hi Andrew,
I just found acer-wmi-fix-memory-leaks-in-wmab_execute-error-path.patch added to -mm tree.
But I think the V2 version is the correct one.
If the second wmab_execute fail (for any reason) , we need to free the existing buffer before return status.
Sould I resend the patch?
Regards,
Axel
於 五，2010-07-09 於 12:37 +0800，Axel Lin 提到：
> When acpi_evaluate_object() is passed ACPI_ALLOCATE_BUFFER,
> the caller must kfree the returned buffer if AE_OK is returned.
>
> Call Trace:
> wmab_execute
> -> wmi_evaluate_method
> -> acpi_evaluate_object
>
> Thus if callers of wmab_execute() pass ACPI_ALLOCATE_BUFFER,
> the return buffer must be kfreed if wmab_execute return AE_OK.
>
> Signed-off-by: Axel Lin <axel.lin@xxxxxxxxx>
> ---
> drivers/platform/x86/acer-wmi.c | 11 ++++++++++-
> 1 files changed, 10 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
> index 1ea6c43..3f44446 100644
> --- a/drivers/platform/x86/acer-wmi.c
> +++ b/drivers/platform/x86/acer-wmi.c
> @@ -555,6 +555,7 @@ static acpi_status AMW0_find_mailled(void)
> obj->buffer.length == sizeof(struct wmab_ret)) {
> ret = *((struct wmab_ret *) obj->buffer.pointer);
> } else {
> + kfree(out.pointer);
> return AE_ERROR;
> }
>
> @@ -598,6 +599,7 @@ static acpi_status AMW0_set_capabilities(void)
> obj->buffer.length == sizeof(struct wmab_ret)) {
> ret = *((struct wmab_ret *) obj->buffer.pointer);
> } else {
> + kfree(out.pointer);
> return AE_ERROR;
> }
>
> @@ -607,15 +609,22 @@ static acpi_status AMW0_set_capabilities(void)
> args.ebx = 2 << 8;
> args.ebx |= ACER_AMW0_BLUETOOTH_MASK;
>
> + /*
> + * It's ok to use existing buffer for next wmab_execute call.
> + * But we need to kfree(out.pointer) if next wmab_execute fail.
> + */
> status = wmab_execute(&args, &out);
> - if (ACPI_FAILURE(status))
> + if (ACPI_FAILURE(status)) {
> + kfree(out.pointer);
> return status;
> + }
>
> obj = (union acpi_object *) out.pointer;
> if (obj && obj->type == ACPI_TYPE_BUFFER
> && obj->buffer.length == sizeof(struct wmab_ret)) {
> ret = *((struct wmab_ret *) obj->buffer.pointer);
> } else {
> + kfree(out.pointer);
> return AE_ERROR;
> }
>
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