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    Subject[PATCH 2/2][next] clk: visconti: Add bounds-checking coverage for struct visconti_pll_provider
    In order to gain the bounds-checking coverage that __counted_by provides
    to flexible-array members at run-time via CONFIG_UBSAN_BOUNDS (for array
    indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions),
    we must make sure that the counter member, in this particular case `num`,
    is updated before the first access to the flex-array member, in this
    particular case array `hws`. See below:

    commit f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with
    __counted_by") introduced `__counted_by` for `struct clk_hw_onecell_data`
    together with changes to relocate some of assignments of counter `num`
    before `hws` is accessed:

    include/linux/clk-provider.h:
    1380 struct clk_hw_onecell_data {
    1381 unsigned int num;
    1382 struct clk_hw *hws[] __counted_by(num);
    1383 };

    However, this structure is used as a member in other structs, in this
    case in `struct visconti_pll_provider`:

    drivers/clk/visconti/pll.h:
    16 struct visconti_pll_provider {
    17 void __iomem *reg_base;
    18 struct device_node *node;
    19
    20 /* Must be last */
    21 struct clk_hw_onecell_data clk_data;
    22 };

    Hence, we need to move the assignments to `ctx->clk_data.num` after
    allocation for `struct visconti_pll_provider` and before accessing the
    flexible array `ctx->clk_data.hws`. And, as assignments for all members
    in `struct visconti_pll_provider` are originally adjacent to each other,
    relocate all assignments together, so we don't split up
    `ctx->clk_data.hws = nr_plls` from the rest. :)

    Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
    ---
    drivers/clk/visconti/pll.c | 6 +++---
    1 file changed, 3 insertions(+), 3 deletions(-)

    diff --git a/drivers/clk/visconti/pll.c b/drivers/clk/visconti/pll.c
    index 1f3234f22667..e9cd80e085dc 100644
    --- a/drivers/clk/visconti/pll.c
    +++ b/drivers/clk/visconti/pll.c
    @@ -329,12 +329,12 @@ struct visconti_pll_provider * __init visconti_init_pll(struct device_node *np,
    if (!ctx)
    return ERR_PTR(-ENOMEM);

    - for (i = 0; i < nr_plls; ++i)
    - ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
    -
    ctx->node = np;
    ctx->reg_base = base;
    ctx->clk_data.num = nr_plls;

    + for (i = 0; i < nr_plls; ++i)
    + ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
    +
    return ctx;
    }
    --
    2.34.1
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