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 --- arch/arm/lib/interrupts.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/arch/arm/lib/interrupts.c b/arch/arm/lib/interrupts.c index 066c172..5d06196 100644 --- a/arch/arm/lib/interrupts.c +++ b/arch/arm/lib/interrupts.c @@ -93,10 +93,18 @@ void show_regs (struct pt_regs *regs) 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 @@ void do_software_interrupt (struct pt_regs *pt_regs) { efi_restore_gd(); printf ("software interrupt\n"); + fixup_pc(pt_regs, -4); show_regs (pt_regs); bad_mode (); } @@ -113,6 +122,7 @@ void do_prefetch_abort (struct pt_regs *pt_regs) { efi_restore_gd(); printf ("prefetch abort\n"); + fixup_pc(pt_regs, -8); show_regs (pt_regs); bad_mode (); } @@ -121,6 +131,7 @@ void do_data_abort (struct pt_regs *pt_regs) { efi_restore_gd(); printf ("data abort\n"); + fixup_pc(pt_regs, -8); show_regs (pt_regs); bad_mode (); } @@ -129,6 +140,7 @@ void do_not_used (struct pt_regs *pt_regs) { efi_restore_gd(); printf ("not used\n"); + fixup_pc(pt_regs, -8); show_regs (pt_regs); bad_mode (); } @@ -137,6 +149,7 @@ void do_fiq (struct pt_regs *pt_regs) { efi_restore_gd(); printf ("fast interrupt request\n"); + fixup_pc(pt_regs, -8); show_regs (pt_regs); bad_mode (); } @@ -145,6 +158,7 @@ void do_irq (struct pt_regs *pt_regs) { efi_restore_gd(); printf ("interrupt request\n"); + fixup_pc(pt_regs, -8); show_regs (pt_regs); bad_mode (); }