Re: [PATCH 11/11] drm/i915: Fix undefined behavior due to shift overflowing the constant

From: Randy Dunlap
Date: Tue May 17 2022 - 19:06:12 EST



On 4/5/22 08:15, Borislav Petkov wrote:
> From: Borislav Petkov <bp@xxxxxxx>
>
> Fix:
>
> In file included from <command-line>:0:0:
> drivers/gpu/drm/i915/gt/uc/intel_guc.c: In function ‘intel_guc_send_mmio’:
> ././include/linux/compiler_types.h:352:38: error: call to ‘__compiletime_assert_1047’ \
> declared with attribute error: FIELD_PREP: mask is not constant
> _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
>
> and other build errors due to shift overflowing values.
>
> See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@xxxxxxx for the gory
> details as to why it triggers with older gccs only.
>

Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Tested-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

Is this merged anywhere?
It could/should at least be in linux-next so that other people
don't waste time on it.

thanks.

> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> ---
> .../gpu/drm/i915/gt/uc/abi/guc_actions_abi.h | 2 +-
> .../i915/gt/uc/abi/guc_communication_ctb_abi.h | 2 +-
> .../gpu/drm/i915/gt/uc/abi/guc_messages_abi.h | 2 +-
> drivers/gpu/drm/i915/gt/uc/intel_guc_reg.h | 2 +-
> drivers/gpu/drm/i915/i915_reg.h | 18 +++++++++---------
> 5 files changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
> index 7afdadc7656f..e835f28c0020 100644
> --- a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
> +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
> @@ -50,7 +50,7 @@
>
> #define HOST2GUC_SELF_CFG_REQUEST_MSG_LEN (GUC_HXG_REQUEST_MSG_MIN_LEN + 3u)
> #define HOST2GUC_SELF_CFG_REQUEST_MSG_0_MBZ GUC_HXG_REQUEST_MSG_0_DATA0
> -#define HOST2GUC_SELF_CFG_REQUEST_MSG_1_KLV_KEY (0xffff << 16)
> +#define HOST2GUC_SELF_CFG_REQUEST_MSG_1_KLV_KEY (0xffffU << 16)
> #define HOST2GUC_SELF_CFG_REQUEST_MSG_1_KLV_LEN (0xffff << 0)
> #define HOST2GUC_SELF_CFG_REQUEST_MSG_2_VALUE32 GUC_HXG_REQUEST_MSG_n_DATAn
> #define HOST2GUC_SELF_CFG_REQUEST_MSG_3_VALUE64 GUC_HXG_REQUEST_MSG_n_DATAn
> diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h
> index c9086a600bce..df83c1cc7c7a 100644
> --- a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h
> +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h
> @@ -82,7 +82,7 @@ static_assert(sizeof(struct guc_ct_buffer_desc) == 64);
> #define GUC_CTB_HDR_LEN 1u
> #define GUC_CTB_MSG_MIN_LEN GUC_CTB_HDR_LEN
> #define GUC_CTB_MSG_MAX_LEN 256u
> -#define GUC_CTB_MSG_0_FENCE (0xffff << 16)
> +#define GUC_CTB_MSG_0_FENCE (0xffffU << 16)
> #define GUC_CTB_MSG_0_FORMAT (0xf << 12)
> #define GUC_CTB_FORMAT_HXG 0u
> #define GUC_CTB_MSG_0_RESERVED (0xf << 8)
> diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_messages_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_messages_abi.h
> index 29ac823acd4c..7d5ba4d97d70 100644
> --- a/drivers/gpu/drm/i915/gt/uc/abi/guc_messages_abi.h
> +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_messages_abi.h
> @@ -40,7 +40,7 @@
> */
>
> #define GUC_HXG_MSG_MIN_LEN 1u
> -#define GUC_HXG_MSG_0_ORIGIN (0x1 << 31)
> +#define GUC_HXG_MSG_0_ORIGIN (0x1U << 31)
> #define GUC_HXG_ORIGIN_HOST 0u
> #define GUC_HXG_ORIGIN_GUC 1u
> #define GUC_HXG_MSG_0_TYPE (0x7 << 28)
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_reg.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_reg.h
> index 66027a42cda9..ad570fa002a6 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_reg.h
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_reg.h
> @@ -28,7 +28,7 @@
> #define GS_MIA_HALT_REQUESTED (0x02 << GS_MIA_SHIFT)
> #define GS_MIA_ISR_ENTRY (0x04 << GS_MIA_SHIFT)
> #define GS_AUTH_STATUS_SHIFT 30
> -#define GS_AUTH_STATUS_MASK (0x03 << GS_AUTH_STATUS_SHIFT)
> +#define GS_AUTH_STATUS_MASK (0x03U << GS_AUTH_STATUS_SHIFT)
> #define GS_AUTH_STATUS_BAD (0x01 << GS_AUTH_STATUS_SHIFT)
> #define GS_AUTH_STATUS_GOOD (0x02 << GS_AUTH_STATUS_SHIFT)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 3c87d77d2cf6..f3ba3d0a430b 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -7555,19 +7555,19 @@ enum skl_power_gate {
> #define PORT_CLK_SEL_LCPLL_810 (2 << 29)
> #define PORT_CLK_SEL_SPLL (3 << 29)
> #define PORT_CLK_SEL_WRPLL(pll) (((pll) + 4) << 29)
> -#define PORT_CLK_SEL_WRPLL1 (4 << 29)
> -#define PORT_CLK_SEL_WRPLL2 (5 << 29)
> -#define PORT_CLK_SEL_NONE (7 << 29)
> -#define PORT_CLK_SEL_MASK (7 << 29)
> +#define PORT_CLK_SEL_WRPLL1 (4U << 29)
> +#define PORT_CLK_SEL_WRPLL2 (5U << 29)
> +#define PORT_CLK_SEL_NONE (7U << 29)
> +#define PORT_CLK_SEL_MASK (7U << 29)
>
> /* On ICL+ this is the same as PORT_CLK_SEL, but all bits change. */
> #define DDI_CLK_SEL(port) PORT_CLK_SEL(port)
> #define DDI_CLK_SEL_NONE (0x0 << 28)
> -#define DDI_CLK_SEL_MG (0x8 << 28)
> -#define DDI_CLK_SEL_TBT_162 (0xC << 28)
> -#define DDI_CLK_SEL_TBT_270 (0xD << 28)
> -#define DDI_CLK_SEL_TBT_540 (0xE << 28)
> -#define DDI_CLK_SEL_TBT_810 (0xF << 28)
> +#define DDI_CLK_SEL_MG (0x8U << 28)
> +#define DDI_CLK_SEL_TBT_162 (0xCU << 28)
> +#define DDI_CLK_SEL_TBT_270 (0xDU << 28)
> +#define DDI_CLK_SEL_TBT_540 (0xEU << 28)
> +#define DDI_CLK_SEL_TBT_810 (0xFU << 28)
> #define DDI_CLK_SEL_MASK (0xF << 28)
>
> /* Transcoder clock selection */

--
~Randy