Pull Kbuild fixes from Masahiro Yamada:
- hand-off primary maintainership of Kbuild
- fix build warnings
- fix build error when GCOV is enabled with old compiler
- fix HAVE_ASM_GOTO check when GCC plugin is enabled
* tag 'kbuild-fixes-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
gconfig: remove misleading parentheses around a condition
jump label: fix passing kbuild_cflags when checking for asm goto support
Kbuild: use cc-disable-warning consistently for maybe-uninitialized
kbuild: external module build warnings when KBUILD_OUTPUT set and W=1
MAINTAINERS: add Masahiro Yamada as a Kbuild maintainer
The GCC '-maccumulate-outgoing-args' flag is enabled for most configs,
mostly because of issues which are no longer relevant. For most
configs, and with most recent versions of GCC, it's no longer needed.
Clarify which cases need it, and only enable it for those cases. Also
produce a compile-time error for the ftrace graph + mcount + '-Os' case,
which will otherwise cause runtime failures.
The main benefit of '-maccumulate-outgoing-args' is that it prevents an
ugly prologue for functions which have aligned stacks. But removing the
option also has some benefits: more readable argument saves, smaller
text size, and (presumably) slightly improved performance.
Here are the object size savings for 32-bit and 64-bit defconfig
kernels:
text data bss dec hex filename
10006710 3543328 1773568 15323606 e9d1d6 vmlinux.x86-32.before
9706358 3547424 1773568 15027350 e54c96 vmlinux.x86-32.after
text data bss dec hex filename
10652105 4537576 843776 16033457 f4a6b1 vmlinux.x86-64.before
10639629 4537576 843776 16020981 f475f5 vmlinux.x86-64.after
That comes out to a 3% text size improvement on x86-32 and a 0.1% text
size improvement on x86-64.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170316193133.zrj6gug53766m6nn@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When building the kernel with clang, the compiler complains about the
presence of a condition inside two pairs of parentheses:
scripts/kconfig/gconf.c:917:19: error: equality comparison with
extraneous parentheses [-Werror,-Wparentheses-equality]
} else if ((col == COL_OPTION)) {
~~~~^~~~~~~~~~~~~
scripts/kconfig/gconf.c:917:19: note: remove extraneous parentheses
around the comparison to silence this warning
} else if ((col == COL_OPTION)) {
~ ^ ~
scripts/kconfig/gconf.c:917:19: note: use '=' to turn this equality
comparison into an assignment
} else if ((col == COL_OPTION)) {
^~
=
Silence this warning by removing a level of parentheses.
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Commit db547ef190 ("Kbuild: don't add obj tree in additional includes")
causes warnings (-Wmissing-include-dirs) when compiling external modules
with KBUILD_OUTPUT set and W=1. This is because $src can be an absolute
path to the external module source which when prefixed with -I$(srctree)/
generates an incorrect directory path.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Merge fixes from Andrew Morton:
"26 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (26 commits)
userfaultfd: remove wrong comment from userfaultfd_ctx_get()
fat: fix using uninitialized fields of fat_inode/fsinfo_inode
sh: cayman: IDE support fix
kasan: fix races in quarantine_remove_cache()
kasan: resched in quarantine_remove_cache()
mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
thp: fix another corner case of munlock() vs. THPs
rmap: fix NULL-pointer dereference on THP munlocking
mm/memblock.c: fix memblock_next_valid_pfn()
userfaultfd: selftest: vm: allow to build in vm/ directory
userfaultfd: non-cooperative: userfaultfd_remove revalidate vma in MADV_DONTNEED
userfaultfd: non-cooperative: fix fork fctx->new memleak
mm/cgroup: avoid panic when init with low memory
drivers/md/bcache/util.h: remove duplicate inclusion of blkdev.h
mm/vmstats: add thp_split_pud event for clarity
include/linux/fs.h: fix unsigned enum warning with gcc-4.2
userfaultfd: non-cooperative: release all ctx in dup_userfaultfd_complete
userfaultfd: non-cooperative: robustness check
userfaultfd: non-cooperative: rollback userfaultfd_exit
x86, mm: unify exit paths in gup_pte_range()
...
Pull gcc-plugins fix from Kees Cook:
"Fixes a typo in sancov plugin, exposed in earlier compiler versions"
* tag 'gcc-plugins-v4.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
gcc-plugins: fix sancov_plugin for gcc-5
Pull tracing fixes from Steven Rostedt:
"There was some breakage with the changes for jump labels in the 4.11
merge window:
- powerpc broke as jump labels uses the two LSB bits as flags in
initialization.
A check was added to make sure that all jump label entries were 4
bytes aligned, but powerpc didn't work that way for modules. Adding
an alignment in the module linker script appeared to be the best
solution.
- Jump labels also added an anonymous union to access those LSB bits
as a normal long. But because this structure had static
initialization, it broke older compilers that could not statically
initialize anonymous unions without brackets.
- The command line parameter for setting function graph filter broke
the "EMPTY_HASH" descriptor by modifying it instead of creating a
new hash to hold the entries.
- The command line parameter ftrace_graph_max_depth was added to
allow its setting at boot time. It uses existing code and only the
command line hook was added.
This is not really a fix, but as it uses existing code without
affecting anything else, I added it to this release. It was ready
before the merge window closed, but I wanted to let it sit in
linux-next for a couple of days first"
* tag 'trace-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/graph: Add ftrace_graph_max_depth kernel parameter
tracing: Add #undef to fix compile error
jump_label: Add comment about initialization order for anonymous unions
jump_label: Fix anonymous union initialization
module: set __jump_table alignment to 8
ftrace/graph: Do not modify the EMPTY_HASH for the function_graph filter
tracing: Fix code comment for ftrace_ops_get_func()
For powerpc the __jump_table section in modules is not aligned, this
causes a WARN_ON() splat when loading a module containing a __jump_table.
Strict alignment became necessary with commit 3821fd35b5
("jump_label: Reduce the size of struct static_key"), currently in
linux-next, which uses the two least significant bits of pointers to
__jump_table elements.
Fix by forcing __jump_table to 8, which is the same alignment used for
this section in the kernel proper.
Link: http://lkml.kernel.org/r/20170301220453.4756-1-david.daney@cavium.com
Reviewed-by: Jason Baron <jbaron@akamai.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The '__unreachable' and '__func_stack_frame_non_standard' sections are
only used at compile time. They're discarded for vmlinux but they
should also be discarded for modules.
Since this is a recurring pattern, prefix the section names with
".discard.". It's a nice convention and vmlinux.lds.h already discards
such sections.
Also remove the 'a' (allocatable) flag from the __unreachable section
since it doesn't make sense for a discarded section.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: d1091c7fa3 ("objtool: Improve detection of BUG() and other dead ends")
Link: http://lkml.kernel.org/r/20170301180444.lhd53c5tibc4ns77@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
