Messages in this thread | | | Date | Mon, 19 Sep 2022 15:34:25 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH V5 07/11] riscv: convert to generic entry |
| |
On Sun, Sep 18, 2022 at 11:52:42AM -0400, guoren@kernel.org wrote:
> @@ -123,18 +126,22 @@ int handle_misaligned_store(struct pt_regs *regs); > > asmlinkage void __trap_section do_trap_load_misaligned(struct pt_regs *regs) > { > + irqentry_state_t state = irqentry_enter(regs); > if (!handle_misaligned_load(regs)) > return; > do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc, > "Oops - load address misaligned"); > + irqentry_exit(regs, state); > } > > asmlinkage void __trap_section do_trap_store_misaligned(struct pt_regs *regs) > { > + irqentry_state_t state = irqentry_enter(regs); > if (!handle_misaligned_store(regs)) > return; > do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc, > "Oops - store (or AMO) address misaligned"); > + irqentry_exit(regs, state); > } > #endif > DO_ERROR_INFO(do_trap_store_fault, > @@ -158,6 +165,8 @@ static inline unsigned long get_break_insn_length(unsigned long pc) > > asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs) > { > + irqentry_state_t state = irqentry_enter(regs); > + > #ifdef CONFIG_KPROBES > if (kprobe_single_step_handler(regs)) > return;
FWIW; on x86 I've classified many of the 'from-kernel' traps as NMI-like, since those traps can happen from any context, including with IRQs disabled.
The basic shape of the trap handlers looks a little like:
if (user_mode(regs)) { irqenrty_enter_from_user_mode(regs); do_user_trap(); irqentry_exit_to_user_mode(regs); } else { irqentry_state_t state = irqentry_nmi_enter(regs); do_kernel_trap(); irqentry_nmi_exit(regs, state); }
Not saying you have to match Risc-V in this patch-set, just something to consider.
| |