Re: [PATCH v3 1/4] soc: qcom: smem: add IN_PARTITION_RANGE helper

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 9/24/26 3:10 PM, Albert Esteve wrote:
> From: Sarannya S <quic_sarannya@oss.qualcomm.com>
> 
> Add IN_PARTITION_RANGE() to test that a pointer lies in [start, end]
> and that pointer + size does not wrap.
> 
> Signed-off-by: Sarannya S <quic_sarannya@oss.qualcomm.com>
> Signed-off-by: Pranav Mahesh Phansalkar <quic_pphansal@oss.qualcomm.com>
> Signed-off-by: Sudeepgoud Patil <quic_sudeepgo@oss.qualcomm.com>
> Signed-off-by: Albert Esteve <aesteve@redhat.com>
> ---
>  drivers/soc/qcom/smem.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
> index b5e7bd8c1512..6783a3c533f0 100644
> --- a/drivers/soc/qcom/smem.c
> +++ b/drivers/soc/qcom/smem.c
> @@ -2,6 +2,7 @@
>  /*
>   * Copyright (c) 2015, Sony Mobile Communications AB.
>   * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
>   */
>  
>  #include <linux/debugfs.h>
> @@ -88,6 +89,17 @@
>  /* Processor/host identifier for the global partition */
>  #define SMEM_GLOBAL_HOST	0xfffe
>  
> +/* Entry range check
> + * ptr >= start : Checks if ptr is greater than the start of access region
> + * ptr + size >= ptr: Check for integer overflow (On 32bit system where ptr
> + * and size are 32bits, ptr + size can wrap around to be a small integer)
> + * ptr + size <= end: Checks if ptr+size is less than the end of access region
> + */
> +#define IN_PARTITION_RANGE(ptr, size, start, end)		\
> +	(((void *)(ptr) >= (void *)(start)) &&			\
> +	 (((void *)(ptr) + (size)) >= (void *)(ptr)) &&	\
> +	 (((void *)(ptr) + (size)) <= (void *)(end)))

LLM is unhappy about the 32-bit base and suggests this instead:

#define IN_PARTITION_RANGE(ptr, size, start, end)		\
	((void *)(ptr) >= (void *)(start) &&			\
	 (void *)(ptr) <= (void *)(end) &&			\
	 (size) <= (uintptr_t)(end) - (uintptr_t)(ptr))

Konrad