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Memory Protection Unit (MPU) Enhancements (#705)

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Memory Protection Unit (MPU) Enhancements

This commit introduces a new MPU wrapper that places additional
restrictions on unprivileged tasks. The following is the list of changes
introduced with the new MPU wrapper:

1. Opaque and indirectly verifiable integers for kernel object handles:
   All the kernel object handles (for example, queue handles) are now
   opaque integers. Previously object handles were raw pointers.

2. Saving the task context in Task Control Block (TCB): When a task is
   swapped out by the scheduler, the task's context is now saved in its
   TCB. Previously the task's context was saved on its stack.

3. Execute system calls on a separate privileged only stack: FreeRTOS
   system calls, which execute with elevated privilege, now use a
   separate privileged only stack. Previously system calls used the
   calling task's stack. The application writer can control the size of
   the system call stack using new configSYSTEM_CALL_STACK_SIZE config
   macro.

4. Memory bounds checks: FreeRTOS system calls which accept a pointer
   and de-reference it, now verify that the calling task has required
   permissions to access the memory location referenced by the pointer.

5. System call restrictions: The following system calls are no longer
   available to unprivileged tasks:
    - vQueueDelete
    - xQueueCreateMutex
    - xQueueCreateMutexStatic
    - xQueueCreateCountingSemaphore
    - xQueueCreateCountingSemaphoreStatic
    - xQueueGenericCreate
    - xQueueGenericCreateStatic
    - xQueueCreateSet
    - xQueueRemoveFromSet
    - xQueueGenericReset
    - xTaskCreate
    - xTaskCreateStatic
    - vTaskDelete
    - vTaskPrioritySet
    - vTaskSuspendAll
    - xTaskResumeAll
    - xTaskGetHandle
    - xTaskCallApplicationTaskHook
    - vTaskList
    - vTaskGetRunTimeStats
    - xTaskCatchUpTicks
    - xEventGroupCreate
    - xEventGroupCreateStatic
    - vEventGroupDelete
    - xStreamBufferGenericCreate
    - xStreamBufferGenericCreateStatic
    - vStreamBufferDelete
    - xStreamBufferReset
   Also, an unprivileged task can no longer use vTaskSuspend to suspend
   any task other than itself.

We thank the following people for their inputs in these enhancements:
- David Reiss of Meta Platforms, Inc.
- Lan Luo, Xinhui Shao, Yumeng Wei, Zixia Liu, Huaiyu Yan and Zhen Ling
  of School of Computer Science and Engineering, Southeast University,
  China.
- Xinwen Fu of Department of Computer Science, University of
  Massachusetts Lowell, USA.
- Yuequi Chen, Zicheng Wang, Minghao Lin of University of Colorado
  Boulder, USA.
This commit is contained in:
kar-rahul-aws 2023-07-13 16:51:04 +05:30 • committed by GitHub
parent 18e2937239
commit 97050a17aa
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
123 changed files with 94802 additions and 6515 deletions
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726
portable/ARMv8M/non_secure/port.c
View file

@ -107,6 +107,13 @@
#define portPRIGROUP_SHIFT ( 8UL )
/*-----------------------------------------------------------*/
/**
* @brief Constants used during system call enter and exit.
*/
#define portPSR_STACK_PADDING_MASK ( 1UL << 9UL )
#define portEXC_RETURN_STACK_FRAME_TYPE_MASK ( 1UL << 4UL )
/*-----------------------------------------------------------*/
/**
* @brief Constants required to manipulate the FPU.
*/
@ -123,6 +130,14 @@
#define portFPCCR_LSPEN_MASK ( 1UL << portFPCCR_LSPEN_POS )
/*-----------------------------------------------------------*/
/**
* @brief Offsets in the stack to the parameters when inside the SVC handler.
*/
#define portOFFSET_TO_LR ( 5 )
#define portOFFSET_TO_PC ( 6 )
#define portOFFSET_TO_PSR ( 7 )
/*-----------------------------------------------------------*/
/**
* @brief Constants required to manipulate the MPU.
*/
@ -148,6 +163,8 @@
#define portMPU_RBAR_ADDRESS_MASK ( 0xffffffe0 ) /* Must be 32-byte aligned. */
#define portMPU_RLAR_ADDRESS_MASK ( 0xffffffe0 ) /* Must be 32-byte aligned. */
#define portMPU_RBAR_ACCESS_PERMISSIONS_MASK ( 3UL << 1UL )
#define portMPU_MAIR_ATTR0_POS ( 0UL )
#define portMPU_MAIR_ATTR0_MASK ( 0x000000ff )
@ -191,6 +208,30 @@
/* Expected value of the portMPU_TYPE register. */
#define portEXPECTED_MPU_TYPE_VALUE ( configTOTAL_MPU_REGIONS << 8UL )
/* Extract first address of the MPU region as encoded in the
* RBAR (Region Base Address Register) value. */
#define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
( ( rbar ) & portMPU_RBAR_ADDRESS_MASK )
/* Extract last address of the MPU region as encoded in the
* RLAR (Region Limit Address Register) value. */
#define portEXTRACT_LAST_ADDRESS_FROM_RLAR( rlar ) \
( ( ( rlar ) & portMPU_RLAR_ADDRESS_MASK ) | ~portMPU_RLAR_ADDRESS_MASK )
/* Does addr lies within [start, end] address range? */
#define portIS_ADDRESS_WITHIN_RANGE( addr, start, end ) \
( ( ( addr ) >= ( start ) ) && ( ( addr ) <= ( end ) ) )
/* Is the access request satisfied by the available permissions? */
#define portIS_AUTHORIZED( accessRequest, permissions ) \
( ( ( permissions ) & ( accessRequest ) ) == accessRequest )
/* Max value that fits in a uint32_t type. */
#define portUINT32_MAX ( ~( ( uint32_t ) 0 ) )
/* Check if adding a and b will result in overflow. */
#define portADD_UINT32_WILL_OVERFLOW( a, b ) ( ( a ) > ( portUINT32_MAX - ( b ) ) )
/*-----------------------------------------------------------*/
/**
@ -311,6 +352,19 @@ static void prvTaskExitError( void );
#if ( configENABLE_MPU == 1 )
/**
* @brief Extract MPU region's access permissions from the Region Base Address
* Register (RBAR) value.
*
* @param ulRBARValue RBAR value for the MPU region.
*
* @return uint32_t Access permissions.
*/
static uint32_t prvGetRegionAccessPermissions( uint32_t ulRBARValue ) PRIVILEGED_FUNCTION;
#endif /* configENABLE_MPU */
#if ( configENABLE_MPU == 1 )
/**
* @brief Setup the Memory Protection Unit (MPU).
*/
@ -365,6 +419,60 @@ void SysTick_Handler( void ) PRIVILEGED_FUNCTION;
* @brief C part of SVC handler.
*/
portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIVILEGED_FUNCTION;
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
/**
* @brief Sets up the system call stack so that upon returning from
* SVC, the system call stack is used.
*
* It is used for the system calls with up to 4 parameters.
*
* @param pulTaskStack The current SP when the SVC was raised.
* @param ulLR The value of Link Register (EXC_RETURN) in the SVC handler.
*/
void vSystemCallEnter( uint32_t * pulTaskStack, uint32_t ulLR ) PRIVILEGED_FUNCTION;
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
/**
* @brief Sets up the system call stack so that upon returning from
* SVC, the system call stack is used.
*
* It is used for the system calls with 5 parameters.
*
* @param pulTaskStack The current SP when the SVC was raised.
* @param ulLR The value of Link Register (EXC_RETURN) in the SVC handler.
*/
void vSystemCallEnter_1( uint32_t * pulTaskStack, uint32_t ulLR ) PRIVILEGED_FUNCTION;
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
/**
* @brief Sets up the task stack so that upon returning from
* SVC, the task stack is used again.
*
* @param pulSystemCallStack The current SP when the SVC was raised.
* @param ulLR The value of Link Register (EXC_RETURN) in the SVC handler.
*/
void vSystemCallExit( uint32_t * pulSystemCallStack, uint32_t ulLR ) PRIVILEGED_FUNCTION;
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
#if ( configENABLE_MPU == 1 )
/**
* @brief Checks whether or not the calling task is privileged.
*
* @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
*/
BaseType_t xPortIsTaskPrivileged( void ) PRIVILEGED_FUNCTION;
#endif /* configENABLE_MPU == 1 */
/*-----------------------------------------------------------*/
/**
@ -681,6 +789,26 @@ static void prvTaskExitError( void )
}
/*-----------------------------------------------------------*/
#if ( configENABLE_MPU == 1 )
static uint32_t prvGetRegionAccessPermissions( uint32_t ulRBARValue ) /* PRIVILEGED_FUNCTION */
{
uint32_t ulAccessPermissions = 0;
if( ( ulRBARValue & portMPU_RBAR_ACCESS_PERMISSIONS_MASK ) == portMPU_REGION_READ_ONLY )
{
ulAccessPermissions = tskMPU_READ_PERMISSION;
}
if( ( ulRBARValue & portMPU_RBAR_ACCESS_PERMISSIONS_MASK ) == portMPU_REGION_READ_WRITE )
{
ulAccessPermissions = ( tskMPU_READ_PERMISSION | tskMPU_WRITE_PERMISSION );
}
return ulAccessPermissions;
}
#endif /* configENABLE_MPU */
/*-----------------------------------------------------------*/
#if ( configENABLE_MPU == 1 )
static void prvSetupMPU( void ) /* PRIVILEGED_FUNCTION */
{
@ -853,7 +981,7 @@ void SysTick_Handler( void ) /* PRIVILEGED_FUNCTION */
void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTION portDONT_DISCARD */
{
#if ( configENABLE_MPU == 1 )
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
#if defined( __ARMCC_VERSION )
/* Declaration when these variable are defined in code instead of being
@ -865,7 +993,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
extern uint32_t __syscalls_flash_start__[];
extern uint32_t __syscalls_flash_end__[];
#endif /* defined( __ARMCC_VERSION ) */
#endif /* configENABLE_MPU */
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
uint32_t ulPC;
@ -880,7 +1008,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
/* Register are stored on the stack in the following order - R0, R1, R2, R3,
* R12, LR, PC, xPSR. */
ulPC = pulCallerStackAddress[ 6 ];
ulPC = pulCallerStackAddress[ portOFFSET_TO_PC ];
ucSVCNumber = ( ( uint8_t * ) ulPC )[ -2 ];
switch( ucSVCNumber )
@ -951,18 +1079,18 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
vRestoreContextOfFirstTask();
break;
#if ( configENABLE_MPU == 1 )
case portSVC_RAISE_PRIVILEGE:
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
case portSVC_RAISE_PRIVILEGE:
/* Only raise the privilege, if the svc was raised from any of
* the system calls. */
if( ( ulPC >= ( uint32_t ) __syscalls_flash_start__ ) &&
( ulPC <= ( uint32_t ) __syscalls_flash_end__ ) )
{
vRaisePrivilege();
}
break;
#endif /* configENABLE_MPU */
/* Only raise the privilege, if the svc was raised from any of
* the system calls. */
if( ( ulPC >= ( uint32_t ) __syscalls_flash_start__ ) &&
( ulPC <= ( uint32_t ) __syscalls_flash_end__ ) )
{
vRaisePrivilege();
}
break;
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
default:
/* Incorrect SVC call. */
@ -971,51 +1099,455 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
}
/*-----------------------------------------------------------*/
/* *INDENT-OFF* */
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
void vSystemCallEnter( uint32_t * pulTaskStack, uint32_t ulLR ) /* PRIVILEGED_FUNCTION */
{
extern TaskHandle_t pxCurrentTCB;
xMPU_SETTINGS * pxMpuSettings;
uint32_t * pulSystemCallStack;
uint32_t ulStackFrameSize, ulSystemCallLocation, i;
#if defined( __ARMCC_VERSION )
/* Declaration when these variable are defined in code instead of being
* exported from linker scripts. */
extern uint32_t * __syscalls_flash_start__;
extern uint32_t * __syscalls_flash_end__;
#else
/* Declaration when these variable are exported from linker scripts. */
extern uint32_t __syscalls_flash_start__[];
extern uint32_t __syscalls_flash_end__[];
#endif /* #if defined( __ARMCC_VERSION ) */
ulSystemCallLocation = pulTaskStack[ portOFFSET_TO_PC ];
/* If the request did not come from the system call section, do nothing. */
if( ( ulSystemCallLocation >= ( uint32_t ) __syscalls_flash_start__ ) &&
( ulSystemCallLocation <= ( uint32_t ) __syscalls_flash_end__ ) )
{
pxMpuSettings = xTaskGetMPUSettings( pxCurrentTCB );
pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
/* This is not NULL only for the duration of the system call. */
configASSERT( pxMpuSettings->xSystemCallStackInfo.pulTaskStack == NULL );
#if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
{
if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
{
/* Extended frame i.e. FPU in use. */
ulStackFrameSize = 26;
__asm volatile (
" vpush {s0} \n" /* Trigger lazy stacking. */
" vpop {s0} \n" /* Nullify the affect of the above instruction. */
::: "memory"
);
}
else
{
/* Standard frame i.e. FPU not in use. */
ulStackFrameSize = 8;
}
}
#else
{
ulStackFrameSize = 8;
}
#endif /* configENABLE_FPU || configENABLE_MVE */
/* Make space on the system call stack for the stack frame. */
pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
/* Copy the stack frame. */
for( i = 0; i < ulStackFrameSize; i++ )
{
pulSystemCallStack[ i ] = pulTaskStack[ i ];
}
/* Store the value of the LR and PSPLIM registers before the SVC was raised. We need to
* restore it when we exit from the system call. */
pxMpuSettings->xSystemCallStackInfo.ulLinkRegisterAtSystemCallEntry = pulTaskStack[ portOFFSET_TO_LR ];
__asm volatile ( "mrs %0, psplim" : "=r" ( pxMpuSettings->xSystemCallStackInfo.ulStackLimitRegisterAtSystemCallEntry ) );
/* Use the pulSystemCallStack in thread mode. */
__asm volatile ( "msr psp, %0" : : "r" ( pulSystemCallStack ) );
__asm volatile ( "msr psplim, %0" : : "r" ( pxMpuSettings->xSystemCallStackInfo.pulSystemCallStackLimit ) );
/* Remember the location where we should copy the stack frame when we exit from
* the system call. */
pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
/* Record if the hardware used padding to force the stack pointer
* to be double word aligned. */
if( ( pulTaskStack[ portOFFSET_TO_PSR ] & portPSR_STACK_PADDING_MASK ) == portPSR_STACK_PADDING_MASK )
{
pxMpuSettings->ulTaskFlags |= portSTACK_FRAME_HAS_PADDING_FLAG;
}
else
{
pxMpuSettings->ulTaskFlags &= ( ~portSTACK_FRAME_HAS_PADDING_FLAG );
}
/* We ensure in pxPortInitialiseStack that the system call stack is
* double word aligned and therefore, there is no need of padding.
* Clear the bit[9] of stacked xPSR. */
pulSystemCallStack[ portOFFSET_TO_PSR ] &= ( ~portPSR_STACK_PADDING_MASK );
/* Raise the privilege for the duration of the system call. */
__asm volatile (
" mrs r0, control \n" /* Obtain current control value. */
" movs r1, #1 \n" /* r1 = 1. */
" bics r0, r1 \n" /* Clear nPRIV bit. */
" msr control, r0 \n" /* Write back new control value. */
::: "r0", "r1", "memory"
);
}
}
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
void vSystemCallEnter_1( uint32_t * pulTaskStack, uint32_t ulLR ) /* PRIVILEGED_FUNCTION */
{
extern TaskHandle_t pxCurrentTCB;
xMPU_SETTINGS * pxMpuSettings;
uint32_t * pulSystemCallStack;
uint32_t ulStackFrameSize, ulSystemCallLocation, i;
#if defined( __ARMCC_VERSION )
/* Declaration when these variable are defined in code instead of being
* exported from linker scripts. */
extern uint32_t * __syscalls_flash_start__;
extern uint32_t * __syscalls_flash_end__;
#else
/* Declaration when these variable are exported from linker scripts. */
extern uint32_t __syscalls_flash_start__[];
extern uint32_t __syscalls_flash_end__[];
#endif /* #if defined( __ARMCC_VERSION ) */
ulSystemCallLocation = pulTaskStack[ portOFFSET_TO_PC ];
/* If the request did not come from the system call section, do nothing. */
if( ( ulSystemCallLocation >= ( uint32_t ) __syscalls_flash_start__ ) &&
( ulSystemCallLocation <= ( uint32_t ) __syscalls_flash_end__ ) )
{
pxMpuSettings = xTaskGetMPUSettings( pxCurrentTCB );
pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
/* This is not NULL only for the duration of the system call. */
configASSERT( pxMpuSettings->xSystemCallStackInfo.pulTaskStack == NULL );
#if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
{
if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
{
/* Extended frame i.e. FPU in use. */
ulStackFrameSize = 26;
__asm volatile (
" vpush {s0} \n" /* Trigger lazy stacking. */
" vpop {s0} \n" /* Nullify the affect of the above instruction. */
::: "memory"
);
}
else
{
/* Standard frame i.e. FPU not in use. */
ulStackFrameSize = 8;
}
}
#else
{
ulStackFrameSize = 8;
}
#endif /* configENABLE_FPU || configENABLE_MVE */
/* Make space on the system call stack for the stack frame and
* the parameter passed on the stack. We only need to copy one
* parameter but we still reserve 2 spaces to keep the stack
* double word aligned. */
pulSystemCallStack = pulSystemCallStack - ulStackFrameSize - 2UL;
/* Copy the stack frame. */
for( i = 0; i < ulStackFrameSize; i++ )
{
pulSystemCallStack[ i ] = pulTaskStack[ i ];
}
/* Copy the parameter which is passed the stack. */
if( ( pulTaskStack[ portOFFSET_TO_PSR ] & portPSR_STACK_PADDING_MASK ) == portPSR_STACK_PADDING_MASK )
{
pulSystemCallStack[ ulStackFrameSize ] = pulTaskStack[ ulStackFrameSize + 1 ];
/* Record if the hardware used padding to force the stack pointer
* to be double word aligned. */
pxMpuSettings->ulTaskFlags |= portSTACK_FRAME_HAS_PADDING_FLAG;
}
else
{
pulSystemCallStack[ ulStackFrameSize ] = pulTaskStack[ ulStackFrameSize ];
/* Record if the hardware used padding to force the stack pointer
* to be double word aligned. */
pxMpuSettings->ulTaskFlags &= ( ~portSTACK_FRAME_HAS_PADDING_FLAG );
}
/* Store the value of the LR and PSPLIM registers before the SVC was raised.
* We need to restore it when we exit from the system call. */
pxMpuSettings->xSystemCallStackInfo.ulLinkRegisterAtSystemCallEntry = pulTaskStack[ portOFFSET_TO_LR ];
__asm volatile ( "mrs %0, psplim" : "=r" ( pxMpuSettings->xSystemCallStackInfo.ulStackLimitRegisterAtSystemCallEntry ) );
/* Use the pulSystemCallStack in thread mode. */
__asm volatile ( "msr psp, %0" : : "r" ( pulSystemCallStack ) );
__asm volatile ( "msr psplim, %0" : : "r" ( pxMpuSettings->xSystemCallStackInfo.pulSystemCallStackLimit ) );
/* Remember the location where we should copy the stack frame when we exit from
* the system call. */
pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
/* We ensure in pxPortInitialiseStack that the system call stack is
* double word aligned and therefore, there is no need of padding.
* Clear the bit[9] of stacked xPSR. */
pulSystemCallStack[ portOFFSET_TO_PSR ] &= ( ~portPSR_STACK_PADDING_MASK );
/* Raise the privilege for the duration of the system call. */
__asm volatile (
" mrs r0, control \n" /* Obtain current control value. */
" movs r1, #1 \n" /* r1 = 1. */
" bics r0, r1 \n" /* Clear nPRIV bit. */
" msr control, r0 \n" /* Write back new control value. */
::: "r0", "r1", "memory"
);
}
}
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
void vSystemCallExit( uint32_t * pulSystemCallStack, uint32_t ulLR ) /* PRIVILEGED_FUNCTION */
{
extern TaskHandle_t pxCurrentTCB;
xMPU_SETTINGS * pxMpuSettings;
uint32_t * pulTaskStack;
uint32_t ulStackFrameSize, ulSystemCallLocation, i;
#if defined( __ARMCC_VERSION )
/* Declaration when these variable are defined in code instead of being
* exported from linker scripts. */
extern uint32_t * __syscalls_flash_start__;
extern uint32_t * __syscalls_flash_end__;
#else
/* Declaration when these variable are exported from linker scripts. */
extern uint32_t __syscalls_flash_start__[];
extern uint32_t __syscalls_flash_end__[];
#endif /* #if defined( __ARMCC_VERSION ) */
ulSystemCallLocation = pulSystemCallStack[ portOFFSET_TO_PC ];
/* If the request did not come from the system call section, do nothing. */
if( ( ulSystemCallLocation >= ( uint32_t ) __syscalls_flash_start__ ) &&
( ulSystemCallLocation <= ( uint32_t ) __syscalls_flash_end__ ) )
{
pxMpuSettings = xTaskGetMPUSettings( pxCurrentTCB );
pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
#if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
{
if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
{
/* Extended frame i.e. FPU in use. */
ulStackFrameSize = 26;
__asm volatile (
" vpush {s0} \n" /* Trigger lazy stacking. */
" vpop {s0} \n" /* Nullify the affect of the above instruction. */
::: "memory"
);
}
else
{
/* Standard frame i.e. FPU not in use. */
ulStackFrameSize = 8;
}
}
#else
{
ulStackFrameSize = 8;
}
#endif /* configENABLE_FPU || configENABLE_MVE */
/* Make space on the task stack for the stack frame. */
pulTaskStack = pulTaskStack - ulStackFrameSize;
/* Copy the stack frame. */
for( i = 0; i < ulStackFrameSize; i++ )
{
pulTaskStack[ i ] = pulSystemCallStack[ i ];
}
/* Use the pulTaskStack in thread mode. */
__asm volatile ( "msr psp, %0" : : "r" ( pulTaskStack ) );
/* Restore the LR and PSPLIM to what they were at the time of
* system call entry. */
pulTaskStack[ portOFFSET_TO_LR ] = pxMpuSettings->xSystemCallStackInfo.ulLinkRegisterAtSystemCallEntry;
__asm volatile ( "msr psplim, %0" : : "r" ( pxMpuSettings->xSystemCallStackInfo.ulStackLimitRegisterAtSystemCallEntry ) );
/* If the hardware used padding to force the stack pointer
* to be double word aligned, set the stacked xPSR bit[9],
* otherwise clear it. */
if( ( pxMpuSettings->ulTaskFlags & portSTACK_FRAME_HAS_PADDING_FLAG ) == portSTACK_FRAME_HAS_PADDING_FLAG )
{
pulTaskStack[ portOFFSET_TO_PSR ] |= portPSR_STACK_PADDING_MASK;
}
else
{
pulTaskStack[ portOFFSET_TO_PSR ] &= ( ~portPSR_STACK_PADDING_MASK );
}
/* This is not NULL only for the duration of the system call. */
pxMpuSettings->xSystemCallStackInfo.pulTaskStack = NULL;
/* Drop the privilege before returning to the thread mode. */
__asm volatile (
" mrs r0, control \n" /* Obtain current control value. */
" movs r1, #1 \n" /* r1 = 1. */
" orrs r0, r1 \n" /* Set nPRIV bit. */
" msr control, r0 \n" /* Write back new control value. */
::: "r0", "r1", "memory"
);
}
}
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
#if ( configENABLE_MPU == 1 )
StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
StackType_t * pxEndOfStack,
TaskFunction_t pxCode,
void * pvParameters,
BaseType_t xRunPrivileged ) /* PRIVILEGED_FUNCTION */
#else
StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
StackType_t * pxEndOfStack,
TaskFunction_t pxCode,
void * pvParameters ) /* PRIVILEGED_FUNCTION */
#endif /* configENABLE_MPU */
/* *INDENT-ON* */
BaseType_t xPortIsTaskPrivileged( void ) /* PRIVILEGED_FUNCTION */
{
BaseType_t xTaskIsPrivileged = pdFALSE;
const xMPU_SETTINGS * xTaskMpuSettings = xTaskGetMPUSettings( NULL ); /* Calling task's MPU settings. */
if( ( xTaskMpuSettings->ulTaskFlags & portTASK_IS_PRIVILEGED_FLAG ) == portTASK_IS_PRIVILEGED_FLAG )
{
xTaskIsPrivileged = pdTRUE;
}
return xTaskIsPrivileged;
}
#endif /* configENABLE_MPU == 1 */
/*-----------------------------------------------------------*/
#if( configENABLE_MPU == 1 )
StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
StackType_t * pxEndOfStack,
TaskFunction_t pxCode,
void * pvParameters,
BaseType_t xRunPrivileged,
xMPU_SETTINGS * xMPUSettings ) /* PRIVILEGED_FUNCTION */
{
uint32_t ulIndex = 0;
xMPUSettings->ulContext[ ulIndex ] = 0x04040404; /* r4. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x05050505; /* r5. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x06060606; /* r6. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x07070707; /* r7. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x08080808; /* r8. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x09090909; /* r9. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x10101010; /* r10. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x11111111; /* r11. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = ( uint32_t ) pvParameters; /* r0. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x01010101; /* r1. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x02020202; /* r2. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x03030303; /* r3. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = 0x12121212; /* r12. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = ( uint32_t ) portTASK_RETURN_ADDRESS; /* LR. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = ( uint32_t ) pxCode; /* PC. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = portINITIAL_XPSR; /* xPSR. */
ulIndex++;
#if ( configENABLE_TRUSTZONE == 1 )
{
xMPUSettings->ulContext[ ulIndex ] = portNO_SECURE_CONTEXT; /* xSecureContext. */
ulIndex++;
}
#endif /* configENABLE_TRUSTZONE */
xMPUSettings->ulContext[ ulIndex ] = ( uint32_t ) ( pxTopOfStack - 8 ); /* PSP with the hardware saved stack. */
ulIndex++;
xMPUSettings->ulContext[ ulIndex ] = ( uint32_t ) pxEndOfStack; /* PSPLIM. */
ulIndex++;
if( xRunPrivileged == pdTRUE )
{
xMPUSettings->ulTaskFlags |= portTASK_IS_PRIVILEGED_FLAG;
xMPUSettings->ulContext[ ulIndex ] = ( uint32_t ) portINITIAL_CONTROL_PRIVILEGED; /* CONTROL. */
ulIndex++;
}
else
{
xMPUSettings->ulTaskFlags &= ( ~portTASK_IS_PRIVILEGED_FLAG );
xMPUSettings->ulContext[ ulIndex ] = ( uint32_t ) portINITIAL_CONTROL_UNPRIVILEGED; /* CONTROL. */
ulIndex++;
}
xMPUSettings->ulContext[ ulIndex ] = portINITIAL_EXC_RETURN; /* LR (EXC_RETURN). */
ulIndex++;
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
{
/* Ensure that the system call stack is double word aligned. */
xMPUSettings->xSystemCallStackInfo.pulSystemCallStack = &( xMPUSettings->xSystemCallStackInfo.ulSystemCallStackBuffer[ configSYSTEM_CALL_STACK_SIZE - 1 ] );
xMPUSettings->xSystemCallStackInfo.pulSystemCallStack = ( uint32_t * ) ( ( uint32_t ) ( xMPUSettings->xSystemCallStackInfo.pulSystemCallStack ) &
( uint32_t ) ( ~( portBYTE_ALIGNMENT_MASK ) ) );
xMPUSettings->xSystemCallStackInfo.pulSystemCallStackLimit = &( xMPUSettings->xSystemCallStackInfo.ulSystemCallStackBuffer[ 0 ] );
xMPUSettings->xSystemCallStackInfo.pulSystemCallStackLimit = ( uint32_t * ) ( ( ( uint32_t ) ( xMPUSettings->xSystemCallStackInfo.pulSystemCallStackLimit ) +
( uint32_t ) ( portBYTE_ALIGNMENT - 1 ) ) &
( uint32_t ) ( ~( portBYTE_ALIGNMENT_MASK ) ) );
/* This is not NULL only for the duration of a system call. */
xMPUSettings->xSystemCallStackInfo.pulTaskStack = NULL;
}
#endif /* configUSE_MPU_WRAPPERS_V1 == 0 */
return &( xMPUSettings->ulContext[ ulIndex ] );
}
#else /* configENABLE_MPU */
StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
StackType_t * pxEndOfStack,
TaskFunction_t pxCode,
void * pvParameters ) /* PRIVILEGED_FUNCTION */
{
/* Simulate the stack frame as it would be created by a context switch
* interrupt. */
#if ( portPRELOAD_REGISTERS == 0 )
{
pxTopOfStack--; /* Offset added to account for the way the MCU uses the stack on entry/exit of interrupts. */
*pxTopOfStack = portINITIAL_XPSR; /* xPSR */
*pxTopOfStack = portINITIAL_XPSR; /* xPSR. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pxCode; /* PC */
*pxTopOfStack = ( StackType_t ) pxCode; /* PC. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) portTASK_RETURN_ADDRESS; /* LR */
*pxTopOfStack = ( StackType_t ) portTASK_RETURN_ADDRESS; /* LR. */
pxTopOfStack -= 5; /* R12, R3, R2 and R1. */
*pxTopOfStack = ( StackType_t ) pvParameters; /* R0 */
*pxTopOfStack = ( StackType_t ) pvParameters; /* R0. */
pxTopOfStack -= 9; /* R11..R4, EXC_RETURN. */
*pxTopOfStack = portINITIAL_EXC_RETURN;
#if ( configENABLE_MPU == 1 )
{
pxTopOfStack--;
if( xRunPrivileged == pdTRUE )
{
*pxTopOfStack = portINITIAL_CONTROL_PRIVILEGED; /* Slot used to hold this task's CONTROL value. */
}
else
{
*pxTopOfStack = portINITIAL_CONTROL_UNPRIVILEGED; /* Slot used to hold this task's CONTROL value. */
}
}
#endif /* configENABLE_MPU */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pxEndOfStack; /* Slot used to hold this task's PSPLIM value. */
@ -1029,55 +1561,39 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
#else /* portPRELOAD_REGISTERS */
{
pxTopOfStack--; /* Offset added to account for the way the MCU uses the stack on entry/exit of interrupts. */
*pxTopOfStack = portINITIAL_XPSR; /* xPSR */
*pxTopOfStack = portINITIAL_XPSR; /* xPSR. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pxCode; /* PC */
*pxTopOfStack = ( StackType_t ) pxCode; /* PC. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) portTASK_RETURN_ADDRESS; /* LR */
*pxTopOfStack = ( StackType_t ) portTASK_RETURN_ADDRESS; /* LR. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x12121212UL; /* R12 */
*pxTopOfStack = ( StackType_t ) 0x12121212UL; /* R12. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x03030303UL; /* R3 */
*pxTopOfStack = ( StackType_t ) 0x03030303UL; /* R3. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x02020202UL; /* R2 */
*pxTopOfStack = ( StackType_t ) 0x02020202UL; /* R2. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x01010101UL; /* R1 */
*pxTopOfStack = ( StackType_t ) 0x01010101UL; /* R1. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pvParameters; /* R0 */
*pxTopOfStack = ( StackType_t ) pvParameters; /* R0. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x11111111UL; /* R11 */
*pxTopOfStack = ( StackType_t ) 0x11111111UL; /* R11. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x10101010UL; /* R10 */
*pxTopOfStack = ( StackType_t ) 0x10101010UL; /* R10. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x09090909UL; /* R09 */
*pxTopOfStack = ( StackType_t ) 0x09090909UL; /* R09. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x08080808UL; /* R08 */
*pxTopOfStack = ( StackType_t ) 0x08080808UL; /* R08. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x07070707UL; /* R07 */
*pxTopOfStack = ( StackType_t ) 0x07070707UL; /* R07. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x06060606UL; /* R06 */
*pxTopOfStack = ( StackType_t ) 0x06060606UL; /* R06. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x05050505UL; /* R05 */
*pxTopOfStack = ( StackType_t ) 0x05050505UL; /* R05. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x04040404UL; /* R04 */
*pxTopOfStack = ( StackType_t ) 0x04040404UL; /* R04. */
pxTopOfStack--;
*pxTopOfStack = portINITIAL_EXC_RETURN; /* EXC_RETURN */
#if ( configENABLE_MPU == 1 )
{
pxTopOfStack--;
if( xRunPrivileged == pdTRUE )
{
*pxTopOfStack = portINITIAL_CONTROL_PRIVILEGED; /* Slot used to hold this task's CONTROL value. */
}
else
{
*pxTopOfStack = portINITIAL_CONTROL_UNPRIVILEGED; /* Slot used to hold this task's CONTROL value. */
}
}
#endif /* configENABLE_MPU */
*pxTopOfStack = portINITIAL_EXC_RETURN; /* EXC_RETURN. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pxEndOfStack; /* Slot used to hold this task's PSPLIM value. */
@ -1092,6 +1608,8 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
return pxTopOfStack;
}
#endif /* configENABLE_MPU */
/*-----------------------------------------------------------*/
BaseType_t xPortStartScheduler( void ) /* PRIVILEGED_FUNCTION */
@ -1347,6 +1865,54 @@ void vPortEndScheduler( void ) /* PRIVILEGED_FUNCTION */
#endif /* configENABLE_MPU */
/*-----------------------------------------------------------*/
#if ( configENABLE_MPU == 1 )
BaseType_t xPortIsAuthorizedToAccessBuffer( const void * pvBuffer,
uint32_t ulBufferLength,
uint32_t ulAccessRequested ) /* PRIVILEGED_FUNCTION */
{
uint32_t i, ulBufferStartAddress, ulBufferEndAddress;
BaseType_t xAccessGranted = pdFALSE;
const xMPU_SETTINGS * xTaskMpuSettings = xTaskGetMPUSettings( NULL ); /* Calling task's MPU settings. */
if( ( xTaskMpuSettings->ulTaskFlags & portTASK_IS_PRIVILEGED_FLAG ) == portTASK_IS_PRIVILEGED_FLAG )
{
xAccessGranted = pdTRUE;
}
else
{
if( portADD_UINT32_WILL_OVERFLOW( ( ( uint32_t ) pvBuffer ), ( ulBufferLength - 1UL ) ) == pdFALSE )
{
ulBufferStartAddress = ( uint32_t ) pvBuffer;
ulBufferEndAddress = ( ( ( uint32_t ) pvBuffer ) + ulBufferLength - 1UL );
for( i = 0; i < portTOTAL_NUM_REGIONS; i++ )
{
/* Is the MPU region enabled? */
if( ( xTaskMpuSettings->xRegionsSettings[ i ].ulRLAR & portMPU_RLAR_REGION_ENABLE ) == portMPU_RLAR_REGION_ENABLE )
{
if( portIS_ADDRESS_WITHIN_RANGE( ulBufferStartAddress,
portEXTRACT_FIRST_ADDRESS_FROM_RBAR( xTaskMpuSettings->xRegionsSettings[ i ].ulRBAR ),
portEXTRACT_LAST_ADDRESS_FROM_RLAR( xTaskMpuSettings->xRegionsSettings[ i ].ulRLAR ) ) &&
portIS_ADDRESS_WITHIN_RANGE( ulBufferEndAddress,
portEXTRACT_FIRST_ADDRESS_FROM_RBAR( xTaskMpuSettings->xRegionsSettings[ i ].ulRBAR ),
portEXTRACT_LAST_ADDRESS_FROM_RLAR( xTaskMpuSettings->xRegionsSettings[ i ].ulRLAR ) ) &&
portIS_AUTHORIZED( ulAccessRequested,
prvGetRegionAccessPermissions( xTaskMpuSettings->xRegionsSettings[ i ].ulRBAR ) ) )
{
xAccessGranted = pdTRUE;
break;
}
}
}
}
}
return xAccessGranted;
}
#endif /* configENABLE_MPU */
/*-----------------------------------------------------------*/
BaseType_t xPortIsInsideInterrupt( void )
{
uint32_t ulCurrentInterrupt;