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From:   Hanjun Guo <guohanjun@huawei.com>
To:     Eric Auger <eric.auger@redhat.com>,
        Alex Williamson <alex.williamson@redhat.com>
CC:     <kvm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Sinan Kaya <okaya@codeaurora.org>,
        Hanjun Guo <guohanjun@huawei.com>
Subject: [PATCH] vfio/platform: Remove the ACPI buffer memory to fix memory leak
Date:   Tue, 22 Nov 2022 19:29:58 +0800
Message-ID: <1669116598-25761-1-git-send-email-guohanjun@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

The ACPI buffer memory (buffer.pointer) returned by acpi_evaluate_object()
is not used after the call of _RST method, so it leads to memory leak.

For the calling of ACPI _RST method, we don't need to pass a buffer
for acpi_evaluate_object(), we can just pass NULL and remove the ACPI
buffer memory in vfio_platform_acpi_call_reset(), then we don't need to
free the memory and no memory leak.

Fixes: d30daa33ec1d ("vfio: platform: call _RST method when using ACPI")
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
---
 drivers/vfio/platform/vfio_platform_common.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 55dc4f4..1a0a238 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -72,12 +72,11 @@ static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
 				  const char **extra_dbg)
 {
 #ifdef CONFIG_ACPI
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 	struct device *dev = vdev->device;
 	acpi_handle handle = ACPI_HANDLE(dev);
 	acpi_status acpi_ret;
 
-	acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
+	acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, NULL);
 	if (ACPI_FAILURE(acpi_ret)) {
 		if (extra_dbg)
 			*extra_dbg = acpi_format_exception(acpi_ret);
-- 
1.7.12.4