[PATCH] hwmon: Annotate struct gsc_hwmon_platform_data with __counted_by

[Kees Cook]

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct gsc_hwmon_platform_data.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Tim Harvey <tharvey@xxxxxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 include/linux/platform_data/gsc_hwmon.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/platform_data/gsc_hwmon.h b/include/linux/platform_data/gsc_hwmon.h
index f2781aa7eff8..70e8a6bec0f6 100644
--- a/include/linux/platform_data/gsc_hwmon.h
+++ b/include/linux/platform_data/gsc_hwmon.h
@@ -40,6 +40,6 @@ struct gsc_hwmon_platform_data {
 	unsigned int resolution;
 	unsigned int vreference;
 	unsigned int fan_base;
-	struct gsc_hwmon_channel channels[];
+	struct gsc_hwmon_channel channels[] __counted_by(nchannels);
 };
 #endif
-- 
2.34.1