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Merged
merged 1 commit into from
Nov 18, 2022
Merged

Add justification for use of dynamic memory #581

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12 changes: 12 additions & 0 deletions MISRA.md
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,18 @@ with ( Assuming rule 11.4 violation; with justification in point 2 ):
```
grep 'MISRA Ref 11.4.2' . -rI
```
#### Directive 4.12

_Ref 4.12.1_

- MISRA C:2012 Directive 4.12: Dynamic memory allocation shall not be used.
MISRA warns against the use of dynamic memory allocation as it might
lead to undefined behavior if not used properly. However, the
FreeRTOS-Plus-TCP library only uses the memory allocation primitives
defined by the FreeRTOS-Kernel, which are deterministic. Additionally,
proper care is taken in the code to not use free'd pointers and to check
the validity of malloc'd memory before it is dereferenced or used.

#### Rule 2.2

_Ref 2.2.1_
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4 changes: 4 additions & 0 deletions source/FreeRTOS_DNS_Callback.c
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Expand Up @@ -110,6 +110,10 @@
TickType_t uxIdentifier )
{
size_t lLength = strlen( pcHostName );

/* MISRA Ref 4.12.1 [Use of dynamic memory]. */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#directive-412. */
/* coverity[misra_c_2012_directive_4_12_violation] */
DNSCallback_t * pxCallback = ( ( DNSCallback_t * ) pvPortMalloc( sizeof( *pxCallback ) + lLength ) );

/* Translate from ms to number of clock ticks. */
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16 changes: 13 additions & 3 deletions source/FreeRTOS_Sockets.c
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Expand Up @@ -404,7 +404,7 @@ Socket_t FreeRTOS_socket( BaseType_t xDomain,
if( prvDetermineSocketSize( xDomain, xType, xProtocolCpy, &uxSocketSize ) == pdFAIL )
{
/* MISRA Ref 11.4.1 [Socket error and integer to pointer conversion] */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-114 */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-114 */
/* coverity[misra_c_2012_rule_11_4_violation] */
xReturn = FREERTOS_INVALID_SOCKET;
}
Expand All @@ -414,12 +414,16 @@ Socket_t FreeRTOS_socket( BaseType_t xDomain,
* size depends on the type of socket: UDP sockets need less space. A
* define 'pvPortMallocSocket' will used to allocate the necessary space.
* By default it points to the FreeRTOS function 'pvPortMalloc()'. */

/* MISRA Ref 4.12.1 [Use of dynamic memory]. */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#directive-412. */
/* coverity[misra_c_2012_directive_4_12_violation] */
pxSocket = ( ( FreeRTOS_Socket_t * ) pvPortMallocSocket( uxSocketSize ) );

if( pxSocket == NULL )
{
/* MISRA Ref 11.4.1 [Socket error and integer to pointer conversion] */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-114 */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-114 */
/* coverity[misra_c_2012_rule_11_4_violation] */
xReturn = FREERTOS_INVALID_SOCKET;
iptraceFAILED_TO_CREATE_SOCKET();
Expand All @@ -433,7 +437,7 @@ Socket_t FreeRTOS_socket( BaseType_t xDomain,
vPortFreeSocket( pxSocket );

/* MISRA Ref 11.4.1 [Socket error and integer to pointer conversion] */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-114 */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-114 */
/* coverity[misra_c_2012_rule_11_4_violation] */
xReturn = FREERTOS_INVALID_SOCKET;
iptraceFAILED_TO_CREATE_EVENT_GROUP();
Expand Down Expand Up @@ -528,6 +532,9 @@ Socket_t FreeRTOS_socket( BaseType_t xDomain,
{
SocketSelect_t * pxSocketSet;

/* MISRA Ref 4.12.1 [Use of dynamic memory]. */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#directive-412. */
/* coverity[misra_c_2012_directive_4_12_violation] */
pxSocketSet = ( ( SocketSelect_t * ) pvPortMalloc( sizeof( *pxSocketSet ) ) );

if( pxSocketSet != NULL )
Expand Down Expand Up @@ -4235,6 +4242,9 @@ void vSocketWakeUpUser( FreeRTOS_Socket_t * pxSocket )

uxSize = ( sizeof( *pxBuffer ) + uxLength ) - sizeof( pxBuffer->ucArray );

/* MISRA Ref 4.12.1 [Use of dynamic memory]. */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#directive-412. */
/* coverity[misra_c_2012_directive_4_12_violation] */
pxBuffer = ( ( StreamBuffer_t * ) pvPortMallocLarge( uxSize ) );

if( pxBuffer == NULL )
Expand Down