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From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: will@kernel.org, linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, bjorn.andersson@linaro.org
Subject: Re: [PATCH] ARM: kernel: Fix interrupted SMC calls
Date: Mon, 18 Jan 2021 16:08:07 +0000	[thread overview]
Message-ID: <20210118160807.GF1551@shell.armlinux.org.uk> (raw)
In-Reply-To: <20210118155153.21520-1-manivannan.sadhasivam@linaro.org>

On Mon, Jan 18, 2021 at 09:21:53PM +0530, Manivannan Sadhasivam wrote:
> @@ -27,10 +29,18 @@ UNWIND(	.fnstart)
>  UNWIND(	.save	{r4-r7})
>  	ldm	r12, {r4-r7}
>  	\instr
> +	mov	r9, r6			// Copy r6 before popping from stack
>  	pop	{r4-r7}
>  	ldr	r12, [sp, #(4 * 4)]
>  	stm	r12, {r0-r3}
> -	bx	lr
> +	ldr	r10, [sp, #20]
> +	cmp	r10, #0
> +	beq	1f			// No quirk structure
> +	ldr     r11, [r10, #ARM_SMCCC_QUIRK_ID_OFFS]
> +	cmp     r11, #ARM_SMCCC_QUIRK_QCOM_A6
> +	bne	1f			// No quirk present
> +	str	r9, [r10, #ARM_SMCCC_QUIRK_STATE_OFFS]
> +1:	bx	lr

NAK. This patch shows little regard for the C ABI. You are corrupting
registers that must be preserved. Please find out about the C ABIs
that are used on ARM.

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

WARNING: multiple messages have this Message-ID (diff)
From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: linux-arm-msm@vger.kernel.org, will@kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, bjorn.andersson@linaro.org
Subject: Re: [PATCH] ARM: kernel: Fix interrupted SMC calls
Date: Mon, 18 Jan 2021 16:08:07 +0000	[thread overview]
Message-ID: <20210118160807.GF1551@shell.armlinux.org.uk> (raw)
In-Reply-To: <20210118155153.21520-1-manivannan.sadhasivam@linaro.org>

On Mon, Jan 18, 2021 at 09:21:53PM +0530, Manivannan Sadhasivam wrote:
> @@ -27,10 +29,18 @@ UNWIND(	.fnstart)
>  UNWIND(	.save	{r4-r7})
>  	ldm	r12, {r4-r7}
>  	\instr
> +	mov	r9, r6			// Copy r6 before popping from stack
>  	pop	{r4-r7}
>  	ldr	r12, [sp, #(4 * 4)]
>  	stm	r12, {r0-r3}
> -	bx	lr
> +	ldr	r10, [sp, #20]
> +	cmp	r10, #0
> +	beq	1f			// No quirk structure
> +	ldr     r11, [r10, #ARM_SMCCC_QUIRK_ID_OFFS]
> +	cmp     r11, #ARM_SMCCC_QUIRK_QCOM_A6
> +	bne	1f			// No quirk present
> +	str	r9, [r10, #ARM_SMCCC_QUIRK_STATE_OFFS]
> +1:	bx	lr

NAK. This patch shows little regard for the C ABI. You are corrupting
registers that must be preserved. Please find out about the C ABIs
that are used on ARM.

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

  reply	other threads:[~2021-01-18 16:10 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-18 15:51 [PATCH] ARM: kernel: Fix interrupted SMC calls Manivannan Sadhasivam
2021-01-18 15:51 ` Manivannan Sadhasivam
2021-01-18 16:08 ` Russell King - ARM Linux admin [this message]
2021-01-18 16:08   ` Russell King - ARM Linux admin
2021-01-18 17:50   ` Manivannan Sadhasivam
2021-01-18 17:50     ` Manivannan Sadhasivam

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