diff options
Diffstat (limited to 'arch/arm64/kernel/traps.c')
-rw-r--r-- | arch/arm64/kernel/traps.c | 69 |
1 files changed, 67 insertions, 2 deletions
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 02cd3f023e9a..0a801e3743d5 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -132,7 +132,6 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) { struct stackframe frame; - const register unsigned long current_sp asm ("sp"); pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); @@ -145,7 +144,7 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) frame.pc = regs->pc; } else if (tsk == current) { frame.fp = (unsigned long)__builtin_frame_address(0); - frame.sp = current_sp; + frame.sp = current_stack_pointer; frame.pc = (unsigned long)dump_backtrace; } else { /* @@ -260,6 +259,69 @@ void arm64_notify_die(const char *str, struct pt_regs *regs, } } +static LIST_HEAD(undef_hook); +static DEFINE_RAW_SPINLOCK(undef_lock); + +void register_undef_hook(struct undef_hook *hook) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&undef_lock, flags); + list_add(&hook->node, &undef_hook); + raw_spin_unlock_irqrestore(&undef_lock, flags); +} + +void unregister_undef_hook(struct undef_hook *hook) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&undef_lock, flags); + list_del(&hook->node); + raw_spin_unlock_irqrestore(&undef_lock, flags); +} + +static int call_undef_hook(struct pt_regs *regs) +{ + struct undef_hook *hook; + unsigned long flags; + u32 instr; + int (*fn)(struct pt_regs *regs, u32 instr) = NULL; + void __user *pc = (void __user *)instruction_pointer(regs); + + if (!user_mode(regs)) + return 1; + + if (compat_thumb_mode(regs)) { + /* 16-bit Thumb instruction */ + if (get_user(instr, (u16 __user *)pc)) + goto exit; + instr = le16_to_cpu(instr); + if (aarch32_insn_is_wide(instr)) { + u32 instr2; + + if (get_user(instr2, (u16 __user *)(pc + 2))) + goto exit; + instr2 = le16_to_cpu(instr2); + instr = (instr << 16) | instr2; + } + } else { + /* 32-bit ARM instruction */ + if (get_user(instr, (u32 __user *)pc)) + goto exit; + instr = le32_to_cpu(instr); + } + + raw_spin_lock_irqsave(&undef_lock, flags); + list_for_each_entry(hook, &undef_hook, node) + if ((instr & hook->instr_mask) == hook->instr_val && + (regs->pstate & hook->pstate_mask) == hook->pstate_val) + fn = hook->fn; + + raw_spin_unlock_irqrestore(&undef_lock, flags); +exit: + return fn ? fn(regs, instr) : 1; +} + asmlinkage void __exception do_undefinstr(struct pt_regs *regs) { siginfo_t info; @@ -269,6 +331,9 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) if (!aarch32_break_handler(regs)) return; + if (call_undef_hook(regs) == 0) + return; + if (show_unhandled_signals && unhandled_signal(current, SIGILL) && printk_ratelimit()) { pr_info("%s[%d]: undefined instruction: pc=%p\n", |