diff options
Diffstat (limited to 'arch/arm64/mm/fault.c')
| -rw-r--r-- | arch/arm64/mm/fault.c | 46 |
1 files changed, 40 insertions, 6 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 50b30ff30de4..88cf0a0cb616 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -827,13 +827,47 @@ void __init hook_debug_fault_code(int nr, debug_fault_info[nr].name = name; } -asmlinkage int __exception do_debug_exception(unsigned long addr, - unsigned int esr, - struct pt_regs *regs) +#ifdef CONFIG_ARM64_ERRATUM_1463225 +DECLARE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa); + +static int __exception +cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) +{ + if (user_mode(regs)) + return 0; + + if (!__this_cpu_read(__in_cortex_a76_erratum_1463225_wa)) + return 0; + + /* + * We've taken a dummy step exception from the kernel to ensure + * that interrupts are re-enabled on the syscall path. Return back + * to cortex_a76_erratum_1463225_svc_handler() with debug exceptions + * masked so that we can safely restore the mdscr and get on with + * handling the syscall. + */ + regs->pstate |= PSR_D_BIT; + return 1; +} +#else +static int __exception +cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) +{ + return 0; +} +#endif /* CONFIG_ARM64_ERRATUM_1463225 */ + +asmlinkage int __exception do_debug_exception(unsigned long addr_if_watchpoint, + unsigned int esr, + struct pt_regs *regs) { const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); + unsigned long pc = instruction_pointer(regs); int rv; + if (cortex_a76_erratum_1463225_debug_handler(regs)) + return 0; + /* * Tell lockdep we disabled irqs in entry.S. Do nothing if they were * already disabled to preserve the last enabled/disabled addresses. @@ -841,10 +875,10 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, if (interrupts_enabled(regs)) trace_hardirqs_off(); - if (user_mode(regs) && instruction_pointer(regs) > TASK_SIZE) + if (user_mode(regs) && pc > TASK_SIZE) arm64_apply_bp_hardening(); - if (!inf->fn(addr, esr, regs)) { + if (!inf->fn(addr_if_watchpoint, esr, regs)) { rv = 1; } else { struct siginfo info; @@ -853,7 +887,7 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, info.si_signo = inf->sig; info.si_errno = 0; info.si_code = inf->code; - info.si_addr = (void __user *)addr; + info.si_addr = (void __user *)pc; arm64_notify_die(inf->name, regs, &info, esr); rv = 0; } |