Fixed bug 3187105.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2744 35acf78f-673a-0410-8e92-d51de3d6d3f4

os/ports/GCC/ARMCMx/chcore_v6m.c

@@ -75,7 +75,7 @@ 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
@@ -84,8 +84,9 @@ 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

@@ -96,8 +96,9 @@ _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

@@ -93,8 +93,9 @@ _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 @@
 *****************************************************************************
 
 *** 2.3.0 ***
+- FIX: Stack overflow in CM0 port when nearing interrupts saturation (bug
+  3187105)(backported to 2.2.1).
 - FIX: Error in MAC driver (bug 3179783)(backported to 2.2.1).
 - FIX: Fixed wrong serial driver macros (bug 3173336)(backported to 2.2.1).
 - NEW: Added experimental generic USB driver, it will evolve in next