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Nadav Amit 0474d5d9d2 x86/extable: Macrofy inline assembly code to work around GCC inlining bugs
As described in:

  77b0bf55bc: ("kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs")

GCC's inlining heuristics are broken with common asm() patterns used in
kernel code, resulting in the effective disabling of inlining.

The workaround is to set an assembly macro and call it from the inline
assembly block - which is also a minor cleanup for the exception table
code.

Text size goes up a bit:

      text     data     bss      dec     hex  filename
  18162555 10226288 2957312 31346155 1de4deb  ./vmlinux before
  18162879 10226256 2957312 31346447 1de4f0f  ./vmlinux after (+292)

But this allows the inlining of functions such as nested_vmx_exit_reflected(),
set_segment_reg(), __copy_xstate_to_user() which is a net benefit.

Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.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: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20181005202718.229565-2-namit@vmware.com
Link: https://lore.kernel.org/lkml/20181003213100.189959-9-namit@vmware.com/T/#u
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-06 15:52:15 +02:00
arch x86/extable: Macrofy inline assembly code to work around GCC inlining bugs 2018-10-06 15:52:15 +02:00
block blk-mq: I/O and timer unplugs are inverted in blktrace 2018-09-27 13:12:44 -06:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto DMAengine updates for v4.19-rc1 2018-08-18 15:55:59 -07:00
Documentation fbdev fixes for v4.19-rc7: 2018-10-02 05:19:43 -07:00
drivers Merge branch 'linus' into x86/core, to pick up fixes 2018-10-04 08:23:03 +02:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge branch 'linus' into x86/core, to pick up fixes 2018-10-04 08:23:03 +02:00
include Merge branch 'core/core' into x86/build, to prevent conflicts 2018-10-06 15:51:56 +02:00
init jump_label: Annotate entries that operate on __init code earlier 2018-09-27 17:56:48 +02:00
ipc ipc/shm: properly return EIDRM in shm_lock() 2018-09-04 16:45:02 -07:00
kernel Merge branch 'core/core' into x86/build, to prevent conflicts 2018-10-06 15:51:56 +02:00
lib lib/Kconfig.debug: fix three typos in help text 2018-09-04 16:45:02 -07:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
mm Merge branch 'linus' into x86/core, to pick up fixes 2018-10-04 08:23:03 +02:00
net ip_tunnel: be careful when accessing the inner header 2018-09-24 12:27:04 -07:00
samples samples/bpf: all XDP samples should unload xdp/bpf prog on SIGTERM 2018-08-16 21:55:32 +02:00
scripts kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs 2018-10-04 10:57:09 +02:00
security Revert "uapi/linux/keyctl.h: don't use C++ reserved keyword as a struct member name" 2018-09-25 13:28:58 +02:00
sound ASoC: Fixes for v4.19 2018-09-17 18:59:21 +02:00
tools Merge branch 'core/core' into x86/build, to prevent conflicts 2018-10-06 15:51:56 +02:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt KVM: Remove obsolete kvm_unmap_hva notifier backend 2018-09-07 15:06:02 +02:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS fbdev fixes for v4.19-rc7: 2018-10-02 05:19:43 -07:00
Makefile kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs 2018-10-04 10:57:09 +02:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.