From: Nicholas Piggin <npiggin@gmail.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Michael Ellerman <mpe@ellerman.id.au>,
msuchanek@suse.de, Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 18/22] powerpc/syscall: Remove FULL_REGS verification in system_call_exception
Date: Wed, 10 Feb 2021 11:57:40 +1000 [thread overview]
Message-ID: <1612922197.2b51jxzeqs.astroid@bobo.none> (raw)
In-Reply-To: <cc1a35a4-07c3-9e64-18d6-57e497f56e33@csgroup.eu>
Excerpts from Christophe Leroy's message of February 10, 2021 12:31 am:
>
>
> Le 09/02/2021 à 03:02, Nicholas Piggin a écrit :
>> Excerpts from Christophe Leroy's message of February 9, 2021 1:10 am:
>>> For book3s/64, FULL_REGS() is 'true' at all time, so the test voids.
>>> For others, non volatile registers are saved inconditionally.
>>>
>>> So the verification is pointless.
>>>
>>> Should one fail to do it, it would anyway be caught by the
>>> CHECK_FULL_REGS() in copy_thread() as we have removed the
>>> special versions ppc_fork() and friends.
>>>
>>> null_syscall benchmark reduction 4 cycles (332 => 328 cycles)
>>
>> I wonder if we rather make a CONFIG option for a bunch of these simpler
>> debug checks here (and also in interrupt exit, wrappers, etc) rather
>> than remove them entirely.
>
> We can drop this patch if you prefer. Anyway, like book3s/64, once ppc32 also do interrupt
> entry/exit in C, FULL_REGS() will already return true.
Sure let's do that.
Thanks,
Nick
next prev parent reply other threads:[~2021-02-10 2:03 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-08 15:10 [PATCH v5 00/22] powerpc/32: Implement C syscall entry/exit Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 01/22] powerpc/32s: Add missing call to kuep_lock on syscall entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 02/22] powerpc/32: Always enable data translation " Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 03/22] powerpc/32: On syscall entry, enable instruction translation at the same time as data Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 04/22] powerpc/32: Reorder instructions to avoid using CTR in syscall entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 05/22] powerpc/irq: Add helper to set regs->softe Christophe Leroy
2021-02-09 1:11 ` Nicholas Piggin
2021-02-09 5:57 ` Christophe Leroy
2021-02-09 7:47 ` Nicholas Piggin
2021-02-09 6:18 ` Christophe Leroy
2021-02-09 7:49 ` Nicholas Piggin
2021-03-05 8:54 ` Christophe Leroy
2021-03-08 8:47 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 06/22] powerpc/irq: Rework helpers that manipulate MSR[EE/RI] Christophe Leroy
2021-02-09 1:14 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 07/22] powerpc/irq: Add stub irq_soft_mask_return() for PPC32 Christophe Leroy
2021-02-09 1:19 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 08/22] powerpc/syscall: Rename syscall_64.c into interrupt.c Christophe Leroy
2021-02-09 1:19 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 09/22] powerpc/syscall: Make interrupt.c buildable on PPC32 Christophe Leroy
2021-02-09 1:27 ` Nicholas Piggin
2021-02-09 6:02 ` Christophe Leroy
2021-02-09 7:50 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 10/22] powerpc/syscall: Use is_compat_task() Christophe Leroy
2021-02-09 1:29 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 11/22] powerpc/syscall: Save r3 in regs->orig_r3 Christophe Leroy
2021-02-09 1:29 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 12/22] powerpc/syscall: Change condition to check MSR_RI Christophe Leroy
2021-02-09 1:36 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 13/22] powerpc/32: Always save non volatile GPRs at syscall entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 14/22] powerpc/syscall: implement system call entry/exit logic in C for PPC32 Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 15/22] powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 16/22] powerpc/syscall: Avoid stack frame in likely part of system_call_exception() Christophe Leroy
2021-02-09 1:55 ` Nicholas Piggin
2021-02-09 16:13 ` Christophe Leroy
2021-02-10 1:56 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 17/22] powerpc/syscall: Do not check unsupported scv vector on PPC32 Christophe Leroy
2021-02-09 2:00 ` Nicholas Piggin
2021-02-09 6:13 ` Christophe Leroy
2021-02-09 7:56 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 18/22] powerpc/syscall: Remove FULL_REGS verification in system_call_exception Christophe Leroy
2021-02-09 2:02 ` Nicholas Piggin
2021-02-09 14:31 ` Christophe Leroy
2021-02-10 1:57 ` Nicholas Piggin [this message]
2021-02-08 15:10 ` [PATCH v5 19/22] powerpc/syscall: Optimise checks in beginning of system_call_exception() Christophe Leroy
2021-02-09 2:06 ` Nicholas Piggin
2021-02-09 14:32 ` Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 20/22] powerpc/syscall: Avoid storing 'current' in another pointer Christophe Leroy
2021-02-09 2:36 ` Nicholas Piggin
2021-02-09 13:50 ` Segher Boessenkool
2021-02-09 14:31 ` David Laight
2021-02-09 17:03 ` Christophe Leroy
2021-02-09 17:16 ` David Laight
2021-02-10 2:00 ` Nicholas Piggin
2021-02-10 8:45 ` Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 21/22] powerpc/32: Remove the counter in global_dbcr0 Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 22/22] powerpc/32: Handle bookE debugging in C in syscall entry/exit Christophe Leroy
2021-02-09 1:03 ` [PATCH v5 00/22] powerpc/32: Implement C " Nicholas Piggin
2021-02-12 0:19 ` Michael Ellerman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1612922197.2b51jxzeqs.astroid@bobo.none \
--to=npiggin@gmail.com \
--cc=benh@kernel.crashing.org \
--cc=christophe.leroy@csgroup.eu \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=msuchanek@suse.de \
--cc=paulus@samba.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).