Fixed bug 3187105.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/branches/stable_2.2.x@2748 35acf78f-673a-0410-8e92-d51de3d6d3f4

os/ports/GCC/ARMCMx/chcore_v6m.c

@@ -40,7 +40,7 @@
 regarm_t _port_saved_pc;
 
 /**
- * @brief   IRQ nesting counter.
+ * @brief   IRQ nesting counter.
  */
 unsigned _port_irq_nesting;
 
@@ -82,7 +82,7 @@ void _port_switch_from_isr(void) {
 
   chSchDoRescheduleI();
 
-  /* Note, the last registers are restored alone after re-enabling the
+  /* Note, the last register is restored alone after re-enabling the
      interrupts in order to minimize the (very remote and unlikely)
      possibility that the stack is filled by continuous and saturating
      interrupts that would not allow that last words to be pulled out of
@@ -91,8 +91,9 @@ void _port_switch_from_isr(void) {
                 "mov     r12, r1                                \n\t"
                 "msr     APSR, r0                               \n\t"
                 "mov     lr, r2                                 \n\t"
+                "pop     {r0, r1, r2, r3}                       \n\t"
                 "cpsie   i                                      \n\t"
-                "pop     {r0, r1, r2, r3, pc}" : : : "memory");
+                "pop     {pc}" : : : "memory");
 }
 
 #define PUSH_CONTEXT(sp) {                                                  \

os/ports/IAR/ARMCMx/chcoreasm_v6m.s

@@ -103,8 +103,9 @@ _port_switch_from_isr:
         mov     r12, r1
         msr     APSR, r0
         mov     lr, r2
+        pop     {r0, r1, r2, r3}
         cpsie   i
-        pop     {r0, r1, r2, r3, pc}
+        pop     {pc}
 
 /*
  * Reschedule verification and setup after an IRQ.

os/ports/RVCT/ARMCMx/chcoreasm_v6m.s

@@ -100,8 +100,9 @@ _port_switch_from_isr PROC
                 mov     r12, r1
                 msr     APSR, r0
                 mov     lr, r2
+                pop     {r0, r1, r2, r3}
                 cpsie   i
-                pop     {r0, r1, r2, r3, pc}
+                pop     {pc}
                 ENDP
 
 /*

readme.txt

@@ -69,6 +69,8 @@
 *****************************************************************************
 
 *** 2.2.1 ***
+- FIX: Stack overflow in CM0 ports when nearing interrupts saturation (bug
+  3187105).
 - FIX: Fixed missing e200z test report (bug 3182611).
 - FIX: Fixed error in _BSEMAPHORE_DATA macro (bug 3184139).
 - FIX: Error in MAC driver (bug 3179783).