arm: adjust PC displayed in exception handlers to point to the failing instruction
Adjust the program counter register to point to the failing
instruction depending on the exeption type.
This makes it easier to localize the offending instruction leading to
a fatal exception.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
diff --git a/arch/arm/lib/interrupts.c b/arch/arm/lib/interrupts.c
index 066c172..80869ad 100644
--- a/arch/arm/lib/interrupts.c
+++ b/arch/arm/lib/interrupts.c
@@ -93,10 +93,18 @@
thumb_mode (regs) ? " (T)" : "");
}
+/* fixup PC to point to the instruction leading to the exception */
+static inline void fixup_pc(struct pt_regs *regs, int offset)
+{
+ uint32_t pc = instruction_pointer(regs) + offset;
+ regs->ARM_pc = pc | (regs->ARM_pc & PCMASK);
+}
+
void do_undefined_instruction (struct pt_regs *pt_regs)
{
efi_restore_gd();
printf ("undefined instruction\n");
+ fixup_pc(pt_regs, -4);
show_regs (pt_regs);
bad_mode ();
}
@@ -105,6 +113,7 @@
{
efi_restore_gd();
printf ("software interrupt\n");
+ fixup_pc(pt_regs, -4);
show_regs (pt_regs);
bad_mode ();
}
@@ -113,6 +122,7 @@
{
efi_restore_gd();
printf ("prefetch abort\n");
+ fixup_pc(pt_regs, -8);
show_regs (pt_regs);
bad_mode ();
}
@@ -121,6 +131,7 @@
{
efi_restore_gd();
printf ("data abort\n");
+ fixup_pc(pt_regs, -8);
show_regs (pt_regs);
bad_mode ();
}
@@ -129,6 +140,7 @@
{
efi_restore_gd();
printf ("not used\n");
+ fixup_pc(pt_regs, -8);
show_regs (pt_regs);
bad_mode ();
}
@@ -137,6 +149,7 @@
{
efi_restore_gd();
printf ("fast interrupt request\n");
+ fixup_pc(pt_regs, -8);
show_regs (pt_regs);
bad_mode ();
}
@@ -145,6 +158,7 @@
{
efi_restore_gd();
printf ("interrupt request\n");
+ fixup_pc(pt_regs, -8);
show_regs (pt_regs);
bad_mode ();
}