[PATCH v2 12/15] platform/chrome: use krealloc() for `din` and `dout`

From: Tzung-Bi Shih
Date: Tue Jun 07 2022 - 10:57:58 EST


Use krealloc() to re-allocate `din` and `dout`. Don't use devm variant
because the two buffers could be re-allocated multiple times during
runtime. Their life cycles aren't quite aligned to the device's.

Free the memory in cros_ec_unregister() if any.

No need to free memory if krealloc() fails. They will be freed
eventually in either of the following:
- Error handling path in cros_ec_register().
- In cros_ec_unregister().
- Next krealloc() in cros_ec_query_all().

Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
---
Changes from v1:
- Don't use devm.
- Free in cros_ec_unregister().

drivers/platform/chrome/cros_ec.c | 4 +++
drivers/platform/chrome/cros_ec_proto.c | 29 +++++++-------------
drivers/platform/chrome/cros_ec_proto_test.c | 3 +-
3 files changed, 15 insertions(+), 21 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index 29d3b544dafb..fb8cb8a73295 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -285,6 +285,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
exit:
platform_device_unregister(ec_dev->ec);
platform_device_unregister(ec_dev->pd);
+ kfree(ec_dev->din);
+ kfree(ec_dev->dout);
return err;
}
EXPORT_SYMBOL(cros_ec_register);
@@ -302,6 +304,8 @@ void cros_ec_unregister(struct cros_ec_device *ec_dev)
if (ec_dev->pd)
platform_device_unregister(ec_dev->pd);
platform_device_unregister(ec_dev->ec);
+ kfree(ec_dev->din);
+ kfree(ec_dev->dout);
}
EXPORT_SYMBOL(cros_ec_unregister);

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 473654f50bca..de6bc457e496 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -469,9 +469,9 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
*/
int cros_ec_query_all(struct cros_ec_device *ec_dev)
{
- struct device *dev = ec_dev->dev;
u32 ver_mask = 0;
int ret;
+ u8 *din, *dout;

/* First try sending with proto v3. */
if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) {
@@ -492,21 +492,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
}
}

- devm_kfree(dev, ec_dev->din);
- devm_kfree(dev, ec_dev->dout);
-
- ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
- if (!ec_dev->din) {
- ret = -ENOMEM;
- goto exit;
- }
+ din = krealloc(ec_dev->din, ec_dev->din_size, GFP_KERNEL);
+ if (!din)
+ return -ENOMEM;
+ ec_dev->din = din;

- ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
- if (!ec_dev->dout) {
- devm_kfree(dev, ec_dev->din);
- ret = -ENOMEM;
- goto exit;
- }
+ dout = krealloc(ec_dev->dout, ec_dev->dout_size, GFP_KERNEL);
+ if (!dout)
+ return -ENOMEM;
+ ec_dev->dout = dout;

/* Probe if MKBP event is supported */
ret = cros_ec_get_host_command_version_mask(ec_dev,
@@ -555,10 +549,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
"failed to retrieve wake mask: %d\n", ret);
}

- ret = 0;
-
-exit:
- return ret;
+ return 0;
}
EXPORT_SYMBOL(cros_ec_query_all);

diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c
index 730248be42a7..27b81a5a9880 100644
--- a/drivers/platform/chrome/cros_ec_proto_test.c
+++ b/drivers/platform/chrome/cros_ec_proto_test.c
@@ -180,8 +180,7 @@ static void cros_ec_proto_test_query_all_pretest(struct kunit *test)

/*
* cros_ec_query_all() will free din and dout and allocate them again to fit the usage by
- * calling devm_kfree() and devm_kzalloc(). Set them to NULL as they aren't managed by
- * ec_dev->dev.
+ * calling krealloc(). Set them to NULL as they aren't allocated by kalloc().
*/
ec_dev->din = NULL;
ec_dev->dout = NULL;
--
2.36.1.255.ge46751e96f-goog