbAFO6Fbz4gUdDEvryA9IZEPPn1Z0Btfpp7UOxiWEqE61oHReCNdkiad94
 Oonl+ROZw5UOT3AZD3xCZTf9bTnQoCFccHTmnbaKqqSiDWxxLUXum7sNfnJ6GXEb
 fNQDuwuxtsPStaWoU93QNrGyl5e8jYTKFdphUCnZZ2/hE8ygoQ06PYmeBAk+UKfN
 UI2IqR8PHgmA97XJg+fHhbw6X4nQcPsg/usLqxGItAZNO2O4uXgaN24dOcHG74Bu
 2Dk/gQQB2sVB/Dxfmlaxvvj98MVg7IMtpusAT2bQ7miiSS3EqPFT8KQMZYLICWuZ
 u7QQe20yCho3ZULmsRwH
 =0PCt
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:
 "Kbuild core:
   - remove unneeded $(call cc-option,...) switches
   - consolidate Clang compiler flags into CLANG_FLAGS
   - announce the deprecation of SUBDIRS
   - fix single target build for external module
   - simplify the dependencies of 'prepare' stage targets
   - allow fixdep to directly write to .*.cmd files
   - simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS
   - change if_changed_rule to accept multi-line recipe
   - move .SECONDARY special target to scripts/Kbuild.include
   - remove redundant 'set -e'
   - improve parallel execution for CONFIG_HEADERS_CHECK
   - misc cleanups

  Treewide fixes and cleanups
   - set Clang flags correctly for PowerPC boot images
   - fix UML build error with CONFIG_GCC_PLUGINS
   - remove unneeded patterns from .gitignore files
   - refactor firmware/Makefile
   - remove unneeded rules for *offsets.s
   - avoid unneeded regeneration of intermediate .s files
   - clean up ./Kbuild

  Modpost:
   - remove unused -M, -K options
   - fix false positive warnings about section mismatch
   - use simple devtable lookup instead of linker magic
   - misc cleanups

  Coccinelle:
   - relax boolinit.cocci checks for overall consistency
   - fix warning messages of boolinit.cocci

  Other tools:
   - improve -dirty check of scripts/setlocalversion
   - add a tool to generate compile_commands.json from .*.cmd files"

* tag 'kbuild-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (51 commits)
  kbuild: remove unused cmd_gentimeconst
  kbuild: remove $(obj)/ prefixes in ./Kbuild
  treewide: add intermediate .s files to targets
  treewide: remove explicit rules for *offsets.s
  firmware: refactor firmware/Makefile
  firmware: remove unnecessary patterns from .gitignore
  scripts: remove unnecessary ihex2fw and check-lc_ctypes from .gitignore
  um: remove unused filechk_gen_header in Makefile
  scripts: add a tool to produce a compile_commands.json file
  kbuild: add -Werror=implicit-int flag unconditionally
  kbuild: add -Werror=strict-prototypes flag unconditionally
  kbuild: add -fno-PIE flag unconditionally
  scripts: coccinelle: Correct warning message
  scripts: coccinelle: only suggest true/false in files that already use them
  kbuild: handle part-of-module correctly for *.ll and *.symtypes
  kbuild: refactor part-of-module
  kbuild: refactor quiet_modtag
  kbuild: remove redundant quiet_modtag for $(obj-m)
  kbuild: refactor Makefile.asm-generic
  user/Makefile: Fix typo and capitalization in comment section
  ...
2018-12-29 12:03:17 -08:00
Masahiro Yamada 1d467bb8a8 kbuild: handle part-of-module correctly for *.ll and *.symtypes
The single targets *.ll and *.symtypes have never been treated as
a module. Fix it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-17 00:33:43 +09:00
Masahiro Yamada 96c0a9180a kbuild: refactor part-of-module
Use $(foreach ...) to make it shorter.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-17 00:33:43 +09:00
Masahiro Yamada 45c4372d00 kbuild: refactor quiet_modtag
part-of-module and quiet_modtag are set for the same targets.
Define quiet_modtag based on part-of-module.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-17 00:33:42 +09:00
Masahiro Yamada b39a691617 kbuild: remove redundant quiet_modtag for $(obj-m)
All objects in $(obj-m) are contained in $(real-obj-m) as well.

It is true composite objects are only contained in $(obj-m),
but [M] is hard-coded in quiet_cmd_link_multi-m.

This line is redundant.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-17 00:33:42 +09:00
Masahiro Yamada 8e9b61b293 kbuild: move .SECONDARY special target to Kbuild.include
In commit 54a702f705 ("kbuild: mark $(targets) as .SECONDARY and
remove .PRECIOUS markers"), I missed one important feature of the
.SECONDARY target:

    .SECONDARY with no prerequisites causes all targets to be
    treated as secondary.

... which agrees with the policy of Kbuild.

Let's move it to scripts/Kbuild.include, with no prerequisites.

Note:
If an intermediate file is generated by $(call if_changed,...), you
still need to add it to "targets" so its .*.cmd file is included.

The arm/arm64 crypto files are generated by $(call cmd,shipped),
so they do not need to be added to "targets", but need to be added
to "clean-files" so "make clean" can properly clean them away.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-02 14:11:49 +09:00
Masahiro Yamada 5439f09f48 kbuild: remove redundant 'set -e' from cmd_* defines
These three cmd_* are invoked in the $(call cmd,*) form.

Now that 'set -e' moved to the 'cmd' macro, they do not need to
explicitly give 'set -e'.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-01 23:13:14 +09:00
Masahiro Yamada e5d289100d kbuild: remove trailing semicolon from cmd_* passed to if_changed_rule
With the change of rule_cc_o_c / rule_as_o_S in the last commit, each
command is executed in a separate subshell. Rip off unneeded semicolons.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-01 23:13:14 +09:00
Masahiro Yamada 3a2429e1fa kbuild: change if_changed_rule for multi-line recipe
The 'define' ... 'endef' directive is useful to confine a series of
shell commands into a single macro:

  define foo
          [action1]
          [action2]
          [action3]
  endif

Each action is executed in a separate subshell.

However, rule_cc_o_c and rule_as_o_S in scripts/Makefile.build are
written as follows (with a trailing semicolon in each cmd_*):

  define rule_cc_o_c
          [action1] ; \
          [action2] ; \
          [action3] ;
  endef

All shell commands are concatenated with '; \' so that it looks like
a single command from the Makefile point of view. This does not
exploit the benefits of 'define' ... 'endef' form because a single
shell command can be more simply written, like this:

  rule_cc_o_c = \
          [action1] ; \
          [action2] ; \
          [action3] ;

I guess the intention for the command concatenation was to let the
'@set -e' in if_changed_rule cover all the commands.

We can improve the readability by moving '@set -e' to the 'cmd' macro.
The combo of $(call echo-cmd,*) $(cmd_*) in rule_cc_o_c and rule_as_o_S
have been replaced with $(call cmd,*). The trailing back-slashes have
been removed.

Here is a note about the performance: the commands in rule_cc_o_c and
rule_as_o_S were previously executed all together in a single subshell,
but now each line in a separate subshell. This means Make will spawn
extra subshells [1]. I measured the build performance for
  x86_64_defconfig + CONFIG_MODVERSIONS + CONFIG_TRIM_UNUSED_KSYMS
and I saw slight performance regression, but I believe code readability
and maintainability wins.

[1] Precisely, GNU Make may optimize this by executing the command
    directly instead of forking a subshell, if no shell special
    characters are found in the command line and omitting the subshell
    will not change the behavior.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-01 23:13:14 +09:00
Masahiro Yamada bbda5ec671 kbuild: simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS
My main motivation of this commit is to clean up scripts/Kbuild.include
and scripts/Makefile.build.

Currently, CONFIG_TRIM_UNUSED_KSYMS works with a tricky gimmick;
possibly exported symbols are detected by letting $(CPP) replace
EXPORT_SYMBOL* with a special string '=== __KSYM_*===', which is
post-processed by sed, and passed to fixdep. The extra preprocessing
is costly, and hacking cmd_and_fixdep is ugly.

I came up with a new way to find exported symbols; insert a dummy
symbol __ksym_marker_* to each potentially exported symbol. Those
dummy symbols are picked up by $(NM), post-processed by sed, then
appended to .*.cmd files. I collected the post-process part to a
new shell script scripts/gen_ksymdeps.sh for readability. The dummy
symbols are put into the .discard.* section so that the linker
script rips them off the final vmlinux or modules.

A nice side-effect is building with CONFIG_TRIM_UNUSED_KSYMS will
be much faster.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
2018-12-01 23:13:14 +09:00
Masahiro Yamada ee3e46b7ef kbuild: refactor modversions build rules
Let $(CC) compile objects into normal files *.o instead of .tmp_*.o
whether CONFIG_MODVERSIONS is enabled or not. With this, the input
file for objtool is always *.o so objtool_o can go away.

I guess the reason of using .tmp_*.o for intermediate objects was
to avoid leaving incomplete *.o file (, whose timestamp says it is
up-to-date) when the genksyms tool failed for some reasons.

It no longer matters because any targets are deleted on errors since
commit 9c2af1c737 ("kbuild: add .DELETE_ON_ERROR special target").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-01 23:13:14 +09:00
Masahiro Yamada 4317ee3b6a kbuild: remove redundant 'set -e' from sub_cmd_record_mcount
This is executed inside the if_changed_rule, which already sets
'set -e'.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-01 23:13:14 +09:00
Masahiro Yamada 392885ee82 kbuild: let fixdep directly write to .*.cmd files
Currently, fixdep writes dependencies to .*.tmp, which is renamed to
.*.cmd after everything succeeds. This is a very safe way to avoid
corrupted .*.cmd files. The if_changed_dep has carried this safety
mechanism since it was added in 2002.

If fixdep fails for some reasons or a user terminates the build while
fixdep is running, the incomplete output from the fixdep could be
troublesome.

This is my insight about some bad scenarios:

[1] If the compiler succeeds to generate *.o file, but fixdep fails
    to write necessary dependencies to .*.cmd file, Make will miss
    to rebuild the object when headers or CONFIG options are changed.
    In this case, fixdep should not generate .*.cmd file at all so
    that 'arg-check' will surely trigger the rebuild of the object.

[2] A partially constructed .*.cmd file may not be a syntactically
    correct makefile. The next time Make runs, it would include it,
    then fail to parse it. Once this happens, 'make clean' is be the
    only way to fix it.

In fact, [1] is no longer a problem since commit 9c2af1c737 ("kbuild:
add .DELETE_ON_ERROR special target"). Make deletes a target file on
any failure in its recipe. Because fixdep is a part of the recipe of
*.o target, if it fails, the *.o is deleted anyway. However, I am a
bit worried about the slight possibility of [2].

So, here is a solution. Let fixdep directly write to a .*.cmd file,
but allow makefiles to include it only when its corresponding target
exists.

This effectively reverts commit 2982c95357 ("kbuild: remove redundant
$(wildcard ...) for cmd_files calculation"), and commit 00d78ab2ba
("kbuild: remove dead code in cmd_files calculation in top Makefile")
because now we must check the presence of targets.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-01 23:13:14 +09:00
Zhenzhong Duan 4cd24de3a0 x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support
Since retpoline capable compilers are widely available, make
CONFIG_RETPOLINE hard depend on the compiler capability.

Break the build when CONFIG_RETPOLINE is enabled and the compiler does not
support it. Emit an error message in that case:

 "arch/x86/Makefile:226: *** You are building kernel with non-retpoline
  compiler, please update your compiler..  Stop."

[dwmw: Fail the build with non-retpoline compiler]

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Borislav Petkov <bp@suse.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: <srinivas.eeda@oracle.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/cca0cb20-f9e2-4094-840b-fb0f8810cd34@default
2018-11-28 11:57:03 +01:00
Linus Torvalds ac747c0715 Kbuild updates for v4.20
- optimize kallsyms slightly
 
 - remove check for old CFLAGS usage
 
 - add some compiler flags unconditionally instead of evaluating
   $(call cc-option,...)
 
 - fix variable shadowing in host tools
 
 - refactor scripts/mkmakefile
 
 - refactor various makefiles
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJb1eyEAAoJED2LAQed4NsGUjwP/0/W0nLP+nKCJ0NpsSD151Ea
 Vrbm+RMxl8uPuQ0+Bh59rdO2yWR8v7jOX8CPbX1DqW0XwW4vTNRZm9j6A83rJzHv
 dPpinUObq6vXGJCYvMLoumhOkM1lRZie1AeBeLgKF0G0jprxUspGvakSyM/5SOo6
 3gIhpPcczijC980KHIJbmwiGqRFVs3/zwqcKjQaRD3C6f4HdJL3i9Zr7kuZF0g1x
 dxCdN4Shv5x0igggp58z8646bbKlN7hItYaPq2csDop55/jWKzUkBkFkeaDjiUdB
 B6ysQfwkuTb6sbKXE6euYLUTyc6epx9v9pey0FpOx5tjXT+QmgK1ddLQEwdFH2+/
 Fd5VR70h8uKTNvmqFJ+iebpR/aC71sUqYAzsoiTVZibR/F6+QAuhHJPZJDlSSwLC
 QH7j0fwJ3X5p9PYe3JBWyWzOd9BDvtV+HGE67Kx17iRNW0FDyKSvn7tezRVtqvHr
 KENrMT4n+lNQzB+c4lfjOE9ANpOf+PP4+ODhbrtvKItyb5QfF4F+5CDVif3wv3Kt
 6dvh13hvR06gQCpbuxcFgD17mT1T/lVieuzOnWjtEh4HiMI1H0abYfkRWbQshrti
 u7TfYxwAyWKtisiPiT/1THYsW3ux7QmTSIo2iOznQxDlbmzENpQx+f22HsLaC0XU
 AUgvKGBaN0WOar2f2gyq
 =jM4E
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - optimize kallsyms slightly

 - remove check for old CFLAGS usage

 - add some compiler flags unconditionally instead of evaluating
   $(call cc-option,...)

 - fix variable shadowing in host tools

 - refactor scripts/mkmakefile

 - refactor various makefiles

* tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  modpost: Create macro to avoid variable shadowing
  ASN.1: Remove unnecessary shadowed local variable
  kbuild: use 'else ifeq' for checksrc to improve readability
  kbuild: remove unneeded link_multi_deps
  kbuild: add -Wno-unused-but-set-variable flag unconditionally
  kbuild: add -Wdeclaration-after-statement flag unconditionally
  kbuild: add -Wno-pointer-sign flag unconditionally
  modpost: remove leftover symbol prefix handling for module device table
  kbuild: simplify command line creation in scripts/mkmakefile
  kbuild: do not pass $(objtree) to scripts/mkmakefile
  kbuild: remove user ID check in scripts/mkmakefile
  kbuild: remove VERSION and PATCHLEVEL from $(objtree)/Makefile
  kbuild: add --include-dir flag only for out-of-tree build
  kbuild: remove dead code in cmd_files calculation in top Makefile
  kbuild: hide most of targets when running config or mixed targets
  kbuild: remove old check for CFLAGS use
  kbuild: prefix Makefile.dtbinst path with $(srctree) unconditionally
  kallsyms: remove left-over Blackfin code
  kallsyms: reduce size a little on 64-bit
2018-10-28 13:22:35 -07:00
Masahiro Yamada 7d0ea25242 kbuild: use 'else ifeq' for checksrc to improve readability
'ifeq ... else ifeq ... endif' notation is supported by GNU Make 3.81
or later, which is the requirement for building the kernel since
commit 37d69ee308 ("docs: bump minimal GNU Make version to 3.81").

Use it to improve the readability.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-19 09:48:47 +09:00
Masahiro Yamada 69ea912fda kbuild: remove unneeded link_multi_deps
Since commit c8589d1e9e ("kbuild: handle multi-objs dependency
appropriately"), $^ really represents all the prerequisite of the
composite object being built.

Hence, $(filter %.o,$^) contains all the objects to link together,
which is much simpler than link_multi_deps calculation.

Please note $(filter-out FORCE,$^) does not work here. When a single
object module is turned into a multi object module, $^ will contain
header files that were previously included for building the single
object, and recorded in the .*.cmd file. To filter out such headers,
$(filter %.o,$^) should be used here.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-10-19 09:47:46 +09:00
Joel Stanley 5a4630aadb ftrace: Build with CPPFLAGS to get -Qunused-arguments
When building to record the mcount locations the kernel uses
KBUILD_CFLAGS but not KBUILD_CPPFLAGS. This means it lacks
-Qunused-arguments when building with clang, resulting in a lot of
noisy warnings.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-09-19 23:53:54 +09:00
Masahiro Yamada 0d91bf584f kbuild: remove old check for CFLAGS use
This check has been here for more than a decade since
commit 0c53c8e6eb ("kbuild: check for wrong use of CFLAGS").

Enough time for migration has passed.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-09-13 00:01:16 +09:00
Masahiro Yamada 113fc08357 objtool: Remove workaround for unreachable warnings from old GCC
Commit cafa0010cd ("Raise the minimum required gcc version to 4.6")
bumped the minimum GCC version to 4.6 for all architectures.

This effectively reverts commit da541b2002 ("objtool: Skip unreachable
warnings for GCC 4.4 and older"), which was a workaround for GCC 4.4 or
older.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: linux-kbuild@vger.kernel.org
Link: https://lkml.kernel.org/r/1535341183-19994-1-git-send-email-yamada.masahiro@socionext.com
2018-08-30 12:56:40 +02:00
Masahiro Yamada d503ac531a kbuild: rename LDFLAGS to KBUILD_LDFLAGS
Commit a0f97e06a4 ("kbuild: enable 'make CFLAGS=...' to add
additional options to CC") renamed CFLAGS to KBUILD_CFLAGS.

Commit 222d394d30 ("kbuild: enable 'make AFLAGS=...' to add
additional options to AS") renamed AFLAGS to KBUILD_AFLAGS.

Commit 06c5040cdb ("kbuild: enable 'make CPPFLAGS=...' to add
additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS.

For some reason, LDFLAGS was not renamed.

Using a well-known variable like LDFLAGS may result in accidental
override of the variable.

Kbuild generally uses KBUILD_ prefixed variables for the internally
appended options, so here is one more conversion to sanitize the
naming convention.

I did not touch Makefiles under tools/ since the tools build system
is a different world.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-24 08:22:08 +09:00
Masahiro Yamada 87a32e6240 kbuild: pass LDFLAGS to recordmcount.pl
Since commit 0fbe9a245c ("microblaze: add endianness options to
LDFLAGS instead of LD"), you cannot build the kernel for microblaze
with CONFIG_DYNAMIC_FTRACE.

Fixes: 0fbe9a245c ("microblaze: add endianness options to LDFLAGS instead of LD")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-24 08:22:08 +09:00
Linus Torvalds 7140ad3898 Updates for v4.19:
- Restructure of lockdep and latency tracers
 
    This is the biggest change. Joel Fernandes restructured the hooks
    from irqs and preemption disabling and enabling. He got rid of
    a lot of the preprocessor #ifdef mess that they caused.
 
    He turned both lockdep and the latency tracers to use trace events
    inserted in the preempt/irqs disabling paths. But unfortunately,
    these started to cause issues in corner cases. Thus, parts of the
    code was reverted back to where lockde and the latency tracers
    just get called directly (without using the trace events).
    But because the original change cleaned up the code very nicely
    we kept that, as well as the trace events for preempt and irqs
    disabling, but they are limited to not being called in NMIs.
 
  - Have trace events use SRCU for "rcu idle" calls. This was required
    for the preempt/irqs off trace events. But it also had to not
    allow them to be called in NMI context. Waiting till Paul makes
    an NMI safe SRCU API.
 
  - New notrace SRCU API to allow trace events to use SRCU.
 
  - Addition of mcount-nop option support
 
  - SPDX headers replacing GPL templates.
 
  - Various other fixes and clean ups.
 
  - Some fixes are marked for stable, but were not fully tested
    before the merge window opened.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCW3ruhRQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qiM7AP47NhYdSnCFCRUJfrt6PovXmQtuCHt3
 c3QMoGGdvzh9YAEAqcSXwh7uLhpHUp1LjMAPkXdZVwNddf4zJQ1zyxQ+EAU=
 =vgEr
 -----END PGP SIGNATURE-----

Merge tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Restructure of lockdep and latency tracers

   This is the biggest change. Joel Fernandes restructured the hooks
   from irqs and preemption disabling and enabling. He got rid of a lot
   of the preprocessor #ifdef mess that they caused.

   He turned both lockdep and the latency tracers to use trace events
   inserted in the preempt/irqs disabling paths. But unfortunately,
   these started to cause issues in corner cases. Thus, parts of the
   code was reverted back to where lockdep and the latency tracers just
   get called directly (without using the trace events). But because the
   original change cleaned up the code very nicely we kept that, as well
   as the trace events for preempt and irqs disabling, but they are
   limited to not being called in NMIs.

 - Have trace events use SRCU for "rcu idle" calls. This was required
   for the preempt/irqs off trace events. But it also had to not allow
   them to be called in NMI context. Waiting till Paul makes an NMI safe
   SRCU API.

 - New notrace SRCU API to allow trace events to use SRCU.

 - Addition of mcount-nop option support

 - SPDX headers replacing GPL templates.

 - Various other fixes and clean ups.

 - Some fixes are marked for stable, but were not fully tested before
   the merge window opened.

* tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
  tracing: Fix SPDX format headers to use C++ style comments
  tracing: Add SPDX License format tags to tracing files
  tracing: Add SPDX License format to bpf_trace.c
  blktrace: Add SPDX License format header
  s390/ftrace: Add -mfentry and -mnop-mcount support
  tracing: Add -mcount-nop option support
  tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
  tracing: Handle CC_FLAGS_FTRACE more accurately
  Uprobe: Additional argument arch_uprobe to uprobe_write_opcode()
  Uprobes: Simplify uprobe_register() body
  tracepoints: Free early tracepoints after RCU is initialized
  uprobes: Use synchronize_rcu() not synchronize_sched()
  tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister()
  ftrace: Remove unused pointer ftrace_swapper_pid
  tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage"
  tracing/irqsoff: Handle preempt_count for different configs
  tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage"
  tracing: irqsoff: Account for additional preempt_disable
  trace: Use rcu_dereference_raw for hooks from trace-event subsystem
  tracing/kprobes: Fix within_notrace_func() to check only notrace functions
  ...
2018-08-20 18:32:00 -07:00
Vasily Gorbik 07d0408120 tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount
compiler flag support is tested for every Makefile.

Top 4 cc-option usages:
    511 -mrecord-mcount
     11  -fno-stack-protector
      9 -Wno-override-init
      2 -fsched-pressure

To address that move cc-option from scripts/Makefile.build to top Makefile
and export CC_USING_RECORD_MCOUNT to be used in original place.

While doing that also add -mrecord-mcount to CC_FLAGS_FTRACE (if gcc
actually supports it).

Link: http://lkml.kernel.org/r/patch-2.thread-aa7b8d.git-de935bace15a.your-ad-here.call-01533557518-ext-9465@work.hours

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-15 22:37:22 -04:00
Masahiro Yamada d6c6ab93e1 kbuild: remove deprecated host-progs variable
The host-progs has been kept as an alias of hostprogs-y for a long time
(at least since the beginning of Git era), with the clear prompt:
  Usage of host-progs is deprecated. Please replace with hostprogs-y!

Enough time for the migration has passed.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
2018-08-09 21:51:17 +09:00
Masahiro Yamada 6916162c73 kbuild: remove duplicated comments about PHONY
The comment is the same as in the top-level Makefile.

Also, the comments contain typos:
  - the .PHONY variable  ->  the PHONY variable
  - se we can ...        ->  so we can ...

Instead of fixing the typos, just remove the duplicated comments.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-06 22:04:03 +09:00
Greg Thelen ed7d40bc67 tracing: Fix SKIP_STACK_VALIDATION=1 build due to bad merge with -mrecord-mcount
Non gcc-5 builds with CONFIG_STACK_VALIDATION=y and
SKIP_STACK_VALIDATION=1 fail.
Example output:
  /bin/sh: init/.tmp_main.o: Permission denied

commit 96f60dfa58 ("trace: Use -mcount-record for dynamic ftrace"),
added a mismatched endif.  This causes cmd_objtool to get mistakenly
set.

Relocate endif to balance the newly added -record-mcount check.

Link: http://lkml.kernel.org/r/20180608214746.136554-1-gthelen@google.com

Fixes: 96f60dfa58 ("trace: Use -mcount-record for dynamic ftrace")
Acked-by: Andi Kleen <ak@linux.intel.com>
Tested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-06-21 15:12:56 -04:00
Linus Torvalds 5eb6eed7e0 One new feature was added to ftrace, which is the trace_marker now supports
triggers. For example:
 
   # cd /sys/kernel/debug/tracing
   # echo 'snapshot' > events/ftrace/print/trigger
   # echo 'cause snapshot' > trace_marker
 
 The rest of the changes are various clean ups and also one stable fix that
 was added late in the cycle.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCWxftjBQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qosyAQCgmhb+/HgRYIbsKa8Q70E2pMx5A/za
 4rQ37Q9PhDUJlAD/aWXfrqcMm+buAU0yY4K+eb+f2feKXWXxdZ/fuh7+nA4=
 =lpXM
 -----END PGP SIGNATURE-----

Merge tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "One new feature was added to ftrace, which is the trace_marker now
  supports triggers. For example:

    # cd /sys/kernel/debug/tracing
    # echo 'snapshot' > events/ftrace/print/trigger
    # echo 'cause snapshot' > trace_marker

  The rest of the changes are various clean ups and also one stable fix
  that was added late in the cycle"

* tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (21 commits)
  tracing: Use match_string() instead of open coding it in trace_set_options()
  branch-check: fix long->int truncation when profiling branches
  ring-buffer: Fix typo in comment
  ring-buffer: Fix a bunch of typos in comments
  tracing/selftest: Add test to test simple snapshot trigger for trace_marker
  tracing/selftest: Add test to test hist trigger between kernel event and trace_marker
  tracing/selftest: Add selftests to test trace_marker histogram triggers
  ftrace/selftest: Fix reset_trigger() to handle triggers with filters
  ftrace/selftest: Have the reset_trigger code be a bit more careful
  tracing: Document trace_marker triggers
  tracing: Allow histogram triggers to access ftrace internal events
  tracing: Prevent further users of zero size static arrays in trace events
  tracing: Have zero size length in filter logic be full string
  tracing: Add trigger file for trace_markers tracefs/ftrace/print
  tracing: Do not show filter file for ftrace internal events
  tracing: Add brackets in ftrace event dynamic arrays
  tracing: Have event_trace_init() called by trace_init_tracefs()
  tracing: Add __find_event_file() to find event files without restrictions
  tracing: Do not reference event data in post call triggers
  tracepoints: Fix the descriptions of tracepoint_probe_register{_prio}
  ...
2018-06-06 16:39:18 -07:00
Andi Kleen 96f60dfa58 trace: Use -mcount-record for dynamic ftrace
gcc 5 supports a new -mcount-record option to generate ftrace
tables directly. This avoids the need to run record_mcount
manually.

Use this option when available.

So far doesn't use -mcount-nop, which also exists now.

This is needed to make ftrace work with LTO because the
normal record-mcount script doesn't run over the link
time output.

It should also improve build times slightly in the general
case.
Link: http://lkml.kernel.org/r/20171127213423.27218-12-andi@firstfloor.org

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-28 12:49:51 -04:00