Messages in this thread | | | From | Huacai Chen <> | Date | Tue, 27 Dec 2022 15:37:02 +0800 | Subject | Re: [PATCH] LoongArch: Fix irq enable in exception handlers |
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Hi, Jinyang,
Move die_if_kernel to irq disabled context to solve what? And LBT is surely allowed to be triggered in kernel context.
Huacai
On Wed, Dec 21, 2022 at 3:43 PM Jinyang He <hejinyang@loongson.cn> wrote: > > The interrupt state can be got by regs->csr_prmd. Once previous > interrupt state is disable, we shouldn't enable interrupt if we > triggered exception which can be triggered in kernel mode. So > conditionally enable interrupt. For those do_\exception which > can not triggered in kernel mode but need enable interrupt, call > die_if_kernel() firstly. And for do_lsx, do_lasx and do_lbt cannot > triggered in kernel mode, too. > > Signed-off-by: Jinyang He <hejinyang@loongson.cn> > --- > arch/loongarch/kernel/traps.c | 19 ++++++++++--------- > 1 file changed, 10 insertions(+), 9 deletions(-) > > diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c > index 1ea14f6c18d3..3ac7b32d1e15 100644 > --- a/arch/loongarch/kernel/traps.c > +++ b/arch/loongarch/kernel/traps.c > @@ -340,9 +340,9 @@ asmlinkage void noinstr do_fpe(struct pt_regs *regs, unsigned long fcsr) > > /* Clear FCSR.Cause before enabling interrupts */ > write_fcsr(LOONGARCH_FCSR0, fcsr & ~mask_fcsr_x(fcsr)); > - local_irq_enable(); > > die_if_kernel("FP exception in kernel code", regs); > + local_irq_enable(); > > sig = SIGFPE; > fault_addr = (void __user *) regs->csr_era; > @@ -432,7 +432,8 @@ asmlinkage void noinstr do_bp(struct pt_regs *regs) > unsigned long era = exception_era(regs); > irqentry_state_t state = irqentry_enter(regs); > > - local_irq_enable(); > + if (regs->csr_prmd & CSR_PRMD_PIE) > + local_irq_enable(); > current->thread.trap_nr = read_csr_excode(); > if (__get_inst(&opcode, (u32 *)era, user)) > goto out_sigsegv; > @@ -514,7 +515,8 @@ asmlinkage void noinstr do_ri(struct pt_regs *regs) > unsigned int __user *era = (unsigned int __user *)exception_era(regs); > irqentry_state_t state = irqentry_enter(regs); > > - local_irq_enable(); > + if (regs->csr_prmd & CSR_PRMD_PIE) > + local_irq_enable(); > current->thread.trap_nr = read_csr_excode(); > > if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr, > @@ -606,8 +608,8 @@ asmlinkage void noinstr do_fpu(struct pt_regs *regs) > { > irqentry_state_t state = irqentry_enter(regs); > > - local_irq_enable(); > die_if_kernel("do_fpu invoked from kernel context!", regs); > + local_irq_enable(); > BUG_ON(is_lsx_enabled()); > BUG_ON(is_lasx_enabled()); > > @@ -623,13 +625,13 @@ asmlinkage void noinstr do_lsx(struct pt_regs *regs) > { > irqentry_state_t state = irqentry_enter(regs); > > + die_if_kernel("do_lsx invoked from kernel context!", regs); > local_irq_enable(); > if (!cpu_has_lsx) { > force_sig(SIGILL); > goto out; > } > > - die_if_kernel("do_lsx invoked from kernel context!", regs); > BUG_ON(is_lasx_enabled()); > > preempt_disable(); > @@ -645,14 +647,13 @@ asmlinkage void noinstr do_lasx(struct pt_regs *regs) > { > irqentry_state_t state = irqentry_enter(regs); > > + die_if_kernel("do_lasx invoked from kernel context!", regs); > local_irq_enable(); > if (!cpu_has_lasx) { > force_sig(SIGILL); > goto out; > } > > - die_if_kernel("do_lasx invoked from kernel context!", regs); > - > preempt_disable(); > init_restore_lasx(); > preempt_enable(); > @@ -666,6 +667,7 @@ asmlinkage void noinstr do_lbt(struct pt_regs *regs) > { > irqentry_state_t state = irqentry_enter(regs); > > + die_if_kernel("do_lbt invoked from kernel context!", regs); > local_irq_enable(); > force_sig(SIGILL); > local_irq_disable(); > @@ -677,7 +679,6 @@ asmlinkage void noinstr do_reserved(struct pt_regs *regs) > { > irqentry_state_t state = irqentry_enter(regs); > > - local_irq_enable(); > /* > * Game over - no way to handle this if it ever occurs. Most probably > * caused by a fatal error after another hardware/software error. > @@ -685,8 +686,8 @@ asmlinkage void noinstr do_reserved(struct pt_regs *regs) > pr_err("Caught reserved exception %u on pid:%d [%s] - should not happen\n", > read_csr_excode(), current->pid, current->comm); > die_if_kernel("do_reserved exception", regs); > + local_irq_enable(); > force_sig(SIGUNUSED); > - > local_irq_disable(); > > irqentry_exit(regs, state); > -- > 2.34.3 >
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