Re: [PATCH] drm/imagination: fix firmware memory leaks

[Matt Coster]

On 18/03/2025 14:55, Brendan King via B4 Relay wrote:
> From: Brendan King <Brendan.King@xxxxxxxxxx>
> 
> Free the memory used to hold the results of firmware image processing
> when the module is unloaded.
> 
> Fix the related issue of the same memory being leaked if processing
> of the firmware image fails during module load.
> 
> Ensure all firmware GEM objects are destroyed if firmware image
> processing fails.
> 
> Fixes memory leaks on powervr module unload detected by Kmemleak:
> 
> unreferenced object 0xffff000042e20000 (size 94208):
>   comm "modprobe", pid 470, jiffies 4295277154
>   hex dump (first 32 bytes):
>     02 ae 7f ed bf 45 84 00 3c 5b 1f ed 9f 45 45 05  .....E..<[...EE.
>     d5 4f 5d 14 6c 00 3d 23 30 d0 3a 4a 66 0e 48 c8  .O].l.=#0.:Jf.H.
>   backtrace (crc dd329dec):
>     kmemleak_alloc+0x30/0x40
>     ___kmalloc_large_node+0x140/0x188
>     __kmalloc_large_node_noprof+0x2c/0x13c
>     __kmalloc_noprof+0x48/0x4c0
>     pvr_fw_init+0xaa4/0x1f50 [powervr]
> 
> unreferenced object 0xffff000042d20000 (size 20480):
>   comm "modprobe", pid 470, jiffies 4295277154
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 09 00 00 00 0b 00 00 00  ................
>     00 00 00 00 00 00 00 00 07 00 00 00 08 00 00 00  ................
>   backtrace (crc 395b02e3):
>     kmemleak_alloc+0x30/0x40
>     ___kmalloc_large_node+0x140/0x188
>     __kmalloc_large_node_noprof+0x2c/0x13c
>     __kmalloc_noprof+0x48/0x4c0
>     pvr_fw_init+0xb0c/0x1f50 [powervr]
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: cc1aeedb98ad ("drm/imagination: Implement firmware infrastructure and META FW support")
> Signed-off-by: Brendan King <brendan.king@xxxxxxxxxx>

Reviewed-by: Matt Coster <matt.coster@xxxxxxxxxx>

I'll apply this to drm-misc-fixes tomorrow if there are no objections.

> ---
>  drivers/gpu/drm/imagination/pvr_fw.c | 27 ++++++++++++++++++++-------
>  1 file changed, 20 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/imagination/pvr_fw.c b/drivers/gpu/drm/imagination/pvr_fw.c
> index 3debc9870a82ae7de9b2dc173df84c466c137bb3..d09c4c68411627714c14dee5ed4e61b07baca1ba 100644
> --- a/drivers/gpu/drm/imagination/pvr_fw.c
> +++ b/drivers/gpu/drm/imagination/pvr_fw.c
> @@ -732,7 +732,7 @@ pvr_fw_process(struct pvr_device *pvr_dev)
>  					       fw_mem->core_data, fw_mem->core_code_alloc_size);
>  
>  	if (err)
> -		goto err_free_fw_core_data_obj;
> +		goto err_free_kdata;
>  
>  	memcpy(fw_code_ptr, fw_mem->code, fw_mem->code_alloc_size);
>  	memcpy(fw_data_ptr, fw_mem->data, fw_mem->data_alloc_size);
> @@ -742,10 +742,14 @@ pvr_fw_process(struct pvr_device *pvr_dev)
>  		memcpy(fw_core_data_ptr, fw_mem->core_data, fw_mem->core_data_alloc_size);
>  
>  	/* We're finished with the firmware section memory on the CPU, unmap. */
> -	if (fw_core_data_ptr)
> +	if (fw_core_data_ptr) {
>  		pvr_fw_object_vunmap(fw_mem->core_data_obj);
> -	if (fw_core_code_ptr)
> +		fw_core_data_ptr = NULL;
> +	}
> +	if (fw_core_code_ptr) {
>  		pvr_fw_object_vunmap(fw_mem->core_code_obj);
> +		fw_core_code_ptr = NULL;
> +	}
>  	pvr_fw_object_vunmap(fw_mem->data_obj);
>  	fw_data_ptr = NULL;
>  	pvr_fw_object_vunmap(fw_mem->code_obj);
> @@ -753,7 +757,7 @@ pvr_fw_process(struct pvr_device *pvr_dev)
>  
>  	err = pvr_fw_create_fwif_connection_ctl(pvr_dev);
>  	if (err)
> -		goto err_free_fw_core_data_obj;
> +		goto err_free_kdata;
>  
>  	return 0;
>  
> @@ -763,13 +767,16 @@ pvr_fw_process(struct pvr_device *pvr_dev)
>  	kfree(fw_mem->data);
>  	kfree(fw_mem->code);
>  
> -err_free_fw_core_data_obj:
>  	if (fw_core_data_ptr)
> -		pvr_fw_object_unmap_and_destroy(fw_mem->core_data_obj);
> +		pvr_fw_object_vunmap(fw_mem->core_data_obj);
> +	if (fw_mem->core_data_obj)
> +		pvr_fw_object_destroy(fw_mem->core_data_obj);
>  
>  err_free_fw_core_code_obj:
>  	if (fw_core_code_ptr)
> -		pvr_fw_object_unmap_and_destroy(fw_mem->core_code_obj);
> +		pvr_fw_object_vunmap(fw_mem->core_code_obj);
> +	if (fw_mem->core_code_obj)
> +		pvr_fw_object_destroy(fw_mem->core_code_obj);
>  
>  err_free_fw_data_obj:
>  	if (fw_data_ptr)
> @@ -836,6 +843,12 @@ pvr_fw_cleanup(struct pvr_device *pvr_dev)
>  	struct pvr_fw_mem *fw_mem = &pvr_dev->fw_dev.mem;
>  
>  	pvr_fw_fini_fwif_connection_ctl(pvr_dev);
> +
> +	kfree(fw_mem->core_data);
> +	kfree(fw_mem->core_code);
> +	kfree(fw_mem->data);
> +	kfree(fw_mem->code);
> +
>  	if (fw_mem->core_code_obj)
>  		pvr_fw_object_destroy(fw_mem->core_code_obj);
>  	if (fw_mem->core_data_obj)
> 
> ---
> base-commit: 96c85e428ebaeacd2c640eba075479ab92072ccd
> change-id: 20250318-ddkopsrc-1339-firmware-related-memory-leak-on-module-unload-c18a9a4fd0db
> 
> Best regards,


-- 
Matt Coster
E: matt.coster@xxxxxxxxxx

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