[PATCH 2/3] stackchk: Use a const pattern to check
Sebastian Huber
sebastian.huber at embedded-brains.de
Wed Sep 7 12:45:35 UTC 2016
---
cpukit/libmisc/stackchk/check.c | 131 +++++++++--------------------
cpukit/score/cpu/powerpc/rtems/score/cpu.h | 10 ++-
2 files changed, 51 insertions(+), 90 deletions(-)
diff --git a/cpukit/libmisc/stackchk/check.c b/cpukit/libmisc/stackchk/check.c
index 2cf490a..6b6b98b 100644
--- a/cpukit/libmisc/stackchk/check.c
+++ b/cpukit/libmisc/stackchk/check.c
@@ -50,14 +50,14 @@
* pattern area must be a multiple of 4 words.
*/
-#ifdef CPU_STACK_CHECK_SIZE
-#define PATTERN_SIZE_WORDS (((CPU_STACK_CHECK_SIZE / 4) + 3) & ~0x3)
-#else
-#define PATTERN_SIZE_WORDS (4)
+#if !defined(CPU_STACK_CHECK_PATTERN_INITIALIZER)
+#define CPU_STACK_CHECK_PATTERN_INITIALIZER \
+ { \
+ 0xFEEDF00D, 0x0BAD0D06, /* FEED FOOD to BAD DOG */ \
+ 0xDEADF00D, 0x600D0D06 /* DEAD FOOD but GOOD DOG */ \
+ }
#endif
-#define PATTERN_SIZE_BYTES (PATTERN_SIZE_WORDS * sizeof(uint32_t))
-
/*
* The pattern used to fill the entire stack.
*/
@@ -65,10 +65,6 @@
#define BYTE_PATTERN 0xA5
#define U32_PATTERN 0xA5A5A5A5
-typedef struct {
- uint32_t pattern[ PATTERN_SIZE_WORDS ];
-} Stack_check_Control;
-
/*
* Variable to indicate when the stack checker has been initialized.
*/
@@ -77,7 +73,12 @@ static int Stack_check_Initialized = 0;
/*
* The "magic pattern" used to mark the end of the stack.
*/
-Stack_check_Control Stack_check_Pattern;
+static const uint32_t Stack_check_Pattern[] =
+ CPU_STACK_CHECK_PATTERN_INITIALIZER;
+
+#define PATTERN_SIZE_BYTES sizeof(Stack_check_Pattern)
+
+#define PATTERN_SIZE_WORDS RTEMS_ARRAY_SIZE(Stack_check_Pattern)
/*
* Helper function to report if the actual stack pointer is in range.
@@ -85,11 +86,12 @@ Stack_check_Control Stack_check_Pattern;
* NOTE: This uses a GCC specific method.
*/
static inline bool Stack_check_Frame_pointer_in_range(
- Stack_Control *the_stack
+ const Thread_Control *the_thread
)
{
#if defined(__GNUC__)
void *sp = __builtin_frame_address(0);
+ const Stack_Control *the_stack = &the_thread->Start.Initial_stack;
if ( sp < the_stack->area ) {
return false;
@@ -110,7 +112,7 @@ static inline bool Stack_check_Frame_pointer_in_range(
#if (CPU_STACK_GROWS_UP == TRUE)
#define Stack_check_Get_pattern( _the_stack ) \
((char *)(_the_stack)->area + \
- (_the_stack)->size - sizeof( Stack_check_Control ) )
+ (_the_stack)->size - PATTERN_SIZE_BYTES )
#define Stack_check_Calculate_used( _low, _size, _high_water ) \
((char *)(_high_water) - (char *)(_low))
@@ -132,22 +134,16 @@ static inline bool Stack_check_Frame_pointer_in_range(
( ((char *)(_low) + (_size)) - (char *)(_high_water) )
#define Stack_check_usable_stack_start(_the_stack) \
- ((char *)(_the_stack)->area + sizeof(Stack_check_Control))
+ ((char *)(_the_stack)->area + PATTERN_SIZE_BYTES)
#endif
/*
- * Obtain a properly typed pointer to the area to check.
- */
-#define Stack_check_Get_pattern_area( _the_stack ) \
- (Stack_check_Control *) Stack_check_Get_pattern( _the_stack )
-
-/*
* The assumption is that if the pattern gets overwritten, the task
* is too close. This defines the usable stack memory.
*/
#define Stack_check_usable_stack_size(_the_stack) \
- ((_the_stack)->size - sizeof(Stack_check_Control))
+ ((_the_stack)->size - PATTERN_SIZE_BYTES)
#if (CPU_ALLOCATE_INTERRUPT_STACK == TRUE)
/*
@@ -169,25 +165,10 @@ static inline bool Stack_check_Frame_pointer_in_range(
*/
static void Stack_check_Initialize( void )
{
- int i;
- uint32_t *p;
- static uint32_t pattern[ 4 ] = {
- 0xFEEDF00D, 0x0BAD0D06, /* FEED FOOD to BAD DOG */
- 0xDEADF00D, 0x600D0D06 /* DEAD FOOD but GOOD DOG */
- };
-
if ( Stack_check_Initialized )
return;
/*
- * Dope the pattern and fill areas
- */
- p = Stack_check_Pattern.pattern;
- for ( i = 0; i < PATTERN_SIZE_WORDS; i++ ) {
- p[i] = pattern[ i%4 ];
- }
-
- /*
* If appropriate, setup the interrupt stack for high water testing
* also.
*/
@@ -203,6 +184,15 @@ static void Stack_check_Initialize( void )
Stack_check_Initialized = 1;
}
+static bool Stack_check_Is_pattern_valid(const Thread_Control *the_thread)
+{
+ return memcmp(
+ Stack_check_Get_pattern(&the_thread->Start.Initial_stack),
+ Stack_check_Pattern,
+ PATTERN_SIZE_BYTES
+ ) == 0;
+}
+
/*
* rtems_stack_checker_create_extension
*/
@@ -226,14 +216,14 @@ void rtems_stack_checker_begin_extension(
Thread_Control *the_thread
)
{
- Stack_check_Control *the_pattern;
-
if ( the_thread->Object.id == 0 ) /* skip system tasks */
return;
- the_pattern = Stack_check_Get_pattern_area(&the_thread->Start.Initial_stack);
-
- *the_pattern = Stack_check_Pattern;
+ memcpy(
+ Stack_check_Get_pattern(&the_thread->Start.Initial_stack),
+ Stack_check_Pattern,
+ PATTERN_SIZE_BYTES
+ );
}
/*
@@ -245,16 +235,14 @@ void rtems_stack_checker_begin_extension(
* NOTE: The system is in a questionable state... we may not get
* the following message out.
*/
-void Stack_check_report_blown_task(
- Thread_Control *running,
+static void Stack_check_report_blown_task(
+ const Thread_Control *running,
bool pattern_ok
-) RTEMS_NO_RETURN;
-
-void Stack_check_report_blown_task(Thread_Control *running, bool pattern_ok)
+)
{
- Stack_Control *stack = &running->Start.Initial_stack;
- void *pattern_area = Stack_check_Get_pattern(stack);
- char name[32];
+ const Stack_Control *stack = &running->Start.Initial_stack;
+ void *pattern_area = Stack_check_Get_pattern(stack);
+ char name[32];
printk("BLOWN STACK!!!\n");
printk("task control block: 0x%08" PRIxPTR "\n", (intptr_t) running);
@@ -305,20 +293,15 @@ void rtems_stack_checker_switch_extension(
Thread_Control *heir RTEMS_UNUSED
)
{
- Stack_Control *the_stack = &running->Start.Initial_stack;
- void *pattern;
- bool sp_ok;
- bool pattern_ok = true;
-
- pattern = Stack_check_Get_pattern_area(the_stack);
+ bool sp_ok;
+ bool pattern_ok;
/*
* Check for an out of bounds stack pointer or an overwrite
*/
- sp_ok = Stack_check_Frame_pointer_in_range( the_stack );
+ sp_ok = Stack_check_Frame_pointer_in_range( running );
- pattern_ok = (!memcmp( pattern,
- (void *) Stack_check_Pattern.pattern, PATTERN_SIZE_BYTES));
+ pattern_ok = Stack_check_Is_pattern_valid( running );
if ( !sp_ok || !pattern_ok ) {
Stack_check_report_blown_task( running, pattern_ok );
@@ -330,37 +313,7 @@ void rtems_stack_checker_switch_extension(
*/
bool rtems_stack_checker_is_blown( void )
{
- Thread_Control *executing = _Thread_Get_executing();
- Stack_Control *the_stack = &executing->Start.Initial_stack;
- bool sp_ok;
- bool pattern_ok = true;
-
- /*
- * Check for an out of bounds stack pointer
- */
-
- sp_ok = Stack_check_Frame_pointer_in_range( the_stack );
-
- /*
- * The stack checker must be initialized before the pattern is there
- * to check.
- */
- if ( Stack_check_Initialized ) {
- pattern_ok = (!memcmp(
- Stack_check_Get_pattern(the_stack),
- (void *) Stack_check_Pattern.pattern,
- PATTERN_SIZE_BYTES
- ));
- }
-
-
- /*
- * Let's report as much as we can.
- */
- if ( !sp_ok || !pattern_ok ) {
- Stack_check_report_blown_task( executing, pattern_ok );
- /* DOES NOT RETURN */
- }
+ rtems_stack_checker_switch_extension( _Thread_Get_executing(), NULL );
/*
* The Stack Pointer and the Pattern Area are OK so return false.
diff --git a/cpukit/score/cpu/powerpc/rtems/score/cpu.h b/cpukit/score/cpu/powerpc/rtems/score/cpu.h
index 7a0fa23..b7be5ad 100644
--- a/cpukit/score/cpu/powerpc/rtems/score/cpu.h
+++ b/cpukit/score/cpu/powerpc/rtems/score/cpu.h
@@ -649,7 +649,15 @@ typedef struct CPU_Interrupt_frame {
* for most architectures.
*/
-#define CPU_STACK_CHECK_SIZE (128)
+#define CPU_STACK_CHECK_PATTERN_INITIALIZER \
+ { 0xFEEDF00D, 0x0BAD0D06, 0xDEADF00D, 0x600D0D06, \
+ 0xFEEDF00D, 0x0BAD0D06, 0xDEADF00D, 0x600D0D06, \
+ 0xFEEDF00D, 0x0BAD0D06, 0xDEADF00D, 0x600D0D06, \
+ 0xFEEDF00D, 0x0BAD0D06, 0xDEADF00D, 0x600D0D06, \
+ 0xFEEDF00D, 0x0BAD0D06, 0xDEADF00D, 0x600D0D06, \
+ 0xFEEDF00D, 0x0BAD0D06, 0xDEADF00D, 0x600D0D06, \
+ 0xFEEDF00D, 0x0BAD0D06, 0xDEADF00D, 0x600D0D06, \
+ 0xFEEDF00D, 0x0BAD0D06, 0xDEADF00D, 0x600D0D06 }
/*
* Amount of extra stack (above minimum stack size) required by
--
1.8.4.5
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