Compiling: error: cast increases required alignment of target type [-Werror=cast-align]

Compiling: error: cast increases required alignment of target type [-Werror=cast-align]

[=?unknown-8bit?q?Pi=C4=8Dugins?= Arsenijs]

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Re: Compiling: error: cast increases required alignment of target type [-Werror=cast-align]

[Denis Kenzior]

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Hi,

On 02/04/2019 04:28 PM, Pičugins Arsenijs wrote:
>    CC       drivers/mbimmodem/mbim-message.o
> drivers/mbimmodem/mbim-message.c: In function ‘_iter_copy_string’:
> drivers/mbimmodem/mbim-message.c:199:18: error: cast increases required 
> alignment of target type [-Werror=cast-align]
>     uint16_t *le = (uint16_t *) buf;
>                    ^

Does the attached patch fix this?

Regards,
-Denis




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>From 85b218730efad7143b9be0c3653ad3f4545ff0c7 Mon Sep 17 00:00:00 2001
From: Denis Kenzior <denkenz@gmail.com>
Date: Fri, 8 Feb 2019 14:14:09 -0600
Subject: [PATCH] mbim: Fix compile warning
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

  CC       drivers/mbimmodem/mbim-message.o
drivers/mbimmodem/mbim-message.c: In function ‘_iter_copy_string’:
drivers/mbimmodem/mbim-message.c:199:18: error: cast increases required alignment of target type [-Werror=cast-align]
   uint16_t *le = (uint16_t *) buf;
                  ^
---
 drivers/mbimmodem/mbim-message.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/mbimmodem/mbim-message.c b/drivers/mbimmodem/mbim-message.c
index 7899bc65..0c117658 100644
--- a/drivers/mbimmodem/mbim-message.c
+++ b/drivers/mbimmodem/mbim-message.c
@@ -153,8 +153,8 @@ static bool _iter_copy_string(struct mbim_message_iter *iter,
 					uint32_t offset, uint32_t len,
 					char **out)
 {
-	uint8_t buf[len];
-	uint8_t *dest = buf;
+	uint16_t buf[len / 2 + 1];
+	uint8_t *dest = (uint8_t *) buf;
 	uint32_t remaining = len;
 	uint32_t iov_start = 0;
 	uint32_t i = 0;
@@ -196,7 +196,7 @@ static bool _iter_copy_string(struct mbim_message_iter *iter,
 
 	/* Strings are in UTF16-LE, so convert to UTF16-CPU first if needed */
 	if (L_CPU_TO_LE16(0x8000) != 0x8000) {
-		uint16_t *le = (uint16_t *) buf;
+		uint16_t *le = buf;
 
 		for (i = 0; i < len / 2; i++)
 			le[i] = __builtin_bswap16(le[i]);
-- 
2.13.5

Re: Compiling: error: cast increases required alignment of target type [-Werror=cast-align]

[Martin =?unknown-8bit?q?Hundeb=C3=B8ll?=]

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Hi Denis,

On 08/02/2019 21.15, Denis Kenzior wrote:
> Hi,
> 
> On 02/04/2019 04:28 PM, Pičugins Arsenijs wrote:
>>    CC       drivers/mbimmodem/mbim-message.o
>> drivers/mbimmodem/mbim-message.c: In function ‘_iter_copy_string’:
>> drivers/mbimmodem/mbim-message.c:199:18: error: cast increases 
>> required alignment of target type [-Werror=cast-align]
>>     uint16_t *le = (uint16_t *) buf;
>>                    ^
> 
> Does the attached patch fix this?

It fixes it for me. Please apply.

// Martin

Re: Compiling: error: cast increases required alignment of target type [-Werror=cast-align]

[Denis Kenzior]

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Hi Martin,

On 06/21/2019 04:52 AM, Martin Hundebøll wrote:
> Hi Denis,
> 
> On 08/02/2019 21.15, Denis Kenzior wrote:
>> Hi,
>>
>> On 02/04/2019 04:28 PM, Pičugins Arsenijs wrote:
>>>    CC       drivers/mbimmodem/mbim-message.o
>>> drivers/mbimmodem/mbim-message.c: In function ‘_iter_copy_string’:
>>> drivers/mbimmodem/mbim-message.c:199:18: error: cast increases 
>>> required alignment of target type [-Werror=cast-align]
>>>     uint16_t *le = (uint16_t *) buf;
>>>                    ^
>>
>> Does the attached patch fix this?
> 
> It fixes it for me. Please apply.
> 
> // Martin

All right, applied.

Regards,
-Denis

Re: Compiling: error: cast increases required alignment of target type [-Werror=cast-align]

[Marcel Holtmann]

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Hi Denis,

>>> On 02/04/2019 04:28 PM, Pičugins Arsenijs wrote:
>>>>    CC       drivers/mbimmodem/mbim-message.o
>>>> drivers/mbimmodem/mbim-message.c: In function ‘_iter_copy_string’:
>>>> drivers/mbimmodem/mbim-message.c:199:18: error: cast increases required alignment of target type [-Werror=cast-align]
>>>>     uint16_t *le = (uint16_t *) buf;
>>>>                    ^
>>> 
>>> Does the attached patch fix this?
>> It fixes it for me. Please apply.
>> // Martin
> 
> All right, applied.

I wonder if using l_get_u16 here to ensure that we always get the alignment right isn’t better.

Regards

Marcel