Re: [PATCH 00/16] x86/asm changes for 4.1 for review

[Andy Lutomirski <luto@amacapital.net>]

On Wed, Mar 4, 2015 at 1:50 PM, Ingo Molnar <mingo@kernel.org> wrote:
>
> * Andy Lutomirski <luto@amacapital.net> wrote:
>
>> Hi all-
>>
>> After much handwringing, painful review, and curation, here's round
>> 1 of the x86/asm changes.  (This is not intended to imply that there
>> will or will not be a round 2.)
>>
>> For ease of review for git users:
>>
>> The following changes since commit 7453311d68f16a5c587c3cbf19563c9a4fbbd41a:
>>
>>   Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (2015-02-09 17:16:44 -0800)
>>
>> are available in the git repository at:
>>
>>   git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git
>>
>> for you to fetch changes up to 4710be56d76ef994ddf59087aad98c000fbab9a4:
>>
>>   x86_64, entry: Remove a bogus ret_from_fork optimization (2015-02-26 07:09:36 -0800)
>>
>> Ingo, if you like these, feel free to pull.  I will try to review
>> the scary change *again* this evening if I have time.  In the mean
>> time, these are queued as is for -next.  I will remove them from my
>> -next branch if they turn out to be buggy or if they end up in -tip
>> in any form.
>>
>> Andy Lutomirski (2):
>>   x86, entry: Remove int_check_syscall_exit_work
>>   x86_64, entry: Remove a bogus ret_from_fork optimization
>>
>> Denys Vlasenko (14):
>>   x86: open-code register save/restore in trace_hardirqs thunks
>>   x86: introduce push/pop macros which generate CFI_REL_OFFSET and
>>     CFI_RESTORE
>>   x86: entry_64.S: fix wrong symbolic constant usage: R11->ARGOFFSET
>>   x86: entry_64.S: always allocate complete "struct pt_regs"
>>   x86: entry_64.S: fix comments. No code changes
>>   x86: code shrink in paranoid_exit
>>   x86: mass removal of ARGOFFSET. No code changes
>>   x86: add comments about various syscall instructions, no code changes
>>   x86: entry_64.S: move save_paranoid and ret_from_fork closer to their
>>     users
>>   x86: entry_64.S: rename save_paranoid to paranoid_entry, no code
>>     changes
>>   x86: ia32entry.S: fold IA32_ARG_FIXUP macro into its callers
>>   x86: entry_64.S: use more understandable constants
>>   x86: ia32entry.S: use more understandable constant
>>   x86: entry.S: simplify optimistic SYSRET
>>
>>  arch/x86/ia32/ia32entry.S              | 342 ++++++++++++----------
>>  arch/x86/include/asm/calling.h         | 267 ++++++++---------
>>  arch/x86/include/asm/dwarf2.h          |  24 ++
>>  arch/x86/include/asm/irqflags.h        |   4 +-
>>  arch/x86/include/asm/ptrace.h          |  13 +-
>>  arch/x86/include/uapi/asm/ptrace-abi.h |  16 +-
>>  arch/x86/include/uapi/asm/ptrace.h     |  13 +-
>>  arch/x86/kernel/entry_32.S             |  21 +-
>>  arch/x86/kernel/entry_64.S             | 510 ++++++++++++++++-----------------
>>  arch/x86/lib/atomic64_cx8_32.S         |  50 ++--
>>  arch/x86/lib/checksum_32.S             |  60 ++--
>>  arch/x86/lib/msr-reg.S                 |  24 +-
>>  arch/x86/lib/rwsem.S                   |  44 ++-
>>  arch/x86/lib/thunk_32.S                |  18 +-
>>  arch/x86/lib/thunk_64.S                |  28 +-
>>  15 files changed, 724 insertions(+), 710 deletions(-)
>
> Ok, I had a really close look, and these changes are all looking good
> to me.
>
> While reviewing the patches I also fixed up the patch titles and tons
> of small details in the changelogs, so I didn't pull but applied the
> patches out of email, to tip:x86/asm.
>
> Thanks guys, this is really good progress and a big step forward for
> the x86 entry code's readability and maintainability!

Thanks!

I removed my version from -next to avoid merge confusion.

--Andy

>
> Thanks,
>
>         Ingo



-- 
Andy Lutomirski
AMA Capital Management, LLC