[PATCH] powerpc/rtas_flash: Free kmem upon module exit

[PATCH] powerpc/rtas_flash: Free kmem upon module exit

[Vasant Hegde]

Memory allocated to rtas_firmware_flash_list in rtas_flash_write
is not freed during module exit. We hit below call trace if we
unload rtas_flash module after loading new firmware image and
before rebooting the system.

Call trace:
----------
Feb  6 08:42:10 eagle3 kernel: kmem_cache_destroy rtas_flash_cache: Slab cache still has objects
Feb  6 08:42:10 eagle3 kernel: Call Trace:
Feb  6 08:42:10 eagle3 kernel: [c00000001c303b40] [c000000000014940] .show_stack+0x70/0x1c0 (unreliable)
Feb  6 08:42:10 eagle3 kernel: [c00000001c303bf0] [c000000000199bec] .kmem_cache_destroy+0x15c/0x170
Feb  6 08:42:10 eagle3 kernel: [c00000001c303c90] [d000000006fa1208] .rtas_flash_cleanup+0x3c/0x80 [rtas_flash]
Feb  6 08:42:10 eagle3 kernel: [c00000001c303d20] [c0000000000f8970] .SyS_delete_module+0x1d0/0x2e0
Feb  6 08:42:10 eagle3 kernel: [c00000001c303e30] [c000000000009954] syscall_exit+0x0/0x94

This patch frees rtas_firmware_flash_list during module exit.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/rtas_flash.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c
index 8329190..e22ef34 100644
--- a/arch/powerpc/kernel/rtas_flash.c
+++ b/arch/powerpc/kernel/rtas_flash.c
@@ -790,6 +790,11 @@ static void __exit rtas_flash_cleanup(void)
 {
 	rtas_flash_term_hook = NULL;
 
+	if (rtas_firmware_flash_list) {
+		free_flash_list(rtas_firmware_flash_list);
+		rtas_firmware_flash_list = NULL;
+	}
+
 	if (flash_block_cache)
 		kmem_cache_destroy(flash_block_cache);
 

Re: [PATCH] powerpc/rtas_flash: Free kmem upon module exit

[Vasant Hegde]

Ben,

	Let me know your thoughts on this patch.

-Vasant


On 02/08/2013 04:48 PM, Vasant Hegde wrote:
> Memory allocated to rtas_firmware_flash_list in rtas_flash_write
> is not freed during module exit. We hit below call trace if we
> unload rtas_flash module after loading new firmware image and
> before rebooting the system.
>
> Call trace:
> ----------
> Feb  6 08:42:10 eagle3 kernel: kmem_cache_destroy rtas_flash_cache: Slab cache still has objects
> Feb  6 08:42:10 eagle3 kernel: Call Trace:
> Feb  6 08:42:10 eagle3 kernel: [c00000001c303b40] [c000000000014940] .show_stack+0x70/0x1c0 (unreliable)
> Feb  6 08:42:10 eagle3 kernel: [c00000001c303bf0] [c000000000199bec] .kmem_cache_destroy+0x15c/0x170
> Feb  6 08:42:10 eagle3 kernel: [c00000001c303c90] [d000000006fa1208] .rtas_flash_cleanup+0x3c/0x80 [rtas_flash]
> Feb  6 08:42:10 eagle3 kernel: [c00000001c303d20] [c0000000000f8970] .SyS_delete_module+0x1d0/0x2e0
> Feb  6 08:42:10 eagle3 kernel: [c00000001c303e30] [c000000000009954] syscall_exit+0x0/0x94
>
> This patch frees rtas_firmware_flash_list during module exit.
>
> Signed-off-by: Vasant Hegde<hegdevasant@linux.vnet.ibm.com>
> ---
>   arch/powerpc/kernel/rtas_flash.c |    5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c
> index 8329190..e22ef34 100644
> --- a/arch/powerpc/kernel/rtas_flash.c
> +++ b/arch/powerpc/kernel/rtas_flash.c
> @@ -790,6 +790,11 @@ static void __exit rtas_flash_cleanup(void)
>   {
>   	rtas_flash_term_hook = NULL;
>
> +	if (rtas_firmware_flash_list) {
> +		free_flash_list(rtas_firmware_flash_list);
> +		rtas_firmware_flash_list = NULL;
> +	}
> +
>   	if (flash_block_cache)
>   		kmem_cache_destroy(flash_block_cache);
>
>
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