All of lore.kernel.org
 help / color / mirror / Atom feed
From: christoffer.dall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 4/6] arm: Add icache invalidation on switch_mm for Cortex-A15
Date: Mon, 5 Feb 2018 11:00:34 +0100	[thread overview]
Message-ID: <20180205100034.GS21802@cbox> (raw)
In-Reply-To: <20180201110738.5421-5-marc.zyngier@arm.com>

On Thu, Feb 01, 2018 at 11:07:36AM +0000, Marc Zyngier wrote:
> In order to avoid aliasing attacks against the branch predictor,
> Cortex-A15 require to invalidate the BTB when switching
> from one user context to another. The only way to do so on this
> CPU is to perform an ICIALLU, having set ACTLR[0] to 1 from secure
> mode.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  arch/arm/mm/proc-v7-2level.S | 10 ++++++++++
>  arch/arm/mm/proc-v7-3level.S | 10 ++++++++++
>  arch/arm/mm/proc-v7.S        | 23 ++++++++++++++++++++++-
>  3 files changed, 42 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
> index 0422e58b74e8..6d81ed7b2cb0 100644
> --- a/arch/arm/mm/proc-v7-2level.S
> +++ b/arch/arm/mm/proc-v7-2level.S
> @@ -40,7 +40,16 @@
>   *	Note that we always need to flush BTAC/BTB if IBE is set
>   *	even on Cortex-A8 revisions not affected by 430973.
>   *	If IBE is not set, the flush BTAC/BTB won't do anything.
> + *
> + *	Cortex-A15 requires ACTLR[0] to be set from secure in order
> + *	for the icache invalidation to also invalidate the BTB.
>   */
> +ENTRY(cpu_v7_icinv_switch_mm)
> +#ifdef CONFIG_MMU
> +	mcr	p15, 0, r0, c7, c5, 0		@ ICIALLU
> +	/* Fall through to switch_mm... */
> +#endif

aren't we falling through to cpu_v7_btbinv_switch_mm including the 
btb invalidation used for ca8 et al. here?  Maybe we just don't care?
> +
>  ENTRY(cpu_v7_btbinv_switch_mm)
>  #ifdef CONFIG_MMU
>  	mov	r2, #0
> @@ -67,6 +76,7 @@ ENTRY(cpu_v7_switch_mm)
>  	bx	lr
>  ENDPROC(cpu_v7_switch_mm)
>  ENDPROC(cpu_v7_btbinv_switch_mm)
> +ENDPROC(cpu_v7_icinv_switch_mm)
>  
>  /*
>   *	cpu_v7_set_pte_ext(ptep, pte)
> diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S
> index c616afd1b8f4..797053980755 100644
> --- a/arch/arm/mm/proc-v7-3level.S
> +++ b/arch/arm/mm/proc-v7-3level.S
> @@ -54,6 +54,15 @@
>   * Set the translation table base pointer to be pgd_phys (physical address of
>   * the new TTB).
>   */
> +ENTRY(cpu_v7_icinv_switch_mm)
> +#ifdef CONFIG_MMU
> +	/*
> +	 * Cortex-A15 requires ACTLR[0] to be set from secure in order
> +	 * for the icache invalidation to also invalidate the BTB.
> +	 */
> +	mcr	p15, 0, r0, c7, c5, 0		@ ICIALLU
> +	/* Fall through to switch_mm... */
> +#endif

same question...

>  ENTRY(cpu_v7_btbinv_switch_mm)
>  #ifdef CONFIG_MMU
>  	mcr	p15, 0, r0, c7, c5, 6			@ flush BTAC/BTB
> @@ -69,6 +78,7 @@ ENTRY(cpu_v7_switch_mm)
>  	ret	lr
>  ENDPROC(cpu_v7_switch_mm)
>  ENDPROC(cpu_v7_btbinv_switch_mm)
> +ENDPROC(cpu_v7_icinv_switch_mm)
>  
>  #ifdef __ARMEB__
>  #define rl r3
> diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
> index 389a7c442058..ba13e4e45c3b 100644
> --- a/arch/arm/mm/proc-v7.S
> +++ b/arch/arm/mm/proc-v7.S
> @@ -232,6 +232,26 @@ ENDPROC(cpu_ca9mp_do_resume)
>  	globl_equ	cpu_ca17_do_resume,	cpu_v7_do_resume
>  #endif
>  
> +/*
> + * Cortex-A15
> + */
> +	globl_equ	cpu_ca15_proc_init,	cpu_v7_proc_init
> +	globl_equ	cpu_ca15_proc_fin,	cpu_v7_proc_fin
> +	globl_equ	cpu_ca15_reset,		cpu_v7_reset
> +	globl_equ	cpu_ca15_do_idle,	cpu_v7_do_idle
> +	globl_equ	cpu_ca15_dcache_clean_area, cpu_v7_dcache_clean_area
> +	globl_equ	cpu_ca15_set_pte_ext,	cpu_v7_set_pte_ext
> +	globl_equ	cpu_ca15_suspend_size,	cpu_v7_suspend_size
> +#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
> +	globl_equ	cpu_ca15_switch_mm,	cpu_v7_icinv_switch_mm
> +#else
> +	globl_equ	cpu_ca15_switch_mm,	cpu_v7_switch_mm
> +#endif
> +#ifdef CONFIG_ARM_CPU_SUSPEND
> +	globl_equ	cpu_ca15_do_suspend,	cpu_v7_do_suspend
> +	globl_equ	cpu_ca15_do_resume,	cpu_v7_do_resume
> +#endif
> +
>  #ifdef CONFIG_CPU_PJ4B
>  	globl_equ	cpu_pj4b_switch_mm,     cpu_v7_switch_mm
>  	globl_equ	cpu_pj4b_set_pte_ext,	cpu_v7_set_pte_ext
> @@ -573,6 +593,7 @@ __v7_setup_stack:
>  
>  	@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
>  	define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
> +	define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
>  	define_processor_functions ca17, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
>  #ifndef CONFIG_ARM_LPAE
>  	define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
> @@ -694,7 +715,7 @@ __v7_ca12mp_proc_info:
>  __v7_ca15mp_proc_info:
>  	.long	0x410fc0f0
>  	.long	0xff0ffff0
> -	__v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup
> +	__v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup, proc_fns = ca15_processor_functions
>  	.size	__v7_ca15mp_proc_info, . - __v7_ca15mp_proc_info
>  
>  	/*
> -- 
> 2.14.2
> 

Thanks,
-Christoffer

  reply	other threads:[~2018-02-05 10:00 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-01 11:07 [PATCH v4 0/6] 32bit ARM branch predictor hardening Marc Zyngier
2018-02-01 11:07 ` [PATCH v4 1/6] arm: Add BTB invalidation on switch_mm for Cortex-A9, A12 and A17 Marc Zyngier
2018-02-01 11:07 ` [PATCH v4 2/6] arm: Invalidate BTB on prefetch abort outside of user mapping on Cortex A8, A9, " Marc Zyngier
2018-02-01 11:07 ` [PATCH v4 3/6] arm: KVM: Invalidate BTB on guest exit for Cortex-A12/A17 Marc Zyngier
2018-02-01 11:34   ` Robin Murphy
2018-02-01 14:54     ` Robin Murphy
2018-02-01 11:07 ` [PATCH v4 4/6] arm: Add icache invalidation on switch_mm for Cortex-A15 Marc Zyngier
2018-02-05 10:00   ` Christoffer Dall [this message]
2018-02-05 10:09     ` Marc Zyngier
2018-02-01 11:07 ` [PATCH v4 5/6] arm: Invalidate icache on prefetch abort outside of user mapping on Cortex-A15 Marc Zyngier
2018-02-01 11:07 ` [PATCH v4 6/6] arm: KVM: Invalidate icache on guest exit for Cortex-A15 Marc Zyngier
2018-02-01 11:46   ` Robin Murphy
2018-02-04  2:51 ` [PATCH v4 0/6] 32bit ARM branch predictor hardening Florian Fainelli
2018-02-04 10:39   ` Marc Zyngier
2018-02-05 10:01 ` Christoffer Dall
2018-02-05 10:22   ` Marc Zyngier
2018-02-05 10:14 ` Andre Przywara

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=20180205100034.GS21802@cbox \
    --to=christoffer.dall@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.