[PATCH AUTOSEL 4.19 39/66] drm/amd/display: dal_ddc_i2c_payloads_create can fail causing panic

Sasha Levin
2020-04-11T23:23:01Z

From: Aric Cyr <aric.cyr@amd.com>

[ Upstream commit 6a6c4a4d459ecacc9013c45dcbf2bc9747fdbdbd ]

[Why]
Since the i2c payload allocation can fail need to check return codes

[How]
Clean up i2c payload allocations and check for errors

Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Reviewed-by: Joshua Aberback <Joshua.Aberback@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../gpu/drm/amd/display/dc/core/dc_link_ddc.c | 52 +++++++++----------
1 file changed, 25 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c
index 46c9cb47a96e5..145af3bb2dfcb 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c
@@ -127,22 +127,16 @@ struct aux_payloads {
struct vector payloads;
};

-static struct i2c_payloads *dal_ddc_i2c_payloads_create(struct dc_context *ctx, uint32_t count)
+static bool dal_ddc_i2c_payloads_create(
+ struct dc_context *ctx,
+ struct i2c_payloads *payloads,
+ uint32_t count)
{
- struct i2c_payloads *payloads;
-
- payloads = kzalloc(sizeof(struct i2c_payloads), GFP_KERNEL);
-
- if (!payloads)
- return NULL;
-
if (dal_vector_construct(
&payloads->payloads, ctx, count, sizeof(struct i2c_payload)))
- return payloads;
-
- kfree(payloads);
- return NULL;
+ return true;

+ return false;
}

static struct i2c_payload *dal_ddc_i2c_payloads_get(struct i2c_payloads *p)
@@ -155,14 +149,12 @@ static uint32_t dal_ddc_i2c_payloads_get_count(struct i2c_payloads *p)
return p->payloads.count;
}

-static void dal_ddc_i2c_payloads_destroy(struct i2c_payloads **p)
+static void dal_ddc_i2c_payloads_destroy(struct i2c_payloads *p)
{
- if (!p || !*p)
+ if (!p)
return;
- dal_vector_destruct(&(*p)->payloads);
- kfree(*p);
- *p = NULL;

+ dal_vector_destruct(&p->payloads);
}

static struct aux_payloads *dal_ddc_aux_payloads_create(struct dc_context *ctx, uint32_t count)
@@ -580,9 +572,13 @@ bool dal_ddc_service_query_ddc_data(

uint32_t payloads_num = write_payloads + read_payloads;

+
if (write_size > EDID_SEGMENT_SIZE || read_size > EDID_SEGMENT_SIZE)
return false;

+ if (!payloads_num)
+ return false;
+
/*TODO: len of payload data for i2c and aux is uint8!!!!,
* but we want to read 256 over i2c!!!!*/
if (dal_ddc_service_is_in_aux_transaction_mode(ddc)) {
@@ -613,23 +609,25 @@ bool dal_ddc_service_query_ddc_data(
dal_ddc_aux_payloads_destroy(&payloads);

} else {
- struct i2c_payloads *payloads =
- dal_ddc_i2c_payloads_create(ddc->ctx, payloads_num);
+ struct i2c_command command = {0};
+ struct i2c_payloads payloads;

- struct i2c_command command = {
- .payloads = dal_ddc_i2c_payloads_get(payloads),
- .number_of_payloads = 0,
- .engine = DDC_I2C_COMMAND_ENGINE,
- .speed = ddc->ctx->dc->caps.i2c_speed_in_khz };
+ if (!dal_ddc_i2c_payloads_create(ddc->ctx, &payloads, payloads_num))
+ return false;
+
+ command.payloads = dal_ddc_i2c_payloads_get(&payloads);
+ command.number_of_payloads = 0;
+ command.engine = DDC_I2C_COMMAND_ENGINE;
+ command.speed = ddc->ctx->dc->caps.i2c_speed_in_khz;

dal_ddc_i2c_payloads_add(
- payloads, address, write_size, write_buf, true);
+ &payloads, address, write_size, write_buf, true);

dal_ddc_i2c_payloads_add(
- payloads, address, read_size, read_buf, false);
+ &payloads, address, read_size, read_buf, false);

command.number_of_payloads =
- dal_ddc_i2c_payloads_get_count(payloads);
+ dal_ddc_i2c_payloads_get_count(&payloads);

ret = dm_helpers_submit_i2c(
ddc->ctx,
--
2.20.1