On Sun, Sep 6, 2026 at 2:40 AM Aamir Ahmed <[email protected]> wrote: > > Commit f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with > __counted_by") annotated the hws member of 'struct clk_hw_onecell_data' > with __counted_by, which informs the bounds sanitizer (UBSAN_BOUNDS) > about the number of elements in .hws[], so that it can warn when .hws[] > is accessed out of bounds. As noted in that change, the __counted_by > member must be initialized with the number of elements before the first > array access happens, otherwise there will be a warning from each access > prior to the initialization because the number of elements is zero. > This occurs in ac100_rtc_register_clks() due to .num being assigned only > after every clkout clock has been stored in .hws[]. With > CONFIG_UBSAN_BOUNDS and a compiler that implements __counted_by (GCC > 15.1+ or Clang 20.1+), this triggers an array-index-out-of-bounds report > during probe, and with CONFIG_UBSAN_TRAP the first store traps. > > Initialize .num with AC100_CLKOUT_NUM, the number of elements .hws[] was > allocated with, right after the allocation. That is the value the loop > counter ends up at on the success path anyway, so the provider's > behaviour is unchanged. > > Cc: [email protected] > Fixes: f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with > __counted_by") > Assisted-by: LLM > Signed-off-by: Aamir Ahmed <[email protected]>
Reviewed-by: Chen-Yu Tsai <[email protected]>
