Rosen Penev <[email protected]> writes:
> Use a flexible array member (FAM) to combine hwmods array allocation
> with the omap_device structure. This reduces the number of allocations
> from two separate calls (one for the device, one for the array) to a
> single allocation, improving efficiency and reducing memory fragmentation.
>
> The FAM approach also enables bounds checking through __counted_by(),
> which provides runtime verification that array accesses stay within
> the allocated size. This improves security and helps catch bugs during
> development.
>
> Simplify error handling by removing the unnecessary multi-label goto
> pattern. The new code is more straightforward: allocate, verify, copy
> data, and either return success or error immediately.
>
> Also removes the now-redundant kfree(od->hwmods) in omap_device_delete()
> since the hwmods array is now embedded in the structure rather than
> separately allocated.
>
> Signed-off-by: Rosen Penev <[email protected]>
Thanks for this cleanup.
> ---
> v3: add a verbose description explaining why. Powered by Claude Sonnet
> 4.5.
> v2: remove kfree and fix compilation.
> arch/arm/mach-omap2/omap_device.c | 29 ++++++++++-------------------
> arch/arm/mach-omap2/omap_device.h | 4 ++--
> 2 files changed, 12 insertions(+), 21 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/omap_device.c
> b/arch/arm/mach-omap2/omap_device.c
> index 79db4c49ffc9..77a75b0b9ae6 100644
> --- a/arch/arm/mach-omap2/omap_device.c
> +++ b/arch/arm/mach-omap2/omap_device.c
> @@ -307,35 +307,27 @@ static struct omap_device *omap_device_alloc(struct
> platform_device *pdev,
> int ret = -ENOMEM;
> struct omap_device *od;
> int i;
> - struct omap_hwmod **hwmods;
> + struct omap_hwmod *hwmod;
>
> - od = kzalloc_obj(struct omap_device);
> - if (!od)
> - goto oda_exit1;
> + od = kzalloc_flex(*od, hwmods, oh_cnt);
> + if (!od) {
> + dev_err(&pdev->dev, "omap_device: build failed (%d)\n", ret);
> + return ERR_PTR(ret);
> + }
>
> od->hwmods_cnt = oh_cnt;
minor nit: isn't this assignment redundant now, as kalloc_flex() should
assign the count?
> + memcpy(od->hwmods, ohs, oh_cnt * sizeof(*od->hwmods));
>
> - hwmods = kmemdup_array(ohs, oh_cnt, sizeof(*hwmods), GFP_KERNEL);
> - if (!hwmods)
> - goto oda_exit2;
> -
> - od->hwmods = hwmods;
> od->pdev = pdev;
> pdev->archdata.od = od;
>
> for (i = 0; i < oh_cnt; i++) {
> - hwmods[i]->od = od;
> - _add_hwmod_clocks_clkdev(od, hwmods[i]);
> + hwmod = od->hwmods[i];
> + hwmod->od = od;
> + _add_hwmod_clocks_clkdev(od, hwmod);
> }
>
> return od;
> -
> -oda_exit2:
> - kfree(od);
> -oda_exit1:
> - dev_err(&pdev->dev, "omap_device: build failed (%d)\n", ret);
> -
> - return ERR_PTR(ret);
> }
Kevin
