[PATCH] firmware: cs_dsp: avoid large local variables

Arnd Bergmann posted 1 patch 1 year ago
There is a newer version of this series
.../firmware/cirrus/test/cs_dsp_test_bin.c    | 36 +++++++++++--------
1 file changed, 22 insertions(+), 14 deletions(-)
[PATCH] firmware: cs_dsp: avoid large local variables
Posted by Arnd Bergmann 1 year ago
From: Arnd Bergmann <arnd@arndb.de>

Having 1280 bytes of local variables on the stack exceeds the limit
on 32-bit architectures:

drivers/firmware/cirrus/test/cs_dsp_test_bin.c: In function 'bin_patch_mixed_packed_unpacked_random':
drivers/firmware/cirrus/test/cs_dsp_test_bin.c:2097:1: error: the frame size of 1784 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

Use dynamic allocation for the largest two here.

Fixes: dd0b6b1f29b9 ("firmware: cs_dsp: Add KUnit testing of bin file download")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 .../firmware/cirrus/test/cs_dsp_test_bin.c    | 36 +++++++++++--------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/drivers/firmware/cirrus/test/cs_dsp_test_bin.c b/drivers/firmware/cirrus/test/cs_dsp_test_bin.c
index 689190453307..f1955813919c 100644
--- a/drivers/firmware/cirrus/test/cs_dsp_test_bin.c
+++ b/drivers/firmware/cirrus/test/cs_dsp_test_bin.c
@@ -1978,8 +1978,10 @@ static void bin_patch_mixed_packed_unpacked_random(struct kunit *test)
 		 4, 51, 76, 72, 16,  6, 39, 62, 15, 41, 28, 73, 53, 40, 45, 54,
 		14, 55, 46, 66, 64, 59, 23,  9, 67, 47, 19, 71, 35, 18, 42,  1,
 	};
-	u32 packed_payload[80][3];
-	u32 unpacked_payload[80];
+	struct {
+		u32 packed[80][3];
+		u32 unpacked[80];
+	} *payload;
 	u32 readback[3];
 	unsigned int alg_base_words, patch_pos_words;
 	unsigned int alg_base_in_packed_regs, patch_pos_in_packed_regs;
@@ -1988,8 +1990,12 @@ static void bin_patch_mixed_packed_unpacked_random(struct kunit *test)
 	struct firmware *fw;
 	int i;
 
-	get_random_bytes(packed_payload, sizeof(packed_payload));
-	get_random_bytes(unpacked_payload, sizeof(unpacked_payload));
+	payload = kmalloc(sizeof(*payload), GFP_KERNEL);
+	if (!payload)
+		return;
+
+	get_random_bytes(payload->packed, sizeof(payload->packed));
+	get_random_bytes(payload->unpacked, sizeof(payload->unpacked));
 
 	/* Create a patch entry for every offset in offset_words[] */
 	for (i = 0; i < ARRAY_SIZE(offset_words); ++i) {
@@ -2010,8 +2016,8 @@ static void bin_patch_mixed_packed_unpacked_random(struct kunit *test)
 						  bin_test_mock_algs[0].ver,
 						  param->mem_type,
 						  payload_offset,
-						  packed_payload[i],
-						  sizeof(packed_payload[i]));
+						  payload->packed[i],
+						  sizeof(payload->packed[i]));
 		} else {
 			payload_offset = offset_words[i] * 4;
 			cs_dsp_mock_bin_add_patch(priv->local->bin_builder,
@@ -2019,8 +2025,8 @@ static void bin_patch_mixed_packed_unpacked_random(struct kunit *test)
 						  bin_test_mock_algs[0].ver,
 						  unpacked_mem_type,
 						  payload_offset,
-						  &unpacked_payload[i],
-						  sizeof(unpacked_payload[i]));
+						  &payload->unpacked[i],
+						  sizeof(payload->unpacked[i]));
 		}
 	}
 
@@ -2033,7 +2039,7 @@ static void bin_patch_mixed_packed_unpacked_random(struct kunit *test)
 	/*
 	 * Readback the packed registers that should have been written.
 	 * Place the values into the expected location in readback[] so
-	 * that the content of readback[] should match packed_payload[]
+	 * that the content of readback[] should match payload->packed[]
 	 */
 	for (i = 0; i < ARRAY_SIZE(offset_words); ++i) {
 		alg_base_words = cs_dsp_mock_xm_header_get_alg_base_in_words(priv,
@@ -2055,16 +2061,16 @@ static void bin_patch_mixed_packed_unpacked_random(struct kunit *test)
 				regmap_raw_read(priv->dsp->regmap, reg_addr, readback,
 						sizeof(readback)),
 				0);
-		KUNIT_EXPECT_MEMEQ(test, readback, packed_payload[i], sizeof(packed_payload[i]));
+		KUNIT_EXPECT_MEMEQ(test, readback, payload->packed[i], sizeof(payload->packed[i]));
 
 		/* Drop expected writes from the cache */
-		cs_dsp_mock_regmap_drop_bytes(priv, reg_addr, sizeof(packed_payload[i]));
+		cs_dsp_mock_regmap_drop_bytes(priv, reg_addr, sizeof(payload->packed[i]));
 	}
 
 	/*
 	 * Readback the unpacked registers that should have been written.
 	 * Place the values into the expected location in readback[] so
-	 * that the content of readback[] should match unpacked_payload[]
+	 * that the content of readback[] should match payload->unpacked[]
 	 */
 	for (i = 0; i < ARRAY_SIZE(offset_words); ++i) {
 		alg_base_words = cs_dsp_mock_xm_header_get_alg_base_in_words(priv,
@@ -2085,15 +2091,17 @@ static void bin_patch_mixed_packed_unpacked_random(struct kunit *test)
 				regmap_raw_read(priv->dsp->regmap, reg_addr,
 						&readback[0], sizeof(readback[0])),
 				0);
-		KUNIT_EXPECT_EQ(test, readback[0], unpacked_payload[i]);
+		KUNIT_EXPECT_EQ(test, readback[0], payload->unpacked[i]);
 
 		/* Drop expected writes from the cache */
-		cs_dsp_mock_regmap_drop_bytes(priv, reg_addr, sizeof(unpacked_payload[i]));
+		cs_dsp_mock_regmap_drop_bytes(priv, reg_addr, sizeof(payload->unpacked[i]));
 	}
 
 	/* Drop expected writes and the cache should then be clean */
 	cs_dsp_mock_xm_header_drop_from_regmap_cache(priv);
 	KUNIT_EXPECT_FALSE(test, cs_dsp_mock_regmap_is_dirty(priv, true));
+
+	kfree(payload);
 }
 
 /* Bin file with name and multiple info blocks */
-- 
2.39.5
Re: [PATCH] firmware: cs_dsp: avoid large local variables
Posted by Richard Fitzgerald 1 year ago
On 16/12/2024 8:33 am, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Having 1280 bytes of local variables on the stack exceeds the limit
> on 32-bit architectures:
> 
> drivers/firmware/cirrus/test/cs_dsp_test_bin.c: In function 'bin_patch_mixed_packed_unpacked_random':
> drivers/firmware/cirrus/test/cs_dsp_test_bin.c:2097:1: error: the frame size of 1784 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
> 
> Use dynamic allocation for the largest two here.
> 
> Fixes: dd0b6b1f29b9 ("firmware: cs_dsp: Add KUnit testing of bin file download")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   .../firmware/cirrus/test/cs_dsp_test_bin.c    | 36 +++++++++++--------
>   1 file changed, 22 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/firmware/cirrus/test/cs_dsp_test_bin.c b/drivers/firmware/cirrus/test/cs_dsp_test_bin.c
> index 689190453307..f1955813919c 100644
> --- a/drivers/firmware/cirrus/test/cs_dsp_test_bin.c
> +++ b/drivers/firmware/cirrus/test/cs_dsp_test_bin.c
> @@ -1978,8 +1978,10 @@ static void bin_patch_mixed_packed_unpacked_random(struct kunit *test)
>   		 4, 51, 76, 72, 16,  6, 39, 62, 15, 41, 28, 73, 53, 40, 45, 54,
>   		14, 55, 46, 66, 64, 59, 23,  9, 67, 47, 19, 71, 35, 18, 42,  1,
>   	};
> -	u32 packed_payload[80][3];
> -	u32 unpacked_payload[80];
> +	struct {
> +		u32 packed[80][3];
> +		u32 unpacked[80];
> +	} *payload;
>   	u32 readback[3];
>   	unsigned int alg_base_words, patch_pos_words;
>   	unsigned int alg_base_in_packed_regs, patch_pos_in_packed_regs;
> @@ -1988,8 +1990,12 @@ static void bin_patch_mixed_packed_unpacked_random(struct kunit *test)
>   	struct firmware *fw;
>   	int i;
>   
> -	get_random_bytes(packed_payload, sizeof(packed_payload));
> -	get_random_bytes(unpacked_payload, sizeof(unpacked_payload));
> +	payload = kmalloc(sizeof(*payload), GFP_KERNEL);

Should be kunit_kmalloc() so the kunit framework frees it automatically
if any test case fails and the test terminates early.

Apart from that it looks ok to me.
Re: [PATCH] firmware: cs_dsp: avoid large local variables
Posted by Richard Fitzgerald 1 year ago
On 16/12/2024 10:38 am, Richard Fitzgerald wrote:
> On 16/12/2024 8:33 am, Arnd Bergmann wrote:
>> From: Arnd Bergmann <arnd@arndb.de>
>>
>> Having 1280 bytes of local variables on the stack exceeds the limit
>> on 32-bit architectures:
>>
>> drivers/firmware/cirrus/test/cs_dsp_test_bin.c: In function 
>> 'bin_patch_mixed_packed_unpacked_random':
>> drivers/firmware/cirrus/test/cs_dsp_test_bin.c:2097:1: error: the 
>> frame size of 1784 bytes is larger than 1024 bytes [-Werror=frame- 
>> larger-than=]
>>
>> Use dynamic allocation for the largest two here.
>>
>> Fixes: dd0b6b1f29b9 ("firmware: cs_dsp: Add KUnit testing of bin file 
>> download")
>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>> ---
>>   .../firmware/cirrus/test/cs_dsp_test_bin.c    | 36 +++++++++++--------
>>   1 file changed, 22 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/firmware/cirrus/test/cs_dsp_test_bin.c b/drivers/ 
>> firmware/cirrus/test/cs_dsp_test_bin.c
>> index 689190453307..f1955813919c 100644
>> --- a/drivers/firmware/cirrus/test/cs_dsp_test_bin.c
>> +++ b/drivers/firmware/cirrus/test/cs_dsp_test_bin.c
>> @@ -1978,8 +1978,10 @@ static void 
>> bin_patch_mixed_packed_unpacked_random(struct kunit *test)
>>            4, 51, 76, 72, 16,  6, 39, 62, 15, 41, 28, 73, 53, 40, 45, 54,
>>           14, 55, 46, 66, 64, 59, 23,  9, 67, 47, 19, 71, 35, 18, 42,  1,
>>       };
>> -    u32 packed_payload[80][3];
>> -    u32 unpacked_payload[80];
>> +    struct {
>> +        u32 packed[80][3];
>> +        u32 unpacked[80];
>> +    } *payload;
>>       u32 readback[3];
>>       unsigned int alg_base_words, patch_pos_words;
>>       unsigned int alg_base_in_packed_regs, patch_pos_in_packed_regs;
>> @@ -1988,8 +1990,12 @@ static void 
>> bin_patch_mixed_packed_unpacked_random(struct kunit *test)
>>       struct firmware *fw;
>>       int i;
>> -    get_random_bytes(packed_payload, sizeof(packed_payload));
>> -    get_random_bytes(unpacked_payload, sizeof(unpacked_payload));
>> +    payload = kmalloc(sizeof(*payload), GFP_KERNEL);
> 
> Should be kunit_kmalloc() so the kunit framework frees it automatically
> if any test case fails and the test terminates early.
> 
> Apart from that it looks ok to me.

Also the check for NULL should use KUNIT_ASSERT_NOT_NULL() so the test
case will error-out.