Re: [PATCH] iio: adc: qcom-adc5-gen3: Annotate struct adc5_device_data with __counted_by_ptr
From: Daniel Lezcano
Date: Wed Sep 23 2026 - 04:05:36 EST
On 9/23/26 00:09, Bill Wendling wrote:
Under compiler-supported bounds checking (via KASAN or UBSAN), pointer
fields inside structures can be annotated with the '__counted_by_ptr'
attribute to specify which field in the same structure holds the element
count. This enables the compiler to perform runtime bounds checking on
the pointer.
Annotate the "base" pointer field in "struct adc5_device_data" with the
"__counted_by_ptr" attribute pointing to "num_sdams". The number of
SDAMs is determined from the device property and assigned to "num_sdams"
which is then used to initialize "base" via "devm_kcalloc".
By ensuring "num_sdams" is set to the correct element count prior to
the "base" pointer allocation, and since the size of "base" is never
reallocated or changed, this annotation is safe and will not cause any
false-positive runtime bounds check panics or KASAN issues.
Cc: codemender-patching+linux@xxxxxxxxxx
Assisted-by: LLM
Signed-off-by: Bill Wendling <morbo@xxxxxxxxxx>
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Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxxxxxxxx>