From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Linux ARM <linux-arm-kernel@lists.infradead.org>,
Keith Packard <keithpac@amazon.com>,
Kees Cook <keescook@chromium.org>, Arnd Bergmann <arnd@arndb.de>,
Linus Walleij <linus.walleij@linaro.org>
Subject: Re: [PATCH v4 4/5] ARM: smp: Store current pointer in TPIDRURO register if available
Date: Mon, 13 Sep 2021 14:52:45 +0100 [thread overview]
Message-ID: <YT9XrdCY5JbdpOMl@shell.armlinux.org.uk> (raw)
In-Reply-To: <CAMj1kXF+B-N0bTykEsfPZNwRTP+YnwhNB=-+vf+nqi27AT0Y6g@mail.gmail.com>
On Mon, Sep 13, 2021 at 02:52:46PM +0200, Ard Biesheuvel wrote:
> Hi Russell,
>
> Thanks for taking a look.
>
> However, the next patch drops the 'ldr ip, [r4, #TI_TASK]' I am adding
> here, so I won't be able to use this as-is.
>
> I could just split the ldr/set_current sequence into two, and change
> the first one into a mov in the following patch, and move the
> set_current to right before where sp is updated.
>
> I.e., in this patch
>
> @@ -762,6 +764,8 @@ ENTRY(__switch_to)
> add r7, r7, #TSK_STACK_CANARY & ~IMM12_MASK
> .endif
> ldr r7, [r7, #TSK_STACK_CANARY & IMM12_MASK]
> +#elif defined(CONFIG_CURRENT_POINTER_IN_TPIDRURO)
> + ldr r7, [r2, #TI_TASK]
> #endif
> #ifdef CONFIG_CPU_USE_DOMAINS
> mcr p15, 0, r6, c3, c0, 0 @ Set domain register
> @@ -776,6 +780,7 @@ ENTRY(__switch_to)
> #endif
> THUMB( mov ip, r4 )
> mov r0, r5
> + set_current r7
> ARM( ldmia r4, {r4 - sl, fp, sp, pc} )
> THUMB( ldmia ip!, {r4 - sl, fp} )
> THUMB( ldr sp, [ip], #4 )
>
> and in the next one
>
> @@ -765,7 +765,7 @@ ENTRY(__switch_to)
> .endif
> ldr r7, [r7, #TSK_STACK_CANARY & IMM12_MASK]
> #elif defined(CONFIG_CURRENT_POINTER_IN_TPIDRURO)
> - ldr r7, [r2, #TI_TASK]
> + mov r7, r2 @ Preserve 'next'
> #endif
> #ifdef CONFIG_CPU_USE_DOMAINS
> mcr p15, 0, r6, c3, c0, 0 @ Set domain register
>
> Would that work for you?
Definitely does! Thanks.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-09-13 13:54 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-13 10:39 [PATCH v4 0/5] ARM: support THREAD_INFO_IN_TASK Ard Biesheuvel
2021-09-13 10:39 ` [PATCH v4 1/5] gcc-plugins: arm-ssp: Prepare for THREAD_INFO_IN_TASK support Ard Biesheuvel
2021-09-13 15:40 ` Kees Cook
2021-09-14 22:04 ` Linus Walleij
2021-09-15 6:37 ` Ard Biesheuvel
2021-09-15 16:26 ` Kees Cook
2021-09-13 10:39 ` [PATCH v4 2/5] ARM: smp: Pass task to secondary_start_kernel Ard Biesheuvel
2021-09-13 23:25 ` Linus Walleij
2021-09-13 10:39 ` [PATCH v4 3/5] ARM: smp: Free up the TLS register while running in the kernel Ard Biesheuvel
2021-09-13 10:40 ` [PATCH v4 4/5] ARM: smp: Store current pointer in TPIDRURO register if available Ard Biesheuvel
2021-09-13 11:22 ` Russell King (Oracle)
2021-09-13 12:52 ` Ard Biesheuvel
2021-09-13 13:52 ` Russell King (Oracle) [this message]
2021-09-13 10:40 ` [PATCH v4 5/5] ARM: smp: Enable THREAD_INFO_IN_TASK Ard Biesheuvel
2021-09-13 11:23 ` [PATCH v4 0/5] ARM: support THREAD_INFO_IN_TASK Russell King (Oracle)
2021-09-13 15:40 ` Kees Cook
2021-09-14 9:44 ` Arnd Bergmann
2021-09-14 9:50 ` Ard Biesheuvel
2021-09-14 13:07 ` Arnd Bergmann
2021-09-14 17:10 ` Ard Biesheuvel
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=YT9XrdCY5JbdpOMl@shell.armlinux.org.uk \
--to=linux@armlinux.org.uk \
--cc=ardb@kernel.org \
--cc=arnd@arndb.de \
--cc=keescook@chromium.org \
--cc=keithpac@amazon.com \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.