Quoting Gustavo A. R. Silva (2024-11-14 14:49:21)
> Some heap space is allocated for the flexible structure `struct
> clk_hw_onecell_data` and its flexible-array member `hws` through
> the composite structure `struct loongson2_clk_provider` in function
> `loongson2_clk_probe()`, as shown below:
>
> 289 struct loongson2_clk_provider *clp;
> ...
> 296 for (p = data; p->name; p++)
> 297 clks_num++;
> 298
> 299 clp = devm_kzalloc(dev, struct_size(clp, clk_data.hws, clks_num),
> 300 GFP_KERNEL);
>
> Then some data is written into the flexible array:
>
> 350 clp->clk_data.hws[p->id] = hw;
>
> This corrupts `clk_lock`, which is the spinlock variable immediately
> following the `clk_data` member in `struct loongson2_clk_provider`:
>
> struct loongson2_clk_provider {
> void __iomem *base;
> struct device *dev;
> struct clk_hw_onecell_data clk_data;
> spinlock_t clk_lock; /* protect access to DIV registers */
> };
>
> The problem is that the flexible structure is currently placed in the
> middle of `struct loongson2_clk_provider` instead of at the end.
>
> Fix this by moving `struct clk_hw_onecell_data clk_data;` to the end of
> `struct loongson2_clk_provider`. Also, add a code comment to help
> prevent this from happening again in case new members are added to the
> structure in the future.
>
> This change also fixes the following -Wflex-array-member-not-at-end
> warning:
>
> drivers/clk/clk-loongson2.c:32:36: warning: structure containing a flexible
> array member is not at the end of another structure
> [-Wflex-array-member-not-at-end]
>
> Fixes: 9796ec0bd04b ("clk: clk-loongson2: Refactor driver for adding new
> platforms")
> Cc: sta...@vger.kernel.org
> Signed-off-by: Gustavo A. R. Silva <gustavo...@kernel.org>
> ---
Applied to clk-next
