davids5 commented on a change in pull request #3517:
URL: https://github.com/apache/incubator-nuttx/pull/3517#discussion_r612735629
##########
File path: arch/arm/src/common/arm_usestack.c
##########
@@ -127,37 +117,17 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t
stack_size)
/* Save the new stack allocation */
tcb->stack_alloc_ptr = stack;
-
- /* Align stack top */
-
- tcb->adj_stack_ptr =
- (FAR void *)STACK_ALIGN_DOWN((uintptr_t)stack + stack_size);
-
- /* Offset by tls_size */
-
- stack = (FAR void *)((uintptr_t)stack + tls_size);
-
- /* Is there enough room for at least TLS ? */
-
- if ((uintptr_t)stack > (uintptr_t)tcb->adj_stack_ptr)
- {
- return -ENOMEM;
- }
-
- tcb->adj_stack_size = (uintptr_t)tcb->adj_stack_ptr - (uintptr_t)stack;
-
- /* Initialize the TLS data structure */
-
- memset(tcb->stack_alloc_ptr, 0, tls_size);
+ tcb->adj_stack_ptr = tcb->stack_alloc_ptr;
+ tcb->adj_stack_size =
+ STACK_ALIGN_DOWN((uintptr_t)stack + stack_size) - (uintptr_t)stack;
Review comment:
Yes. My head is stuck in the days were the alloc pointer was not
aligned. (it was also freed if not 0) Now it is aligned on allocation. So that
is one change not in the same place that added to my not understanding it.
Am I understanding the sizing correctly: If I have 300 byte stack it will
now be either much larger with CONFIG_TLS_ALIGNED lit or it will be smaller by
the sizeof(tls) and args? Before this change it looked (CONFIG_TLS_ALIGNED not
lit) like 300+sizeof(tls) which I got what I asked for and the OS got what it
needed. Is that still the case?
Also it is correct that if I ask for an 11K stack it may get truncated by 3K
without warning if the TLS_MAXSTACK (log and friends) ends up at 8K?
##########
File path: arch/arm/src/common/arm_usestack.c
##########
@@ -127,37 +117,17 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t
stack_size)
/* Save the new stack allocation */
tcb->stack_alloc_ptr = stack;
-
- /* Align stack top */
-
- tcb->adj_stack_ptr =
- (FAR void *)STACK_ALIGN_DOWN((uintptr_t)stack + stack_size);
-
- /* Offset by tls_size */
-
- stack = (FAR void *)((uintptr_t)stack + tls_size);
-
- /* Is there enough room for at least TLS ? */
-
- if ((uintptr_t)stack > (uintptr_t)tcb->adj_stack_ptr)
- {
- return -ENOMEM;
- }
-
- tcb->adj_stack_size = (uintptr_t)tcb->adj_stack_ptr - (uintptr_t)stack;
-
- /* Initialize the TLS data structure */
-
- memset(tcb->stack_alloc_ptr, 0, tls_size);
+ tcb->adj_stack_ptr = tcb->stack_alloc_ptr;
+ tcb->adj_stack_size =
+ STACK_ALIGN_DOWN((uintptr_t)stack + stack_size) - (uintptr_t)stack;
Review comment:
Yes. My head is stuck in the days were the alloc pointer was not
aligned. (it was also freed if not 0) Now it is aligned on allocation. So that
is one change not in the same place that added to my not understanding it.
Am I understanding the sizing correctly: If I have 300 byte stack it will
now be either much larger with CONFIG_TLS_ALIGNED lit or it will be smaller by
the sizeof(tls) and args? Before this change it looked (CONFIG_TLS_ALIGNED not
lit) like 300+sizeof(tls) which I got what I asked for and the OS got what it
needed. Is that still the case?
Also is it correct that if I ask for an 11K stack it may get truncated by 3K
without warning if the TLS_MAXSTACK (log and friends) ends up at 8K?
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