[PATCH] clk: renesas: cpg-mssr: use struct_size

[PATCH] clk: renesas: cpg-mssr: use struct_size

[Rosen Penev]

struct_size is what is normally used when a flexible array member is
present to avoid accidental mistakes. pm_size is still needed for the
memcpy call below.

Added __counted_by for extra runtime analysis.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/clk/renesas/renesas-cpg-mssr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/renesas/renesas-cpg-mssr.c b/drivers/clk/renesas/renesas-cpg-mssr.c
index 64a432fd0e8a..26ea85cfaa02 100644
--- a/drivers/clk/renesas/renesas-cpg-mssr.c
+++ b/drivers/clk/renesas/renesas-cpg-mssr.c
@@ -569,7 +569,7 @@ static void __init cpg_mssr_register_mod_clk(const struct mssr_mod_clk *mod,
 struct cpg_mssr_clk_domain {
 	struct generic_pm_domain genpd;
 	unsigned int num_core_pm_clks;
-	unsigned int core_pm_clks[];
+	unsigned int core_pm_clks[] __counted_by(num_core_pm_clks);
 };
 
 static struct cpg_mssr_clk_domain *cpg_mssr_clk_domain;
@@ -667,7 +667,7 @@ static int __init cpg_mssr_add_clk_domain(struct device *dev,
 	size_t pm_size = num_core_pm_clks * sizeof(core_pm_clks[0]);
 	int ret;
 
-	pd = devm_kzalloc(dev, sizeof(*pd) + pm_size, GFP_KERNEL);
+	pd = devm_kzalloc(dev, struct_size(pd, core_pm_clks, num_core_pm_clks), GFP_KERNEL);
 	if (!pd)
 		return -ENOMEM;
 
-- 
2.53.0

Re: [PATCH] clk: renesas: cpg-mssr: use struct_size

[Geert Uytterhoeven]

On Tue, 24 Mar 2026 at 03:11, Rosen Penev <rosenp@gmail.com> wrote:
> struct_size is what is normally used when a flexible array member is
> present to avoid accidental mistakes. pm_size is still needed for the
> memcpy call below.
>
> Added __counted_by for extra runtime analysis.
>
> Signed-off-by: Rosen Penev <rosenp@gmail.com>

FTR, no changes in generated  code.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
i.e. will queue in renesas-clk for v7.1.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds