v01d opened a new issue #3423:
URL: https://github.com/apache/incubator-nuttx/issues/3423
```
Description: There is bit bit logic in up_fullcontextrestore() that
executes on
return from interrupts (and other context switches) that
looks like:
ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the stored CPSR value
*/
msr cpsr, r1 /* Set the CPSR */
/* Now recover r0 and r1 */
ldr r0, [sp]
ldr r1, [sp, #4]
add sp, sp, #(2*4)
/* Then return to the address at the stop of the stack,
* destroying the stack frame
*/
ldr pc, [sp], #4
Under conditions of excessively high interrupt conditions,
many
nested interrupts can occur just after the 'msr cpsr'
instruction.
At that time, there are 4 bytes on the stack and, with each
interrupt, the stack pointer may increment and possibly
overflow.
This can happen only under conditions of continuous
interrupts.
One suggested change is:
ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the stored CPSR value
*/
msr spsr_cxsf, r1 /* Set the CPSR */
ldmia r0, {r0-r15}
But this has not been proven to be a solution.
UPDATE: Other ARM architectures have a similar issue.
Status: Open
Priority: Low. The conditions of continuous interrupts is really the
problem.
If your design needs continuous interrupts like this, please
try
the above change and, please, submit a patch with the working
fix.
```
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